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1 | package SQL::Abstract; # see doc at end of file |
2 | |
3 | # LDNOTE : this code is heavy refactoring from original SQLA. |
4 | # Several design decisions will need discussion during |
5 | # the test / diffusion / acceptance phase; those are marked with flag |
6 | # 'LDNOTE' (note by laurent.dami AT free.fr) |
7 | |
8 | use Carp; |
9 | use strict; |
10 | use warnings; |
fffe6900 |
11 | use List::Util qw/first/; |
12 | use Scalar::Util qw/blessed/; |
96449e8e |
13 | |
14 | #====================================================================== |
15 | # GLOBALS |
16 | #====================================================================== |
17 | |
a120d3e3 |
18 | our $VERSION = '1.56'; |
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19 | |
22f1a437 |
20 | # This would confuse some packagers |
21 | #$VERSION = eval $VERSION; # numify for warning-free dev releases |
96449e8e |
22 | |
23 | our $AUTOLOAD; |
24 | |
25 | # special operators (-in, -between). May be extended/overridden by user. |
26 | # See section WHERE: BUILTIN SPECIAL OPERATORS below for implementation |
27 | my @BUILTIN_SPECIAL_OPS = ( |
3a2e1a5e |
28 | {regex => qr/^(not )?between$/i, handler => '_where_field_BETWEEN'}, |
29 | {regex => qr/^(not )?in$/i, handler => '_where_field_IN'}, |
96449e8e |
30 | ); |
31 | |
97a920ef |
32 | # unaryish operators - key maps to handler |
59f23b3d |
33 | my @BUILTIN_UNARY_OPS = ( |
2463c5e4 |
34 | { regex => qr/^and (\s? \d+)?$/xi, handler => '_where_op_ANDOR', numchk => 1 }, |
35 | { regex => qr/^or (\s? \d+)?$/xi, handler => '_where_op_ANDOR', numchk => 1 }, |
36 | { regex => qr/^nest (\s? \d+)?$/xi, handler => '_where_op_NEST', numchk => 1 }, |
59f23b3d |
37 | { regex => qr/^(not \s?)? bool$/xi, handler => '_where_op_BOOL' }, |
38 | ); |
97a920ef |
39 | |
96449e8e |
40 | #====================================================================== |
41 | # DEBUGGING AND ERROR REPORTING |
42 | #====================================================================== |
43 | |
44 | sub _debug { |
45 | return unless $_[0]->{debug}; shift; # a little faster |
46 | my $func = (caller(1))[3]; |
47 | warn "[$func] ", @_, "\n"; |
48 | } |
49 | |
50 | sub belch (@) { |
51 | my($func) = (caller(1))[3]; |
52 | carp "[$func] Warning: ", @_; |
53 | } |
54 | |
55 | sub puke (@) { |
56 | my($func) = (caller(1))[3]; |
57 | croak "[$func] Fatal: ", @_; |
58 | } |
59 | |
60 | |
61 | #====================================================================== |
62 | # NEW |
63 | #====================================================================== |
64 | |
65 | sub new { |
66 | my $self = shift; |
67 | my $class = ref($self) || $self; |
68 | my %opt = (ref $_[0] eq 'HASH') ? %{$_[0]} : @_; |
69 | |
70 | # choose our case by keeping an option around |
71 | delete $opt{case} if $opt{case} && $opt{case} ne 'lower'; |
72 | |
73 | # default logic for interpreting arrayrefs |
ef559da3 |
74 | $opt{logic} = $opt{logic} ? uc $opt{logic} : 'OR'; |
96449e8e |
75 | |
76 | # how to return bind vars |
77 | # LDNOTE: changed nwiger code : why this 'delete' ?? |
78 | # $opt{bindtype} ||= delete($opt{bind_type}) || 'normal'; |
79 | $opt{bindtype} ||= 'normal'; |
80 | |
81 | # default comparison is "=", but can be overridden |
82 | $opt{cmp} ||= '='; |
83 | |
84 | # try to recognize which are the 'equality' and 'unequality' ops |
85 | # (temporary quickfix, should go through a more seasoned API) |
86 | $opt{equality_op} = qr/^(\Q$opt{cmp}\E|is|(is\s+)?like)$/i; |
87 | $opt{inequality_op} = qr/^(!=|<>|(is\s+)?not(\s+like)?)$/i; |
88 | |
89 | # SQL booleans |
90 | $opt{sqltrue} ||= '1=1'; |
91 | $opt{sqlfalse} ||= '0=1'; |
92 | |
93 | # special operators |
94 | $opt{special_ops} ||= []; |
95 | push @{$opt{special_ops}}, @BUILTIN_SPECIAL_OPS; |
96 | |
59f23b3d |
97 | # unary operators |
98 | $opt{unary_ops} ||= []; |
99 | push @{$opt{unary_ops}}, @BUILTIN_UNARY_OPS; |
100 | |
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101 | return bless \%opt, $class; |
102 | } |
103 | |
104 | |
105 | |
106 | #====================================================================== |
107 | # INSERT methods |
108 | #====================================================================== |
109 | |
110 | sub insert { |
111 | my $self = shift; |
112 | my $table = $self->_table(shift); |
113 | my $data = shift || return; |
114 | |
115 | my $method = $self->_METHOD_FOR_refkind("_insert", $data); |
116 | my ($sql, @bind) = $self->$method($data); |
117 | $sql = join " ", $self->_sqlcase('insert into'), $table, $sql; |
118 | return wantarray ? ($sql, @bind) : $sql; |
119 | } |
120 | |
121 | sub _insert_HASHREF { # explicit list of fields and then values |
122 | my ($self, $data) = @_; |
123 | |
124 | my @fields = sort keys %$data; |
125 | |
fe3ae272 |
126 | my ($sql, @bind) = $self->_insert_values($data); |
96449e8e |
127 | |
128 | # assemble SQL |
129 | $_ = $self->_quote($_) foreach @fields; |
130 | $sql = "( ".join(", ", @fields).") ".$sql; |
131 | |
132 | return ($sql, @bind); |
133 | } |
134 | |
135 | sub _insert_ARRAYREF { # just generate values(?,?) part (no list of fields) |
136 | my ($self, $data) = @_; |
137 | |
138 | # no names (arrayref) so can't generate bindtype |
139 | $self->{bindtype} ne 'columns' |
140 | or belch "can't do 'columns' bindtype when called with arrayref"; |
141 | |
fe3ae272 |
142 | # fold the list of values into a hash of column name - value pairs |
143 | # (where the column names are artificially generated, and their |
144 | # lexicographical ordering keep the ordering of the original list) |
145 | my $i = "a"; # incremented values will be in lexicographical order |
146 | my $data_in_hash = { map { ($i++ => $_) } @$data }; |
147 | |
148 | return $self->_insert_values($data_in_hash); |
149 | } |
150 | |
151 | sub _insert_ARRAYREFREF { # literal SQL with bind |
152 | my ($self, $data) = @_; |
153 | |
154 | my ($sql, @bind) = @${$data}; |
155 | $self->_assert_bindval_matches_bindtype(@bind); |
156 | |
157 | return ($sql, @bind); |
158 | } |
159 | |
160 | |
161 | sub _insert_SCALARREF { # literal SQL without bind |
162 | my ($self, $data) = @_; |
163 | |
164 | return ($$data); |
165 | } |
166 | |
167 | sub _insert_values { |
168 | my ($self, $data) = @_; |
169 | |
96449e8e |
170 | my (@values, @all_bind); |
fe3ae272 |
171 | foreach my $column (sort keys %$data) { |
172 | my $v = $data->{$column}; |
96449e8e |
173 | |
174 | $self->_SWITCH_refkind($v, { |
175 | |
176 | ARRAYREF => sub { |
177 | if ($self->{array_datatypes}) { # if array datatype are activated |
178 | push @values, '?'; |
fe3ae272 |
179 | push @all_bind, $self->_bindtype($column, $v); |
96449e8e |
180 | } |
181 | else { # else literal SQL with bind |
182 | my ($sql, @bind) = @$v; |
fe3ae272 |
183 | $self->_assert_bindval_matches_bindtype(@bind); |
96449e8e |
184 | push @values, $sql; |
185 | push @all_bind, @bind; |
186 | } |
187 | }, |
188 | |
189 | ARRAYREFREF => sub { # literal SQL with bind |
190 | my ($sql, @bind) = @${$v}; |
fe3ae272 |
191 | $self->_assert_bindval_matches_bindtype(@bind); |
96449e8e |
192 | push @values, $sql; |
193 | push @all_bind, @bind; |
194 | }, |
195 | |
196 | # THINK : anything useful to do with a HASHREF ? |
5db47f9f |
197 | HASHREF => sub { # (nothing, but old SQLA passed it through) |
198 | #TODO in SQLA >= 2.0 it will die instead |
199 | belch "HASH ref as bind value in insert is not supported"; |
200 | push @values, '?'; |
fe3ae272 |
201 | push @all_bind, $self->_bindtype($column, $v); |
5db47f9f |
202 | }, |
96449e8e |
203 | |
204 | SCALARREF => sub { # literal SQL without bind |
205 | push @values, $$v; |
206 | }, |
207 | |
208 | SCALAR_or_UNDEF => sub { |
209 | push @values, '?'; |
fe3ae272 |
210 | push @all_bind, $self->_bindtype($column, $v); |
96449e8e |
211 | }, |
212 | |
213 | }); |
214 | |
215 | } |
216 | |
217 | my $sql = $self->_sqlcase('values')." ( ".join(", ", @values)." )"; |
218 | return ($sql, @all_bind); |
219 | } |
220 | |
221 | |
96449e8e |
222 | |
223 | #====================================================================== |
224 | # UPDATE methods |
225 | #====================================================================== |
226 | |
227 | |
228 | sub update { |
229 | my $self = shift; |
230 | my $table = $self->_table(shift); |
231 | my $data = shift || return; |
232 | my $where = shift; |
233 | |
234 | # first build the 'SET' part of the sql statement |
235 | my (@set, @all_bind); |
236 | puke "Unsupported data type specified to \$sql->update" |
237 | unless ref $data eq 'HASH'; |
238 | |
239 | for my $k (sort keys %$data) { |
240 | my $v = $data->{$k}; |
241 | my $r = ref $v; |
242 | my $label = $self->_quote($k); |
243 | |
244 | $self->_SWITCH_refkind($v, { |
245 | ARRAYREF => sub { |
246 | if ($self->{array_datatypes}) { # array datatype |
247 | push @set, "$label = ?"; |
248 | push @all_bind, $self->_bindtype($k, $v); |
249 | } |
250 | else { # literal SQL with bind |
251 | my ($sql, @bind) = @$v; |
fe3ae272 |
252 | $self->_assert_bindval_matches_bindtype(@bind); |
96449e8e |
253 | push @set, "$label = $sql"; |
fe3ae272 |
254 | push @all_bind, @bind; |
96449e8e |
255 | } |
256 | }, |
257 | ARRAYREFREF => sub { # literal SQL with bind |
258 | my ($sql, @bind) = @${$v}; |
fe3ae272 |
259 | $self->_assert_bindval_matches_bindtype(@bind); |
96449e8e |
260 | push @set, "$label = $sql"; |
fe3ae272 |
261 | push @all_bind, @bind; |
96449e8e |
262 | }, |
263 | SCALARREF => sub { # literal SQL without bind |
264 | push @set, "$label = $$v"; |
265 | }, |
266 | SCALAR_or_UNDEF => sub { |
267 | push @set, "$label = ?"; |
268 | push @all_bind, $self->_bindtype($k, $v); |
269 | }, |
270 | }); |
271 | } |
272 | |
273 | # generate sql |
274 | my $sql = $self->_sqlcase('update') . " $table " . $self->_sqlcase('set ') |
275 | . join ', ', @set; |
276 | |
277 | if ($where) { |
278 | my($where_sql, @where_bind) = $self->where($where); |
279 | $sql .= $where_sql; |
280 | push @all_bind, @where_bind; |
281 | } |
282 | |
283 | return wantarray ? ($sql, @all_bind) : $sql; |
284 | } |
285 | |
286 | |
287 | |
288 | |
289 | #====================================================================== |
290 | # SELECT |
291 | #====================================================================== |
292 | |
293 | |
294 | sub select { |
295 | my $self = shift; |
296 | my $table = $self->_table(shift); |
297 | my $fields = shift || '*'; |
298 | my $where = shift; |
299 | my $order = shift; |
300 | |
301 | my($where_sql, @bind) = $self->where($where, $order); |
302 | |
303 | my $f = (ref $fields eq 'ARRAY') ? join ', ', map { $self->_quote($_) } @$fields |
304 | : $fields; |
305 | my $sql = join(' ', $self->_sqlcase('select'), $f, |
306 | $self->_sqlcase('from'), $table) |
307 | . $where_sql; |
308 | |
309 | return wantarray ? ($sql, @bind) : $sql; |
310 | } |
311 | |
312 | #====================================================================== |
313 | # DELETE |
314 | #====================================================================== |
315 | |
316 | |
317 | sub delete { |
318 | my $self = shift; |
319 | my $table = $self->_table(shift); |
320 | my $where = shift; |
321 | |
322 | |
323 | my($where_sql, @bind) = $self->where($where); |
324 | my $sql = $self->_sqlcase('delete from') . " $table" . $where_sql; |
325 | |
326 | return wantarray ? ($sql, @bind) : $sql; |
327 | } |
328 | |
329 | |
330 | #====================================================================== |
331 | # WHERE: entry point |
332 | #====================================================================== |
333 | |
334 | |
335 | |
336 | # Finally, a separate routine just to handle WHERE clauses |
337 | sub where { |
338 | my ($self, $where, $order) = @_; |
339 | |
340 | # where ? |
341 | my ($sql, @bind) = $self->_recurse_where($where); |
342 | $sql = $sql ? $self->_sqlcase(' where ') . "( $sql )" : ''; |
343 | |
344 | # order by? |
345 | if ($order) { |
346 | $sql .= $self->_order_by($order); |
347 | } |
348 | |
349 | return wantarray ? ($sql, @bind) : $sql; |
350 | } |
351 | |
352 | |
353 | sub _recurse_where { |
354 | my ($self, $where, $logic) = @_; |
355 | |
356 | # dispatch on appropriate method according to refkind of $where |
357 | my $method = $self->_METHOD_FOR_refkind("_where", $where); |
311b2151 |
358 | |
359 | |
360 | my ($sql, @bind) = $self->$method($where, $logic); |
361 | |
362 | # DBIx::Class directly calls _recurse_where in scalar context, so |
363 | # we must implement it, even if not in the official API |
364 | return wantarray ? ($sql, @bind) : $sql; |
96449e8e |
365 | } |
366 | |
367 | |
368 | |
369 | #====================================================================== |
370 | # WHERE: top-level ARRAYREF |
371 | #====================================================================== |
372 | |
373 | |
374 | sub _where_ARRAYREF { |
5e1d09d5 |
375 | my ($self, $where, $logic) = @_; |
96449e8e |
376 | |
5e1d09d5 |
377 | $logic = uc($logic || $self->{logic}); |
96449e8e |
378 | $logic eq 'AND' or $logic eq 'OR' or puke "unknown logic: $logic"; |
379 | |
380 | my @clauses = @$where; |
381 | |
96449e8e |
382 | my (@sql_clauses, @all_bind); |
96449e8e |
383 | # need to use while() so can shift() for pairs |
384 | while (my $el = shift @clauses) { |
385 | |
386 | # switch according to kind of $el and get corresponding ($sql, @bind) |
387 | my ($sql, @bind) = $self->_SWITCH_refkind($el, { |
388 | |
389 | # skip empty elements, otherwise get invalid trailing AND stuff |
390 | ARRAYREF => sub {$self->_recurse_where($el) if @$el}, |
391 | |
474e3335 |
392 | ARRAYREFREF => sub { @{${$el}} if @{${$el}}}, |
393 | |
96449e8e |
394 | HASHREF => sub {$self->_recurse_where($el, 'and') if %$el}, |
395 | # LDNOTE : previous SQLA code for hashrefs was creating a dirty |
396 | # side-effect: the first hashref within an array would change |
397 | # the global logic to 'AND'. So [ {cond1, cond2}, [cond3, cond4] ] |
398 | # was interpreted as "(cond1 AND cond2) OR (cond3 AND cond4)", |
399 | # whereas it should be "(cond1 AND cond2) OR (cond3 OR cond4)". |
400 | |
401 | SCALARREF => sub { ($$el); }, |
402 | |
403 | SCALAR => sub {# top-level arrayref with scalars, recurse in pairs |
404 | $self->_recurse_where({$el => shift(@clauses)})}, |
405 | |
406 | UNDEF => sub {puke "not supported : UNDEF in arrayref" }, |
407 | }); |
408 | |
4b7b6026 |
409 | if ($sql) { |
410 | push @sql_clauses, $sql; |
411 | push @all_bind, @bind; |
412 | } |
96449e8e |
413 | } |
414 | |
415 | return $self->_join_sql_clauses($logic, \@sql_clauses, \@all_bind); |
416 | } |
417 | |
474e3335 |
418 | #====================================================================== |
419 | # WHERE: top-level ARRAYREFREF |
420 | #====================================================================== |
96449e8e |
421 | |
474e3335 |
422 | sub _where_ARRAYREFREF { |
423 | my ($self, $where) = @_; |
424 | my ($sql, @bind) = @{${$where}}; |
425 | |
426 | return ($sql, @bind); |
427 | } |
96449e8e |
428 | |
429 | #====================================================================== |
430 | # WHERE: top-level HASHREF |
431 | #====================================================================== |
432 | |
433 | sub _where_HASHREF { |
434 | my ($self, $where) = @_; |
435 | my (@sql_clauses, @all_bind); |
436 | |
96449e8e |
437 | for my $k (sort keys %$where) { |
438 | my $v = $where->{$k}; |
439 | |
440 | # ($k => $v) is either a special op or a regular hashpair |
441 | my ($sql, @bind) = ($k =~ /^-(.+)/) ? $self->_where_op_in_hash($1, $v) |
442 | : do { |
443 | my $method = $self->_METHOD_FOR_refkind("_where_hashpair", $v); |
444 | $self->$method($k, $v); |
445 | }; |
446 | |
447 | push @sql_clauses, $sql; |
448 | push @all_bind, @bind; |
449 | } |
450 | |
451 | return $self->_join_sql_clauses('and', \@sql_clauses, \@all_bind); |
452 | } |
453 | |
454 | |
455 | sub _where_op_in_hash { |
59f23b3d |
456 | my ($self, $op, $v) = @_; |
6dae476e |
457 | |
59f23b3d |
458 | # put the operator in canonical form |
459 | $op =~ s/^-//; # remove initial dash |
2463c5e4 |
460 | $op =~ tr/_ \t/ /s; # underscores and whitespace become single spaces |
96449e8e |
461 | |
96449e8e |
462 | $self->_debug("OP(-$op) within hashref, recursing..."); |
463 | |
59f23b3d |
464 | my $op_entry = first {$op =~ $_->{regex}} @{$self->{unary_ops}}; |
465 | my $handler = $op_entry->{handler}; |
97a920ef |
466 | if (! $handler) { |
59f23b3d |
467 | puke "unknown operator: -$op"; |
97a920ef |
468 | } |
469 | elsif (not ref $handler) { |
2463c5e4 |
470 | if ($op_entry->{numchk} && ($op =~ s/\s?\d+$//)) { |
471 | belch 'Use of [and|or|nest]_N modifiers is deprecated and will be removed in SQLA v2.0. ' |
472 | . "You probably wanted ...-and => [ $op => COND1, $op => COND2 ... ]"; |
473 | } |
97a920ef |
474 | return $self->$handler ($op, $v); |
475 | } |
476 | elsif (ref $handler eq 'CODE') { |
477 | return $handler->($self, $op, $v); |
478 | } |
479 | else { |
480 | puke "Illegal handler for operator $op - expecting a method name or a coderef"; |
481 | } |
482 | } |
483 | |
484 | sub _where_op_ANDOR { |
485 | my ($self, $op, $v) = @_; |
486 | |
487 | $self->_SWITCH_refkind($v, { |
488 | ARRAYREF => sub { |
489 | return $self->_where_ARRAYREF($v, $op); |
490 | }, |
491 | |
492 | HASHREF => sub { |
59f23b3d |
493 | return ( $op =~ /^or/i ) |
97a920ef |
494 | ? $self->_where_ARRAYREF( [ map { $_ => $v->{$_} } ( sort keys %$v ) ], $op ) |
495 | : $self->_where_HASHREF($v); |
496 | }, |
497 | |
498 | SCALARREF => sub { |
499 | puke "-$op => \\\$scalar not supported, use -nest => ..."; |
500 | }, |
501 | |
502 | ARRAYREFREF => sub { |
503 | puke "-$op => \\[..] not supported, use -nest => ..."; |
504 | }, |
505 | |
506 | SCALAR => sub { # permissively interpreted as SQL |
507 | puke "-$op => 'scalar' not supported, use -nest => \\'scalar'"; |
508 | }, |
509 | |
510 | UNDEF => sub { |
511 | puke "-$op => undef not supported"; |
512 | }, |
513 | }); |
514 | } |
515 | |
516 | sub _where_op_NEST { |
517 | my ($self, $op, $v) = @_; |
518 | |
96449e8e |
519 | $self->_SWITCH_refkind($v, { |
520 | |
521 | ARRAYREF => sub { |
97a920ef |
522 | return $self->_where_ARRAYREF($v, ''); |
96449e8e |
523 | }, |
524 | |
525 | HASHREF => sub { |
97a920ef |
526 | return $self->_where_HASHREF($v); |
96449e8e |
527 | }, |
528 | |
529 | SCALARREF => sub { # literal SQL |
96449e8e |
530 | return ($$v); |
531 | }, |
532 | |
533 | ARRAYREFREF => sub { # literal SQL |
96449e8e |
534 | return @{${$v}}; |
535 | }, |
536 | |
537 | SCALAR => sub { # permissively interpreted as SQL |
01a01e57 |
538 | belch "literal SQL should be -nest => \\'scalar' " |
539 | . "instead of -nest => 'scalar' "; |
96449e8e |
540 | return ($v); |
541 | }, |
542 | |
543 | UNDEF => sub { |
544 | puke "-$op => undef not supported"; |
545 | }, |
546 | }); |
547 | } |
548 | |
549 | |
97a920ef |
550 | sub _where_op_BOOL { |
551 | my ($self, $op, $v) = @_; |
552 | |
59f23b3d |
553 | my $prefix = ($op =~ /\bnot\b/i) ? 'NOT ' : ''; |
97a920ef |
554 | $self->_SWITCH_refkind($v, { |
555 | SCALARREF => sub { # literal SQL |
556 | return ($prefix . $$v); |
557 | }, |
558 | |
559 | SCALAR => sub { # interpreted as SQL column |
560 | return ($prefix . $self->_convert($self->_quote($v))); |
561 | }, |
562 | }); |
563 | } |
564 | |
565 | |
96449e8e |
566 | sub _where_hashpair_ARRAYREF { |
567 | my ($self, $k, $v) = @_; |
568 | |
569 | if( @$v ) { |
570 | my @v = @$v; # need copy because of shift below |
571 | $self->_debug("ARRAY($k) means distribute over elements"); |
572 | |
573 | # put apart first element if it is an operator (-and, -or) |
e3cecb45 |
574 | my $op = ( |
575 | (defined $v[0] && $v[0] =~ /^ - (?: AND|OR ) $/ix) |
576 | ? shift @v |
577 | : '' |
04d940de |
578 | ); |
96449e8e |
579 | my @distributed = map { {$k => $_} } @v; |
04d940de |
580 | |
581 | if ($op) { |
582 | $self->_debug("OP($op) reinjected into the distributed array"); |
583 | unshift @distributed, $op; |
584 | } |
585 | |
f67591bf |
586 | my $logic = $op ? substr($op, 1) : ''; |
96449e8e |
587 | |
f67591bf |
588 | return $self->_recurse_where(\@distributed, $logic); |
96449e8e |
589 | } |
590 | else { |
591 | # LDNOTE : not sure of this one. What does "distribute over nothing" mean? |
592 | $self->_debug("empty ARRAY($k) means 0=1"); |
593 | return ($self->{sqlfalse}); |
594 | } |
595 | } |
596 | |
597 | sub _where_hashpair_HASHREF { |
eb49170d |
598 | my ($self, $k, $v, $logic) = @_; |
599 | $logic ||= 'and'; |
96449e8e |
600 | |
eb49170d |
601 | my ($all_sql, @all_bind); |
96449e8e |
602 | |
603 | for my $op (sort keys %$v) { |
604 | my $val = $v->{$op}; |
605 | |
606 | # put the operator in canonical form |
607 | $op =~ s/^-//; # remove initial dash |
608 | $op =~ tr/_/ /; # underscores become spaces |
609 | $op =~ s/^\s+//; # no initial space |
610 | $op =~ s/\s+$//; # no final space |
611 | $op =~ s/\s+/ /; # multiple spaces become one |
612 | |
613 | my ($sql, @bind); |
614 | |
615 | # CASE: special operators like -in or -between |
616 | my $special_op = first {$op =~ $_->{regex}} @{$self->{special_ops}}; |
617 | if ($special_op) { |
3a2e1a5e |
618 | my $handler = $special_op->{handler}; |
619 | if (! $handler) { |
620 | puke "No handler supplied for special operator matching $special_op->{regex}"; |
621 | } |
622 | elsif (not ref $handler) { |
623 | ($sql, @bind) = $self->$handler ($k, $op, $val); |
624 | } |
625 | elsif (ref $handler eq 'CODE') { |
626 | ($sql, @bind) = $handler->($self, $k, $op, $val); |
627 | } |
628 | else { |
629 | puke "Illegal handler for special operator matching $special_op->{regex} - expecting a method name or a coderef"; |
630 | } |
96449e8e |
631 | } |
96449e8e |
632 | else { |
cf838930 |
633 | $self->_SWITCH_refkind($val, { |
634 | |
635 | ARRAYREF => sub { # CASE: col => {op => \@vals} |
636 | ($sql, @bind) = $self->_where_field_op_ARRAYREF($k, $op, $val); |
637 | }, |
638 | |
fe3ae272 |
639 | SCALARREF => sub { # CASE: col => {op => \$scalar} (literal SQL without bind) |
cf838930 |
640 | $sql = join ' ', $self->_convert($self->_quote($k)), |
641 | $self->_sqlcase($op), |
642 | $$val; |
643 | }, |
644 | |
fe3ae272 |
645 | ARRAYREFREF => sub { # CASE: col => {op => \[$sql, @bind]} (literal SQL with bind) |
b3be7bd0 |
646 | my ($sub_sql, @sub_bind) = @$$val; |
fe3ae272 |
647 | $self->_assert_bindval_matches_bindtype(@sub_bind); |
b3be7bd0 |
648 | $sql = join ' ', $self->_convert($self->_quote($k)), |
649 | $self->_sqlcase($op), |
650 | $sub_sql; |
fe3ae272 |
651 | @bind = @sub_bind; |
b3be7bd0 |
652 | }, |
653 | |
eb49170d |
654 | HASHREF => sub { |
655 | ($sql, @bind) = $self->_where_hashpair_HASHREF($k, $val, $op); |
656 | }, |
657 | |
cf838930 |
658 | UNDEF => sub { # CASE: col => {op => undef} : sql "IS (NOT)? NULL" |
659 | my $is = ($op =~ $self->{equality_op}) ? 'is' : |
660 | ($op =~ $self->{inequality_op}) ? 'is not' : |
661 | puke "unexpected operator '$op' with undef operand"; |
662 | $sql = $self->_quote($k) . $self->_sqlcase(" $is null"); |
663 | }, |
664 | |
665 | FALLBACK => sub { # CASE: col => {op => $scalar} |
666 | $sql = join ' ', $self->_convert($self->_quote($k)), |
667 | $self->_sqlcase($op), |
668 | $self->_convert('?'); |
669 | @bind = $self->_bindtype($k, $val); |
670 | }, |
671 | }); |
96449e8e |
672 | } |
673 | |
eb49170d |
674 | ($all_sql) = (defined $all_sql and $all_sql) ? $self->_join_sql_clauses($logic, [$all_sql, $sql], []) : $sql; |
96449e8e |
675 | push @all_bind, @bind; |
676 | } |
eb49170d |
677 | return ($all_sql, @all_bind); |
96449e8e |
678 | } |
679 | |
680 | |
681 | |
682 | sub _where_field_op_ARRAYREF { |
683 | my ($self, $k, $op, $vals) = @_; |
684 | |
ce261791 |
685 | my @vals = @$vals; #always work on a copy |
686 | |
687 | if(@vals) { |
688 | $self->_debug("ARRAY($vals) means multiple elements: [ @vals ]"); |
96449e8e |
689 | |
4030915f |
690 | # see if the first element is an -and/-or op |
691 | my $logic; |
ce261791 |
692 | if ($vals[0] =~ /^ - ( AND|OR ) $/ix) { |
4030915f |
693 | $logic = uc $1; |
ce261791 |
694 | shift @vals; |
4030915f |
695 | } |
696 | |
ce261791 |
697 | # distribute $op over each remaining member of @vals, append logic if exists |
698 | return $self->_recurse_where([map { {$k => {$op, $_}} } @vals], $logic); |
4030915f |
699 | |
f2d5020d |
700 | # LDNOTE : had planned to change the distribution logic when |
96449e8e |
701 | # $op =~ $self->{inequality_op}, because of Morgan laws : |
702 | # with {field => {'!=' => [22, 33]}}, it would be ridiculous to generate |
703 | # WHERE field != 22 OR field != 33 : the user probably means |
704 | # WHERE field != 22 AND field != 33. |
4030915f |
705 | # To do this, replace the above to roughly : |
f2d5020d |
706 | # my $logic = ($op =~ $self->{inequality_op}) ? 'AND' : 'OR'; |
ce261791 |
707 | # return $self->_recurse_where([map { {$k => {$op, $_}} } @vals], $logic); |
96449e8e |
708 | |
96449e8e |
709 | } |
710 | else { |
711 | # try to DWIM on equality operators |
712 | # LDNOTE : not 100% sure this is the correct thing to do ... |
713 | return ($self->{sqlfalse}) if $op =~ $self->{equality_op}; |
714 | return ($self->{sqltrue}) if $op =~ $self->{inequality_op}; |
715 | |
716 | # otherwise |
717 | puke "operator '$op' applied on an empty array (field '$k')"; |
718 | } |
719 | } |
720 | |
721 | |
722 | sub _where_hashpair_SCALARREF { |
723 | my ($self, $k, $v) = @_; |
724 | $self->_debug("SCALAR($k) means literal SQL: $$v"); |
725 | my $sql = $self->_quote($k) . " " . $$v; |
726 | return ($sql); |
727 | } |
728 | |
fe3ae272 |
729 | # literal SQL with bind |
96449e8e |
730 | sub _where_hashpair_ARRAYREFREF { |
731 | my ($self, $k, $v) = @_; |
732 | $self->_debug("REF($k) means literal SQL: @${$v}"); |
733 | my ($sql, @bind) = @${$v}; |
fe3ae272 |
734 | $self->_assert_bindval_matches_bindtype(@bind); |
96449e8e |
735 | $sql = $self->_quote($k) . " " . $sql; |
96449e8e |
736 | return ($sql, @bind ); |
737 | } |
738 | |
fe3ae272 |
739 | # literal SQL without bind |
96449e8e |
740 | sub _where_hashpair_SCALAR { |
741 | my ($self, $k, $v) = @_; |
742 | $self->_debug("NOREF($k) means simple key=val: $k $self->{cmp} $v"); |
743 | my $sql = join ' ', $self->_convert($self->_quote($k)), |
744 | $self->_sqlcase($self->{cmp}), |
745 | $self->_convert('?'); |
746 | my @bind = $self->_bindtype($k, $v); |
747 | return ( $sql, @bind); |
748 | } |
749 | |
750 | |
751 | sub _where_hashpair_UNDEF { |
752 | my ($self, $k, $v) = @_; |
753 | $self->_debug("UNDEF($k) means IS NULL"); |
754 | my $sql = $self->_quote($k) . $self->_sqlcase(' is null'); |
755 | return ($sql); |
756 | } |
757 | |
758 | #====================================================================== |
759 | # WHERE: TOP-LEVEL OTHERS (SCALARREF, SCALAR, UNDEF) |
760 | #====================================================================== |
761 | |
762 | |
763 | sub _where_SCALARREF { |
764 | my ($self, $where) = @_; |
765 | |
766 | # literal sql |
767 | $self->_debug("SCALAR(*top) means literal SQL: $$where"); |
768 | return ($$where); |
769 | } |
770 | |
771 | |
772 | sub _where_SCALAR { |
773 | my ($self, $where) = @_; |
774 | |
775 | # literal sql |
776 | $self->_debug("NOREF(*top) means literal SQL: $where"); |
777 | return ($where); |
778 | } |
779 | |
780 | |
781 | sub _where_UNDEF { |
782 | my ($self) = @_; |
783 | return (); |
784 | } |
785 | |
786 | |
787 | #====================================================================== |
788 | # WHERE: BUILTIN SPECIAL OPERATORS (-in, -between) |
789 | #====================================================================== |
790 | |
791 | |
792 | sub _where_field_BETWEEN { |
793 | my ($self, $k, $op, $vals) = @_; |
794 | |
cf02fc47 |
795 | (ref $vals eq 'ARRAY' && @$vals == 2) or |
796 | (ref $vals eq 'REF' && (@$$vals == 1 || @$$vals == 2 || @$$vals == 3)) |
797 | or puke "special op 'between' requires an arrayref of two values (or a scalarref or arrayrefref for literal SQL)"; |
96449e8e |
798 | |
cf02fc47 |
799 | my ($clause, @bind, $label, $and, $placeholder); |
800 | $label = $self->_convert($self->_quote($k)); |
801 | $and = ' ' . $self->_sqlcase('and') . ' '; |
802 | $placeholder = $self->_convert('?'); |
96449e8e |
803 | $op = $self->_sqlcase($op); |
804 | |
cf02fc47 |
805 | if (ref $vals eq 'REF') { |
806 | ($clause, @bind) = @$$vals; |
807 | } |
808 | else { |
809 | my (@all_sql, @all_bind); |
810 | |
811 | foreach my $val (@$vals) { |
812 | my ($sql, @bind) = $self->_SWITCH_refkind($val, { |
813 | SCALAR => sub { |
814 | return ($placeholder, ($val)); |
815 | }, |
816 | SCALARREF => sub { |
817 | return ($self->_convert($$val), ()); |
818 | }, |
819 | }); |
820 | push @all_sql, $sql; |
821 | push @all_bind, @bind; |
822 | } |
823 | |
824 | $clause = (join $and, @all_sql); |
825 | @bind = $self->_bindtype($k, @all_bind); |
826 | } |
827 | my $sql = "( $label $op $clause )"; |
96449e8e |
828 | return ($sql, @bind) |
829 | } |
830 | |
831 | |
832 | sub _where_field_IN { |
833 | my ($self, $k, $op, $vals) = @_; |
834 | |
835 | # backwards compatibility : if scalar, force into an arrayref |
836 | $vals = [$vals] if defined $vals && ! ref $vals; |
837 | |
96449e8e |
838 | my ($label) = $self->_convert($self->_quote($k)); |
839 | my ($placeholder) = $self->_convert('?'); |
96449e8e |
840 | $op = $self->_sqlcase($op); |
841 | |
8a0d798a |
842 | my ($sql, @bind) = $self->_SWITCH_refkind($vals, { |
843 | ARRAYREF => sub { # list of choices |
844 | if (@$vals) { # nonempty list |
845 | my $placeholders = join ", ", (($placeholder) x @$vals); |
846 | my $sql = "$label $op ( $placeholders )"; |
847 | my @bind = $self->_bindtype($k, @$vals); |
96449e8e |
848 | |
8a0d798a |
849 | return ($sql, @bind); |
850 | } |
851 | else { # empty list : some databases won't understand "IN ()", so DWIM |
852 | my $sql = ($op =~ /\bnot\b/i) ? $self->{sqltrue} : $self->{sqlfalse}; |
853 | return ($sql); |
854 | } |
855 | }, |
856 | |
857 | ARRAYREFREF => sub { # literal SQL with bind |
858 | my ($sql, @bind) = @$$vals; |
fe3ae272 |
859 | $self->_assert_bindval_matches_bindtype(@bind); |
8a0d798a |
860 | return ("$label $op ( $sql )", @bind); |
861 | }, |
862 | |
863 | FALLBACK => sub { |
864 | puke "special op 'in' requires an arrayref (or arrayref-ref)"; |
865 | }, |
866 | }); |
867 | |
868 | return ($sql, @bind); |
96449e8e |
869 | } |
870 | |
871 | |
872 | |
873 | |
96449e8e |
874 | #====================================================================== |
875 | # ORDER BY |
876 | #====================================================================== |
877 | |
878 | sub _order_by { |
879 | my ($self, $arg) = @_; |
880 | |
f267b646 |
881 | my (@sql, @bind); |
882 | for my $c ($self->_order_by_chunks ($arg) ) { |
883 | $self->_SWITCH_refkind ($c, { |
884 | SCALAR => sub { push @sql, $c }, |
885 | ARRAYREF => sub { push @sql, shift @$c; push @bind, @$c }, |
886 | }); |
887 | } |
888 | |
889 | my $sql = @sql |
890 | ? sprintf ('%s %s', |
891 | $self->_sqlcase(' order by'), |
892 | join (', ', @sql) |
893 | ) |
894 | : '' |
895 | ; |
896 | |
897 | return wantarray ? ($sql, @bind) : $sql; |
898 | } |
899 | |
900 | sub _order_by_chunks { |
901 | my ($self, $arg) = @_; |
902 | |
903 | return $self->_SWITCH_refkind($arg, { |
96449e8e |
904 | |
905 | ARRAYREF => sub { |
f267b646 |
906 | map { $self->_order_by_chunks ($_ ) } @$arg; |
96449e8e |
907 | }, |
908 | |
f267b646 |
909 | ARRAYREFREF => sub { [ @$$arg ] }, |
910 | |
96449e8e |
911 | SCALAR => sub {$self->_quote($arg)}, |
f267b646 |
912 | |
913 | UNDEF => sub {return () }, |
914 | |
96449e8e |
915 | SCALARREF => sub {$$arg}, # literal SQL, no quoting |
96449e8e |
916 | |
f267b646 |
917 | HASHREF => sub { |
918 | # get first pair in hash |
919 | my ($key, $val) = each %$arg; |
96449e8e |
920 | |
f267b646 |
921 | return () unless $key; |
96449e8e |
922 | |
f267b646 |
923 | if ( (keys %$arg) > 1 or not $key =~ /^-(desc|asc)/i ) { |
924 | puke "hash passed to _order_by must have exactly one key (-desc or -asc)"; |
925 | } |
96449e8e |
926 | |
f267b646 |
927 | my $direction = $1; |
96449e8e |
928 | |
e9bd3547 |
929 | my @ret; |
f267b646 |
930 | for my $c ($self->_order_by_chunks ($val)) { |
e9bd3547 |
931 | my ($sql, @bind); |
96449e8e |
932 | |
f267b646 |
933 | $self->_SWITCH_refkind ($c, { |
934 | SCALAR => sub { |
e9bd3547 |
935 | $sql = $c; |
f267b646 |
936 | }, |
937 | ARRAYREF => sub { |
e9bd3547 |
938 | ($sql, @bind) = @$c; |
f267b646 |
939 | }, |
940 | }); |
96449e8e |
941 | |
e9bd3547 |
942 | $sql = $sql . ' ' . $self->_sqlcase($direction); |
96449e8e |
943 | |
e9bd3547 |
944 | push @ret, [ $sql, @bind]; |
945 | } |
96449e8e |
946 | |
e9bd3547 |
947 | return @ret; |
f267b646 |
948 | }, |
949 | }); |
96449e8e |
950 | } |
951 | |
952 | |
96449e8e |
953 | #====================================================================== |
954 | # DATASOURCE (FOR NOW, JUST PLAIN TABLE OR LIST OF TABLES) |
955 | #====================================================================== |
956 | |
957 | sub _table { |
958 | my $self = shift; |
959 | my $from = shift; |
960 | $self->_SWITCH_refkind($from, { |
961 | ARRAYREF => sub {join ', ', map { $self->_quote($_) } @$from;}, |
962 | SCALAR => sub {$self->_quote($from)}, |
963 | SCALARREF => sub {$$from}, |
964 | ARRAYREFREF => sub {join ', ', @$from;}, |
965 | }); |
966 | } |
967 | |
968 | |
969 | #====================================================================== |
970 | # UTILITY FUNCTIONS |
971 | #====================================================================== |
972 | |
973 | sub _quote { |
974 | my $self = shift; |
975 | my $label = shift; |
976 | |
977 | $label or puke "can't quote an empty label"; |
978 | |
979 | # left and right quote characters |
980 | my ($ql, $qr, @other) = $self->_SWITCH_refkind($self->{quote_char}, { |
981 | SCALAR => sub {($self->{quote_char}, $self->{quote_char})}, |
982 | ARRAYREF => sub {@{$self->{quote_char}}}, |
983 | UNDEF => sub {()}, |
984 | }); |
985 | not @other |
986 | or puke "quote_char must be an arrayref of 2 values"; |
987 | |
988 | # no quoting if no quoting chars |
989 | $ql or return $label; |
990 | |
991 | # no quoting for literal SQL |
992 | return $$label if ref($label) eq 'SCALAR'; |
993 | |
994 | # separate table / column (if applicable) |
995 | my $sep = $self->{name_sep} || ''; |
996 | my @to_quote = $sep ? split /\Q$sep\E/, $label : ($label); |
997 | |
998 | # do the quoting, except for "*" or for `table`.* |
999 | my @quoted = map { $_ eq '*' ? $_: $ql.$_.$qr} @to_quote; |
1000 | |
1001 | # reassemble and return. |
1002 | return join $sep, @quoted; |
1003 | } |
1004 | |
1005 | |
1006 | # Conversion, if applicable |
1007 | sub _convert ($) { |
1008 | my ($self, $arg) = @_; |
1009 | |
1010 | # LDNOTE : modified the previous implementation below because |
1011 | # it was not consistent : the first "return" is always an array, |
1012 | # the second "return" is context-dependent. Anyway, _convert |
1013 | # seems always used with just a single argument, so make it a |
1014 | # scalar function. |
1015 | # return @_ unless $self->{convert}; |
1016 | # my $conv = $self->_sqlcase($self->{convert}); |
1017 | # my @ret = map { $conv.'('.$_.')' } @_; |
1018 | # return wantarray ? @ret : $ret[0]; |
1019 | if ($self->{convert}) { |
1020 | my $conv = $self->_sqlcase($self->{convert}); |
1021 | $arg = $conv.'('.$arg.')'; |
1022 | } |
1023 | return $arg; |
1024 | } |
1025 | |
1026 | # And bindtype |
1027 | sub _bindtype (@) { |
1028 | my $self = shift; |
1029 | my($col, @vals) = @_; |
1030 | |
1031 | #LDNOTE : changed original implementation below because it did not make |
1032 | # sense when bindtype eq 'columns' and @vals > 1. |
1033 | # return $self->{bindtype} eq 'columns' ? [ $col, @vals ] : @vals; |
1034 | |
1035 | return $self->{bindtype} eq 'columns' ? map {[$col, $_]} @vals : @vals; |
1036 | } |
1037 | |
fe3ae272 |
1038 | # Dies if any element of @bind is not in [colname => value] format |
1039 | # if bindtype is 'columns'. |
1040 | sub _assert_bindval_matches_bindtype { |
1041 | my ($self, @bind) = @_; |
1042 | |
1043 | if ($self->{bindtype} eq 'columns') { |
1044 | foreach my $val (@bind) { |
1045 | if (!defined $val || ref($val) ne 'ARRAY' || @$val != 2) { |
1046 | die "bindtype 'columns' selected, you need to pass: [column_name => bind_value]" |
1047 | } |
1048 | } |
1049 | } |
1050 | } |
1051 | |
96449e8e |
1052 | sub _join_sql_clauses { |
1053 | my ($self, $logic, $clauses_aref, $bind_aref) = @_; |
1054 | |
1055 | if (@$clauses_aref > 1) { |
1056 | my $join = " " . $self->_sqlcase($logic) . " "; |
1057 | my $sql = '( ' . join($join, @$clauses_aref) . ' )'; |
1058 | return ($sql, @$bind_aref); |
1059 | } |
1060 | elsif (@$clauses_aref) { |
1061 | return ($clauses_aref->[0], @$bind_aref); # no parentheses |
1062 | } |
1063 | else { |
1064 | return (); # if no SQL, ignore @$bind_aref |
1065 | } |
1066 | } |
1067 | |
1068 | |
1069 | # Fix SQL case, if so requested |
1070 | sub _sqlcase { |
1071 | my $self = shift; |
1072 | |
1073 | # LDNOTE: if $self->{case} is true, then it contains 'lower', so we |
1074 | # don't touch the argument ... crooked logic, but let's not change it! |
1075 | return $self->{case} ? $_[0] : uc($_[0]); |
1076 | } |
1077 | |
1078 | |
1079 | #====================================================================== |
1080 | # DISPATCHING FROM REFKIND |
1081 | #====================================================================== |
1082 | |
1083 | sub _refkind { |
1084 | my ($self, $data) = @_; |
1085 | my $suffix = ''; |
1086 | my $ref; |
90aab162 |
1087 | my $n_steps = 0; |
96449e8e |
1088 | |
96449e8e |
1089 | while (1) { |
90aab162 |
1090 | # blessed objects are treated like scalars |
1091 | $ref = (blessed $data) ? '' : ref $data; |
1092 | $n_steps += 1 if $ref; |
1093 | last if $ref ne 'REF'; |
96449e8e |
1094 | $data = $$data; |
1095 | } |
1096 | |
90aab162 |
1097 | my $base = $ref || (defined $data ? 'SCALAR' : 'UNDEF'); |
1098 | |
1099 | return $base . ('REF' x $n_steps); |
96449e8e |
1100 | } |
1101 | |
90aab162 |
1102 | |
1103 | |
96449e8e |
1104 | sub _try_refkind { |
1105 | my ($self, $data) = @_; |
1106 | my @try = ($self->_refkind($data)); |
1107 | push @try, 'SCALAR_or_UNDEF' if $try[0] eq 'SCALAR' || $try[0] eq 'UNDEF'; |
1108 | push @try, 'FALLBACK'; |
1109 | return @try; |
1110 | } |
1111 | |
1112 | sub _METHOD_FOR_refkind { |
1113 | my ($self, $meth_prefix, $data) = @_; |
1114 | my $method = first {$_} map {$self->can($meth_prefix."_".$_)} |
1115 | $self->_try_refkind($data) |
1116 | or puke "cannot dispatch on '$meth_prefix' for ".$self->_refkind($data); |
1117 | return $method; |
1118 | } |
1119 | |
1120 | |
1121 | sub _SWITCH_refkind { |
1122 | my ($self, $data, $dispatch_table) = @_; |
1123 | |
1124 | my $coderef = first {$_} map {$dispatch_table->{$_}} |
1125 | $self->_try_refkind($data) |
1126 | or puke "no dispatch entry for ".$self->_refkind($data); |
1127 | $coderef->(); |
1128 | } |
1129 | |
1130 | |
1131 | |
1132 | |
1133 | #====================================================================== |
1134 | # VALUES, GENERATE, AUTOLOAD |
1135 | #====================================================================== |
1136 | |
1137 | # LDNOTE: original code from nwiger, didn't touch code in that section |
1138 | # I feel the AUTOLOAD stuff should not be the default, it should |
1139 | # only be activated on explicit demand by user. |
1140 | |
1141 | sub values { |
1142 | my $self = shift; |
1143 | my $data = shift || return; |
1144 | puke "Argument to ", __PACKAGE__, "->values must be a \\%hash" |
1145 | unless ref $data eq 'HASH'; |
bab725ce |
1146 | |
1147 | my @all_bind; |
1148 | foreach my $k ( sort keys %$data ) { |
1149 | my $v = $data->{$k}; |
1150 | $self->_SWITCH_refkind($v, { |
1151 | ARRAYREF => sub { |
1152 | if ($self->{array_datatypes}) { # array datatype |
1153 | push @all_bind, $self->_bindtype($k, $v); |
1154 | } |
1155 | else { # literal SQL with bind |
1156 | my ($sql, @bind) = @$v; |
1157 | $self->_assert_bindval_matches_bindtype(@bind); |
1158 | push @all_bind, @bind; |
1159 | } |
1160 | }, |
1161 | ARRAYREFREF => sub { # literal SQL with bind |
1162 | my ($sql, @bind) = @${$v}; |
1163 | $self->_assert_bindval_matches_bindtype(@bind); |
1164 | push @all_bind, @bind; |
1165 | }, |
1166 | SCALARREF => sub { # literal SQL without bind |
1167 | }, |
1168 | SCALAR_or_UNDEF => sub { |
1169 | push @all_bind, $self->_bindtype($k, $v); |
1170 | }, |
1171 | }); |
1172 | } |
1173 | |
1174 | return @all_bind; |
96449e8e |
1175 | } |
1176 | |
1177 | sub generate { |
1178 | my $self = shift; |
1179 | |
1180 | my(@sql, @sqlq, @sqlv); |
1181 | |
1182 | for (@_) { |
1183 | my $ref = ref $_; |
1184 | if ($ref eq 'HASH') { |
1185 | for my $k (sort keys %$_) { |
1186 | my $v = $_->{$k}; |
1187 | my $r = ref $v; |
1188 | my $label = $self->_quote($k); |
1189 | if ($r eq 'ARRAY') { |
fe3ae272 |
1190 | # literal SQL with bind |
1191 | my ($sql, @bind) = @$v; |
1192 | $self->_assert_bindval_matches_bindtype(@bind); |
96449e8e |
1193 | push @sqlq, "$label = $sql"; |
fe3ae272 |
1194 | push @sqlv, @bind; |
96449e8e |
1195 | } elsif ($r eq 'SCALAR') { |
fe3ae272 |
1196 | # literal SQL without bind |
96449e8e |
1197 | push @sqlq, "$label = $$v"; |
1198 | } else { |
1199 | push @sqlq, "$label = ?"; |
1200 | push @sqlv, $self->_bindtype($k, $v); |
1201 | } |
1202 | } |
1203 | push @sql, $self->_sqlcase('set'), join ', ', @sqlq; |
1204 | } elsif ($ref eq 'ARRAY') { |
1205 | # unlike insert(), assume these are ONLY the column names, i.e. for SQL |
1206 | for my $v (@$_) { |
1207 | my $r = ref $v; |
fe3ae272 |
1208 | if ($r eq 'ARRAY') { # literal SQL with bind |
1209 | my ($sql, @bind) = @$v; |
1210 | $self->_assert_bindval_matches_bindtype(@bind); |
1211 | push @sqlq, $sql; |
1212 | push @sqlv, @bind; |
1213 | } elsif ($r eq 'SCALAR') { # literal SQL without bind |
96449e8e |
1214 | # embedded literal SQL |
1215 | push @sqlq, $$v; |
1216 | } else { |
1217 | push @sqlq, '?'; |
1218 | push @sqlv, $v; |
1219 | } |
1220 | } |
1221 | push @sql, '(' . join(', ', @sqlq) . ')'; |
1222 | } elsif ($ref eq 'SCALAR') { |
1223 | # literal SQL |
1224 | push @sql, $$_; |
1225 | } else { |
1226 | # strings get case twiddled |
1227 | push @sql, $self->_sqlcase($_); |
1228 | } |
1229 | } |
1230 | |
1231 | my $sql = join ' ', @sql; |
1232 | |
1233 | # this is pretty tricky |
1234 | # if ask for an array, return ($stmt, @bind) |
1235 | # otherwise, s/?/shift @sqlv/ to put it inline |
1236 | if (wantarray) { |
1237 | return ($sql, @sqlv); |
1238 | } else { |
1239 | 1 while $sql =~ s/\?/my $d = shift(@sqlv); |
1240 | ref $d ? $d->[1] : $d/e; |
1241 | return $sql; |
1242 | } |
1243 | } |
1244 | |
1245 | |
1246 | sub DESTROY { 1 } |
1247 | |
1248 | sub AUTOLOAD { |
1249 | # This allows us to check for a local, then _form, attr |
1250 | my $self = shift; |
1251 | my($name) = $AUTOLOAD =~ /.*::(.+)/; |
1252 | return $self->generate($name, @_); |
1253 | } |
1254 | |
1255 | 1; |
1256 | |
1257 | |
1258 | |
1259 | __END__ |
32eab2da |
1260 | |
1261 | =head1 NAME |
1262 | |
1263 | SQL::Abstract - Generate SQL from Perl data structures |
1264 | |
1265 | =head1 SYNOPSIS |
1266 | |
1267 | use SQL::Abstract; |
1268 | |
1269 | my $sql = SQL::Abstract->new; |
1270 | |
1271 | my($stmt, @bind) = $sql->select($table, \@fields, \%where, \@order); |
1272 | |
1273 | my($stmt, @bind) = $sql->insert($table, \%fieldvals || \@values); |
1274 | |
1275 | my($stmt, @bind) = $sql->update($table, \%fieldvals, \%where); |
1276 | |
1277 | my($stmt, @bind) = $sql->delete($table, \%where); |
1278 | |
1279 | # Then, use these in your DBI statements |
1280 | my $sth = $dbh->prepare($stmt); |
1281 | $sth->execute(@bind); |
1282 | |
1283 | # Just generate the WHERE clause |
abe72f94 |
1284 | my($stmt, @bind) = $sql->where(\%where, \@order); |
32eab2da |
1285 | |
1286 | # Return values in the same order, for hashed queries |
1287 | # See PERFORMANCE section for more details |
1288 | my @bind = $sql->values(\%fieldvals); |
1289 | |
1290 | =head1 DESCRIPTION |
1291 | |
1292 | This module was inspired by the excellent L<DBIx::Abstract>. |
1293 | However, in using that module I found that what I really wanted |
1294 | to do was generate SQL, but still retain complete control over my |
1295 | statement handles and use the DBI interface. So, I set out to |
1296 | create an abstract SQL generation module. |
1297 | |
1298 | While based on the concepts used by L<DBIx::Abstract>, there are |
1299 | several important differences, especially when it comes to WHERE |
1300 | clauses. I have modified the concepts used to make the SQL easier |
1301 | to generate from Perl data structures and, IMO, more intuitive. |
1302 | The underlying idea is for this module to do what you mean, based |
1303 | on the data structures you provide it. The big advantage is that |
1304 | you don't have to modify your code every time your data changes, |
1305 | as this module figures it out. |
1306 | |
1307 | To begin with, an SQL INSERT is as easy as just specifying a hash |
1308 | of C<key=value> pairs: |
1309 | |
1310 | my %data = ( |
1311 | name => 'Jimbo Bobson', |
1312 | phone => '123-456-7890', |
1313 | address => '42 Sister Lane', |
1314 | city => 'St. Louis', |
1315 | state => 'Louisiana', |
1316 | ); |
1317 | |
1318 | The SQL can then be generated with this: |
1319 | |
1320 | my($stmt, @bind) = $sql->insert('people', \%data); |
1321 | |
1322 | Which would give you something like this: |
1323 | |
1324 | $stmt = "INSERT INTO people |
1325 | (address, city, name, phone, state) |
1326 | VALUES (?, ?, ?, ?, ?)"; |
1327 | @bind = ('42 Sister Lane', 'St. Louis', 'Jimbo Bobson', |
1328 | '123-456-7890', 'Louisiana'); |
1329 | |
1330 | These are then used directly in your DBI code: |
1331 | |
1332 | my $sth = $dbh->prepare($stmt); |
1333 | $sth->execute(@bind); |
1334 | |
96449e8e |
1335 | =head2 Inserting and Updating Arrays |
1336 | |
1337 | If your database has array types (like for example Postgres), |
1338 | activate the special option C<< array_datatypes => 1 >> |
1339 | when creating the C<SQL::Abstract> object. |
1340 | Then you may use an arrayref to insert and update database array types: |
1341 | |
1342 | my $sql = SQL::Abstract->new(array_datatypes => 1); |
1343 | my %data = ( |
1344 | planets => [qw/Mercury Venus Earth Mars/] |
1345 | ); |
1346 | |
1347 | my($stmt, @bind) = $sql->insert('solar_system', \%data); |
1348 | |
1349 | This results in: |
1350 | |
1351 | $stmt = "INSERT INTO solar_system (planets) VALUES (?)" |
1352 | |
1353 | @bind = (['Mercury', 'Venus', 'Earth', 'Mars']); |
1354 | |
1355 | |
1356 | =head2 Inserting and Updating SQL |
1357 | |
1358 | In order to apply SQL functions to elements of your C<%data> you may |
1359 | specify a reference to an arrayref for the given hash value. For example, |
1360 | if you need to execute the Oracle C<to_date> function on a value, you can |
1361 | say something like this: |
32eab2da |
1362 | |
1363 | my %data = ( |
1364 | name => 'Bill', |
96449e8e |
1365 | date_entered => \["to_date(?,'MM/DD/YYYY')", "03/02/2003"], |
32eab2da |
1366 | ); |
1367 | |
1368 | The first value in the array is the actual SQL. Any other values are |
1369 | optional and would be included in the bind values array. This gives |
1370 | you: |
1371 | |
1372 | my($stmt, @bind) = $sql->insert('people', \%data); |
1373 | |
1374 | $stmt = "INSERT INTO people (name, date_entered) |
1375 | VALUES (?, to_date(?,'MM/DD/YYYY'))"; |
1376 | @bind = ('Bill', '03/02/2003'); |
1377 | |
1378 | An UPDATE is just as easy, all you change is the name of the function: |
1379 | |
1380 | my($stmt, @bind) = $sql->update('people', \%data); |
1381 | |
1382 | Notice that your C<%data> isn't touched; the module will generate |
1383 | the appropriately quirky SQL for you automatically. Usually you'll |
1384 | want to specify a WHERE clause for your UPDATE, though, which is |
1385 | where handling C<%where> hashes comes in handy... |
1386 | |
96449e8e |
1387 | =head2 Complex where statements |
1388 | |
32eab2da |
1389 | This module can generate pretty complicated WHERE statements |
1390 | easily. For example, simple C<key=value> pairs are taken to mean |
1391 | equality, and if you want to see if a field is within a set |
1392 | of values, you can use an arrayref. Let's say we wanted to |
1393 | SELECT some data based on this criteria: |
1394 | |
1395 | my %where = ( |
1396 | requestor => 'inna', |
1397 | worker => ['nwiger', 'rcwe', 'sfz'], |
1398 | status => { '!=', 'completed' } |
1399 | ); |
1400 | |
1401 | my($stmt, @bind) = $sql->select('tickets', '*', \%where); |
1402 | |
1403 | The above would give you something like this: |
1404 | |
1405 | $stmt = "SELECT * FROM tickets WHERE |
1406 | ( requestor = ? ) AND ( status != ? ) |
1407 | AND ( worker = ? OR worker = ? OR worker = ? )"; |
1408 | @bind = ('inna', 'completed', 'nwiger', 'rcwe', 'sfz'); |
1409 | |
1410 | Which you could then use in DBI code like so: |
1411 | |
1412 | my $sth = $dbh->prepare($stmt); |
1413 | $sth->execute(@bind); |
1414 | |
1415 | Easy, eh? |
1416 | |
1417 | =head1 FUNCTIONS |
1418 | |
1419 | The functions are simple. There's one for each major SQL operation, |
1420 | and a constructor you use first. The arguments are specified in a |
1421 | similar order to each function (table, then fields, then a where |
1422 | clause) to try and simplify things. |
1423 | |
83cab70b |
1424 | |
83cab70b |
1425 | |
32eab2da |
1426 | |
1427 | =head2 new(option => 'value') |
1428 | |
1429 | The C<new()> function takes a list of options and values, and returns |
1430 | a new B<SQL::Abstract> object which can then be used to generate SQL |
1431 | through the methods below. The options accepted are: |
1432 | |
1433 | =over |
1434 | |
1435 | =item case |
1436 | |
1437 | If set to 'lower', then SQL will be generated in all lowercase. By |
1438 | default SQL is generated in "textbook" case meaning something like: |
1439 | |
1440 | SELECT a_field FROM a_table WHERE some_field LIKE '%someval%' |
1441 | |
96449e8e |
1442 | Any setting other than 'lower' is ignored. |
1443 | |
32eab2da |
1444 | =item cmp |
1445 | |
1446 | This determines what the default comparison operator is. By default |
1447 | it is C<=>, meaning that a hash like this: |
1448 | |
1449 | %where = (name => 'nwiger', email => 'nate@wiger.org'); |
1450 | |
1451 | Will generate SQL like this: |
1452 | |
1453 | WHERE name = 'nwiger' AND email = 'nate@wiger.org' |
1454 | |
1455 | However, you may want loose comparisons by default, so if you set |
1456 | C<cmp> to C<like> you would get SQL such as: |
1457 | |
1458 | WHERE name like 'nwiger' AND email like 'nate@wiger.org' |
1459 | |
1460 | You can also override the comparsion on an individual basis - see |
1461 | the huge section on L</"WHERE CLAUSES"> at the bottom. |
1462 | |
96449e8e |
1463 | =item sqltrue, sqlfalse |
1464 | |
1465 | Expressions for inserting boolean values within SQL statements. |
6e0c6552 |
1466 | By default these are C<1=1> and C<1=0>. They are used |
1467 | by the special operators C<-in> and C<-not_in> for generating |
1468 | correct SQL even when the argument is an empty array (see below). |
96449e8e |
1469 | |
32eab2da |
1470 | =item logic |
1471 | |
1472 | This determines the default logical operator for multiple WHERE |
7cac25e6 |
1473 | statements in arrays or hashes. If absent, the default logic is "or" |
1474 | for arrays, and "and" for hashes. This means that a WHERE |
32eab2da |
1475 | array of the form: |
1476 | |
1477 | @where = ( |
1478 | event_date => {'>=', '2/13/99'}, |
1479 | event_date => {'<=', '4/24/03'}, |
1480 | ); |
1481 | |
7cac25e6 |
1482 | will generate SQL like this: |
32eab2da |
1483 | |
1484 | WHERE event_date >= '2/13/99' OR event_date <= '4/24/03' |
1485 | |
1486 | This is probably not what you want given this query, though (look |
1487 | at the dates). To change the "OR" to an "AND", simply specify: |
1488 | |
1489 | my $sql = SQL::Abstract->new(logic => 'and'); |
1490 | |
1491 | Which will change the above C<WHERE> to: |
1492 | |
1493 | WHERE event_date >= '2/13/99' AND event_date <= '4/24/03' |
1494 | |
96449e8e |
1495 | The logic can also be changed locally by inserting |
7cac25e6 |
1496 | a modifier in front of an arrayref : |
96449e8e |
1497 | |
7cac25e6 |
1498 | @where = (-and => [event_date => {'>=', '2/13/99'}, |
1499 | event_date => {'<=', '4/24/03'} ]); |
96449e8e |
1500 | |
1501 | See the L</"WHERE CLAUSES"> section for explanations. |
1502 | |
32eab2da |
1503 | =item convert |
1504 | |
1505 | This will automatically convert comparisons using the specified SQL |
1506 | function for both column and value. This is mostly used with an argument |
1507 | of C<upper> or C<lower>, so that the SQL will have the effect of |
1508 | case-insensitive "searches". For example, this: |
1509 | |
1510 | $sql = SQL::Abstract->new(convert => 'upper'); |
1511 | %where = (keywords => 'MaKe iT CAse inSeNSItive'); |
1512 | |
1513 | Will turn out the following SQL: |
1514 | |
1515 | WHERE upper(keywords) like upper('MaKe iT CAse inSeNSItive') |
1516 | |
1517 | The conversion can be C<upper()>, C<lower()>, or any other SQL function |
1518 | that can be applied symmetrically to fields (actually B<SQL::Abstract> does |
1519 | not validate this option; it will just pass through what you specify verbatim). |
1520 | |
1521 | =item bindtype |
1522 | |
1523 | This is a kludge because many databases suck. For example, you can't |
1524 | just bind values using DBI's C<execute()> for Oracle C<CLOB> or C<BLOB> fields. |
1525 | Instead, you have to use C<bind_param()>: |
1526 | |
1527 | $sth->bind_param(1, 'reg data'); |
1528 | $sth->bind_param(2, $lots, {ora_type => ORA_CLOB}); |
1529 | |
1530 | The problem is, B<SQL::Abstract> will normally just return a C<@bind> array, |
1531 | which loses track of which field each slot refers to. Fear not. |
1532 | |
1533 | If you specify C<bindtype> in new, you can determine how C<@bind> is returned. |
1534 | Currently, you can specify either C<normal> (default) or C<columns>. If you |
1535 | specify C<columns>, you will get an array that looks like this: |
1536 | |
1537 | my $sql = SQL::Abstract->new(bindtype => 'columns'); |
1538 | my($stmt, @bind) = $sql->insert(...); |
1539 | |
1540 | @bind = ( |
1541 | [ 'column1', 'value1' ], |
1542 | [ 'column2', 'value2' ], |
1543 | [ 'column3', 'value3' ], |
1544 | ); |
1545 | |
1546 | You can then iterate through this manually, using DBI's C<bind_param()>. |
e3f9dff4 |
1547 | |
32eab2da |
1548 | $sth->prepare($stmt); |
1549 | my $i = 1; |
1550 | for (@bind) { |
1551 | my($col, $data) = @$_; |
1552 | if ($col eq 'details' || $col eq 'comments') { |
1553 | $sth->bind_param($i, $data, {ora_type => ORA_CLOB}); |
1554 | } elsif ($col eq 'image') { |
1555 | $sth->bind_param($i, $data, {ora_type => ORA_BLOB}); |
1556 | } else { |
1557 | $sth->bind_param($i, $data); |
1558 | } |
1559 | $i++; |
1560 | } |
1561 | $sth->execute; # execute without @bind now |
1562 | |
1563 | Now, why would you still use B<SQL::Abstract> if you have to do this crap? |
1564 | Basically, the advantage is still that you don't have to care which fields |
1565 | are or are not included. You could wrap that above C<for> loop in a simple |
1566 | sub called C<bind_fields()> or something and reuse it repeatedly. You still |
1567 | get a layer of abstraction over manual SQL specification. |
1568 | |
deb148a2 |
1569 | Note that if you set L</bindtype> to C<columns>, the C<\[$sql, @bind]> |
1570 | construct (see L</Literal SQL with placeholders and bind values (subqueries)>) |
1571 | will expect the bind values in this format. |
1572 | |
32eab2da |
1573 | =item quote_char |
1574 | |
1575 | This is the character that a table or column name will be quoted |
1576 | with. By default this is an empty string, but you could set it to |
1577 | the character C<`>, to generate SQL like this: |
1578 | |
1579 | SELECT `a_field` FROM `a_table` WHERE `some_field` LIKE '%someval%' |
1580 | |
96449e8e |
1581 | Alternatively, you can supply an array ref of two items, the first being the left |
1582 | hand quote character, and the second the right hand quote character. For |
1583 | example, you could supply C<['[',']']> for SQL Server 2000 compliant quotes |
1584 | that generates SQL like this: |
1585 | |
1586 | SELECT [a_field] FROM [a_table] WHERE [some_field] LIKE '%someval%' |
1587 | |
1588 | Quoting is useful if you have tables or columns names that are reserved |
1589 | words in your database's SQL dialect. |
32eab2da |
1590 | |
1591 | =item name_sep |
1592 | |
1593 | This is the character that separates a table and column name. It is |
1594 | necessary to specify this when the C<quote_char> option is selected, |
1595 | so that tables and column names can be individually quoted like this: |
1596 | |
1597 | SELECT `table`.`one_field` FROM `table` WHERE `table`.`other_field` = 1 |
1598 | |
96449e8e |
1599 | =item array_datatypes |
32eab2da |
1600 | |
96449e8e |
1601 | When this option is true, arrayrefs in INSERT or UPDATE are |
1602 | interpreted as array datatypes and are passed directly |
1603 | to the DBI layer. |
1604 | When this option is false, arrayrefs are interpreted |
1605 | as literal SQL, just like refs to arrayrefs |
1606 | (but this behavior is for backwards compatibility; when writing |
1607 | new queries, use the "reference to arrayref" syntax |
1608 | for literal SQL). |
32eab2da |
1609 | |
32eab2da |
1610 | |
96449e8e |
1611 | =item special_ops |
32eab2da |
1612 | |
96449e8e |
1613 | Takes a reference to a list of "special operators" |
1614 | to extend the syntax understood by L<SQL::Abstract>. |
1615 | See section L</"SPECIAL OPERATORS"> for details. |
32eab2da |
1616 | |
59f23b3d |
1617 | =item unary_ops |
1618 | |
1619 | Takes a reference to a list of "unary operators" |
1620 | to extend the syntax understood by L<SQL::Abstract>. |
1621 | See section L</"UNARY OPERATORS"> for details. |
1622 | |
32eab2da |
1623 | |
32eab2da |
1624 | |
96449e8e |
1625 | =back |
32eab2da |
1626 | |
1627 | =head2 insert($table, \@values || \%fieldvals) |
1628 | |
1629 | This is the simplest function. You simply give it a table name |
1630 | and either an arrayref of values or hashref of field/value pairs. |
1631 | It returns an SQL INSERT statement and a list of bind values. |
96449e8e |
1632 | See the sections on L</"Inserting and Updating Arrays"> and |
1633 | L</"Inserting and Updating SQL"> for information on how to insert |
1634 | with those data types. |
32eab2da |
1635 | |
1636 | =head2 update($table, \%fieldvals, \%where) |
1637 | |
1638 | This takes a table, hashref of field/value pairs, and an optional |
86298391 |
1639 | hashref L<WHERE clause|/WHERE CLAUSES>. It returns an SQL UPDATE function and a list |
32eab2da |
1640 | of bind values. |
96449e8e |
1641 | See the sections on L</"Inserting and Updating Arrays"> and |
1642 | L</"Inserting and Updating SQL"> for information on how to insert |
1643 | with those data types. |
32eab2da |
1644 | |
96449e8e |
1645 | =head2 select($source, $fields, $where, $order) |
32eab2da |
1646 | |
96449e8e |
1647 | This returns a SQL SELECT statement and associated list of bind values, as |
1648 | specified by the arguments : |
32eab2da |
1649 | |
96449e8e |
1650 | =over |
32eab2da |
1651 | |
96449e8e |
1652 | =item $source |
32eab2da |
1653 | |
96449e8e |
1654 | Specification of the 'FROM' part of the statement. |
1655 | The argument can be either a plain scalar (interpreted as a table |
1656 | name, will be quoted), or an arrayref (interpreted as a list |
1657 | of table names, joined by commas, quoted), or a scalarref |
1658 | (literal table name, not quoted), or a ref to an arrayref |
1659 | (list of literal table names, joined by commas, not quoted). |
32eab2da |
1660 | |
96449e8e |
1661 | =item $fields |
32eab2da |
1662 | |
96449e8e |
1663 | Specification of the list of fields to retrieve from |
1664 | the source. |
1665 | The argument can be either an arrayref (interpreted as a list |
1666 | of field names, will be joined by commas and quoted), or a |
1667 | plain scalar (literal SQL, not quoted). |
1668 | Please observe that this API is not as flexible as for |
e3f9dff4 |
1669 | the first argument C<$table>, for backwards compatibility reasons. |
32eab2da |
1670 | |
96449e8e |
1671 | =item $where |
32eab2da |
1672 | |
96449e8e |
1673 | Optional argument to specify the WHERE part of the query. |
1674 | The argument is most often a hashref, but can also be |
1675 | an arrayref or plain scalar -- |
1676 | see section L<WHERE clause|/"WHERE CLAUSES"> for details. |
32eab2da |
1677 | |
96449e8e |
1678 | =item $order |
32eab2da |
1679 | |
96449e8e |
1680 | Optional argument to specify the ORDER BY part of the query. |
1681 | The argument can be a scalar, a hashref or an arrayref |
1682 | -- see section L<ORDER BY clause|/"ORDER BY CLAUSES"> |
1683 | for details. |
32eab2da |
1684 | |
96449e8e |
1685 | =back |
32eab2da |
1686 | |
32eab2da |
1687 | |
1688 | =head2 delete($table, \%where) |
1689 | |
86298391 |
1690 | This takes a table name and optional hashref L<WHERE clause|/WHERE CLAUSES>. |
32eab2da |
1691 | It returns an SQL DELETE statement and list of bind values. |
1692 | |
32eab2da |
1693 | =head2 where(\%where, \@order) |
1694 | |
1695 | This is used to generate just the WHERE clause. For example, |
1696 | if you have an arbitrary data structure and know what the |
1697 | rest of your SQL is going to look like, but want an easy way |
1698 | to produce a WHERE clause, use this. It returns an SQL WHERE |
1699 | clause and list of bind values. |
1700 | |
32eab2da |
1701 | |
1702 | =head2 values(\%data) |
1703 | |
1704 | This just returns the values from the hash C<%data>, in the same |
1705 | order that would be returned from any of the other above queries. |
1706 | Using this allows you to markedly speed up your queries if you |
1707 | are affecting lots of rows. See below under the L</"PERFORMANCE"> section. |
1708 | |
32eab2da |
1709 | =head2 generate($any, 'number', $of, \@data, $struct, \%types) |
1710 | |
1711 | Warning: This is an experimental method and subject to change. |
1712 | |
1713 | This returns arbitrarily generated SQL. It's a really basic shortcut. |
1714 | It will return two different things, depending on return context: |
1715 | |
1716 | my($stmt, @bind) = $sql->generate('create table', \$table, \@fields); |
1717 | my $stmt_and_val = $sql->generate('create table', \$table, \@fields); |
1718 | |
1719 | These would return the following: |
1720 | |
1721 | # First calling form |
1722 | $stmt = "CREATE TABLE test (?, ?)"; |
1723 | @bind = (field1, field2); |
1724 | |
1725 | # Second calling form |
1726 | $stmt_and_val = "CREATE TABLE test (field1, field2)"; |
1727 | |
1728 | Depending on what you're trying to do, it's up to you to choose the correct |
1729 | format. In this example, the second form is what you would want. |
1730 | |
1731 | By the same token: |
1732 | |
1733 | $sql->generate('alter session', { nls_date_format => 'MM/YY' }); |
1734 | |
1735 | Might give you: |
1736 | |
1737 | ALTER SESSION SET nls_date_format = 'MM/YY' |
1738 | |
1739 | You get the idea. Strings get their case twiddled, but everything |
1740 | else remains verbatim. |
1741 | |
32eab2da |
1742 | |
32eab2da |
1743 | |
32eab2da |
1744 | |
1745 | =head1 WHERE CLAUSES |
1746 | |
96449e8e |
1747 | =head2 Introduction |
1748 | |
32eab2da |
1749 | This module uses a variation on the idea from L<DBIx::Abstract>. It |
1750 | is B<NOT>, repeat I<not> 100% compatible. B<The main logic of this |
1751 | module is that things in arrays are OR'ed, and things in hashes |
1752 | are AND'ed.> |
1753 | |
1754 | The easiest way to explain is to show lots of examples. After |
1755 | each C<%where> hash shown, it is assumed you used: |
1756 | |
1757 | my($stmt, @bind) = $sql->where(\%where); |
1758 | |
1759 | However, note that the C<%where> hash can be used directly in any |
1760 | of the other functions as well, as described above. |
1761 | |
96449e8e |
1762 | =head2 Key-value pairs |
1763 | |
32eab2da |
1764 | So, let's get started. To begin, a simple hash: |
1765 | |
1766 | my %where = ( |
1767 | user => 'nwiger', |
1768 | status => 'completed' |
1769 | ); |
1770 | |
1771 | Is converted to SQL C<key = val> statements: |
1772 | |
1773 | $stmt = "WHERE user = ? AND status = ?"; |
1774 | @bind = ('nwiger', 'completed'); |
1775 | |
1776 | One common thing I end up doing is having a list of values that |
1777 | a field can be in. To do this, simply specify a list inside of |
1778 | an arrayref: |
1779 | |
1780 | my %where = ( |
1781 | user => 'nwiger', |
1782 | status => ['assigned', 'in-progress', 'pending']; |
1783 | ); |
1784 | |
1785 | This simple code will create the following: |
1786 | |
1787 | $stmt = "WHERE user = ? AND ( status = ? OR status = ? OR status = ? )"; |
1788 | @bind = ('nwiger', 'assigned', 'in-progress', 'pending'); |
1789 | |
7cac25e6 |
1790 | A field associated to an empty arrayref will be considered a |
1791 | logical false and will generate 0=1. |
8a68b5be |
1792 | |
6e0c6552 |
1793 | =head2 Specific comparison operators |
96449e8e |
1794 | |
32eab2da |
1795 | If you want to specify a different type of operator for your comparison, |
1796 | you can use a hashref for a given column: |
1797 | |
1798 | my %where = ( |
1799 | user => 'nwiger', |
1800 | status => { '!=', 'completed' } |
1801 | ); |
1802 | |
1803 | Which would generate: |
1804 | |
1805 | $stmt = "WHERE user = ? AND status != ?"; |
1806 | @bind = ('nwiger', 'completed'); |
1807 | |
1808 | To test against multiple values, just enclose the values in an arrayref: |
1809 | |
96449e8e |
1810 | status => { '=', ['assigned', 'in-progress', 'pending'] }; |
1811 | |
f2d5020d |
1812 | Which would give you: |
96449e8e |
1813 | |
1814 | "WHERE status = ? OR status = ? OR status = ?" |
1815 | |
1816 | |
1817 | The hashref can also contain multiple pairs, in which case it is expanded |
32eab2da |
1818 | into an C<AND> of its elements: |
1819 | |
1820 | my %where = ( |
1821 | user => 'nwiger', |
1822 | status => { '!=', 'completed', -not_like => 'pending%' } |
1823 | ); |
1824 | |
1825 | # Or more dynamically, like from a form |
1826 | $where{user} = 'nwiger'; |
1827 | $where{status}{'!='} = 'completed'; |
1828 | $where{status}{'-not_like'} = 'pending%'; |
1829 | |
1830 | # Both generate this |
1831 | $stmt = "WHERE user = ? AND status != ? AND status NOT LIKE ?"; |
1832 | @bind = ('nwiger', 'completed', 'pending%'); |
1833 | |
96449e8e |
1834 | |
32eab2da |
1835 | To get an OR instead, you can combine it with the arrayref idea: |
1836 | |
1837 | my %where => ( |
1838 | user => 'nwiger', |
1839 | priority => [ {'=', 2}, {'!=', 1} ] |
1840 | ); |
1841 | |
1842 | Which would generate: |
1843 | |
1844 | $stmt = "WHERE user = ? AND priority = ? OR priority != ?"; |
1845 | @bind = ('nwiger', '2', '1'); |
1846 | |
44b9e502 |
1847 | If you want to include literal SQL (with or without bind values), just use a |
1848 | scalar reference or array reference as the value: |
1849 | |
1850 | my %where = ( |
1851 | date_entered => { '>' => \["to_date(?, 'MM/DD/YYYY')", "11/26/2008"] }, |
1852 | date_expires => { '<' => \"now()" } |
1853 | ); |
1854 | |
1855 | Which would generate: |
1856 | |
1857 | $stmt = "WHERE date_entered > "to_date(?, 'MM/DD/YYYY') AND date_expires < now()"; |
1858 | @bind = ('11/26/2008'); |
1859 | |
96449e8e |
1860 | |
1861 | =head2 Logic and nesting operators |
1862 | |
1863 | In the example above, |
1864 | there is a subtle trap if you want to say something like |
32eab2da |
1865 | this (notice the C<AND>): |
1866 | |
1867 | WHERE priority != ? AND priority != ? |
1868 | |
1869 | Because, in Perl you I<can't> do this: |
1870 | |
1871 | priority => { '!=', 2, '!=', 1 } |
1872 | |
1873 | As the second C<!=> key will obliterate the first. The solution |
1874 | is to use the special C<-modifier> form inside an arrayref: |
1875 | |
96449e8e |
1876 | priority => [ -and => {'!=', 2}, |
1877 | {'!=', 1} ] |
1878 | |
32eab2da |
1879 | |
1880 | Normally, these would be joined by C<OR>, but the modifier tells it |
1881 | to use C<AND> instead. (Hint: You can use this in conjunction with the |
1882 | C<logic> option to C<new()> in order to change the way your queries |
1883 | work by default.) B<Important:> Note that the C<-modifier> goes |
1884 | B<INSIDE> the arrayref, as an extra first element. This will |
1885 | B<NOT> do what you think it might: |
1886 | |
1887 | priority => -and => [{'!=', 2}, {'!=', 1}] # WRONG! |
1888 | |
1889 | Here is a quick list of equivalencies, since there is some overlap: |
1890 | |
1891 | # Same |
1892 | status => {'!=', 'completed', 'not like', 'pending%' } |
1893 | status => [ -and => {'!=', 'completed'}, {'not like', 'pending%'}] |
1894 | |
1895 | # Same |
1896 | status => {'=', ['assigned', 'in-progress']} |
1897 | status => [ -or => {'=', 'assigned'}, {'=', 'in-progress'}] |
1898 | status => [ {'=', 'assigned'}, {'=', 'in-progress'} ] |
1899 | |
e3f9dff4 |
1900 | |
1901 | |
96449e8e |
1902 | =head2 Special operators : IN, BETWEEN, etc. |
1903 | |
32eab2da |
1904 | You can also use the hashref format to compare a list of fields using the |
1905 | C<IN> comparison operator, by specifying the list as an arrayref: |
1906 | |
1907 | my %where = ( |
1908 | status => 'completed', |
1909 | reportid => { -in => [567, 2335, 2] } |
1910 | ); |
1911 | |
1912 | Which would generate: |
1913 | |
1914 | $stmt = "WHERE status = ? AND reportid IN (?,?,?)"; |
1915 | @bind = ('completed', '567', '2335', '2'); |
1916 | |
96449e8e |
1917 | The reverse operator C<-not_in> generates SQL C<NOT IN> and is used in |
1918 | the same way. |
1919 | |
6e0c6552 |
1920 | If the argument to C<-in> is an empty array, 'sqlfalse' is generated |
1921 | (by default : C<1=0>). Similarly, C<< -not_in => [] >> generates |
1922 | 'sqltrue' (by default : C<1=1>). |
1923 | |
1924 | |
1925 | |
96449e8e |
1926 | Another pair of operators is C<-between> and C<-not_between>, |
1927 | used with an arrayref of two values: |
32eab2da |
1928 | |
1929 | my %where = ( |
1930 | user => 'nwiger', |
1931 | completion_date => { |
1932 | -not_between => ['2002-10-01', '2003-02-06'] |
1933 | } |
1934 | ); |
1935 | |
1936 | Would give you: |
1937 | |
1938 | WHERE user = ? AND completion_date NOT BETWEEN ( ? AND ? ) |
1939 | |
96449e8e |
1940 | These are the two builtin "special operators"; but the |
1941 | list can be expanded : see section L</"SPECIAL OPERATORS"> below. |
1942 | |
59f23b3d |
1943 | =head2 Unary operators: bool |
97a920ef |
1944 | |
1945 | If you wish to test against boolean columns or functions within your |
1946 | database you can use the C<-bool> and C<-not_bool> operators. For |
1947 | example to test the column C<is_user> being true and the column |
1948 | <is_enabled> being false you would use:- |
1949 | |
1950 | my %where = ( |
1951 | -bool => 'is_user', |
1952 | -not_bool => 'is_enabled', |
1953 | ); |
1954 | |
1955 | Would give you: |
1956 | |
1957 | WHERE is_user AND NOT is_enabledmv |
1958 | |
1959 | |
1960 | |
107b72f1 |
1961 | =head2 Nested conditions, -and/-or prefixes |
96449e8e |
1962 | |
32eab2da |
1963 | So far, we've seen how multiple conditions are joined with a top-level |
1964 | C<AND>. We can change this by putting the different conditions we want in |
1965 | hashes and then putting those hashes in an array. For example: |
1966 | |
1967 | my @where = ( |
1968 | { |
1969 | user => 'nwiger', |
1970 | status => { -like => ['pending%', 'dispatched'] }, |
1971 | }, |
1972 | { |
1973 | user => 'robot', |
1974 | status => 'unassigned', |
1975 | } |
1976 | ); |
1977 | |
1978 | This data structure would create the following: |
1979 | |
1980 | $stmt = "WHERE ( user = ? AND ( status LIKE ? OR status LIKE ? ) ) |
1981 | OR ( user = ? AND status = ? ) )"; |
1982 | @bind = ('nwiger', 'pending', 'dispatched', 'robot', 'unassigned'); |
1983 | |
107b72f1 |
1984 | |
01a01e57 |
1985 | There is also a special C<-nest> |
107b72f1 |
1986 | operator which adds an additional set of parens, to create a subquery. |
1987 | For example, to get something like this: |
1988 | |
1989 | $stmt = "WHERE user = ? AND ( workhrs > ? OR geo = ? )"; |
1990 | @bind = ('nwiger', '20', 'ASIA'); |
1991 | |
1992 | You would do: |
1993 | |
1994 | my %where = ( |
1995 | user => 'nwiger', |
01a01e57 |
1996 | -nest => [ workhrs => {'>', 20}, geo => 'ASIA' ], |
107b72f1 |
1997 | ); |
1998 | |
1999 | |
2000 | Finally, clauses in hashrefs or arrayrefs can be |
7cac25e6 |
2001 | prefixed with an C<-and> or C<-or> to change the logic |
2002 | inside : |
32eab2da |
2003 | |
2004 | my @where = ( |
2005 | -and => [ |
2006 | user => 'nwiger', |
01a01e57 |
2007 | -nest => [ |
7cac25e6 |
2008 | -and => [workhrs => {'>', 20}, geo => 'ASIA' ], |
2009 | -and => [workhrs => {'<', 50}, geo => 'EURO' ] |
32eab2da |
2010 | ], |
2011 | ], |
2012 | ); |
2013 | |
2014 | That would yield: |
2015 | |
2016 | WHERE ( user = ? AND |
2017 | ( ( workhrs > ? AND geo = ? ) |
2018 | OR ( workhrs < ? AND geo = ? ) ) ) |
2019 | |
107b72f1 |
2020 | |
2021 | =head2 Algebraic inconsistency, for historical reasons |
2022 | |
7cac25e6 |
2023 | C<Important note>: when connecting several conditions, the C<-and->|C<-or> |
2024 | operator goes C<outside> of the nested structure; whereas when connecting |
2025 | several constraints on one column, the C<-and> operator goes |
2026 | C<inside> the arrayref. Here is an example combining both features : |
2027 | |
2028 | my @where = ( |
2029 | -and => [a => 1, b => 2], |
2030 | -or => [c => 3, d => 4], |
2031 | e => [-and => {-like => 'foo%'}, {-like => '%bar'} ] |
2032 | ) |
2033 | |
2034 | yielding |
2035 | |
2036 | WHERE ( ( ( a = ? AND b = ? ) |
2037 | OR ( c = ? OR d = ? ) |
2038 | OR ( e LIKE ? AND e LIKE ? ) ) ) |
2039 | |
107b72f1 |
2040 | This difference in syntax is unfortunate but must be preserved for |
2041 | historical reasons. So be careful : the two examples below would |
2042 | seem algebraically equivalent, but they are not |
2043 | |
2044 | {col => [-and => {-like => 'foo%'}, {-like => '%bar'}]} |
2045 | # yields : WHERE ( ( col LIKE ? AND col LIKE ? ) ) |
2046 | |
2047 | [-and => {col => {-like => 'foo%'}, {col => {-like => '%bar'}}]] |
2048 | # yields : WHERE ( ( col LIKE ? OR col LIKE ? ) ) |
2049 | |
7cac25e6 |
2050 | |
96449e8e |
2051 | =head2 Literal SQL |
2052 | |
32eab2da |
2053 | Finally, sometimes only literal SQL will do. If you want to include |
2054 | literal SQL verbatim, you can specify it as a scalar reference, namely: |
2055 | |
2056 | my $inn = 'is Not Null'; |
2057 | my %where = ( |
2058 | priority => { '<', 2 }, |
2059 | requestor => \$inn |
2060 | ); |
2061 | |
2062 | This would create: |
2063 | |
2064 | $stmt = "WHERE priority < ? AND requestor is Not Null"; |
2065 | @bind = ('2'); |
2066 | |
2067 | Note that in this example, you only get one bind parameter back, since |
2068 | the verbatim SQL is passed as part of the statement. |
2069 | |
2070 | Of course, just to prove a point, the above can also be accomplished |
2071 | with this: |
2072 | |
2073 | my %where = ( |
2074 | priority => { '<', 2 }, |
2075 | requestor => { '!=', undef }, |
2076 | ); |
2077 | |
96449e8e |
2078 | |
32eab2da |
2079 | TMTOWTDI. |
2080 | |
96449e8e |
2081 | Conditions on boolean columns can be expressed in the |
2082 | same way, passing a reference to an empty string : |
2083 | |
2084 | my %where = ( |
2085 | priority => { '<', 2 }, |
2086 | is_ready => \""; |
2087 | ); |
2088 | |
2089 | which yields |
2090 | |
2091 | $stmt = "WHERE priority < ? AND is_ready"; |
2092 | @bind = ('2'); |
2093 | |
2094 | |
2095 | =head2 Literal SQL with placeholders and bind values (subqueries) |
2096 | |
2097 | If the literal SQL to be inserted has placeholders and bind values, |
2098 | use a reference to an arrayref (yes this is a double reference -- |
2099 | not so common, but perfectly legal Perl). For example, to find a date |
2100 | in Postgres you can use something like this: |
2101 | |
2102 | my %where = ( |
2103 | date_column => \[q/= date '2008-09-30' - ?::integer/, 10/] |
2104 | ) |
2105 | |
2106 | This would create: |
2107 | |
d2a8fe1a |
2108 | $stmt = "WHERE ( date_column = date '2008-09-30' - ?::integer )" |
96449e8e |
2109 | @bind = ('10'); |
2110 | |
deb148a2 |
2111 | Note that you must pass the bind values in the same format as they are returned |
62552e7d |
2112 | by L</where>. That means that if you set L</bindtype> to C<columns>, you must |
26f2dca5 |
2113 | provide the bind values in the C<< [ column_meta => value ] >> format, where |
2114 | C<column_meta> is an opaque scalar value; most commonly the column name, but |
62552e7d |
2115 | you can use any scalar value (including references and blessed references), |
2116 | L<SQL::Abstract> will simply pass it through intact. So if C<bindtype> is set |
2117 | to C<columns> the above example will look like: |
deb148a2 |
2118 | |
2119 | my %where = ( |
2120 | date_column => \[q/= date '2008-09-30' - ?::integer/, [ dummy => 10 ]/] |
2121 | ) |
96449e8e |
2122 | |
2123 | Literal SQL is especially useful for nesting parenthesized clauses in the |
2124 | main SQL query. Here is a first example : |
2125 | |
2126 | my ($sub_stmt, @sub_bind) = ("SELECT c1 FROM t1 WHERE c2 < ? AND c3 LIKE ?", |
2127 | 100, "foo%"); |
2128 | my %where = ( |
2129 | foo => 1234, |
2130 | bar => \["IN ($sub_stmt)" => @sub_bind], |
2131 | ); |
2132 | |
2133 | This yields : |
2134 | |
2135 | $stmt = "WHERE (foo = ? AND bar IN (SELECT c1 FROM t1 |
2136 | WHERE c2 < ? AND c3 LIKE ?))"; |
2137 | @bind = (1234, 100, "foo%"); |
2138 | |
2139 | Other subquery operators, like for example C<"E<gt> ALL"> or C<"NOT IN">, |
2140 | are expressed in the same way. Of course the C<$sub_stmt> and |
2141 | its associated bind values can be generated through a former call |
2142 | to C<select()> : |
2143 | |
2144 | my ($sub_stmt, @sub_bind) |
2145 | = $sql->select("t1", "c1", {c2 => {"<" => 100}, |
2146 | c3 => {-like => "foo%"}}); |
2147 | my %where = ( |
2148 | foo => 1234, |
2149 | bar => \["> ALL ($sub_stmt)" => @sub_bind], |
2150 | ); |
2151 | |
2152 | In the examples above, the subquery was used as an operator on a column; |
2153 | but the same principle also applies for a clause within the main C<%where> |
2154 | hash, like an EXISTS subquery : |
2155 | |
2156 | my ($sub_stmt, @sub_bind) |
2157 | = $sql->select("t1", "*", {c1 => 1, c2 => \"> t0.c0"}); |
2158 | my %where = ( |
2159 | foo => 1234, |
01a01e57 |
2160 | -nest => \["EXISTS ($sub_stmt)" => @sub_bind], |
96449e8e |
2161 | ); |
2162 | |
2163 | which yields |
2164 | |
2165 | $stmt = "WHERE (foo = ? AND EXISTS (SELECT * FROM t1 |
2166 | WHERE c1 = ? AND c2 > t0.c0))"; |
2167 | @bind = (1234, 1); |
2168 | |
2169 | |
2170 | Observe that the condition on C<c2> in the subquery refers to |
2171 | column C<t0.c0> of the main query : this is I<not> a bind |
2172 | value, so we have to express it through a scalar ref. |
2173 | Writing C<< c2 => {">" => "t0.c0"} >> would have generated |
2174 | C<< c2 > ? >> with bind value C<"t0.c0"> ... not exactly |
2175 | what we wanted here. |
2176 | |
2177 | Another use of the subquery technique is when some SQL clauses need |
2178 | parentheses, as it often occurs with some proprietary SQL extensions |
2179 | like for example fulltext expressions, geospatial expressions, |
2180 | NATIVE clauses, etc. Here is an example of a fulltext query in MySQL : |
2181 | |
2182 | my %where = ( |
01a01e57 |
2183 | -nest => \["MATCH (col1, col2) AGAINST (?)" => qw/apples/] |
96449e8e |
2184 | ); |
2185 | |
2186 | Finally, here is an example where a subquery is used |
2187 | for expressing unary negation: |
2188 | |
2189 | my ($sub_stmt, @sub_bind) |
2190 | = $sql->where({age => [{"<" => 10}, {">" => 20}]}); |
2191 | $sub_stmt =~ s/^ where //i; # don't want "WHERE" in the subclause |
2192 | my %where = ( |
2193 | lname => {like => '%son%'}, |
01a01e57 |
2194 | -nest => \["NOT ($sub_stmt)" => @sub_bind], |
96449e8e |
2195 | ); |
2196 | |
2197 | This yields |
2198 | |
2199 | $stmt = "lname LIKE ? AND NOT ( age < ? OR age > ? )" |
2200 | @bind = ('%son%', 10, 20) |
2201 | |
2202 | |
2203 | |
2204 | =head2 Conclusion |
2205 | |
32eab2da |
2206 | These pages could go on for a while, since the nesting of the data |
2207 | structures this module can handle are pretty much unlimited (the |
2208 | module implements the C<WHERE> expansion as a recursive function |
2209 | internally). Your best bet is to "play around" with the module a |
2210 | little to see how the data structures behave, and choose the best |
2211 | format for your data based on that. |
2212 | |
2213 | And of course, all the values above will probably be replaced with |
2214 | variables gotten from forms or the command line. After all, if you |
2215 | knew everything ahead of time, you wouldn't have to worry about |
2216 | dynamically-generating SQL and could just hardwire it into your |
2217 | script. |
2218 | |
96449e8e |
2219 | |
2220 | |
2221 | |
86298391 |
2222 | =head1 ORDER BY CLAUSES |
2223 | |
2224 | Some functions take an order by clause. This can either be a scalar (just a |
2225 | column name,) a hash of C<< { -desc => 'col' } >> or C<< { -asc => 'col' } >>, |
1cfa1db3 |
2226 | or an array of either of the two previous forms. Examples: |
2227 | |
952f9e2d |
2228 | Given | Will Generate |
1cfa1db3 |
2229 | ---------------------------------------------------------- |
952f9e2d |
2230 | | |
2231 | \'colA DESC' | ORDER BY colA DESC |
2232 | | |
2233 | 'colA' | ORDER BY colA |
2234 | | |
2235 | [qw/colA colB/] | ORDER BY colA, colB |
2236 | | |
2237 | {-asc => 'colA'} | ORDER BY colA ASC |
2238 | | |
2239 | {-desc => 'colB'} | ORDER BY colB DESC |
2240 | | |
2241 | ['colA', {-asc => 'colB'}] | ORDER BY colA, colB ASC |
2242 | | |
2243 | { -asc => [qw/colA colB] } | ORDER BY colA ASC, colB ASC |
2244 | | |
2245 | [ | |
2246 | { -asc => 'colA' }, | ORDER BY colA ASC, colB DESC, |
2247 | { -desc => [qw/colB/], | colC ASC, colD ASC |
2248 | { -asc => [qw/colC colD/],| |
2249 | ] | |
2250 | =========================================================== |
86298391 |
2251 | |
96449e8e |
2252 | |
2253 | |
2254 | =head1 SPECIAL OPERATORS |
2255 | |
e3f9dff4 |
2256 | my $sqlmaker = SQL::Abstract->new(special_ops => [ |
3a2e1a5e |
2257 | { |
2258 | regex => qr/.../, |
e3f9dff4 |
2259 | handler => sub { |
2260 | my ($self, $field, $op, $arg) = @_; |
2261 | ... |
3a2e1a5e |
2262 | }, |
2263 | }, |
2264 | { |
2265 | regex => qr/.../, |
2266 | handler => 'method_name', |
e3f9dff4 |
2267 | }, |
2268 | ]); |
2269 | |
2270 | A "special operator" is a SQL syntactic clause that can be |
2271 | applied to a field, instead of a usual binary operator. |
2272 | For example : |
2273 | |
2274 | WHERE field IN (?, ?, ?) |
2275 | WHERE field BETWEEN ? AND ? |
2276 | WHERE MATCH(field) AGAINST (?, ?) |
96449e8e |
2277 | |
e3f9dff4 |
2278 | Special operators IN and BETWEEN are fairly standard and therefore |
3a2e1a5e |
2279 | are builtin within C<SQL::Abstract> (as the overridable methods |
2280 | C<_where_field_IN> and C<_where_field_BETWEEN>). For other operators, |
2281 | like the MATCH .. AGAINST example above which is specific to MySQL, |
2282 | you can write your own operator handlers - supply a C<special_ops> |
2283 | argument to the C<new> method. That argument takes an arrayref of |
2284 | operator definitions; each operator definition is a hashref with two |
2285 | entries: |
96449e8e |
2286 | |
e3f9dff4 |
2287 | =over |
2288 | |
2289 | =item regex |
2290 | |
2291 | the regular expression to match the operator |
96449e8e |
2292 | |
e3f9dff4 |
2293 | =item handler |
2294 | |
3a2e1a5e |
2295 | Either a coderef or a plain scalar method name. In both cases |
2296 | the expected return is C<< ($sql, @bind) >>. |
2297 | |
2298 | When supplied with a method name, it is simply called on the |
2299 | L<SQL::Abstract/> object as: |
2300 | |
2301 | $self->$method_name ($field, $op, $arg) |
2302 | |
2303 | Where: |
2304 | |
2305 | $op is the part that matched the handler regex |
2306 | $field is the LHS of the operator |
2307 | $arg is the RHS |
2308 | |
2309 | When supplied with a coderef, it is called as: |
2310 | |
2311 | $coderef->($self, $field, $op, $arg) |
2312 | |
e3f9dff4 |
2313 | |
2314 | =back |
2315 | |
2316 | For example, here is an implementation |
2317 | of the MATCH .. AGAINST syntax for MySQL |
2318 | |
2319 | my $sqlmaker = SQL::Abstract->new(special_ops => [ |
2320 | |
2321 | # special op for MySql MATCH (field) AGAINST(word1, word2, ...) |
2322 | {regex => qr/^match$/i, |
2323 | handler => sub { |
2324 | my ($self, $field, $op, $arg) = @_; |
2325 | $arg = [$arg] if not ref $arg; |
2326 | my $label = $self->_quote($field); |
2327 | my ($placeholder) = $self->_convert('?'); |
2328 | my $placeholders = join ", ", (($placeholder) x @$arg); |
2329 | my $sql = $self->_sqlcase('match') . " ($label) " |
2330 | . $self->_sqlcase('against') . " ($placeholders) "; |
2331 | my @bind = $self->_bindtype($field, @$arg); |
2332 | return ($sql, @bind); |
2333 | } |
2334 | }, |
2335 | |
2336 | ]); |
96449e8e |
2337 | |
2338 | |
59f23b3d |
2339 | =head1 UNARY OPERATORS |
2340 | |
112b5232 |
2341 | my $sqlmaker = SQL::Abstract->new(unary_ops => [ |
59f23b3d |
2342 | { |
2343 | regex => qr/.../, |
2344 | handler => sub { |
2345 | my ($self, $op, $arg) = @_; |
2346 | ... |
2347 | }, |
2348 | }, |
2349 | { |
2350 | regex => qr/.../, |
2351 | handler => 'method_name', |
2352 | }, |
2353 | ]); |
2354 | |
2355 | A "unary operator" is a SQL syntactic clause that can be |
2356 | applied to a field - the operator goes before the field |
2357 | |
2358 | You can write your own operator handlers - supply a C<unary_ops> |
2359 | argument to the C<new> method. That argument takes an arrayref of |
2360 | operator definitions; each operator definition is a hashref with two |
2361 | entries: |
2362 | |
2363 | =over |
2364 | |
2365 | =item regex |
2366 | |
2367 | the regular expression to match the operator |
2368 | |
2369 | =item handler |
2370 | |
2371 | Either a coderef or a plain scalar method name. In both cases |
2372 | the expected return is C<< $sql >>. |
2373 | |
2374 | When supplied with a method name, it is simply called on the |
2375 | L<SQL::Abstract/> object as: |
2376 | |
2377 | $self->$method_name ($op, $arg) |
2378 | |
2379 | Where: |
2380 | |
2381 | $op is the part that matched the handler regex |
2382 | $arg is the RHS or argument of the operator |
2383 | |
2384 | When supplied with a coderef, it is called as: |
2385 | |
2386 | $coderef->($self, $op, $arg) |
2387 | |
2388 | |
2389 | =back |
2390 | |
2391 | |
32eab2da |
2392 | =head1 PERFORMANCE |
2393 | |
2394 | Thanks to some benchmarking by Mark Stosberg, it turns out that |
2395 | this module is many orders of magnitude faster than using C<DBIx::Abstract>. |
2396 | I must admit this wasn't an intentional design issue, but it's a |
2397 | byproduct of the fact that you get to control your C<DBI> handles |
2398 | yourself. |
2399 | |
2400 | To maximize performance, use a code snippet like the following: |
2401 | |
2402 | # prepare a statement handle using the first row |
2403 | # and then reuse it for the rest of the rows |
2404 | my($sth, $stmt); |
2405 | for my $href (@array_of_hashrefs) { |
2406 | $stmt ||= $sql->insert('table', $href); |
2407 | $sth ||= $dbh->prepare($stmt); |
2408 | $sth->execute($sql->values($href)); |
2409 | } |
2410 | |
2411 | The reason this works is because the keys in your C<$href> are sorted |
2412 | internally by B<SQL::Abstract>. Thus, as long as your data retains |
2413 | the same structure, you only have to generate the SQL the first time |
2414 | around. On subsequent queries, simply use the C<values> function provided |
2415 | by this module to return your values in the correct order. |
2416 | |
96449e8e |
2417 | |
32eab2da |
2418 | =head1 FORMBUILDER |
2419 | |
2420 | If you use my C<CGI::FormBuilder> module at all, you'll hopefully |
2421 | really like this part (I do, at least). Building up a complex query |
2422 | can be as simple as the following: |
2423 | |
2424 | #!/usr/bin/perl |
2425 | |
2426 | use CGI::FormBuilder; |
2427 | use SQL::Abstract; |
2428 | |
2429 | my $form = CGI::FormBuilder->new(...); |
2430 | my $sql = SQL::Abstract->new; |
2431 | |
2432 | if ($form->submitted) { |
2433 | my $field = $form->field; |
2434 | my $id = delete $field->{id}; |
2435 | my($stmt, @bind) = $sql->update('table', $field, {id => $id}); |
2436 | } |
2437 | |
2438 | Of course, you would still have to connect using C<DBI> to run the |
2439 | query, but the point is that if you make your form look like your |
2440 | table, the actual query script can be extremely simplistic. |
2441 | |
2442 | If you're B<REALLY> lazy (I am), check out C<HTML::QuickTable> for |
2443 | a fast interface to returning and formatting data. I frequently |
2444 | use these three modules together to write complex database query |
2445 | apps in under 50 lines. |
2446 | |
32eab2da |
2447 | |
96449e8e |
2448 | =head1 CHANGES |
2449 | |
2450 | Version 1.50 was a major internal refactoring of C<SQL::Abstract>. |
2451 | Great care has been taken to preserve the I<published> behavior |
2452 | documented in previous versions in the 1.* family; however, |
2453 | some features that were previously undocumented, or behaved |
2454 | differently from the documentation, had to be changed in order |
2455 | to clarify the semantics. Hence, client code that was relying |
2456 | on some dark areas of C<SQL::Abstract> v1.* |
2457 | B<might behave differently> in v1.50. |
32eab2da |
2458 | |
d2a8fe1a |
2459 | The main changes are : |
2460 | |
96449e8e |
2461 | =over |
32eab2da |
2462 | |
96449e8e |
2463 | =item * |
32eab2da |
2464 | |
96449e8e |
2465 | support for literal SQL through the C<< \ [$sql, bind] >> syntax. |
2466 | |
2467 | =item * |
2468 | |
145fbfc8 |
2469 | support for the { operator => \"..." } construct (to embed literal SQL) |
2470 | |
2471 | =item * |
2472 | |
9c37b9c0 |
2473 | support for the { operator => \["...", @bind] } construct (to embed literal SQL with bind values) |
2474 | |
2475 | =item * |
2476 | |
96449e8e |
2477 | optional support for L<array datatypes|/"Inserting and Updating Arrays"> |
2478 | |
2479 | =item * |
2480 | |
2481 | defensive programming : check arguments |
2482 | |
2483 | =item * |
2484 | |
2485 | fixed bug with global logic, which was previously implemented |
7cac25e6 |
2486 | through global variables yielding side-effects. Prior versions would |
96449e8e |
2487 | interpret C<< [ {cond1, cond2}, [cond3, cond4] ] >> |
2488 | as C<< "(cond1 AND cond2) OR (cond3 AND cond4)" >>. |
2489 | Now this is interpreted |
2490 | as C<< "(cond1 AND cond2) OR (cond3 OR cond4)" >>. |
2491 | |
96449e8e |
2492 | |
2493 | =item * |
2494 | |
2495 | fixed semantics of _bindtype on array args |
2496 | |
2497 | =item * |
2498 | |
2499 | dropped the C<_anoncopy> of the %where tree. No longer necessary, |
2500 | we just avoid shifting arrays within that tree. |
2501 | |
2502 | =item * |
2503 | |
2504 | dropped the C<_modlogic> function |
2505 | |
2506 | =back |
32eab2da |
2507 | |
32eab2da |
2508 | |
32eab2da |
2509 | |
2510 | =head1 ACKNOWLEDGEMENTS |
2511 | |
2512 | There are a number of individuals that have really helped out with |
2513 | this module. Unfortunately, most of them submitted bugs via CPAN |
2514 | so I have no idea who they are! But the people I do know are: |
2515 | |
86298391 |
2516 | Ash Berlin (order_by hash term support) |
b643abe1 |
2517 | Matt Trout (DBIx::Class support) |
32eab2da |
2518 | Mark Stosberg (benchmarking) |
2519 | Chas Owens (initial "IN" operator support) |
2520 | Philip Collins (per-field SQL functions) |
2521 | Eric Kolve (hashref "AND" support) |
2522 | Mike Fragassi (enhancements to "BETWEEN" and "LIKE") |
2523 | Dan Kubb (support for "quote_char" and "name_sep") |
f5aab26e |
2524 | Guillermo Roditi (patch to cleanup "IN" and "BETWEEN", fix and tests for _order_by) |
01a01e57 |
2525 | Laurent Dami (internal refactoring, multiple -nest, extensible list of special operators, literal SQL) |
dbdf7648 |
2526 | Norbert Buchmuller (support for literal SQL in hashpair, misc. fixes & tests) |
e96c510a |
2527 | Peter Rabbitson (rewrite of SQLA::Test, misc. fixes & tests) |
32eab2da |
2528 | |
2529 | Thanks! |
2530 | |
32eab2da |
2531 | =head1 SEE ALSO |
2532 | |
86298391 |
2533 | L<DBIx::Class>, L<DBIx::Abstract>, L<CGI::FormBuilder>, L<HTML::QuickTable>. |
32eab2da |
2534 | |
32eab2da |
2535 | =head1 AUTHOR |
2536 | |
b643abe1 |
2537 | Copyright (c) 2001-2007 Nathan Wiger <nwiger@cpan.org>. All Rights Reserved. |
2538 | |
2539 | This module is actively maintained by Matt Trout <mst@shadowcatsystems.co.uk> |
32eab2da |
2540 | |
abe72f94 |
2541 | For support, your best bet is to try the C<DBIx::Class> users mailing list. |
2542 | While not an official support venue, C<DBIx::Class> makes heavy use of |
2543 | C<SQL::Abstract>, and as such list members there are very familiar with |
2544 | how to create queries. |
2545 | |
0d067ded |
2546 | =head1 LICENSE |
2547 | |
32eab2da |
2548 | This module is free software; you may copy this under the terms of |
2549 | the GNU General Public License, or the Artistic License, copies of |
2550 | which should have accompanied your Perl kit. |
2551 | |
2552 | =cut |
2553 | |