1 package SQL::Abstract; # see doc at end of file
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)
11 use List::Util qw/first/;
12 use Scalar::Util qw/blessed/;
14 #======================================================================
16 #======================================================================
18 our $VERSION = '1.55';
20 # This would confuse some packagers
21 #$VERSION = eval $VERSION; # numify for warning-free dev releases
25 # special operators (-in, -between). May be extended/overridden by user.
26 # See section WHERE: BUILTIN SPECIAL OPERATORS below for implementation
27 my @BUILTIN_SPECIAL_OPS = (
28 {regex => qr/^(not )?between$/i, handler => '_where_field_BETWEEN'},
29 {regex => qr/^(not )?in$/i, handler => '_where_field_IN'},
32 #======================================================================
33 # DEBUGGING AND ERROR REPORTING
34 #======================================================================
37 return unless $_[0]->{debug}; shift; # a little faster
38 my $func = (caller(1))[3];
39 warn "[$func] ", @_, "\n";
43 my($func) = (caller(1))[3];
44 carp "[$func] Warning: ", @_;
48 my($func) = (caller(1))[3];
49 croak "[$func] Fatal: ", @_;
53 #======================================================================
55 #======================================================================
59 my $class = ref($self) || $self;
60 my %opt = (ref $_[0] eq 'HASH') ? %{$_[0]} : @_;
62 # choose our case by keeping an option around
63 delete $opt{case} if $opt{case} && $opt{case} ne 'lower';
65 # default logic for interpreting arrayrefs
66 $opt{logic} = $opt{logic} ? uc $opt{logic} : 'OR';
68 # how to return bind vars
69 # LDNOTE: changed nwiger code : why this 'delete' ??
70 # $opt{bindtype} ||= delete($opt{bind_type}) || 'normal';
71 $opt{bindtype} ||= 'normal';
73 # default comparison is "=", but can be overridden
76 # try to recognize which are the 'equality' and 'unequality' ops
77 # (temporary quickfix, should go through a more seasoned API)
78 $opt{equality_op} = qr/^(\Q$opt{cmp}\E|is|(is\s+)?like)$/i;
79 $opt{inequality_op} = qr/^(!=|<>|(is\s+)?not(\s+like)?)$/i;
82 $opt{sqltrue} ||= '1=1';
83 $opt{sqlfalse} ||= '0=1';
86 $opt{special_ops} ||= [];
87 push @{$opt{special_ops}}, @BUILTIN_SPECIAL_OPS;
89 return bless \%opt, $class;
94 #======================================================================
96 #======================================================================
100 my $table = $self->_table(shift);
101 my $data = shift || return;
103 my $method = $self->_METHOD_FOR_refkind("_insert", $data);
104 my ($sql, @bind) = $self->$method($data);
105 $sql = join " ", $self->_sqlcase('insert into'), $table, $sql;
106 return wantarray ? ($sql, @bind) : $sql;
109 sub _insert_HASHREF { # explicit list of fields and then values
110 my ($self, $data) = @_;
112 my @fields = sort keys %$data;
114 my ($sql, @bind) = $self->_insert_values($data);
117 $_ = $self->_quote($_) foreach @fields;
118 $sql = "( ".join(", ", @fields).") ".$sql;
120 return ($sql, @bind);
123 sub _insert_ARRAYREF { # just generate values(?,?) part (no list of fields)
124 my ($self, $data) = @_;
126 # no names (arrayref) so can't generate bindtype
127 $self->{bindtype} ne 'columns'
128 or belch "can't do 'columns' bindtype when called with arrayref";
130 # fold the list of values into a hash of column name - value pairs
131 # (where the column names are artificially generated, and their
132 # lexicographical ordering keep the ordering of the original list)
133 my $i = "a"; # incremented values will be in lexicographical order
134 my $data_in_hash = { map { ($i++ => $_) } @$data };
136 return $self->_insert_values($data_in_hash);
139 sub _insert_ARRAYREFREF { # literal SQL with bind
140 my ($self, $data) = @_;
142 my ($sql, @bind) = @${$data};
143 $self->_assert_bindval_matches_bindtype(@bind);
145 return ($sql, @bind);
149 sub _insert_SCALARREF { # literal SQL without bind
150 my ($self, $data) = @_;
156 my ($self, $data) = @_;
158 my (@values, @all_bind);
159 foreach my $column (sort keys %$data) {
160 my $v = $data->{$column};
162 $self->_SWITCH_refkind($v, {
165 if ($self->{array_datatypes}) { # if array datatype are activated
167 push @all_bind, $self->_bindtype($column, $v);
169 else { # else literal SQL with bind
170 my ($sql, @bind) = @$v;
171 $self->_assert_bindval_matches_bindtype(@bind);
173 push @all_bind, @bind;
177 ARRAYREFREF => sub { # literal SQL with bind
178 my ($sql, @bind) = @${$v};
179 $self->_assert_bindval_matches_bindtype(@bind);
181 push @all_bind, @bind;
184 # THINK : anything useful to do with a HASHREF ?
185 HASHREF => sub { # (nothing, but old SQLA passed it through)
186 #TODO in SQLA >= 2.0 it will die instead
187 belch "HASH ref as bind value in insert is not supported";
189 push @all_bind, $self->_bindtype($column, $v);
192 SCALARREF => sub { # literal SQL without bind
196 SCALAR_or_UNDEF => sub {
198 push @all_bind, $self->_bindtype($column, $v);
205 my $sql = $self->_sqlcase('values')." ( ".join(", ", @values)." )";
206 return ($sql, @all_bind);
211 #======================================================================
213 #======================================================================
218 my $table = $self->_table(shift);
219 my $data = shift || return;
222 # first build the 'SET' part of the sql statement
223 my (@set, @all_bind);
224 puke "Unsupported data type specified to \$sql->update"
225 unless ref $data eq 'HASH';
227 for my $k (sort keys %$data) {
230 my $label = $self->_quote($k);
232 $self->_SWITCH_refkind($v, {
234 if ($self->{array_datatypes}) { # array datatype
235 push @set, "$label = ?";
236 push @all_bind, $self->_bindtype($k, $v);
238 else { # literal SQL with bind
239 my ($sql, @bind) = @$v;
240 $self->_assert_bindval_matches_bindtype(@bind);
241 push @set, "$label = $sql";
242 push @all_bind, @bind;
245 ARRAYREFREF => sub { # literal SQL with bind
246 my ($sql, @bind) = @${$v};
247 $self->_assert_bindval_matches_bindtype(@bind);
248 push @set, "$label = $sql";
249 push @all_bind, @bind;
251 SCALARREF => sub { # literal SQL without bind
252 push @set, "$label = $$v";
254 SCALAR_or_UNDEF => sub {
255 push @set, "$label = ?";
256 push @all_bind, $self->_bindtype($k, $v);
262 my $sql = $self->_sqlcase('update') . " $table " . $self->_sqlcase('set ')
266 my($where_sql, @where_bind) = $self->where($where);
268 push @all_bind, @where_bind;
271 return wantarray ? ($sql, @all_bind) : $sql;
277 #======================================================================
279 #======================================================================
284 my $table = $self->_table(shift);
285 my $fields = shift || '*';
289 my($where_sql, @bind) = $self->where($where, $order);
291 my $f = (ref $fields eq 'ARRAY') ? join ', ', map { $self->_quote($_) } @$fields
293 my $sql = join(' ', $self->_sqlcase('select'), $f,
294 $self->_sqlcase('from'), $table)
297 return wantarray ? ($sql, @bind) : $sql;
300 #======================================================================
302 #======================================================================
307 my $table = $self->_table(shift);
311 my($where_sql, @bind) = $self->where($where);
312 my $sql = $self->_sqlcase('delete from') . " $table" . $where_sql;
314 return wantarray ? ($sql, @bind) : $sql;
318 #======================================================================
320 #======================================================================
324 # Finally, a separate routine just to handle WHERE clauses
326 my ($self, $where, $order) = @_;
329 my ($sql, @bind) = $self->_recurse_where($where);
330 $sql = $sql ? $self->_sqlcase(' where ') . "( $sql )" : '';
334 $sql .= $self->_order_by($order);
337 return wantarray ? ($sql, @bind) : $sql;
342 my ($self, $where, $logic) = @_;
344 # dispatch on appropriate method according to refkind of $where
345 my $method = $self->_METHOD_FOR_refkind("_where", $where);
348 my ($sql, @bind) = $self->$method($where, $logic);
350 # DBIx::Class directly calls _recurse_where in scalar context, so
351 # we must implement it, even if not in the official API
352 return wantarray ? ($sql, @bind) : $sql;
357 #======================================================================
358 # WHERE: top-level ARRAYREF
359 #======================================================================
362 sub _where_ARRAYREF {
363 my ($self, $where, $logic) = @_;
365 $logic = uc($logic || $self->{logic});
366 $logic eq 'AND' or $logic eq 'OR' or puke "unknown logic: $logic";
368 my @clauses = @$where;
370 my (@sql_clauses, @all_bind);
371 # need to use while() so can shift() for pairs
372 while (my $el = shift @clauses) {
374 # switch according to kind of $el and get corresponding ($sql, @bind)
375 my ($sql, @bind) = $self->_SWITCH_refkind($el, {
377 # skip empty elements, otherwise get invalid trailing AND stuff
378 ARRAYREF => sub {$self->_recurse_where($el) if @$el},
380 ARRAYREFREF => sub { @{${$el}} if @{${$el}}},
382 HASHREF => sub {$self->_recurse_where($el, 'and') if %$el},
383 # LDNOTE : previous SQLA code for hashrefs was creating a dirty
384 # side-effect: the first hashref within an array would change
385 # the global logic to 'AND'. So [ {cond1, cond2}, [cond3, cond4] ]
386 # was interpreted as "(cond1 AND cond2) OR (cond3 AND cond4)",
387 # whereas it should be "(cond1 AND cond2) OR (cond3 OR cond4)".
389 SCALARREF => sub { ($$el); },
391 SCALAR => sub {# top-level arrayref with scalars, recurse in pairs
392 $self->_recurse_where({$el => shift(@clauses)})},
394 UNDEF => sub {puke "not supported : UNDEF in arrayref" },
398 push @sql_clauses, $sql;
399 push @all_bind, @bind;
403 return $self->_join_sql_clauses($logic, \@sql_clauses, \@all_bind);
406 #======================================================================
407 # WHERE: top-level ARRAYREFREF
408 #======================================================================
410 sub _where_ARRAYREFREF {
411 my ($self, $where) = @_;
412 my ($sql, @bind) = @{${$where}};
414 return ($sql, @bind);
417 #======================================================================
418 # WHERE: top-level HASHREF
419 #======================================================================
422 my ($self, $where) = @_;
423 my (@sql_clauses, @all_bind);
425 for my $k (sort keys %$where) {
426 my $v = $where->{$k};
428 # ($k => $v) is either a special op or a regular hashpair
429 my ($sql, @bind) = ($k =~ /^-(.+)/) ? $self->_where_op_in_hash($1, $v)
431 my $method = $self->_METHOD_FOR_refkind("_where_hashpair", $v);
432 $self->$method($k, $v);
435 push @sql_clauses, $sql;
436 push @all_bind, @bind;
439 return $self->_join_sql_clauses('and', \@sql_clauses, \@all_bind);
443 sub _where_op_in_hash {
444 my ($self, $op_str, $v) = @_;
446 $op_str =~ /^ (AND|OR|NEST) ( \_? \d* ) $/xi
447 or puke "unknown operator: -$op_str";
449 my $op = uc($1); # uppercase, remove trailing digits
451 belch 'Use of [and|or|nest]_N modifiers is deprecated and will be removed in SQLA v2.0. '
452 . "You probably wanted ...-and => [ $op_str => COND1, $op_str => COND2 ... ]";
455 $self->_debug("OP(-$op) within hashref, recursing...");
457 $self->_SWITCH_refkind($v, {
460 return $self->_where_ARRAYREF($v, $op eq 'NEST' ? '' : $op);
465 return $self->_where_ARRAYREF([ map { $_ => $v->{$_} } (sort keys %$v) ], 'OR');
468 return $self->_where_HASHREF($v);
472 SCALARREF => sub { # literal SQL
474 or puke "-$op => \\\$scalar not supported, use -nest => ...";
478 ARRAYREFREF => sub { # literal SQL
480 or puke "-$op => \\[..] not supported, use -nest => ...";
484 SCALAR => sub { # permissively interpreted as SQL
486 or puke "-$op => 'scalar' not supported, use -nest => \\'scalar'";
487 belch "literal SQL should be -nest => \\'scalar' "
488 . "instead of -nest => 'scalar' ";
493 puke "-$op => undef not supported";
499 sub _where_hashpair_ARRAYREF {
500 my ($self, $k, $v) = @_;
503 my @v = @$v; # need copy because of shift below
504 $self->_debug("ARRAY($k) means distribute over elements");
506 # put apart first element if it is an operator (-and, -or)
508 (defined $v[0] && $v[0] =~ /^ - (?: AND|OR ) $/ix)
512 my @distributed = map { {$k => $_} } @v;
515 $self->_debug("OP($op) reinjected into the distributed array");
516 unshift @distributed, $op;
519 my $logic = $op ? substr($op, 1) : '';
521 return $self->_recurse_where(\@distributed, $logic);
524 # LDNOTE : not sure of this one. What does "distribute over nothing" mean?
525 $self->_debug("empty ARRAY($k) means 0=1");
526 return ($self->{sqlfalse});
530 sub _where_hashpair_HASHREF {
531 my ($self, $k, $v, $logic) = @_;
534 my ($all_sql, @all_bind);
536 for my $op (sort keys %$v) {
539 # put the operator in canonical form
540 $op =~ s/^-//; # remove initial dash
541 $op =~ tr/_/ /; # underscores become spaces
542 $op =~ s/^\s+//; # no initial space
543 $op =~ s/\s+$//; # no final space
544 $op =~ s/\s+/ /; # multiple spaces become one
548 # CASE: special operators like -in or -between
549 my $special_op = first {$op =~ $_->{regex}} @{$self->{special_ops}};
551 my $handler = $special_op->{handler};
553 puke "No handler supplied for special operator matching $special_op->{regex}";
555 elsif (not ref $handler) {
556 ($sql, @bind) = $self->$handler ($k, $op, $val);
558 elsif (ref $handler eq 'CODE') {
559 ($sql, @bind) = $handler->($self, $k, $op, $val);
562 puke "Illegal handler for special operator matching $special_op->{regex} - expecting a method name or a coderef";
566 $self->_SWITCH_refkind($val, {
568 ARRAYREF => sub { # CASE: col => {op => \@vals}
569 ($sql, @bind) = $self->_where_field_op_ARRAYREF($k, $op, $val);
572 SCALARREF => sub { # CASE: col => {op => \$scalar} (literal SQL without bind)
573 $sql = join ' ', $self->_convert($self->_quote($k)),
574 $self->_sqlcase($op),
578 ARRAYREFREF => sub { # CASE: col => {op => \[$sql, @bind]} (literal SQL with bind)
579 my ($sub_sql, @sub_bind) = @$$val;
580 $self->_assert_bindval_matches_bindtype(@sub_bind);
581 $sql = join ' ', $self->_convert($self->_quote($k)),
582 $self->_sqlcase($op),
588 ($sql, @bind) = $self->_where_hashpair_HASHREF($k, $val, $op);
591 UNDEF => sub { # CASE: col => {op => undef} : sql "IS (NOT)? NULL"
592 my $is = ($op =~ $self->{equality_op}) ? 'is' :
593 ($op =~ $self->{inequality_op}) ? 'is not' :
594 puke "unexpected operator '$op' with undef operand";
595 $sql = $self->_quote($k) . $self->_sqlcase(" $is null");
598 FALLBACK => sub { # CASE: col => {op => $scalar}
599 $sql = join ' ', $self->_convert($self->_quote($k)),
600 $self->_sqlcase($op),
601 $self->_convert('?');
602 @bind = $self->_bindtype($k, $val);
607 ($all_sql) = (defined $all_sql and $all_sql) ? $self->_join_sql_clauses($logic, [$all_sql, $sql], []) : $sql;
608 push @all_bind, @bind;
610 return ($all_sql, @all_bind);
615 sub _where_field_op_ARRAYREF {
616 my ($self, $k, $op, $vals) = @_;
618 my @vals = @$vals; #always work on a copy
621 $self->_debug("ARRAY($vals) means multiple elements: [ @vals ]");
623 # see if the first element is an -and/-or op
625 if ($vals[0] =~ /^ - ( AND|OR ) $/ix) {
630 # distribute $op over each remaining member of @vals, append logic if exists
631 return $self->_recurse_where([map { {$k => {$op, $_}} } @vals], $logic);
633 # LDNOTE : had planned to change the distribution logic when
634 # $op =~ $self->{inequality_op}, because of Morgan laws :
635 # with {field => {'!=' => [22, 33]}}, it would be ridiculous to generate
636 # WHERE field != 22 OR field != 33 : the user probably means
637 # WHERE field != 22 AND field != 33.
638 # To do this, replace the above to roughly :
639 # my $logic = ($op =~ $self->{inequality_op}) ? 'AND' : 'OR';
640 # return $self->_recurse_where([map { {$k => {$op, $_}} } @vals], $logic);
644 # try to DWIM on equality operators
645 # LDNOTE : not 100% sure this is the correct thing to do ...
646 return ($self->{sqlfalse}) if $op =~ $self->{equality_op};
647 return ($self->{sqltrue}) if $op =~ $self->{inequality_op};
650 puke "operator '$op' applied on an empty array (field '$k')";
655 sub _where_hashpair_SCALARREF {
656 my ($self, $k, $v) = @_;
657 $self->_debug("SCALAR($k) means literal SQL: $$v");
658 my $sql = $self->_quote($k) . " " . $$v;
662 # literal SQL with bind
663 sub _where_hashpair_ARRAYREFREF {
664 my ($self, $k, $v) = @_;
665 $self->_debug("REF($k) means literal SQL: @${$v}");
666 my ($sql, @bind) = @${$v};
667 $self->_assert_bindval_matches_bindtype(@bind);
668 $sql = $self->_quote($k) . " " . $sql;
669 return ($sql, @bind );
672 # literal SQL without bind
673 sub _where_hashpair_SCALAR {
674 my ($self, $k, $v) = @_;
675 $self->_debug("NOREF($k) means simple key=val: $k $self->{cmp} $v");
676 my $sql = join ' ', $self->_convert($self->_quote($k)),
677 $self->_sqlcase($self->{cmp}),
678 $self->_convert('?');
679 my @bind = $self->_bindtype($k, $v);
680 return ( $sql, @bind);
684 sub _where_hashpair_UNDEF {
685 my ($self, $k, $v) = @_;
686 $self->_debug("UNDEF($k) means IS NULL");
687 my $sql = $self->_quote($k) . $self->_sqlcase(' is null');
691 #======================================================================
692 # WHERE: TOP-LEVEL OTHERS (SCALARREF, SCALAR, UNDEF)
693 #======================================================================
696 sub _where_SCALARREF {
697 my ($self, $where) = @_;
700 $self->_debug("SCALAR(*top) means literal SQL: $$where");
706 my ($self, $where) = @_;
709 $self->_debug("NOREF(*top) means literal SQL: $where");
720 #======================================================================
721 # WHERE: BUILTIN SPECIAL OPERATORS (-in, -between)
722 #======================================================================
725 sub _where_field_BETWEEN {
726 my ($self, $k, $op, $vals) = @_;
728 (ref $vals eq 'ARRAY' && @$vals == 2) or
729 (ref $vals eq 'REF' && (@$$vals == 1 || @$$vals == 2 || @$$vals == 3))
730 or puke "special op 'between' requires an arrayref of two values (or a scalarref or arrayrefref for literal SQL)";
732 my ($clause, @bind, $label, $and, $placeholder);
733 $label = $self->_convert($self->_quote($k));
734 $and = ' ' . $self->_sqlcase('and') . ' ';
735 $placeholder = $self->_convert('?');
736 $op = $self->_sqlcase($op);
738 if (ref $vals eq 'REF') {
739 ($clause, @bind) = @$$vals;
742 my (@all_sql, @all_bind);
744 foreach my $val (@$vals) {
745 my ($sql, @bind) = $self->_SWITCH_refkind($val, {
747 return ($placeholder, ($val));
750 return ($self->_convert($$val), ());
754 push @all_bind, @bind;
757 $clause = (join $and, @all_sql);
758 @bind = $self->_bindtype($k, @all_bind);
760 my $sql = "( $label $op $clause )";
765 sub _where_field_IN {
766 my ($self, $k, $op, $vals) = @_;
768 # backwards compatibility : if scalar, force into an arrayref
769 $vals = [$vals] if defined $vals && ! ref $vals;
771 my ($label) = $self->_convert($self->_quote($k));
772 my ($placeholder) = $self->_convert('?');
773 $op = $self->_sqlcase($op);
775 my ($sql, @bind) = $self->_SWITCH_refkind($vals, {
776 ARRAYREF => sub { # list of choices
777 if (@$vals) { # nonempty list
778 my $placeholders = join ", ", (($placeholder) x @$vals);
779 my $sql = "$label $op ( $placeholders )";
780 my @bind = $self->_bindtype($k, @$vals);
782 return ($sql, @bind);
784 else { # empty list : some databases won't understand "IN ()", so DWIM
785 my $sql = ($op =~ /\bnot\b/i) ? $self->{sqltrue} : $self->{sqlfalse};
790 ARRAYREFREF => sub { # literal SQL with bind
791 my ($sql, @bind) = @$$vals;
792 $self->_assert_bindval_matches_bindtype(@bind);
793 return ("$label $op ( $sql )", @bind);
797 puke "special op 'in' requires an arrayref (or arrayref-ref)";
801 return ($sql, @bind);
809 #======================================================================
811 #======================================================================
814 my ($self, $arg) = @_;
817 for my $c ($self->_order_by_chunks ($arg) ) {
818 $self->_SWITCH_refkind ($c, {
819 SCALAR => sub { push @sql, $c },
820 ARRAYREF => sub { push @sql, shift @$c; push @bind, @$c },
826 $self->_sqlcase(' order by'),
832 return wantarray ? ($sql, @bind) : $sql;
835 sub _order_by_chunks {
836 my ($self, $arg) = @_;
838 return $self->_SWITCH_refkind($arg, {
841 map { $self->_order_by_chunks ($_ ) } @$arg;
844 ARRAYREFREF => sub { [ @$$arg ] },
846 SCALAR => sub {$self->_quote($arg)},
848 UNDEF => sub {return () },
850 SCALARREF => sub {$$arg}, # literal SQL, no quoting
853 # get first pair in hash
854 my ($key, $val) = each %$arg;
856 return () unless $key;
858 if ( (keys %$arg) > 1 or not $key =~ /^-(desc|asc)/i ) {
859 puke "hash passed to _order_by must have exactly one key (-desc or -asc)";
865 for my $c ($self->_order_by_chunks ($val)) {
869 $self->_SWITCH_refkind ($c, {
881 my $sql = join ', ', map { $_ . ' ' . $self->_sqlcase($direction) } @sql;
883 return [$sql, @bind];
889 #======================================================================
890 # DATASOURCE (FOR NOW, JUST PLAIN TABLE OR LIST OF TABLES)
891 #======================================================================
896 $self->_SWITCH_refkind($from, {
897 ARRAYREF => sub {join ', ', map { $self->_quote($_) } @$from;},
898 SCALAR => sub {$self->_quote($from)},
899 SCALARREF => sub {$$from},
900 ARRAYREFREF => sub {join ', ', @$from;},
905 #======================================================================
907 #======================================================================
913 $label or puke "can't quote an empty label";
915 # left and right quote characters
916 my ($ql, $qr, @other) = $self->_SWITCH_refkind($self->{quote_char}, {
917 SCALAR => sub {($self->{quote_char}, $self->{quote_char})},
918 ARRAYREF => sub {@{$self->{quote_char}}},
922 or puke "quote_char must be an arrayref of 2 values";
924 # no quoting if no quoting chars
925 $ql or return $label;
927 # no quoting for literal SQL
928 return $$label if ref($label) eq 'SCALAR';
930 # separate table / column (if applicable)
931 my $sep = $self->{name_sep} || '';
932 my @to_quote = $sep ? split /\Q$sep\E/, $label : ($label);
934 # do the quoting, except for "*" or for `table`.*
935 my @quoted = map { $_ eq '*' ? $_: $ql.$_.$qr} @to_quote;
937 # reassemble and return.
938 return join $sep, @quoted;
942 # Conversion, if applicable
944 my ($self, $arg) = @_;
946 # LDNOTE : modified the previous implementation below because
947 # it was not consistent : the first "return" is always an array,
948 # the second "return" is context-dependent. Anyway, _convert
949 # seems always used with just a single argument, so make it a
951 # return @_ unless $self->{convert};
952 # my $conv = $self->_sqlcase($self->{convert});
953 # my @ret = map { $conv.'('.$_.')' } @_;
954 # return wantarray ? @ret : $ret[0];
955 if ($self->{convert}) {
956 my $conv = $self->_sqlcase($self->{convert});
957 $arg = $conv.'('.$arg.')';
965 my($col, @vals) = @_;
967 #LDNOTE : changed original implementation below because it did not make
968 # sense when bindtype eq 'columns' and @vals > 1.
969 # return $self->{bindtype} eq 'columns' ? [ $col, @vals ] : @vals;
971 return $self->{bindtype} eq 'columns' ? map {[$col, $_]} @vals : @vals;
974 # Dies if any element of @bind is not in [colname => value] format
975 # if bindtype is 'columns'.
976 sub _assert_bindval_matches_bindtype {
977 my ($self, @bind) = @_;
979 if ($self->{bindtype} eq 'columns') {
980 foreach my $val (@bind) {
981 if (!defined $val || ref($val) ne 'ARRAY' || @$val != 2) {
982 die "bindtype 'columns' selected, you need to pass: [column_name => bind_value]"
988 sub _join_sql_clauses {
989 my ($self, $logic, $clauses_aref, $bind_aref) = @_;
991 if (@$clauses_aref > 1) {
992 my $join = " " . $self->_sqlcase($logic) . " ";
993 my $sql = '( ' . join($join, @$clauses_aref) . ' )';
994 return ($sql, @$bind_aref);
996 elsif (@$clauses_aref) {
997 return ($clauses_aref->[0], @$bind_aref); # no parentheses
1000 return (); # if no SQL, ignore @$bind_aref
1005 # Fix SQL case, if so requested
1009 # LDNOTE: if $self->{case} is true, then it contains 'lower', so we
1010 # don't touch the argument ... crooked logic, but let's not change it!
1011 return $self->{case} ? $_[0] : uc($_[0]);
1015 #======================================================================
1016 # DISPATCHING FROM REFKIND
1017 #======================================================================
1020 my ($self, $data) = @_;
1026 # blessed objects are treated like scalars
1027 $ref = (blessed $data) ? '' : ref $data;
1028 $n_steps += 1 if $ref;
1029 last if $ref ne 'REF';
1033 my $base = $ref || (defined $data ? 'SCALAR' : 'UNDEF');
1035 return $base . ('REF' x $n_steps);
1041 my ($self, $data) = @_;
1042 my @try = ($self->_refkind($data));
1043 push @try, 'SCALAR_or_UNDEF' if $try[0] eq 'SCALAR' || $try[0] eq 'UNDEF';
1044 push @try, 'FALLBACK';
1048 sub _METHOD_FOR_refkind {
1049 my ($self, $meth_prefix, $data) = @_;
1050 my $method = first {$_} map {$self->can($meth_prefix."_".$_)}
1051 $self->_try_refkind($data)
1052 or puke "cannot dispatch on '$meth_prefix' for ".$self->_refkind($data);
1057 sub _SWITCH_refkind {
1058 my ($self, $data, $dispatch_table) = @_;
1060 my $coderef = first {$_} map {$dispatch_table->{$_}}
1061 $self->_try_refkind($data)
1062 or puke "no dispatch entry for ".$self->_refkind($data);
1069 #======================================================================
1070 # VALUES, GENERATE, AUTOLOAD
1071 #======================================================================
1073 # LDNOTE: original code from nwiger, didn't touch code in that section
1074 # I feel the AUTOLOAD stuff should not be the default, it should
1075 # only be activated on explicit demand by user.
1079 my $data = shift || return;
1080 puke "Argument to ", __PACKAGE__, "->values must be a \\%hash"
1081 unless ref $data eq 'HASH';
1084 foreach my $k ( sort keys %$data ) {
1085 my $v = $data->{$k};
1086 $self->_SWITCH_refkind($v, {
1088 if ($self->{array_datatypes}) { # array datatype
1089 push @all_bind, $self->_bindtype($k, $v);
1091 else { # literal SQL with bind
1092 my ($sql, @bind) = @$v;
1093 $self->_assert_bindval_matches_bindtype(@bind);
1094 push @all_bind, @bind;
1097 ARRAYREFREF => sub { # literal SQL with bind
1098 my ($sql, @bind) = @${$v};
1099 $self->_assert_bindval_matches_bindtype(@bind);
1100 push @all_bind, @bind;
1102 SCALARREF => sub { # literal SQL without bind
1104 SCALAR_or_UNDEF => sub {
1105 push @all_bind, $self->_bindtype($k, $v);
1116 my(@sql, @sqlq, @sqlv);
1120 if ($ref eq 'HASH') {
1121 for my $k (sort keys %$_) {
1124 my $label = $self->_quote($k);
1125 if ($r eq 'ARRAY') {
1126 # literal SQL with bind
1127 my ($sql, @bind) = @$v;
1128 $self->_assert_bindval_matches_bindtype(@bind);
1129 push @sqlq, "$label = $sql";
1131 } elsif ($r eq 'SCALAR') {
1132 # literal SQL without bind
1133 push @sqlq, "$label = $$v";
1135 push @sqlq, "$label = ?";
1136 push @sqlv, $self->_bindtype($k, $v);
1139 push @sql, $self->_sqlcase('set'), join ', ', @sqlq;
1140 } elsif ($ref eq 'ARRAY') {
1141 # unlike insert(), assume these are ONLY the column names, i.e. for SQL
1144 if ($r eq 'ARRAY') { # literal SQL with bind
1145 my ($sql, @bind) = @$v;
1146 $self->_assert_bindval_matches_bindtype(@bind);
1149 } elsif ($r eq 'SCALAR') { # literal SQL without bind
1150 # embedded literal SQL
1157 push @sql, '(' . join(', ', @sqlq) . ')';
1158 } elsif ($ref eq 'SCALAR') {
1162 # strings get case twiddled
1163 push @sql, $self->_sqlcase($_);
1167 my $sql = join ' ', @sql;
1169 # this is pretty tricky
1170 # if ask for an array, return ($stmt, @bind)
1171 # otherwise, s/?/shift @sqlv/ to put it inline
1173 return ($sql, @sqlv);
1175 1 while $sql =~ s/\?/my $d = shift(@sqlv);
1176 ref $d ? $d->[1] : $d/e;
1185 # This allows us to check for a local, then _form, attr
1187 my($name) = $AUTOLOAD =~ /.*::(.+)/;
1188 return $self->generate($name, @_);
1199 SQL::Abstract - Generate SQL from Perl data structures
1205 my $sql = SQL::Abstract->new;
1207 my($stmt, @bind) = $sql->select($table, \@fields, \%where, \@order);
1209 my($stmt, @bind) = $sql->insert($table, \%fieldvals || \@values);
1211 my($stmt, @bind) = $sql->update($table, \%fieldvals, \%where);
1213 my($stmt, @bind) = $sql->delete($table, \%where);
1215 # Then, use these in your DBI statements
1216 my $sth = $dbh->prepare($stmt);
1217 $sth->execute(@bind);
1219 # Just generate the WHERE clause
1220 my($stmt, @bind) = $sql->where(\%where, \@order);
1222 # Return values in the same order, for hashed queries
1223 # See PERFORMANCE section for more details
1224 my @bind = $sql->values(\%fieldvals);
1228 This module was inspired by the excellent L<DBIx::Abstract>.
1229 However, in using that module I found that what I really wanted
1230 to do was generate SQL, but still retain complete control over my
1231 statement handles and use the DBI interface. So, I set out to
1232 create an abstract SQL generation module.
1234 While based on the concepts used by L<DBIx::Abstract>, there are
1235 several important differences, especially when it comes to WHERE
1236 clauses. I have modified the concepts used to make the SQL easier
1237 to generate from Perl data structures and, IMO, more intuitive.
1238 The underlying idea is for this module to do what you mean, based
1239 on the data structures you provide it. The big advantage is that
1240 you don't have to modify your code every time your data changes,
1241 as this module figures it out.
1243 To begin with, an SQL INSERT is as easy as just specifying a hash
1244 of C<key=value> pairs:
1247 name => 'Jimbo Bobson',
1248 phone => '123-456-7890',
1249 address => '42 Sister Lane',
1250 city => 'St. Louis',
1251 state => 'Louisiana',
1254 The SQL can then be generated with this:
1256 my($stmt, @bind) = $sql->insert('people', \%data);
1258 Which would give you something like this:
1260 $stmt = "INSERT INTO people
1261 (address, city, name, phone, state)
1262 VALUES (?, ?, ?, ?, ?)";
1263 @bind = ('42 Sister Lane', 'St. Louis', 'Jimbo Bobson',
1264 '123-456-7890', 'Louisiana');
1266 These are then used directly in your DBI code:
1268 my $sth = $dbh->prepare($stmt);
1269 $sth->execute(@bind);
1271 =head2 Inserting and Updating Arrays
1273 If your database has array types (like for example Postgres),
1274 activate the special option C<< array_datatypes => 1 >>
1275 when creating the C<SQL::Abstract> object.
1276 Then you may use an arrayref to insert and update database array types:
1278 my $sql = SQL::Abstract->new(array_datatypes => 1);
1280 planets => [qw/Mercury Venus Earth Mars/]
1283 my($stmt, @bind) = $sql->insert('solar_system', \%data);
1287 $stmt = "INSERT INTO solar_system (planets) VALUES (?)"
1289 @bind = (['Mercury', 'Venus', 'Earth', 'Mars']);
1292 =head2 Inserting and Updating SQL
1294 In order to apply SQL functions to elements of your C<%data> you may
1295 specify a reference to an arrayref for the given hash value. For example,
1296 if you need to execute the Oracle C<to_date> function on a value, you can
1297 say something like this:
1301 date_entered => \["to_date(?,'MM/DD/YYYY')", "03/02/2003"],
1304 The first value in the array is the actual SQL. Any other values are
1305 optional and would be included in the bind values array. This gives
1308 my($stmt, @bind) = $sql->insert('people', \%data);
1310 $stmt = "INSERT INTO people (name, date_entered)
1311 VALUES (?, to_date(?,'MM/DD/YYYY'))";
1312 @bind = ('Bill', '03/02/2003');
1314 An UPDATE is just as easy, all you change is the name of the function:
1316 my($stmt, @bind) = $sql->update('people', \%data);
1318 Notice that your C<%data> isn't touched; the module will generate
1319 the appropriately quirky SQL for you automatically. Usually you'll
1320 want to specify a WHERE clause for your UPDATE, though, which is
1321 where handling C<%where> hashes comes in handy...
1323 =head2 Complex where statements
1325 This module can generate pretty complicated WHERE statements
1326 easily. For example, simple C<key=value> pairs are taken to mean
1327 equality, and if you want to see if a field is within a set
1328 of values, you can use an arrayref. Let's say we wanted to
1329 SELECT some data based on this criteria:
1332 requestor => 'inna',
1333 worker => ['nwiger', 'rcwe', 'sfz'],
1334 status => { '!=', 'completed' }
1337 my($stmt, @bind) = $sql->select('tickets', '*', \%where);
1339 The above would give you something like this:
1341 $stmt = "SELECT * FROM tickets WHERE
1342 ( requestor = ? ) AND ( status != ? )
1343 AND ( worker = ? OR worker = ? OR worker = ? )";
1344 @bind = ('inna', 'completed', 'nwiger', 'rcwe', 'sfz');
1346 Which you could then use in DBI code like so:
1348 my $sth = $dbh->prepare($stmt);
1349 $sth->execute(@bind);
1355 The functions are simple. There's one for each major SQL operation,
1356 and a constructor you use first. The arguments are specified in a
1357 similar order to each function (table, then fields, then a where
1358 clause) to try and simplify things.
1363 =head2 new(option => 'value')
1365 The C<new()> function takes a list of options and values, and returns
1366 a new B<SQL::Abstract> object which can then be used to generate SQL
1367 through the methods below. The options accepted are:
1373 If set to 'lower', then SQL will be generated in all lowercase. By
1374 default SQL is generated in "textbook" case meaning something like:
1376 SELECT a_field FROM a_table WHERE some_field LIKE '%someval%'
1378 Any setting other than 'lower' is ignored.
1382 This determines what the default comparison operator is. By default
1383 it is C<=>, meaning that a hash like this:
1385 %where = (name => 'nwiger', email => 'nate@wiger.org');
1387 Will generate SQL like this:
1389 WHERE name = 'nwiger' AND email = 'nate@wiger.org'
1391 However, you may want loose comparisons by default, so if you set
1392 C<cmp> to C<like> you would get SQL such as:
1394 WHERE name like 'nwiger' AND email like 'nate@wiger.org'
1396 You can also override the comparsion on an individual basis - see
1397 the huge section on L</"WHERE CLAUSES"> at the bottom.
1399 =item sqltrue, sqlfalse
1401 Expressions for inserting boolean values within SQL statements.
1402 By default these are C<1=1> and C<1=0>. They are used
1403 by the special operators C<-in> and C<-not_in> for generating
1404 correct SQL even when the argument is an empty array (see below).
1408 This determines the default logical operator for multiple WHERE
1409 statements in arrays or hashes. If absent, the default logic is "or"
1410 for arrays, and "and" for hashes. This means that a WHERE
1414 event_date => {'>=', '2/13/99'},
1415 event_date => {'<=', '4/24/03'},
1418 will generate SQL like this:
1420 WHERE event_date >= '2/13/99' OR event_date <= '4/24/03'
1422 This is probably not what you want given this query, though (look
1423 at the dates). To change the "OR" to an "AND", simply specify:
1425 my $sql = SQL::Abstract->new(logic => 'and');
1427 Which will change the above C<WHERE> to:
1429 WHERE event_date >= '2/13/99' AND event_date <= '4/24/03'
1431 The logic can also be changed locally by inserting
1432 a modifier in front of an arrayref :
1434 @where = (-and => [event_date => {'>=', '2/13/99'},
1435 event_date => {'<=', '4/24/03'} ]);
1437 See the L</"WHERE CLAUSES"> section for explanations.
1441 This will automatically convert comparisons using the specified SQL
1442 function for both column and value. This is mostly used with an argument
1443 of C<upper> or C<lower>, so that the SQL will have the effect of
1444 case-insensitive "searches". For example, this:
1446 $sql = SQL::Abstract->new(convert => 'upper');
1447 %where = (keywords => 'MaKe iT CAse inSeNSItive');
1449 Will turn out the following SQL:
1451 WHERE upper(keywords) like upper('MaKe iT CAse inSeNSItive')
1453 The conversion can be C<upper()>, C<lower()>, or any other SQL function
1454 that can be applied symmetrically to fields (actually B<SQL::Abstract> does
1455 not validate this option; it will just pass through what you specify verbatim).
1459 This is a kludge because many databases suck. For example, you can't
1460 just bind values using DBI's C<execute()> for Oracle C<CLOB> or C<BLOB> fields.
1461 Instead, you have to use C<bind_param()>:
1463 $sth->bind_param(1, 'reg data');
1464 $sth->bind_param(2, $lots, {ora_type => ORA_CLOB});
1466 The problem is, B<SQL::Abstract> will normally just return a C<@bind> array,
1467 which loses track of which field each slot refers to. Fear not.
1469 If you specify C<bindtype> in new, you can determine how C<@bind> is returned.
1470 Currently, you can specify either C<normal> (default) or C<columns>. If you
1471 specify C<columns>, you will get an array that looks like this:
1473 my $sql = SQL::Abstract->new(bindtype => 'columns');
1474 my($stmt, @bind) = $sql->insert(...);
1477 [ 'column1', 'value1' ],
1478 [ 'column2', 'value2' ],
1479 [ 'column3', 'value3' ],
1482 You can then iterate through this manually, using DBI's C<bind_param()>.
1484 $sth->prepare($stmt);
1487 my($col, $data) = @$_;
1488 if ($col eq 'details' || $col eq 'comments') {
1489 $sth->bind_param($i, $data, {ora_type => ORA_CLOB});
1490 } elsif ($col eq 'image') {
1491 $sth->bind_param($i, $data, {ora_type => ORA_BLOB});
1493 $sth->bind_param($i, $data);
1497 $sth->execute; # execute without @bind now
1499 Now, why would you still use B<SQL::Abstract> if you have to do this crap?
1500 Basically, the advantage is still that you don't have to care which fields
1501 are or are not included. You could wrap that above C<for> loop in a simple
1502 sub called C<bind_fields()> or something and reuse it repeatedly. You still
1503 get a layer of abstraction over manual SQL specification.
1505 Note that if you set L</bindtype> to C<columns>, the C<\[$sql, @bind]>
1506 construct (see L</Literal SQL with placeholders and bind values (subqueries)>)
1507 will expect the bind values in this format.
1511 This is the character that a table or column name will be quoted
1512 with. By default this is an empty string, but you could set it to
1513 the character C<`>, to generate SQL like this:
1515 SELECT `a_field` FROM `a_table` WHERE `some_field` LIKE '%someval%'
1517 Alternatively, you can supply an array ref of two items, the first being the left
1518 hand quote character, and the second the right hand quote character. For
1519 example, you could supply C<['[',']']> for SQL Server 2000 compliant quotes
1520 that generates SQL like this:
1522 SELECT [a_field] FROM [a_table] WHERE [some_field] LIKE '%someval%'
1524 Quoting is useful if you have tables or columns names that are reserved
1525 words in your database's SQL dialect.
1529 This is the character that separates a table and column name. It is
1530 necessary to specify this when the C<quote_char> option is selected,
1531 so that tables and column names can be individually quoted like this:
1533 SELECT `table`.`one_field` FROM `table` WHERE `table`.`other_field` = 1
1535 =item array_datatypes
1537 When this option is true, arrayrefs in INSERT or UPDATE are
1538 interpreted as array datatypes and are passed directly
1540 When this option is false, arrayrefs are interpreted
1541 as literal SQL, just like refs to arrayrefs
1542 (but this behavior is for backwards compatibility; when writing
1543 new queries, use the "reference to arrayref" syntax
1549 Takes a reference to a list of "special operators"
1550 to extend the syntax understood by L<SQL::Abstract>.
1551 See section L</"SPECIAL OPERATORS"> for details.
1557 =head2 insert($table, \@values || \%fieldvals)
1559 This is the simplest function. You simply give it a table name
1560 and either an arrayref of values or hashref of field/value pairs.
1561 It returns an SQL INSERT statement and a list of bind values.
1562 See the sections on L</"Inserting and Updating Arrays"> and
1563 L</"Inserting and Updating SQL"> for information on how to insert
1564 with those data types.
1566 =head2 update($table, \%fieldvals, \%where)
1568 This takes a table, hashref of field/value pairs, and an optional
1569 hashref L<WHERE clause|/WHERE CLAUSES>. It returns an SQL UPDATE function and a list
1571 See the sections on L</"Inserting and Updating Arrays"> and
1572 L</"Inserting and Updating SQL"> for information on how to insert
1573 with those data types.
1575 =head2 select($source, $fields, $where, $order)
1577 This returns a SQL SELECT statement and associated list of bind values, as
1578 specified by the arguments :
1584 Specification of the 'FROM' part of the statement.
1585 The argument can be either a plain scalar (interpreted as a table
1586 name, will be quoted), or an arrayref (interpreted as a list
1587 of table names, joined by commas, quoted), or a scalarref
1588 (literal table name, not quoted), or a ref to an arrayref
1589 (list of literal table names, joined by commas, not quoted).
1593 Specification of the list of fields to retrieve from
1595 The argument can be either an arrayref (interpreted as a list
1596 of field names, will be joined by commas and quoted), or a
1597 plain scalar (literal SQL, not quoted).
1598 Please observe that this API is not as flexible as for
1599 the first argument C<$table>, for backwards compatibility reasons.
1603 Optional argument to specify the WHERE part of the query.
1604 The argument is most often a hashref, but can also be
1605 an arrayref or plain scalar --
1606 see section L<WHERE clause|/"WHERE CLAUSES"> for details.
1610 Optional argument to specify the ORDER BY part of the query.
1611 The argument can be a scalar, a hashref or an arrayref
1612 -- see section L<ORDER BY clause|/"ORDER BY CLAUSES">
1618 =head2 delete($table, \%where)
1620 This takes a table name and optional hashref L<WHERE clause|/WHERE CLAUSES>.
1621 It returns an SQL DELETE statement and list of bind values.
1623 =head2 where(\%where, \@order)
1625 This is used to generate just the WHERE clause. For example,
1626 if you have an arbitrary data structure and know what the
1627 rest of your SQL is going to look like, but want an easy way
1628 to produce a WHERE clause, use this. It returns an SQL WHERE
1629 clause and list of bind values.
1632 =head2 values(\%data)
1634 This just returns the values from the hash C<%data>, in the same
1635 order that would be returned from any of the other above queries.
1636 Using this allows you to markedly speed up your queries if you
1637 are affecting lots of rows. See below under the L</"PERFORMANCE"> section.
1639 =head2 generate($any, 'number', $of, \@data, $struct, \%types)
1641 Warning: This is an experimental method and subject to change.
1643 This returns arbitrarily generated SQL. It's a really basic shortcut.
1644 It will return two different things, depending on return context:
1646 my($stmt, @bind) = $sql->generate('create table', \$table, \@fields);
1647 my $stmt_and_val = $sql->generate('create table', \$table, \@fields);
1649 These would return the following:
1651 # First calling form
1652 $stmt = "CREATE TABLE test (?, ?)";
1653 @bind = (field1, field2);
1655 # Second calling form
1656 $stmt_and_val = "CREATE TABLE test (field1, field2)";
1658 Depending on what you're trying to do, it's up to you to choose the correct
1659 format. In this example, the second form is what you would want.
1663 $sql->generate('alter session', { nls_date_format => 'MM/YY' });
1667 ALTER SESSION SET nls_date_format = 'MM/YY'
1669 You get the idea. Strings get their case twiddled, but everything
1670 else remains verbatim.
1675 =head1 WHERE CLAUSES
1679 This module uses a variation on the idea from L<DBIx::Abstract>. It
1680 is B<NOT>, repeat I<not> 100% compatible. B<The main logic of this
1681 module is that things in arrays are OR'ed, and things in hashes
1684 The easiest way to explain is to show lots of examples. After
1685 each C<%where> hash shown, it is assumed you used:
1687 my($stmt, @bind) = $sql->where(\%where);
1689 However, note that the C<%where> hash can be used directly in any
1690 of the other functions as well, as described above.
1692 =head2 Key-value pairs
1694 So, let's get started. To begin, a simple hash:
1698 status => 'completed'
1701 Is converted to SQL C<key = val> statements:
1703 $stmt = "WHERE user = ? AND status = ?";
1704 @bind = ('nwiger', 'completed');
1706 One common thing I end up doing is having a list of values that
1707 a field can be in. To do this, simply specify a list inside of
1712 status => ['assigned', 'in-progress', 'pending'];
1715 This simple code will create the following:
1717 $stmt = "WHERE user = ? AND ( status = ? OR status = ? OR status = ? )";
1718 @bind = ('nwiger', 'assigned', 'in-progress', 'pending');
1720 A field associated to an empty arrayref will be considered a
1721 logical false and will generate 0=1.
1723 =head2 Specific comparison operators
1725 If you want to specify a different type of operator for your comparison,
1726 you can use a hashref for a given column:
1730 status => { '!=', 'completed' }
1733 Which would generate:
1735 $stmt = "WHERE user = ? AND status != ?";
1736 @bind = ('nwiger', 'completed');
1738 To test against multiple values, just enclose the values in an arrayref:
1740 status => { '=', ['assigned', 'in-progress', 'pending'] };
1742 Which would give you:
1744 "WHERE status = ? OR status = ? OR status = ?"
1747 The hashref can also contain multiple pairs, in which case it is expanded
1748 into an C<AND> of its elements:
1752 status => { '!=', 'completed', -not_like => 'pending%' }
1755 # Or more dynamically, like from a form
1756 $where{user} = 'nwiger';
1757 $where{status}{'!='} = 'completed';
1758 $where{status}{'-not_like'} = 'pending%';
1760 # Both generate this
1761 $stmt = "WHERE user = ? AND status != ? AND status NOT LIKE ?";
1762 @bind = ('nwiger', 'completed', 'pending%');
1765 To get an OR instead, you can combine it with the arrayref idea:
1769 priority => [ {'=', 2}, {'!=', 1} ]
1772 Which would generate:
1774 $stmt = "WHERE user = ? AND priority = ? OR priority != ?";
1775 @bind = ('nwiger', '2', '1');
1777 If you want to include literal SQL (with or without bind values), just use a
1778 scalar reference or array reference as the value:
1781 date_entered => { '>' => \["to_date(?, 'MM/DD/YYYY')", "11/26/2008"] },
1782 date_expires => { '<' => \"now()" }
1785 Which would generate:
1787 $stmt = "WHERE date_entered > "to_date(?, 'MM/DD/YYYY') AND date_expires < now()";
1788 @bind = ('11/26/2008');
1791 =head2 Logic and nesting operators
1793 In the example above,
1794 there is a subtle trap if you want to say something like
1795 this (notice the C<AND>):
1797 WHERE priority != ? AND priority != ?
1799 Because, in Perl you I<can't> do this:
1801 priority => { '!=', 2, '!=', 1 }
1803 As the second C<!=> key will obliterate the first. The solution
1804 is to use the special C<-modifier> form inside an arrayref:
1806 priority => [ -and => {'!=', 2},
1810 Normally, these would be joined by C<OR>, but the modifier tells it
1811 to use C<AND> instead. (Hint: You can use this in conjunction with the
1812 C<logic> option to C<new()> in order to change the way your queries
1813 work by default.) B<Important:> Note that the C<-modifier> goes
1814 B<INSIDE> the arrayref, as an extra first element. This will
1815 B<NOT> do what you think it might:
1817 priority => -and => [{'!=', 2}, {'!=', 1}] # WRONG!
1819 Here is a quick list of equivalencies, since there is some overlap:
1822 status => {'!=', 'completed', 'not like', 'pending%' }
1823 status => [ -and => {'!=', 'completed'}, {'not like', 'pending%'}]
1826 status => {'=', ['assigned', 'in-progress']}
1827 status => [ -or => {'=', 'assigned'}, {'=', 'in-progress'}]
1828 status => [ {'=', 'assigned'}, {'=', 'in-progress'} ]
1832 =head2 Special operators : IN, BETWEEN, etc.
1834 You can also use the hashref format to compare a list of fields using the
1835 C<IN> comparison operator, by specifying the list as an arrayref:
1838 status => 'completed',
1839 reportid => { -in => [567, 2335, 2] }
1842 Which would generate:
1844 $stmt = "WHERE status = ? AND reportid IN (?,?,?)";
1845 @bind = ('completed', '567', '2335', '2');
1847 The reverse operator C<-not_in> generates SQL C<NOT IN> and is used in
1850 If the argument to C<-in> is an empty array, 'sqlfalse' is generated
1851 (by default : C<1=0>). Similarly, C<< -not_in => [] >> generates
1852 'sqltrue' (by default : C<1=1>).
1856 Another pair of operators is C<-between> and C<-not_between>,
1857 used with an arrayref of two values:
1861 completion_date => {
1862 -not_between => ['2002-10-01', '2003-02-06']
1868 WHERE user = ? AND completion_date NOT BETWEEN ( ? AND ? )
1870 These are the two builtin "special operators"; but the
1871 list can be expanded : see section L</"SPECIAL OPERATORS"> below.
1873 =head2 Nested conditions, -and/-or prefixes
1875 So far, we've seen how multiple conditions are joined with a top-level
1876 C<AND>. We can change this by putting the different conditions we want in
1877 hashes and then putting those hashes in an array. For example:
1882 status => { -like => ['pending%', 'dispatched'] },
1886 status => 'unassigned',
1890 This data structure would create the following:
1892 $stmt = "WHERE ( user = ? AND ( status LIKE ? OR status LIKE ? ) )
1893 OR ( user = ? AND status = ? ) )";
1894 @bind = ('nwiger', 'pending', 'dispatched', 'robot', 'unassigned');
1897 There is also a special C<-nest>
1898 operator which adds an additional set of parens, to create a subquery.
1899 For example, to get something like this:
1901 $stmt = "WHERE user = ? AND ( workhrs > ? OR geo = ? )";
1902 @bind = ('nwiger', '20', 'ASIA');
1908 -nest => [ workhrs => {'>', 20}, geo => 'ASIA' ],
1912 Finally, clauses in hashrefs or arrayrefs can be
1913 prefixed with an C<-and> or C<-or> to change the logic
1920 -and => [workhrs => {'>', 20}, geo => 'ASIA' ],
1921 -and => [workhrs => {'<', 50}, geo => 'EURO' ]
1928 WHERE ( user = ? AND
1929 ( ( workhrs > ? AND geo = ? )
1930 OR ( workhrs < ? AND geo = ? ) ) )
1933 =head2 Algebraic inconsistency, for historical reasons
1935 C<Important note>: when connecting several conditions, the C<-and->|C<-or>
1936 operator goes C<outside> of the nested structure; whereas when connecting
1937 several constraints on one column, the C<-and> operator goes
1938 C<inside> the arrayref. Here is an example combining both features :
1941 -and => [a => 1, b => 2],
1942 -or => [c => 3, d => 4],
1943 e => [-and => {-like => 'foo%'}, {-like => '%bar'} ]
1948 WHERE ( ( ( a = ? AND b = ? )
1949 OR ( c = ? OR d = ? )
1950 OR ( e LIKE ? AND e LIKE ? ) ) )
1952 This difference in syntax is unfortunate but must be preserved for
1953 historical reasons. So be careful : the two examples below would
1954 seem algebraically equivalent, but they are not
1956 {col => [-and => {-like => 'foo%'}, {-like => '%bar'}]}
1957 # yields : WHERE ( ( col LIKE ? AND col LIKE ? ) )
1959 [-and => {col => {-like => 'foo%'}, {col => {-like => '%bar'}}]]
1960 # yields : WHERE ( ( col LIKE ? OR col LIKE ? ) )
1965 Finally, sometimes only literal SQL will do. If you want to include
1966 literal SQL verbatim, you can specify it as a scalar reference, namely:
1968 my $inn = 'is Not Null';
1970 priority => { '<', 2 },
1976 $stmt = "WHERE priority < ? AND requestor is Not Null";
1979 Note that in this example, you only get one bind parameter back, since
1980 the verbatim SQL is passed as part of the statement.
1982 Of course, just to prove a point, the above can also be accomplished
1986 priority => { '<', 2 },
1987 requestor => { '!=', undef },
1993 Conditions on boolean columns can be expressed in the
1994 same way, passing a reference to an empty string :
1997 priority => { '<', 2 },
2003 $stmt = "WHERE priority < ? AND is_ready";
2007 =head2 Literal SQL with placeholders and bind values (subqueries)
2009 If the literal SQL to be inserted has placeholders and bind values,
2010 use a reference to an arrayref (yes this is a double reference --
2011 not so common, but perfectly legal Perl). For example, to find a date
2012 in Postgres you can use something like this:
2015 date_column => \[q/= date '2008-09-30' - ?::integer/, 10/]
2020 $stmt = "WHERE ( date_column = date '2008-09-30' - ?::integer )"
2023 Note that you must pass the bind values in the same format as they are returned
2024 by L</where>. That means that if you set L</bindtype> to C<columns>, you must
2025 provide the bind values in the C<< [ column_meta => value ] >> format, where
2026 C<column_meta> is an opaque scalar value; most commonly the column name, but
2027 you can use any scalar value (including references and blessed references),
2028 L<SQL::Abstract> will simply pass it through intact. So if C<bindtype> is set
2029 to C<columns> the above example will look like:
2032 date_column => \[q/= date '2008-09-30' - ?::integer/, [ dummy => 10 ]/]
2035 Literal SQL is especially useful for nesting parenthesized clauses in the
2036 main SQL query. Here is a first example :
2038 my ($sub_stmt, @sub_bind) = ("SELECT c1 FROM t1 WHERE c2 < ? AND c3 LIKE ?",
2042 bar => \["IN ($sub_stmt)" => @sub_bind],
2047 $stmt = "WHERE (foo = ? AND bar IN (SELECT c1 FROM t1
2048 WHERE c2 < ? AND c3 LIKE ?))";
2049 @bind = (1234, 100, "foo%");
2051 Other subquery operators, like for example C<"E<gt> ALL"> or C<"NOT IN">,
2052 are expressed in the same way. Of course the C<$sub_stmt> and
2053 its associated bind values can be generated through a former call
2056 my ($sub_stmt, @sub_bind)
2057 = $sql->select("t1", "c1", {c2 => {"<" => 100},
2058 c3 => {-like => "foo%"}});
2061 bar => \["> ALL ($sub_stmt)" => @sub_bind],
2064 In the examples above, the subquery was used as an operator on a column;
2065 but the same principle also applies for a clause within the main C<%where>
2066 hash, like an EXISTS subquery :
2068 my ($sub_stmt, @sub_bind)
2069 = $sql->select("t1", "*", {c1 => 1, c2 => \"> t0.c0"});
2072 -nest => \["EXISTS ($sub_stmt)" => @sub_bind],
2077 $stmt = "WHERE (foo = ? AND EXISTS (SELECT * FROM t1
2078 WHERE c1 = ? AND c2 > t0.c0))";
2082 Observe that the condition on C<c2> in the subquery refers to
2083 column C<t0.c0> of the main query : this is I<not> a bind
2084 value, so we have to express it through a scalar ref.
2085 Writing C<< c2 => {">" => "t0.c0"} >> would have generated
2086 C<< c2 > ? >> with bind value C<"t0.c0"> ... not exactly
2087 what we wanted here.
2089 Another use of the subquery technique is when some SQL clauses need
2090 parentheses, as it often occurs with some proprietary SQL extensions
2091 like for example fulltext expressions, geospatial expressions,
2092 NATIVE clauses, etc. Here is an example of a fulltext query in MySQL :
2095 -nest => \["MATCH (col1, col2) AGAINST (?)" => qw/apples/]
2098 Finally, here is an example where a subquery is used
2099 for expressing unary negation:
2101 my ($sub_stmt, @sub_bind)
2102 = $sql->where({age => [{"<" => 10}, {">" => 20}]});
2103 $sub_stmt =~ s/^ where //i; # don't want "WHERE" in the subclause
2105 lname => {like => '%son%'},
2106 -nest => \["NOT ($sub_stmt)" => @sub_bind],
2111 $stmt = "lname LIKE ? AND NOT ( age < ? OR age > ? )"
2112 @bind = ('%son%', 10, 20)
2118 These pages could go on for a while, since the nesting of the data
2119 structures this module can handle are pretty much unlimited (the
2120 module implements the C<WHERE> expansion as a recursive function
2121 internally). Your best bet is to "play around" with the module a
2122 little to see how the data structures behave, and choose the best
2123 format for your data based on that.
2125 And of course, all the values above will probably be replaced with
2126 variables gotten from forms or the command line. After all, if you
2127 knew everything ahead of time, you wouldn't have to worry about
2128 dynamically-generating SQL and could just hardwire it into your
2134 =head1 ORDER BY CLAUSES
2136 Some functions take an order by clause. This can either be a scalar (just a
2137 column name,) a hash of C<< { -desc => 'col' } >> or C<< { -asc => 'col' } >>,
2138 or an array of either of the two previous forms. Examples:
2140 Given | Will Generate
2141 ----------------------------------------------------------
2143 \'colA DESC' | ORDER BY colA DESC
2145 'colA' | ORDER BY colA
2147 [qw/colA colB/] | ORDER BY colA, colB
2149 {-asc => 'colA'} | ORDER BY colA ASC
2151 {-desc => 'colB'} | ORDER BY colB DESC
2153 ['colA', {-asc => 'colB'}] | ORDER BY colA, colB ASC
2155 { -asc => [qw/colA colB] } | ORDER BY colA ASC, colB ASC
2158 { -asc => 'colA' }, | ORDER BY colA ASC, colB DESC,
2159 { -desc => [qw/colB/], | colC ASC, colD ASC
2160 { -asc => [qw/colC colD/],|
2162 ===========================================================
2166 =head1 SPECIAL OPERATORS
2168 my $sqlmaker = SQL::Abstract->new(special_ops => [
2172 my ($self, $field, $op, $arg) = @_;
2178 handler => 'method_name',
2182 A "special operator" is a SQL syntactic clause that can be
2183 applied to a field, instead of a usual binary operator.
2186 WHERE field IN (?, ?, ?)
2187 WHERE field BETWEEN ? AND ?
2188 WHERE MATCH(field) AGAINST (?, ?)
2190 Special operators IN and BETWEEN are fairly standard and therefore
2191 are builtin within C<SQL::Abstract> (as the overridable methods
2192 C<_where_field_IN> and C<_where_field_BETWEEN>). For other operators,
2193 like the MATCH .. AGAINST example above which is specific to MySQL,
2194 you can write your own operator handlers - supply a C<special_ops>
2195 argument to the C<new> method. That argument takes an arrayref of
2196 operator definitions; each operator definition is a hashref with two
2203 the regular expression to match the operator
2207 Either a coderef or a plain scalar method name. In both cases
2208 the expected return is C<< ($sql, @bind) >>.
2210 When supplied with a method name, it is simply called on the
2211 L<SQL::Abstract/> object as:
2213 $self->$method_name ($field, $op, $arg)
2217 $op is the part that matched the handler regex
2218 $field is the LHS of the operator
2221 When supplied with a coderef, it is called as:
2223 $coderef->($self, $field, $op, $arg)
2228 For example, here is an implementation
2229 of the MATCH .. AGAINST syntax for MySQL
2231 my $sqlmaker = SQL::Abstract->new(special_ops => [
2233 # special op for MySql MATCH (field) AGAINST(word1, word2, ...)
2234 {regex => qr/^match$/i,
2236 my ($self, $field, $op, $arg) = @_;
2237 $arg = [$arg] if not ref $arg;
2238 my $label = $self->_quote($field);
2239 my ($placeholder) = $self->_convert('?');
2240 my $placeholders = join ", ", (($placeholder) x @$arg);
2241 my $sql = $self->_sqlcase('match') . " ($label) "
2242 . $self->_sqlcase('against') . " ($placeholders) ";
2243 my @bind = $self->_bindtype($field, @$arg);
2244 return ($sql, @bind);
2253 Thanks to some benchmarking by Mark Stosberg, it turns out that
2254 this module is many orders of magnitude faster than using C<DBIx::Abstract>.
2255 I must admit this wasn't an intentional design issue, but it's a
2256 byproduct of the fact that you get to control your C<DBI> handles
2259 To maximize performance, use a code snippet like the following:
2261 # prepare a statement handle using the first row
2262 # and then reuse it for the rest of the rows
2264 for my $href (@array_of_hashrefs) {
2265 $stmt ||= $sql->insert('table', $href);
2266 $sth ||= $dbh->prepare($stmt);
2267 $sth->execute($sql->values($href));
2270 The reason this works is because the keys in your C<$href> are sorted
2271 internally by B<SQL::Abstract>. Thus, as long as your data retains
2272 the same structure, you only have to generate the SQL the first time
2273 around. On subsequent queries, simply use the C<values> function provided
2274 by this module to return your values in the correct order.
2279 If you use my C<CGI::FormBuilder> module at all, you'll hopefully
2280 really like this part (I do, at least). Building up a complex query
2281 can be as simple as the following:
2285 use CGI::FormBuilder;
2288 my $form = CGI::FormBuilder->new(...);
2289 my $sql = SQL::Abstract->new;
2291 if ($form->submitted) {
2292 my $field = $form->field;
2293 my $id = delete $field->{id};
2294 my($stmt, @bind) = $sql->update('table', $field, {id => $id});
2297 Of course, you would still have to connect using C<DBI> to run the
2298 query, but the point is that if you make your form look like your
2299 table, the actual query script can be extremely simplistic.
2301 If you're B<REALLY> lazy (I am), check out C<HTML::QuickTable> for
2302 a fast interface to returning and formatting data. I frequently
2303 use these three modules together to write complex database query
2304 apps in under 50 lines.
2309 Version 1.50 was a major internal refactoring of C<SQL::Abstract>.
2310 Great care has been taken to preserve the I<published> behavior
2311 documented in previous versions in the 1.* family; however,
2312 some features that were previously undocumented, or behaved
2313 differently from the documentation, had to be changed in order
2314 to clarify the semantics. Hence, client code that was relying
2315 on some dark areas of C<SQL::Abstract> v1.*
2316 B<might behave differently> in v1.50.
2318 The main changes are :
2324 support for literal SQL through the C<< \ [$sql, bind] >> syntax.
2328 support for the { operator => \"..." } construct (to embed literal SQL)
2332 support for the { operator => \["...", @bind] } construct (to embed literal SQL with bind values)
2336 optional support for L<array datatypes|/"Inserting and Updating Arrays">
2340 defensive programming : check arguments
2344 fixed bug with global logic, which was previously implemented
2345 through global variables yielding side-effects. Prior versions would
2346 interpret C<< [ {cond1, cond2}, [cond3, cond4] ] >>
2347 as C<< "(cond1 AND cond2) OR (cond3 AND cond4)" >>.
2348 Now this is interpreted
2349 as C<< "(cond1 AND cond2) OR (cond3 OR cond4)" >>.
2354 fixed semantics of _bindtype on array args
2358 dropped the C<_anoncopy> of the %where tree. No longer necessary,
2359 we just avoid shifting arrays within that tree.
2363 dropped the C<_modlogic> function
2369 =head1 ACKNOWLEDGEMENTS
2371 There are a number of individuals that have really helped out with
2372 this module. Unfortunately, most of them submitted bugs via CPAN
2373 so I have no idea who they are! But the people I do know are:
2375 Ash Berlin (order_by hash term support)
2376 Matt Trout (DBIx::Class support)
2377 Mark Stosberg (benchmarking)
2378 Chas Owens (initial "IN" operator support)
2379 Philip Collins (per-field SQL functions)
2380 Eric Kolve (hashref "AND" support)
2381 Mike Fragassi (enhancements to "BETWEEN" and "LIKE")
2382 Dan Kubb (support for "quote_char" and "name_sep")
2383 Guillermo Roditi (patch to cleanup "IN" and "BETWEEN", fix and tests for _order_by)
2384 Laurent Dami (internal refactoring, multiple -nest, extensible list of special operators, literal SQL)
2385 Norbert Buchmuller (support for literal SQL in hashpair, misc. fixes & tests)
2386 Peter Rabbitson (rewrite of SQLA::Test, misc. fixes & tests)
2392 L<DBIx::Class>, L<DBIx::Abstract>, L<CGI::FormBuilder>, L<HTML::QuickTable>.
2396 Copyright (c) 2001-2007 Nathan Wiger <nwiger@cpan.org>. All Rights Reserved.
2398 This module is actively maintained by Matt Trout <mst@shadowcatsystems.co.uk>
2400 For support, your best bet is to try the C<DBIx::Class> users mailing list.
2401 While not an official support venue, C<DBIx::Class> makes heavy use of
2402 C<SQL::Abstract>, and as such list members there are very familiar with
2403 how to create queries.
2407 This module is free software; you may copy this under the terms of
2408 the GNU General Public License, or the Artistic License, copies of
2409 which should have accompanied your Perl kit.