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 $VERSION = '1.56';
20 # This would confuse some packagers
21 #$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)) {
868 $self->_SWITCH_refkind ($c, {
877 $sql = $sql . ' ' . $self->_sqlcase($direction);
879 push @ret, [ $sql, @bind];
888 #======================================================================
889 # DATASOURCE (FOR NOW, JUST PLAIN TABLE OR LIST OF TABLES)
890 #======================================================================
895 $self->_SWITCH_refkind($from, {
896 ARRAYREF => sub {join ', ', map { $self->_quote($_) } @$from;},
897 SCALAR => sub {$self->_quote($from)},
898 SCALARREF => sub {$$from},
899 ARRAYREFREF => sub {join ', ', @$from;},
904 #======================================================================
906 #======================================================================
912 $label or puke "can't quote an empty label";
914 # left and right quote characters
915 my ($ql, $qr, @other) = $self->_SWITCH_refkind($self->{quote_char}, {
916 SCALAR => sub {($self->{quote_char}, $self->{quote_char})},
917 ARRAYREF => sub {@{$self->{quote_char}}},
921 or puke "quote_char must be an arrayref of 2 values";
923 # no quoting if no quoting chars
924 $ql or return $label;
926 # no quoting for literal SQL
927 return $$label if ref($label) eq 'SCALAR';
929 # separate table / column (if applicable)
930 my $sep = $self->{name_sep} || '';
931 my @to_quote = $sep ? split /\Q$sep\E/, $label : ($label);
933 # do the quoting, except for "*" or for `table`.*
934 my @quoted = map { $_ eq '*' ? $_: $ql.$_.$qr} @to_quote;
936 # reassemble and return.
937 return join $sep, @quoted;
941 # Conversion, if applicable
943 my ($self, $arg) = @_;
945 # LDNOTE : modified the previous implementation below because
946 # it was not consistent : the first "return" is always an array,
947 # the second "return" is context-dependent. Anyway, _convert
948 # seems always used with just a single argument, so make it a
950 # return @_ unless $self->{convert};
951 # my $conv = $self->_sqlcase($self->{convert});
952 # my @ret = map { $conv.'('.$_.')' } @_;
953 # return wantarray ? @ret : $ret[0];
954 if ($self->{convert}) {
955 my $conv = $self->_sqlcase($self->{convert});
956 $arg = $conv.'('.$arg.')';
964 my($col, @vals) = @_;
966 #LDNOTE : changed original implementation below because it did not make
967 # sense when bindtype eq 'columns' and @vals > 1.
968 # return $self->{bindtype} eq 'columns' ? [ $col, @vals ] : @vals;
970 return $self->{bindtype} eq 'columns' ? map {[$col, $_]} @vals : @vals;
973 # Dies if any element of @bind is not in [colname => value] format
974 # if bindtype is 'columns'.
975 sub _assert_bindval_matches_bindtype {
976 my ($self, @bind) = @_;
978 if ($self->{bindtype} eq 'columns') {
979 foreach my $val (@bind) {
980 if (!defined $val || ref($val) ne 'ARRAY' || @$val != 2) {
981 die "bindtype 'columns' selected, you need to pass: [column_name => bind_value]"
987 sub _join_sql_clauses {
988 my ($self, $logic, $clauses_aref, $bind_aref) = @_;
990 if (@$clauses_aref > 1) {
991 my $join = " " . $self->_sqlcase($logic) . " ";
992 my $sql = '( ' . join($join, @$clauses_aref) . ' )';
993 return ($sql, @$bind_aref);
995 elsif (@$clauses_aref) {
996 return ($clauses_aref->[0], @$bind_aref); # no parentheses
999 return (); # if no SQL, ignore @$bind_aref
1004 # Fix SQL case, if so requested
1008 # LDNOTE: if $self->{case} is true, then it contains 'lower', so we
1009 # don't touch the argument ... crooked logic, but let's not change it!
1010 return $self->{case} ? $_[0] : uc($_[0]);
1014 #======================================================================
1015 # DISPATCHING FROM REFKIND
1016 #======================================================================
1019 my ($self, $data) = @_;
1025 # blessed objects are treated like scalars
1026 $ref = (blessed $data) ? '' : ref $data;
1027 $n_steps += 1 if $ref;
1028 last if $ref ne 'REF';
1032 my $base = $ref || (defined $data ? 'SCALAR' : 'UNDEF');
1034 return $base . ('REF' x $n_steps);
1040 my ($self, $data) = @_;
1041 my @try = ($self->_refkind($data));
1042 push @try, 'SCALAR_or_UNDEF' if $try[0] eq 'SCALAR' || $try[0] eq 'UNDEF';
1043 push @try, 'FALLBACK';
1047 sub _METHOD_FOR_refkind {
1048 my ($self, $meth_prefix, $data) = @_;
1049 my $method = first {$_} map {$self->can($meth_prefix."_".$_)}
1050 $self->_try_refkind($data)
1051 or puke "cannot dispatch on '$meth_prefix' for ".$self->_refkind($data);
1056 sub _SWITCH_refkind {
1057 my ($self, $data, $dispatch_table) = @_;
1059 my $coderef = first {$_} map {$dispatch_table->{$_}}
1060 $self->_try_refkind($data)
1061 or puke "no dispatch entry for ".$self->_refkind($data);
1068 #======================================================================
1069 # VALUES, GENERATE, AUTOLOAD
1070 #======================================================================
1072 # LDNOTE: original code from nwiger, didn't touch code in that section
1073 # I feel the AUTOLOAD stuff should not be the default, it should
1074 # only be activated on explicit demand by user.
1078 my $data = shift || return;
1079 puke "Argument to ", __PACKAGE__, "->values must be a \\%hash"
1080 unless ref $data eq 'HASH';
1083 foreach my $k ( sort keys %$data ) {
1084 my $v = $data->{$k};
1085 $self->_SWITCH_refkind($v, {
1087 if ($self->{array_datatypes}) { # array datatype
1088 push @all_bind, $self->_bindtype($k, $v);
1090 else { # literal SQL with bind
1091 my ($sql, @bind) = @$v;
1092 $self->_assert_bindval_matches_bindtype(@bind);
1093 push @all_bind, @bind;
1096 ARRAYREFREF => sub { # literal SQL with bind
1097 my ($sql, @bind) = @${$v};
1098 $self->_assert_bindval_matches_bindtype(@bind);
1099 push @all_bind, @bind;
1101 SCALARREF => sub { # literal SQL without bind
1103 SCALAR_or_UNDEF => sub {
1104 push @all_bind, $self->_bindtype($k, $v);
1115 my(@sql, @sqlq, @sqlv);
1119 if ($ref eq 'HASH') {
1120 for my $k (sort keys %$_) {
1123 my $label = $self->_quote($k);
1124 if ($r eq 'ARRAY') {
1125 # literal SQL with bind
1126 my ($sql, @bind) = @$v;
1127 $self->_assert_bindval_matches_bindtype(@bind);
1128 push @sqlq, "$label = $sql";
1130 } elsif ($r eq 'SCALAR') {
1131 # literal SQL without bind
1132 push @sqlq, "$label = $$v";
1134 push @sqlq, "$label = ?";
1135 push @sqlv, $self->_bindtype($k, $v);
1138 push @sql, $self->_sqlcase('set'), join ', ', @sqlq;
1139 } elsif ($ref eq 'ARRAY') {
1140 # unlike insert(), assume these are ONLY the column names, i.e. for SQL
1143 if ($r eq 'ARRAY') { # literal SQL with bind
1144 my ($sql, @bind) = @$v;
1145 $self->_assert_bindval_matches_bindtype(@bind);
1148 } elsif ($r eq 'SCALAR') { # literal SQL without bind
1149 # embedded literal SQL
1156 push @sql, '(' . join(', ', @sqlq) . ')';
1157 } elsif ($ref eq 'SCALAR') {
1161 # strings get case twiddled
1162 push @sql, $self->_sqlcase($_);
1166 my $sql = join ' ', @sql;
1168 # this is pretty tricky
1169 # if ask for an array, return ($stmt, @bind)
1170 # otherwise, s/?/shift @sqlv/ to put it inline
1172 return ($sql, @sqlv);
1174 1 while $sql =~ s/\?/my $d = shift(@sqlv);
1175 ref $d ? $d->[1] : $d/e;
1184 # This allows us to check for a local, then _form, attr
1186 my($name) = $AUTOLOAD =~ /.*::(.+)/;
1187 return $self->generate($name, @_);
1198 SQL::Abstract - Generate SQL from Perl data structures
1204 my $sql = SQL::Abstract->new;
1206 my($stmt, @bind) = $sql->select($table, \@fields, \%where, \@order);
1208 my($stmt, @bind) = $sql->insert($table, \%fieldvals || \@values);
1210 my($stmt, @bind) = $sql->update($table, \%fieldvals, \%where);
1212 my($stmt, @bind) = $sql->delete($table, \%where);
1214 # Then, use these in your DBI statements
1215 my $sth = $dbh->prepare($stmt);
1216 $sth->execute(@bind);
1218 # Just generate the WHERE clause
1219 my($stmt, @bind) = $sql->where(\%where, \@order);
1221 # Return values in the same order, for hashed queries
1222 # See PERFORMANCE section for more details
1223 my @bind = $sql->values(\%fieldvals);
1227 This module was inspired by the excellent L<DBIx::Abstract>.
1228 However, in using that module I found that what I really wanted
1229 to do was generate SQL, but still retain complete control over my
1230 statement handles and use the DBI interface. So, I set out to
1231 create an abstract SQL generation module.
1233 While based on the concepts used by L<DBIx::Abstract>, there are
1234 several important differences, especially when it comes to WHERE
1235 clauses. I have modified the concepts used to make the SQL easier
1236 to generate from Perl data structures and, IMO, more intuitive.
1237 The underlying idea is for this module to do what you mean, based
1238 on the data structures you provide it. The big advantage is that
1239 you don't have to modify your code every time your data changes,
1240 as this module figures it out.
1242 To begin with, an SQL INSERT is as easy as just specifying a hash
1243 of C<key=value> pairs:
1246 name => 'Jimbo Bobson',
1247 phone => '123-456-7890',
1248 address => '42 Sister Lane',
1249 city => 'St. Louis',
1250 state => 'Louisiana',
1253 The SQL can then be generated with this:
1255 my($stmt, @bind) = $sql->insert('people', \%data);
1257 Which would give you something like this:
1259 $stmt = "INSERT INTO people
1260 (address, city, name, phone, state)
1261 VALUES (?, ?, ?, ?, ?)";
1262 @bind = ('42 Sister Lane', 'St. Louis', 'Jimbo Bobson',
1263 '123-456-7890', 'Louisiana');
1265 These are then used directly in your DBI code:
1267 my $sth = $dbh->prepare($stmt);
1268 $sth->execute(@bind);
1270 =head2 Inserting and Updating Arrays
1272 If your database has array types (like for example Postgres),
1273 activate the special option C<< array_datatypes => 1 >>
1274 when creating the C<SQL::Abstract> object.
1275 Then you may use an arrayref to insert and update database array types:
1277 my $sql = SQL::Abstract->new(array_datatypes => 1);
1279 planets => [qw/Mercury Venus Earth Mars/]
1282 my($stmt, @bind) = $sql->insert('solar_system', \%data);
1286 $stmt = "INSERT INTO solar_system (planets) VALUES (?)"
1288 @bind = (['Mercury', 'Venus', 'Earth', 'Mars']);
1291 =head2 Inserting and Updating SQL
1293 In order to apply SQL functions to elements of your C<%data> you may
1294 specify a reference to an arrayref for the given hash value. For example,
1295 if you need to execute the Oracle C<to_date> function on a value, you can
1296 say something like this:
1300 date_entered => \["to_date(?,'MM/DD/YYYY')", "03/02/2003"],
1303 The first value in the array is the actual SQL. Any other values are
1304 optional and would be included in the bind values array. This gives
1307 my($stmt, @bind) = $sql->insert('people', \%data);
1309 $stmt = "INSERT INTO people (name, date_entered)
1310 VALUES (?, to_date(?,'MM/DD/YYYY'))";
1311 @bind = ('Bill', '03/02/2003');
1313 An UPDATE is just as easy, all you change is the name of the function:
1315 my($stmt, @bind) = $sql->update('people', \%data);
1317 Notice that your C<%data> isn't touched; the module will generate
1318 the appropriately quirky SQL for you automatically. Usually you'll
1319 want to specify a WHERE clause for your UPDATE, though, which is
1320 where handling C<%where> hashes comes in handy...
1322 =head2 Complex where statements
1324 This module can generate pretty complicated WHERE statements
1325 easily. For example, simple C<key=value> pairs are taken to mean
1326 equality, and if you want to see if a field is within a set
1327 of values, you can use an arrayref. Let's say we wanted to
1328 SELECT some data based on this criteria:
1331 requestor => 'inna',
1332 worker => ['nwiger', 'rcwe', 'sfz'],
1333 status => { '!=', 'completed' }
1336 my($stmt, @bind) = $sql->select('tickets', '*', \%where);
1338 The above would give you something like this:
1340 $stmt = "SELECT * FROM tickets WHERE
1341 ( requestor = ? ) AND ( status != ? )
1342 AND ( worker = ? OR worker = ? OR worker = ? )";
1343 @bind = ('inna', 'completed', 'nwiger', 'rcwe', 'sfz');
1345 Which you could then use in DBI code like so:
1347 my $sth = $dbh->prepare($stmt);
1348 $sth->execute(@bind);
1354 The functions are simple. There's one for each major SQL operation,
1355 and a constructor you use first. The arguments are specified in a
1356 similar order to each function (table, then fields, then a where
1357 clause) to try and simplify things.
1362 =head2 new(option => 'value')
1364 The C<new()> function takes a list of options and values, and returns
1365 a new B<SQL::Abstract> object which can then be used to generate SQL
1366 through the methods below. The options accepted are:
1372 If set to 'lower', then SQL will be generated in all lowercase. By
1373 default SQL is generated in "textbook" case meaning something like:
1375 SELECT a_field FROM a_table WHERE some_field LIKE '%someval%'
1377 Any setting other than 'lower' is ignored.
1381 This determines what the default comparison operator is. By default
1382 it is C<=>, meaning that a hash like this:
1384 %where = (name => 'nwiger', email => 'nate@wiger.org');
1386 Will generate SQL like this:
1388 WHERE name = 'nwiger' AND email = 'nate@wiger.org'
1390 However, you may want loose comparisons by default, so if you set
1391 C<cmp> to C<like> you would get SQL such as:
1393 WHERE name like 'nwiger' AND email like 'nate@wiger.org'
1395 You can also override the comparsion on an individual basis - see
1396 the huge section on L</"WHERE CLAUSES"> at the bottom.
1398 =item sqltrue, sqlfalse
1400 Expressions for inserting boolean values within SQL statements.
1401 By default these are C<1=1> and C<1=0>. They are used
1402 by the special operators C<-in> and C<-not_in> for generating
1403 correct SQL even when the argument is an empty array (see below).
1407 This determines the default logical operator for multiple WHERE
1408 statements in arrays or hashes. If absent, the default logic is "or"
1409 for arrays, and "and" for hashes. This means that a WHERE
1413 event_date => {'>=', '2/13/99'},
1414 event_date => {'<=', '4/24/03'},
1417 will generate SQL like this:
1419 WHERE event_date >= '2/13/99' OR event_date <= '4/24/03'
1421 This is probably not what you want given this query, though (look
1422 at the dates). To change the "OR" to an "AND", simply specify:
1424 my $sql = SQL::Abstract->new(logic => 'and');
1426 Which will change the above C<WHERE> to:
1428 WHERE event_date >= '2/13/99' AND event_date <= '4/24/03'
1430 The logic can also be changed locally by inserting
1431 a modifier in front of an arrayref :
1433 @where = (-and => [event_date => {'>=', '2/13/99'},
1434 event_date => {'<=', '4/24/03'} ]);
1436 See the L</"WHERE CLAUSES"> section for explanations.
1440 This will automatically convert comparisons using the specified SQL
1441 function for both column and value. This is mostly used with an argument
1442 of C<upper> or C<lower>, so that the SQL will have the effect of
1443 case-insensitive "searches". For example, this:
1445 $sql = SQL::Abstract->new(convert => 'upper');
1446 %where = (keywords => 'MaKe iT CAse inSeNSItive');
1448 Will turn out the following SQL:
1450 WHERE upper(keywords) like upper('MaKe iT CAse inSeNSItive')
1452 The conversion can be C<upper()>, C<lower()>, or any other SQL function
1453 that can be applied symmetrically to fields (actually B<SQL::Abstract> does
1454 not validate this option; it will just pass through what you specify verbatim).
1458 This is a kludge because many databases suck. For example, you can't
1459 just bind values using DBI's C<execute()> for Oracle C<CLOB> or C<BLOB> fields.
1460 Instead, you have to use C<bind_param()>:
1462 $sth->bind_param(1, 'reg data');
1463 $sth->bind_param(2, $lots, {ora_type => ORA_CLOB});
1465 The problem is, B<SQL::Abstract> will normally just return a C<@bind> array,
1466 which loses track of which field each slot refers to. Fear not.
1468 If you specify C<bindtype> in new, you can determine how C<@bind> is returned.
1469 Currently, you can specify either C<normal> (default) or C<columns>. If you
1470 specify C<columns>, you will get an array that looks like this:
1472 my $sql = SQL::Abstract->new(bindtype => 'columns');
1473 my($stmt, @bind) = $sql->insert(...);
1476 [ 'column1', 'value1' ],
1477 [ 'column2', 'value2' ],
1478 [ 'column3', 'value3' ],
1481 You can then iterate through this manually, using DBI's C<bind_param()>.
1483 $sth->prepare($stmt);
1486 my($col, $data) = @$_;
1487 if ($col eq 'details' || $col eq 'comments') {
1488 $sth->bind_param($i, $data, {ora_type => ORA_CLOB});
1489 } elsif ($col eq 'image') {
1490 $sth->bind_param($i, $data, {ora_type => ORA_BLOB});
1492 $sth->bind_param($i, $data);
1496 $sth->execute; # execute without @bind now
1498 Now, why would you still use B<SQL::Abstract> if you have to do this crap?
1499 Basically, the advantage is still that you don't have to care which fields
1500 are or are not included. You could wrap that above C<for> loop in a simple
1501 sub called C<bind_fields()> or something and reuse it repeatedly. You still
1502 get a layer of abstraction over manual SQL specification.
1504 Note that if you set L</bindtype> to C<columns>, the C<\[$sql, @bind]>
1505 construct (see L</Literal SQL with placeholders and bind values (subqueries)>)
1506 will expect the bind values in this format.
1510 This is the character that a table or column name will be quoted
1511 with. By default this is an empty string, but you could set it to
1512 the character C<`>, to generate SQL like this:
1514 SELECT `a_field` FROM `a_table` WHERE `some_field` LIKE '%someval%'
1516 Alternatively, you can supply an array ref of two items, the first being the left
1517 hand quote character, and the second the right hand quote character. For
1518 example, you could supply C<['[',']']> for SQL Server 2000 compliant quotes
1519 that generates SQL like this:
1521 SELECT [a_field] FROM [a_table] WHERE [some_field] LIKE '%someval%'
1523 Quoting is useful if you have tables or columns names that are reserved
1524 words in your database's SQL dialect.
1528 This is the character that separates a table and column name. It is
1529 necessary to specify this when the C<quote_char> option is selected,
1530 so that tables and column names can be individually quoted like this:
1532 SELECT `table`.`one_field` FROM `table` WHERE `table`.`other_field` = 1
1534 =item array_datatypes
1536 When this option is true, arrayrefs in INSERT or UPDATE are
1537 interpreted as array datatypes and are passed directly
1539 When this option is false, arrayrefs are interpreted
1540 as literal SQL, just like refs to arrayrefs
1541 (but this behavior is for backwards compatibility; when writing
1542 new queries, use the "reference to arrayref" syntax
1548 Takes a reference to a list of "special operators"
1549 to extend the syntax understood by L<SQL::Abstract>.
1550 See section L</"SPECIAL OPERATORS"> for details.
1556 =head2 insert($table, \@values || \%fieldvals)
1558 This is the simplest function. You simply give it a table name
1559 and either an arrayref of values or hashref of field/value pairs.
1560 It returns an SQL INSERT statement and a list of bind values.
1561 See the sections on L</"Inserting and Updating Arrays"> and
1562 L</"Inserting and Updating SQL"> for information on how to insert
1563 with those data types.
1565 =head2 update($table, \%fieldvals, \%where)
1567 This takes a table, hashref of field/value pairs, and an optional
1568 hashref L<WHERE clause|/WHERE CLAUSES>. It returns an SQL UPDATE function and a list
1570 See the sections on L</"Inserting and Updating Arrays"> and
1571 L</"Inserting and Updating SQL"> for information on how to insert
1572 with those data types.
1574 =head2 select($source, $fields, $where, $order)
1576 This returns a SQL SELECT statement and associated list of bind values, as
1577 specified by the arguments :
1583 Specification of the 'FROM' part of the statement.
1584 The argument can be either a plain scalar (interpreted as a table
1585 name, will be quoted), or an arrayref (interpreted as a list
1586 of table names, joined by commas, quoted), or a scalarref
1587 (literal table name, not quoted), or a ref to an arrayref
1588 (list of literal table names, joined by commas, not quoted).
1592 Specification of the list of fields to retrieve from
1594 The argument can be either an arrayref (interpreted as a list
1595 of field names, will be joined by commas and quoted), or a
1596 plain scalar (literal SQL, not quoted).
1597 Please observe that this API is not as flexible as for
1598 the first argument C<$table>, for backwards compatibility reasons.
1602 Optional argument to specify the WHERE part of the query.
1603 The argument is most often a hashref, but can also be
1604 an arrayref or plain scalar --
1605 see section L<WHERE clause|/"WHERE CLAUSES"> for details.
1609 Optional argument to specify the ORDER BY part of the query.
1610 The argument can be a scalar, a hashref or an arrayref
1611 -- see section L<ORDER BY clause|/"ORDER BY CLAUSES">
1617 =head2 delete($table, \%where)
1619 This takes a table name and optional hashref L<WHERE clause|/WHERE CLAUSES>.
1620 It returns an SQL DELETE statement and list of bind values.
1622 =head2 where(\%where, \@order)
1624 This is used to generate just the WHERE clause. For example,
1625 if you have an arbitrary data structure and know what the
1626 rest of your SQL is going to look like, but want an easy way
1627 to produce a WHERE clause, use this. It returns an SQL WHERE
1628 clause and list of bind values.
1631 =head2 values(\%data)
1633 This just returns the values from the hash C<%data>, in the same
1634 order that would be returned from any of the other above queries.
1635 Using this allows you to markedly speed up your queries if you
1636 are affecting lots of rows. See below under the L</"PERFORMANCE"> section.
1638 =head2 generate($any, 'number', $of, \@data, $struct, \%types)
1640 Warning: This is an experimental method and subject to change.
1642 This returns arbitrarily generated SQL. It's a really basic shortcut.
1643 It will return two different things, depending on return context:
1645 my($stmt, @bind) = $sql->generate('create table', \$table, \@fields);
1646 my $stmt_and_val = $sql->generate('create table', \$table, \@fields);
1648 These would return the following:
1650 # First calling form
1651 $stmt = "CREATE TABLE test (?, ?)";
1652 @bind = (field1, field2);
1654 # Second calling form
1655 $stmt_and_val = "CREATE TABLE test (field1, field2)";
1657 Depending on what you're trying to do, it's up to you to choose the correct
1658 format. In this example, the second form is what you would want.
1662 $sql->generate('alter session', { nls_date_format => 'MM/YY' });
1666 ALTER SESSION SET nls_date_format = 'MM/YY'
1668 You get the idea. Strings get their case twiddled, but everything
1669 else remains verbatim.
1674 =head1 WHERE CLAUSES
1678 This module uses a variation on the idea from L<DBIx::Abstract>. It
1679 is B<NOT>, repeat I<not> 100% compatible. B<The main logic of this
1680 module is that things in arrays are OR'ed, and things in hashes
1683 The easiest way to explain is to show lots of examples. After
1684 each C<%where> hash shown, it is assumed you used:
1686 my($stmt, @bind) = $sql->where(\%where);
1688 However, note that the C<%where> hash can be used directly in any
1689 of the other functions as well, as described above.
1691 =head2 Key-value pairs
1693 So, let's get started. To begin, a simple hash:
1697 status => 'completed'
1700 Is converted to SQL C<key = val> statements:
1702 $stmt = "WHERE user = ? AND status = ?";
1703 @bind = ('nwiger', 'completed');
1705 One common thing I end up doing is having a list of values that
1706 a field can be in. To do this, simply specify a list inside of
1711 status => ['assigned', 'in-progress', 'pending'];
1714 This simple code will create the following:
1716 $stmt = "WHERE user = ? AND ( status = ? OR status = ? OR status = ? )";
1717 @bind = ('nwiger', 'assigned', 'in-progress', 'pending');
1719 A field associated to an empty arrayref will be considered a
1720 logical false and will generate 0=1.
1722 =head2 Specific comparison operators
1724 If you want to specify a different type of operator for your comparison,
1725 you can use a hashref for a given column:
1729 status => { '!=', 'completed' }
1732 Which would generate:
1734 $stmt = "WHERE user = ? AND status != ?";
1735 @bind = ('nwiger', 'completed');
1737 To test against multiple values, just enclose the values in an arrayref:
1739 status => { '=', ['assigned', 'in-progress', 'pending'] };
1741 Which would give you:
1743 "WHERE status = ? OR status = ? OR status = ?"
1746 The hashref can also contain multiple pairs, in which case it is expanded
1747 into an C<AND> of its elements:
1751 status => { '!=', 'completed', -not_like => 'pending%' }
1754 # Or more dynamically, like from a form
1755 $where{user} = 'nwiger';
1756 $where{status}{'!='} = 'completed';
1757 $where{status}{'-not_like'} = 'pending%';
1759 # Both generate this
1760 $stmt = "WHERE user = ? AND status != ? AND status NOT LIKE ?";
1761 @bind = ('nwiger', 'completed', 'pending%');
1764 To get an OR instead, you can combine it with the arrayref idea:
1768 priority => [ {'=', 2}, {'!=', 1} ]
1771 Which would generate:
1773 $stmt = "WHERE user = ? AND priority = ? OR priority != ?";
1774 @bind = ('nwiger', '2', '1');
1776 If you want to include literal SQL (with or without bind values), just use a
1777 scalar reference or array reference as the value:
1780 date_entered => { '>' => \["to_date(?, 'MM/DD/YYYY')", "11/26/2008"] },
1781 date_expires => { '<' => \"now()" }
1784 Which would generate:
1786 $stmt = "WHERE date_entered > "to_date(?, 'MM/DD/YYYY') AND date_expires < now()";
1787 @bind = ('11/26/2008');
1790 =head2 Logic and nesting operators
1792 In the example above,
1793 there is a subtle trap if you want to say something like
1794 this (notice the C<AND>):
1796 WHERE priority != ? AND priority != ?
1798 Because, in Perl you I<can't> do this:
1800 priority => { '!=', 2, '!=', 1 }
1802 As the second C<!=> key will obliterate the first. The solution
1803 is to use the special C<-modifier> form inside an arrayref:
1805 priority => [ -and => {'!=', 2},
1809 Normally, these would be joined by C<OR>, but the modifier tells it
1810 to use C<AND> instead. (Hint: You can use this in conjunction with the
1811 C<logic> option to C<new()> in order to change the way your queries
1812 work by default.) B<Important:> Note that the C<-modifier> goes
1813 B<INSIDE> the arrayref, as an extra first element. This will
1814 B<NOT> do what you think it might:
1816 priority => -and => [{'!=', 2}, {'!=', 1}] # WRONG!
1818 Here is a quick list of equivalencies, since there is some overlap:
1821 status => {'!=', 'completed', 'not like', 'pending%' }
1822 status => [ -and => {'!=', 'completed'}, {'not like', 'pending%'}]
1825 status => {'=', ['assigned', 'in-progress']}
1826 status => [ -or => {'=', 'assigned'}, {'=', 'in-progress'}]
1827 status => [ {'=', 'assigned'}, {'=', 'in-progress'} ]
1831 =head2 Special operators : IN, BETWEEN, etc.
1833 You can also use the hashref format to compare a list of fields using the
1834 C<IN> comparison operator, by specifying the list as an arrayref:
1837 status => 'completed',
1838 reportid => { -in => [567, 2335, 2] }
1841 Which would generate:
1843 $stmt = "WHERE status = ? AND reportid IN (?,?,?)";
1844 @bind = ('completed', '567', '2335', '2');
1846 The reverse operator C<-not_in> generates SQL C<NOT IN> and is used in
1849 If the argument to C<-in> is an empty array, 'sqlfalse' is generated
1850 (by default : C<1=0>). Similarly, C<< -not_in => [] >> generates
1851 'sqltrue' (by default : C<1=1>).
1855 Another pair of operators is C<-between> and C<-not_between>,
1856 used with an arrayref of two values:
1860 completion_date => {
1861 -not_between => ['2002-10-01', '2003-02-06']
1867 WHERE user = ? AND completion_date NOT BETWEEN ( ? AND ? )
1869 These are the two builtin "special operators"; but the
1870 list can be expanded : see section L</"SPECIAL OPERATORS"> below.
1872 =head2 Nested conditions, -and/-or prefixes
1874 So far, we've seen how multiple conditions are joined with a top-level
1875 C<AND>. We can change this by putting the different conditions we want in
1876 hashes and then putting those hashes in an array. For example:
1881 status => { -like => ['pending%', 'dispatched'] },
1885 status => 'unassigned',
1889 This data structure would create the following:
1891 $stmt = "WHERE ( user = ? AND ( status LIKE ? OR status LIKE ? ) )
1892 OR ( user = ? AND status = ? ) )";
1893 @bind = ('nwiger', 'pending', 'dispatched', 'robot', 'unassigned');
1896 There is also a special C<-nest>
1897 operator which adds an additional set of parens, to create a subquery.
1898 For example, to get something like this:
1900 $stmt = "WHERE user = ? AND ( workhrs > ? OR geo = ? )";
1901 @bind = ('nwiger', '20', 'ASIA');
1907 -nest => [ workhrs => {'>', 20}, geo => 'ASIA' ],
1911 Finally, clauses in hashrefs or arrayrefs can be
1912 prefixed with an C<-and> or C<-or> to change the logic
1919 -and => [workhrs => {'>', 20}, geo => 'ASIA' ],
1920 -and => [workhrs => {'<', 50}, geo => 'EURO' ]
1927 WHERE ( user = ? AND
1928 ( ( workhrs > ? AND geo = ? )
1929 OR ( workhrs < ? AND geo = ? ) ) )
1932 =head2 Algebraic inconsistency, for historical reasons
1934 C<Important note>: when connecting several conditions, the C<-and->|C<-or>
1935 operator goes C<outside> of the nested structure; whereas when connecting
1936 several constraints on one column, the C<-and> operator goes
1937 C<inside> the arrayref. Here is an example combining both features :
1940 -and => [a => 1, b => 2],
1941 -or => [c => 3, d => 4],
1942 e => [-and => {-like => 'foo%'}, {-like => '%bar'} ]
1947 WHERE ( ( ( a = ? AND b = ? )
1948 OR ( c = ? OR d = ? )
1949 OR ( e LIKE ? AND e LIKE ? ) ) )
1951 This difference in syntax is unfortunate but must be preserved for
1952 historical reasons. So be careful : the two examples below would
1953 seem algebraically equivalent, but they are not
1955 {col => [-and => {-like => 'foo%'}, {-like => '%bar'}]}
1956 # yields : WHERE ( ( col LIKE ? AND col LIKE ? ) )
1958 [-and => {col => {-like => 'foo%'}, {col => {-like => '%bar'}}]]
1959 # yields : WHERE ( ( col LIKE ? OR col LIKE ? ) )
1964 Finally, sometimes only literal SQL will do. If you want to include
1965 literal SQL verbatim, you can specify it as a scalar reference, namely:
1967 my $inn = 'is Not Null';
1969 priority => { '<', 2 },
1975 $stmt = "WHERE priority < ? AND requestor is Not Null";
1978 Note that in this example, you only get one bind parameter back, since
1979 the verbatim SQL is passed as part of the statement.
1981 Of course, just to prove a point, the above can also be accomplished
1985 priority => { '<', 2 },
1986 requestor => { '!=', undef },
1992 Conditions on boolean columns can be expressed in the
1993 same way, passing a reference to an empty string :
1996 priority => { '<', 2 },
2002 $stmt = "WHERE priority < ? AND is_ready";
2006 =head2 Literal SQL with placeholders and bind values (subqueries)
2008 If the literal SQL to be inserted has placeholders and bind values,
2009 use a reference to an arrayref (yes this is a double reference --
2010 not so common, but perfectly legal Perl). For example, to find a date
2011 in Postgres you can use something like this:
2014 date_column => \[q/= date '2008-09-30' - ?::integer/, 10/]
2019 $stmt = "WHERE ( date_column = date '2008-09-30' - ?::integer )"
2022 Note that you must pass the bind values in the same format as they are returned
2023 by L</where>. That means that if you set L</bindtype> to C<columns>, you must
2024 provide the bind values in the C<< [ column_meta => value ] >> format, where
2025 C<column_meta> is an opaque scalar value; most commonly the column name, but
2026 you can use any scalar value (including references and blessed references),
2027 L<SQL::Abstract> will simply pass it through intact. So if C<bindtype> is set
2028 to C<columns> the above example will look like:
2031 date_column => \[q/= date '2008-09-30' - ?::integer/, [ dummy => 10 ]/]
2034 Literal SQL is especially useful for nesting parenthesized clauses in the
2035 main SQL query. Here is a first example :
2037 my ($sub_stmt, @sub_bind) = ("SELECT c1 FROM t1 WHERE c2 < ? AND c3 LIKE ?",
2041 bar => \["IN ($sub_stmt)" => @sub_bind],
2046 $stmt = "WHERE (foo = ? AND bar IN (SELECT c1 FROM t1
2047 WHERE c2 < ? AND c3 LIKE ?))";
2048 @bind = (1234, 100, "foo%");
2050 Other subquery operators, like for example C<"E<gt> ALL"> or C<"NOT IN">,
2051 are expressed in the same way. Of course the C<$sub_stmt> and
2052 its associated bind values can be generated through a former call
2055 my ($sub_stmt, @sub_bind)
2056 = $sql->select("t1", "c1", {c2 => {"<" => 100},
2057 c3 => {-like => "foo%"}});
2060 bar => \["> ALL ($sub_stmt)" => @sub_bind],
2063 In the examples above, the subquery was used as an operator on a column;
2064 but the same principle also applies for a clause within the main C<%where>
2065 hash, like an EXISTS subquery :
2067 my ($sub_stmt, @sub_bind)
2068 = $sql->select("t1", "*", {c1 => 1, c2 => \"> t0.c0"});
2071 -nest => \["EXISTS ($sub_stmt)" => @sub_bind],
2076 $stmt = "WHERE (foo = ? AND EXISTS (SELECT * FROM t1
2077 WHERE c1 = ? AND c2 > t0.c0))";
2081 Observe that the condition on C<c2> in the subquery refers to
2082 column C<t0.c0> of the main query : this is I<not> a bind
2083 value, so we have to express it through a scalar ref.
2084 Writing C<< c2 => {">" => "t0.c0"} >> would have generated
2085 C<< c2 > ? >> with bind value C<"t0.c0"> ... not exactly
2086 what we wanted here.
2088 Another use of the subquery technique is when some SQL clauses need
2089 parentheses, as it often occurs with some proprietary SQL extensions
2090 like for example fulltext expressions, geospatial expressions,
2091 NATIVE clauses, etc. Here is an example of a fulltext query in MySQL :
2094 -nest => \["MATCH (col1, col2) AGAINST (?)" => qw/apples/]
2097 Finally, here is an example where a subquery is used
2098 for expressing unary negation:
2100 my ($sub_stmt, @sub_bind)
2101 = $sql->where({age => [{"<" => 10}, {">" => 20}]});
2102 $sub_stmt =~ s/^ where //i; # don't want "WHERE" in the subclause
2104 lname => {like => '%son%'},
2105 -nest => \["NOT ($sub_stmt)" => @sub_bind],
2110 $stmt = "lname LIKE ? AND NOT ( age < ? OR age > ? )"
2111 @bind = ('%son%', 10, 20)
2117 These pages could go on for a while, since the nesting of the data
2118 structures this module can handle are pretty much unlimited (the
2119 module implements the C<WHERE> expansion as a recursive function
2120 internally). Your best bet is to "play around" with the module a
2121 little to see how the data structures behave, and choose the best
2122 format for your data based on that.
2124 And of course, all the values above will probably be replaced with
2125 variables gotten from forms or the command line. After all, if you
2126 knew everything ahead of time, you wouldn't have to worry about
2127 dynamically-generating SQL and could just hardwire it into your
2133 =head1 ORDER BY CLAUSES
2135 Some functions take an order by clause. This can either be a scalar (just a
2136 column name,) a hash of C<< { -desc => 'col' } >> or C<< { -asc => 'col' } >>,
2137 or an array of either of the two previous forms. Examples:
2139 Given | Will Generate
2140 ----------------------------------------------------------
2142 \'colA DESC' | ORDER BY colA DESC
2144 'colA' | ORDER BY colA
2146 [qw/colA colB/] | ORDER BY colA, colB
2148 {-asc => 'colA'} | ORDER BY colA ASC
2150 {-desc => 'colB'} | ORDER BY colB DESC
2152 ['colA', {-asc => 'colB'}] | ORDER BY colA, colB ASC
2154 { -asc => [qw/colA colB] } | ORDER BY colA ASC, colB ASC
2157 { -asc => 'colA' }, | ORDER BY colA ASC, colB DESC,
2158 { -desc => [qw/colB/], | colC ASC, colD ASC
2159 { -asc => [qw/colC colD/],|
2161 ===========================================================
2165 =head1 SPECIAL OPERATORS
2167 my $sqlmaker = SQL::Abstract->new(special_ops => [
2171 my ($self, $field, $op, $arg) = @_;
2177 handler => 'method_name',
2181 A "special operator" is a SQL syntactic clause that can be
2182 applied to a field, instead of a usual binary operator.
2185 WHERE field IN (?, ?, ?)
2186 WHERE field BETWEEN ? AND ?
2187 WHERE MATCH(field) AGAINST (?, ?)
2189 Special operators IN and BETWEEN are fairly standard and therefore
2190 are builtin within C<SQL::Abstract> (as the overridable methods
2191 C<_where_field_IN> and C<_where_field_BETWEEN>). For other operators,
2192 like the MATCH .. AGAINST example above which is specific to MySQL,
2193 you can write your own operator handlers - supply a C<special_ops>
2194 argument to the C<new> method. That argument takes an arrayref of
2195 operator definitions; each operator definition is a hashref with two
2202 the regular expression to match the operator
2206 Either a coderef or a plain scalar method name. In both cases
2207 the expected return is C<< ($sql, @bind) >>.
2209 When supplied with a method name, it is simply called on the
2210 L<SQL::Abstract/> object as:
2212 $self->$method_name ($field, $op, $arg)
2216 $op is the part that matched the handler regex
2217 $field is the LHS of the operator
2220 When supplied with a coderef, it is called as:
2222 $coderef->($self, $field, $op, $arg)
2227 For example, here is an implementation
2228 of the MATCH .. AGAINST syntax for MySQL
2230 my $sqlmaker = SQL::Abstract->new(special_ops => [
2232 # special op for MySql MATCH (field) AGAINST(word1, word2, ...)
2233 {regex => qr/^match$/i,
2235 my ($self, $field, $op, $arg) = @_;
2236 $arg = [$arg] if not ref $arg;
2237 my $label = $self->_quote($field);
2238 my ($placeholder) = $self->_convert('?');
2239 my $placeholders = join ", ", (($placeholder) x @$arg);
2240 my $sql = $self->_sqlcase('match') . " ($label) "
2241 . $self->_sqlcase('against') . " ($placeholders) ";
2242 my @bind = $self->_bindtype($field, @$arg);
2243 return ($sql, @bind);
2252 Thanks to some benchmarking by Mark Stosberg, it turns out that
2253 this module is many orders of magnitude faster than using C<DBIx::Abstract>.
2254 I must admit this wasn't an intentional design issue, but it's a
2255 byproduct of the fact that you get to control your C<DBI> handles
2258 To maximize performance, use a code snippet like the following:
2260 # prepare a statement handle using the first row
2261 # and then reuse it for the rest of the rows
2263 for my $href (@array_of_hashrefs) {
2264 $stmt ||= $sql->insert('table', $href);
2265 $sth ||= $dbh->prepare($stmt);
2266 $sth->execute($sql->values($href));
2269 The reason this works is because the keys in your C<$href> are sorted
2270 internally by B<SQL::Abstract>. Thus, as long as your data retains
2271 the same structure, you only have to generate the SQL the first time
2272 around. On subsequent queries, simply use the C<values> function provided
2273 by this module to return your values in the correct order.
2278 If you use my C<CGI::FormBuilder> module at all, you'll hopefully
2279 really like this part (I do, at least). Building up a complex query
2280 can be as simple as the following:
2284 use CGI::FormBuilder;
2287 my $form = CGI::FormBuilder->new(...);
2288 my $sql = SQL::Abstract->new;
2290 if ($form->submitted) {
2291 my $field = $form->field;
2292 my $id = delete $field->{id};
2293 my($stmt, @bind) = $sql->update('table', $field, {id => $id});
2296 Of course, you would still have to connect using C<DBI> to run the
2297 query, but the point is that if you make your form look like your
2298 table, the actual query script can be extremely simplistic.
2300 If you're B<REALLY> lazy (I am), check out C<HTML::QuickTable> for
2301 a fast interface to returning and formatting data. I frequently
2302 use these three modules together to write complex database query
2303 apps in under 50 lines.
2308 Version 1.50 was a major internal refactoring of C<SQL::Abstract>.
2309 Great care has been taken to preserve the I<published> behavior
2310 documented in previous versions in the 1.* family; however,
2311 some features that were previously undocumented, or behaved
2312 differently from the documentation, had to be changed in order
2313 to clarify the semantics. Hence, client code that was relying
2314 on some dark areas of C<SQL::Abstract> v1.*
2315 B<might behave differently> in v1.50.
2317 The main changes are :
2323 support for literal SQL through the C<< \ [$sql, bind] >> syntax.
2327 support for the { operator => \"..." } construct (to embed literal SQL)
2331 support for the { operator => \["...", @bind] } construct (to embed literal SQL with bind values)
2335 optional support for L<array datatypes|/"Inserting and Updating Arrays">
2339 defensive programming : check arguments
2343 fixed bug with global logic, which was previously implemented
2344 through global variables yielding side-effects. Prior versions would
2345 interpret C<< [ {cond1, cond2}, [cond3, cond4] ] >>
2346 as C<< "(cond1 AND cond2) OR (cond3 AND cond4)" >>.
2347 Now this is interpreted
2348 as C<< "(cond1 AND cond2) OR (cond3 OR cond4)" >>.
2353 fixed semantics of _bindtype on array args
2357 dropped the C<_anoncopy> of the %where tree. No longer necessary,
2358 we just avoid shifting arrays within that tree.
2362 dropped the C<_modlogic> function
2368 =head1 ACKNOWLEDGEMENTS
2370 There are a number of individuals that have really helped out with
2371 this module. Unfortunately, most of them submitted bugs via CPAN
2372 so I have no idea who they are! But the people I do know are:
2374 Ash Berlin (order_by hash term support)
2375 Matt Trout (DBIx::Class support)
2376 Mark Stosberg (benchmarking)
2377 Chas Owens (initial "IN" operator support)
2378 Philip Collins (per-field SQL functions)
2379 Eric Kolve (hashref "AND" support)
2380 Mike Fragassi (enhancements to "BETWEEN" and "LIKE")
2381 Dan Kubb (support for "quote_char" and "name_sep")
2382 Guillermo Roditi (patch to cleanup "IN" and "BETWEEN", fix and tests for _order_by)
2383 Laurent Dami (internal refactoring, multiple -nest, extensible list of special operators, literal SQL)
2384 Norbert Buchmuller (support for literal SQL in hashpair, misc. fixes & tests)
2385 Peter Rabbitson (rewrite of SQLA::Test, misc. fixes & tests)
2391 L<DBIx::Class>, L<DBIx::Abstract>, L<CGI::FormBuilder>, L<HTML::QuickTable>.
2395 Copyright (c) 2001-2007 Nathan Wiger <nwiger@cpan.org>. All Rights Reserved.
2397 This module is actively maintained by Matt Trout <mst@shadowcatsystems.co.uk>
2399 For support, your best bet is to try the C<DBIx::Class> users mailing list.
2400 While not an official support venue, C<DBIx::Class> makes heavy use of
2401 C<SQL::Abstract>, and as such list members there are very familiar with
2402 how to create queries.
2406 This module is free software; you may copy this under the terms of
2407 the GNU General Public License, or the Artistic License, copies of
2408 which should have accompanied your Perl kit.