1 package SQL::Abstract; # see doc at end of file
10 our @EXPORT_OK = qw(is_plain_value is_literal_value);
20 *SQL::Abstract::_ENV_::DETECT_AUTOGENERATED_STRINGIFICATION = $ENV{SQLA_ISVALUE_IGNORE_AUTOGENERATED_STRINGIFICATION}
26 #======================================================================
28 #======================================================================
30 our $VERSION = '1.87';
32 # This would confuse some packagers
33 $VERSION = eval $VERSION if $VERSION =~ /_/; # numify for warning-free dev releases
37 # special operators (-in, -between). May be extended/overridden by user.
38 # See section WHERE: BUILTIN SPECIAL OPERATORS below for implementation
39 my @BUILTIN_SPECIAL_OPS = (
40 {regex => qr/^ (?: not \s )? between $/ix, handler => sub { die "NOPE" }},
41 {regex => qr/^ (?: not \s )? in $/ix, handler => sub { die "NOPE" }},
42 {regex => qr/^ is (?: \s+ not )? $/ix, handler => sub { die "NOPE" }},
45 #======================================================================
46 # DEBUGGING AND ERROR REPORTING
47 #======================================================================
50 return unless $_[0]->{debug}; shift; # a little faster
51 my $func = (caller(1))[3];
52 warn "[$func] ", @_, "\n";
56 my($func) = (caller(1))[3];
57 Carp::carp "[$func] Warning: ", @_;
61 my($func) = (caller(1))[3];
62 Carp::croak "[$func] Fatal: ", @_;
65 sub is_literal_value ($) {
66 ref $_[0] eq 'SCALAR' ? [ ${$_[0]} ]
67 : ( ref $_[0] eq 'REF' and ref ${$_[0]} eq 'ARRAY' ) ? [ @${ $_[0] } ]
71 # FIXME XSify - this can be done so much more efficiently
72 sub is_plain_value ($) {
74 ! length ref $_[0] ? \($_[0])
76 ref $_[0] eq 'HASH' and keys %{$_[0]} == 1
78 exists $_[0]->{-value}
79 ) ? \($_[0]->{-value})
81 # reuse @_ for even moar speedz
82 defined ( $_[1] = Scalar::Util::blessed $_[0] )
84 # deliberately not using Devel::OverloadInfo - the checks we are
85 # intersted in are much more limited than the fullblown thing, and
86 # this is a very hot piece of code
88 # simply using ->can('(""') can leave behind stub methods that
89 # break actually using the overload later (see L<perldiag/Stub
90 # found while resolving method "%s" overloading "%s" in package
91 # "%s"> and the source of overload::mycan())
93 # either has stringification which DBI SHOULD prefer out of the box
94 grep { *{ (qq[${_}::(""]) }{CODE} } @{ $_[2] = mro::get_linear_isa( $_[1] ) }
96 # has nummification or boolification, AND fallback is *not* disabled
98 SQL::Abstract::_ENV_::DETECT_AUTOGENERATED_STRINGIFICATION
101 grep { *{"${_}::(0+"}{CODE} } @{$_[2]}
103 grep { *{"${_}::(bool"}{CODE} } @{$_[2]}
107 # no fallback specified at all
108 ! ( ($_[3]) = grep { *{"${_}::()"}{CODE} } @{$_[2]} )
110 # fallback explicitly undef
111 ! defined ${"$_[3]::()"}
124 #======================================================================
126 #======================================================================
130 my $class = ref($self) || $self;
131 my %opt = (ref $_[0] eq 'HASH') ? %{$_[0]} : @_;
133 # choose our case by keeping an option around
134 delete $opt{case} if $opt{case} && $opt{case} ne 'lower';
136 # default logic for interpreting arrayrefs
137 $opt{logic} = $opt{logic} ? uc $opt{logic} : 'OR';
139 # how to return bind vars
140 $opt{bindtype} ||= 'normal';
142 # default comparison is "=", but can be overridden
145 # try to recognize which are the 'equality' and 'inequality' ops
146 # (temporary quickfix (in 2007), should go through a more seasoned API)
147 $opt{equality_op} = qr/^( \Q$opt{cmp}\E | \= )$/ix;
148 $opt{inequality_op} = qr/^( != | <> )$/ix;
150 $opt{like_op} = qr/^ (is\s+)? r?like $/xi;
151 $opt{not_like_op} = qr/^ (is\s+)? not \s+ r?like $/xi;
154 $opt{sqltrue} ||= '1=1';
155 $opt{sqlfalse} ||= '0=1';
158 $opt{special_ops} ||= [];
160 # regexes are applied in order, thus push after user-defines
161 push @{$opt{special_ops}}, @BUILTIN_SPECIAL_OPS;
164 $opt{unary_ops} ||= [];
166 # rudimentary sanity-check for user supplied bits treated as functions/operators
167 # If a purported function matches this regular expression, an exception is thrown.
168 # Literal SQL is *NOT* subject to this check, only functions (and column names
169 # when quoting is not in effect)
172 # need to guard against ()'s in column names too, but this will break tons of
173 # hacks... ideas anyone?
174 $opt{injection_guard} ||= qr/
180 $opt{node_types} = +{
181 map +("-$_" => '_render_'.$_),
182 qw(op func value bind ident literal)
185 $opt{expand_unary} = {};
187 return bless \%opt, $class;
190 sub sqltrue { +{ -literal => [ $_[0]->{sqltrue} ] } }
191 sub sqlfalse { +{ -literal => [ $_[0]->{sqlfalse} ] } }
193 sub _assert_pass_injection_guard {
194 if ($_[1] =~ $_[0]->{injection_guard}) {
195 my $class = ref $_[0];
196 puke "Possible SQL injection attempt '$_[1]'. If this is indeed a part of the "
197 . "desired SQL use literal SQL ( \'...' or \[ '...' ] ) or supply your own "
198 . "{injection_guard} attribute to ${class}->new()"
203 #======================================================================
205 #======================================================================
209 my $table = $self->_table(shift);
210 my $data = shift || return;
213 my $method = $self->_METHOD_FOR_refkind("_insert", $data);
214 my ($sql, @bind) = $self->$method($data);
215 $sql = join " ", $self->_sqlcase('insert into'), $table, $sql;
217 if ($options->{returning}) {
218 my ($s, @b) = $self->_insert_returning($options);
223 return wantarray ? ($sql, @bind) : $sql;
226 # So that subclasses can override INSERT ... RETURNING separately from
227 # UPDATE and DELETE (e.g. DBIx::Class::SQLMaker::Oracle does this)
228 sub _insert_returning { shift->_returning(@_) }
231 my ($self, $options) = @_;
233 my $f = $options->{returning};
235 my ($sql, @bind) = $self->_render_expr(
236 $self->_expand_maybe_list_expr($f, undef, -ident)
239 ? $self->_sqlcase(' returning ') . $sql
240 : ($self->_sqlcase(' returning ').$sql, @bind);
243 sub _insert_HASHREF { # explicit list of fields and then values
244 my ($self, $data) = @_;
246 my @fields = sort keys %$data;
248 my ($sql, @bind) = $self->_insert_values($data);
251 $_ = $self->_quote($_) foreach @fields;
252 $sql = "( ".join(", ", @fields).") ".$sql;
254 return ($sql, @bind);
257 sub _insert_ARRAYREF { # just generate values(?,?) part (no list of fields)
258 my ($self, $data) = @_;
260 # no names (arrayref) so can't generate bindtype
261 $self->{bindtype} ne 'columns'
262 or belch "can't do 'columns' bindtype when called with arrayref";
264 my (@values, @all_bind);
265 foreach my $value (@$data) {
266 my ($values, @bind) = $self->_insert_value(undef, $value);
267 push @values, $values;
268 push @all_bind, @bind;
270 my $sql = $self->_sqlcase('values')." ( ".join(", ", @values)." )";
271 return ($sql, @all_bind);
274 sub _insert_ARRAYREFREF { # literal SQL with bind
275 my ($self, $data) = @_;
277 my ($sql, @bind) = @${$data};
278 $self->_assert_bindval_matches_bindtype(@bind);
280 return ($sql, @bind);
284 sub _insert_SCALARREF { # literal SQL without bind
285 my ($self, $data) = @_;
291 my ($self, $data) = @_;
293 my (@values, @all_bind);
294 foreach my $column (sort keys %$data) {
295 my ($values, @bind) = $self->_insert_value($column, $data->{$column});
296 push @values, $values;
297 push @all_bind, @bind;
299 my $sql = $self->_sqlcase('values')." ( ".join(", ", @values)." )";
300 return ($sql, @all_bind);
304 my ($self, $column, $v) = @_;
306 return $self->_render_expr(
307 $self->_expand_insert_value($column, $v)
311 sub _expand_insert_value {
312 my ($self, $column, $v) = @_;
314 if (ref($v) eq 'ARRAY') {
315 if ($self->{array_datatypes}) {
316 return +{ -bind => [ $column, $v ] };
318 my ($sql, @bind) = @$v;
319 $self->_assert_bindval_matches_bindtype(@bind);
320 return +{ -literal => $v };
322 if (ref($v) eq 'HASH') {
323 if (grep !/^-/, keys %$v) {
324 belch "HASH ref as bind value in insert is not supported";
325 return +{ -bind => [ $column, $v ] };
329 return +{ -bind => [ $column, undef ] };
331 local our $Cur_Col_Meta = $column;
332 return $self->_expand_expr($v);
337 #======================================================================
339 #======================================================================
344 my $table = $self->_table(shift);
345 my $data = shift || return;
349 # first build the 'SET' part of the sql statement
350 puke "Unsupported data type specified to \$sql->update"
351 unless ref $data eq 'HASH';
353 my ($sql, @all_bind) = $self->_update_set_values($data);
354 $sql = $self->_sqlcase('update ') . $table . $self->_sqlcase(' set ')
358 my($where_sql, @where_bind) = $self->where($where);
360 push @all_bind, @where_bind;
363 if ($options->{returning}) {
364 my ($returning_sql, @returning_bind) = $self->_update_returning($options);
365 $sql .= $returning_sql;
366 push @all_bind, @returning_bind;
369 return wantarray ? ($sql, @all_bind) : $sql;
372 sub _update_set_values {
373 my ($self, $data) = @_;
375 return $self->_render_expr(
376 $self->_expand_update_set_values($data),
380 sub _expand_update_set_values {
381 my ($self, $data) = @_;
382 $self->_expand_maybe_list_expr( [
385 $set = { -bind => $_ } unless defined $set;
386 +{ -op => [ '=', { -ident => $k }, $set ] };
392 ? ($self->{array_datatypes}
393 ? [ $k, +{ -bind => [ $k, $v ] } ]
394 : [ $k, +{ -literal => $v } ])
396 local our $Cur_Col_Meta = $k;
397 [ $k, $self->_expand_expr($v) ]
404 # So that subclasses can override UPDATE ... RETURNING separately from
406 sub _update_returning { shift->_returning(@_) }
410 #======================================================================
412 #======================================================================
417 my $table = $self->_table(shift);
418 my $fields = shift || '*';
422 my ($fields_sql, @bind) = $self->_select_fields($fields);
424 my ($where_sql, @where_bind) = $self->where($where, $order);
425 push @bind, @where_bind;
427 my $sql = join(' ', $self->_sqlcase('select'), $fields_sql,
428 $self->_sqlcase('from'), $table)
431 return wantarray ? ($sql, @bind) : $sql;
435 my ($self, $fields) = @_;
436 return $fields unless ref($fields);
437 return $self->_render_expr(
438 $self->_expand_maybe_list_expr($fields, undef, '-ident')
442 #======================================================================
444 #======================================================================
449 my $table = $self->_table(shift);
453 my($where_sql, @bind) = $self->where($where);
454 my $sql = $self->_sqlcase('delete from ') . $table . $where_sql;
456 if ($options->{returning}) {
457 my ($returning_sql, @returning_bind) = $self->_delete_returning($options);
458 $sql .= $returning_sql;
459 push @bind, @returning_bind;
462 return wantarray ? ($sql, @bind) : $sql;
465 # So that subclasses can override DELETE ... RETURNING separately from
467 sub _delete_returning { shift->_returning(@_) }
471 #======================================================================
473 #======================================================================
477 # Finally, a separate routine just to handle WHERE clauses
479 my ($self, $where, $order) = @_;
481 local $self->{convert_where} = $self->{convert};
484 my ($sql, @bind) = defined($where)
485 ? $self->_recurse_where($where)
487 $sql = (defined $sql and length $sql) ? $self->_sqlcase(' where ') . "( $sql )" : '';
491 my ($order_sql, @order_bind) = $self->_order_by($order);
493 push @bind, @order_bind;
496 return wantarray ? ($sql, @bind) : $sql;
500 my ($self, $expr, $logic, $default_scalar_to) = @_;
501 local our $Default_Scalar_To = $default_scalar_to if $default_scalar_to;
502 our $Expand_Depth ||= 0; local $Expand_Depth = $Expand_Depth + 1;
503 return undef unless defined($expr);
504 if (ref($expr) eq 'HASH') {
505 if (keys %$expr > 1) {
509 map $self->_expand_expr_hashpair($_ => $expr->{$_}, $logic),
513 return unless %$expr;
514 return $self->_expand_expr_hashpair(%$expr, $logic);
516 if (ref($expr) eq 'ARRAY') {
517 my $logic = lc($logic || $self->{logic});
518 $logic eq 'and' or $logic eq 'or' or puke "unknown logic: $logic";
524 while (my ($el) = splice @expr, 0, 1) {
525 puke "Supplying an empty left hand side argument is not supported in array-pairs"
526 unless defined($el) and length($el);
527 my $elref = ref($el);
529 push(@res, $self->_expand_expr({ $el, shift(@expr) }));
530 } elsif ($elref eq 'ARRAY') {
531 push(@res, $self->_expand_expr($el)) if @$el;
532 } elsif (my $l = is_literal_value($el)) {
533 push @res, { -literal => $l };
534 } elsif ($elref eq 'HASH') {
535 push @res, $self->_expand_expr($el);
540 return { -op => [ $logic, @res ] };
542 if (my $literal = is_literal_value($expr)) {
543 return +{ -literal => $literal };
545 if (!ref($expr) or Scalar::Util::blessed($expr)) {
546 if (my $d = $Default_Scalar_To) {
547 return +{ $d => $expr };
549 if (my $m = our $Cur_Col_Meta) {
550 return +{ -bind => [ $m, $expr ] };
552 return +{ -value => $expr };
559 sub _expand_expr_hashpair {
560 my ($self, $k, $v, $logic) = @_;
561 unless (defined($k) and length($k)) {
562 if (defined($k) and my $literal = is_literal_value($v)) {
563 belch 'Hash-pairs consisting of an empty string with a literal are deprecated, and will be removed in 2.0: use -and => [ $literal ] instead';
564 return { -literal => $literal };
566 puke "Supplying an empty left hand side argument is not supported";
569 $self->_assert_pass_injection_guard($k =~ /^-(.*)$/s);
570 if ($k =~ s/ [_\s]? \d+ $//x ) {
571 belch 'Use of [and|or|nest]_N modifiers is deprecated and will be removed in SQLA v2.0. '
572 . "You probably wanted ...-and => [ $k => COND1, $k => COND2 ... ]";
575 # DBIx::Class requires a nest warning to be emitted once but the private
576 # method it overrode to do so no longer exists
577 if (ref($self) =~ /^DBIx::Class::SQLMaker/) {
578 unless ($Nest_Warned) {
580 "-nest in search conditions is deprecated, you most probably wanted:\n"
581 .q|{..., -and => [ \%cond0, \@cond1, \'cond2', \[ 'cond3', [ col => bind ] ], etc. ], ... }|
586 return $self->_expand_expr($v);
590 return $self->_expand_expr($v);
592 puke "-bool => undef not supported" unless defined($v);
593 return { -ident => $v };
596 return { -op => [ 'not', $self->_expand_expr($v) ] };
598 if (my ($rest) = $k =~/^-not[_ ](.*)$/) {
601 $self->_expand_expr_hashpair("-${rest}", $v, $logic)
604 if (my ($logic) = $k =~ /^-(and|or)$/i) {
605 if (ref($v) eq 'HASH') {
606 return $self->_expand_expr($v, $logic);
608 if (ref($v) eq 'ARRAY') {
609 return $self->_expand_expr($v, $logic);
614 $op =~ s/^-// if length($op) > 1;
616 # top level special ops are illegal in general
617 # note that, arguably, if it makes no sense at top level, it also
618 # makes no sense on the other side of an = sign or similar but DBIC
619 # gets disappointingly upset if I disallow it
621 (our $Expand_Depth) == 1
622 and List::Util::first { $op =~ $_->{regex} } @{$self->{special_ops}}
624 puke "Illegal use of top-level '-$op'"
626 if (my $us = List::Util::first { $op =~ $_->{regex} } @{$self->{unary_ops}}) {
627 return { -op => [ $op, $v ] };
630 if ($k eq '-value' and my $m = our $Cur_Col_Meta) {
631 return +{ -bind => [ $m, $v ] };
633 if (my $custom = $self->{expand_unary}{$k}) {
634 return $self->$custom($v);
636 if ($self->{node_types}{$k}) {
642 and (keys %$v)[0] =~ /^-/
644 my ($func) = $k =~ /^-(.*)$/;
645 if (List::Util::first { $func =~ $_->{regex} } @{$self->{special_ops}}) {
646 return +{ -op => [ $func, $self->_expand_expr($v) ] };
648 return +{ -func => [ $func, $self->_expand_expr($v) ] };
650 if (!ref($v) or is_literal_value($v)) {
651 return +{ -op => [ $k =~ /^-(.*)$/, $self->_expand_expr($v) ] };
658 and exists $v->{-value}
659 and not defined $v->{-value}
662 return $self->_expand_expr_hashpair($k => { $self->{cmp} => undef });
664 if (!ref($v) or Scalar::Util::blessed($v)) {
665 my $d = our $Default_Scalar_To;
670 ($d ? { $d => $v } : { -bind => [ $k, $v ] })
674 if (ref($v) eq 'HASH') {
678 map $self->_expand_expr_hashpair($k => { $_ => $v->{$_} }),
685 $self->_assert_pass_injection_guard($vk);
686 if ($vk =~ s/ [_\s]? \d+ $//x ) {
687 belch 'Use of [and|or|nest]_N modifiers is deprecated and will be removed in SQLA v2.0. '
688 . "You probably wanted ...-and => [ -$vk => COND1, -$vk => COND2 ... ]";
690 if ($vk =~ /^(?:not[ _])?between$/) {
691 local our $Cur_Col_Meta = $k;
692 my @rhs = map $self->_expand_expr($_),
693 ref($vv) eq 'ARRAY' ? @$vv : $vv;
695 (@rhs == 1 and ref($rhs[0]) eq 'HASH' and $rhs[0]->{-literal})
697 (@rhs == 2 and defined($rhs[0]) and defined($rhs[1]))
699 puke "Operator '${\uc($vk)}' requires either an arrayref with two defined values or expressions, or a single literal scalarref/arrayref-ref";
702 join(' ', split '_', $vk),
707 if ($vk =~ /^(?:not[ _])?in$/) {
708 if (my $literal = is_literal_value($vv)) {
709 my ($sql, @bind) = @$literal;
710 my $opened_sql = $self->_open_outer_paren($sql);
712 $vk, { -ident => $k },
713 [ { -literal => [ $opened_sql, @bind ] } ]
717 'SQL::Abstract before v1.75 used to generate incorrect SQL when the '
718 . "-${\uc($vk)} operator was given an undef-containing list: !!!AUDIT YOUR CODE "
719 . 'AND DATA!!! (the upcoming Data::Query-based version of SQL::Abstract '
720 . 'will emit the logically correct SQL instead of raising this exception)'
722 puke("Argument passed to the '${\uc($vk)}' operator can not be undefined")
724 my @rhs = map $self->_expand_expr($_),
725 map { ref($_) ? $_ : { -bind => [ $k, $_ ] } }
726 map { defined($_) ? $_: puke($undef_err) }
727 (ref($vv) eq 'ARRAY' ? @$vv : $vv);
728 return $self->${\($vk =~ /^not/ ? 'sqltrue' : 'sqlfalse')} unless @rhs;
731 join(' ', split '_', $vk),
736 if ($vk eq 'ident') {
737 if (! defined $vv or (ref($vv) and ref($vv) eq 'ARRAY')) {
738 puke "-$vk requires a single plain scalar argument (a quotable identifier) or an arrayref of identifier parts";
746 if ($vk eq 'value') {
747 return $self->_expand_expr_hashpair($k, undef) unless defined($vv);
751 { -bind => [ $k, $vv ] }
754 if ($vk =~ /^is(?:[ _]not)?$/) {
755 puke "$vk can only take undef as argument"
759 and exists($vv->{-value})
760 and !defined($vv->{-value})
763 return +{ -op => [ $vk.' null', { -ident => $k } ] };
765 if ($vk =~ /^(and|or)$/) {
766 if (ref($vv) eq 'HASH') {
769 map $self->_expand_expr_hashpair($k, { $_ => $vv->{$_} }),
774 if (my $us = List::Util::first { $vk =~ $_->{regex} } @{$self->{special_ops}}) {
775 return { -op => [ $vk, { -ident => $k }, $vv ] };
777 if (my $us = List::Util::first { $vk =~ $_->{regex} } @{$self->{unary_ops}}) {
781 { -op => [ $vk, $vv ] }
784 if (ref($vv) eq 'ARRAY') {
785 my ($logic, @values) = (
786 (defined($vv->[0]) and $vv->[0] =~ /^-(and|or)$/i)
791 $vk =~ $self->{inequality_op}
792 or join(' ', split '_', $vk) =~ $self->{not_like_op}
794 if (lc($logic) eq '-or' and @values > 1) {
795 my $op = uc join ' ', split '_', $vk;
796 belch "A multi-element arrayref as an argument to the inequality op '$op' "
797 . 'is technically equivalent to an always-true 1=1 (you probably wanted '
798 . "to say ...{ \$inequality_op => [ -and => \@values ] }... instead)"
803 # try to DWIM on equality operators
804 my $op = join ' ', split '_', $vk;
806 $op =~ $self->{equality_op} ? $self->sqlfalse
807 : $op =~ $self->{like_op} ? belch("Supplying an empty arrayref to '@{[ uc $op]}' is deprecated") && $self->sqlfalse
808 : $op =~ $self->{inequality_op} ? $self->sqltrue
809 : $op =~ $self->{not_like_op} ? belch("Supplying an empty arrayref to '@{[ uc $op]}' is deprecated") && $self->sqltrue
810 : puke "operator '$op' applied on an empty array (field '$k')";
814 map $self->_expand_expr_hashpair($k => { $vk => $_ }),
822 and exists $vv->{-value}
823 and not defined $vv->{-value}
826 my $op = join ' ', split '_', $vk;
828 $op =~ /^not$/i ? 'is not' # legacy
829 : $op =~ $self->{equality_op} ? 'is'
830 : $op =~ $self->{like_op} ? belch("Supplying an undefined argument to '@{[ uc $op]}' is deprecated") && 'is'
831 : $op =~ $self->{inequality_op} ? 'is not'
832 : $op =~ $self->{not_like_op} ? belch("Supplying an undefined argument to '@{[ uc $op]}' is deprecated") && 'is not'
833 : puke "unexpected operator '$op' with undef operand";
834 return +{ -op => [ $is.' null', { -ident => $k } ] };
836 local our $Cur_Col_Meta = $k;
840 $self->_expand_expr($vv)
843 if (ref($v) eq 'ARRAY') {
844 return $self->sqlfalse unless @$v;
845 $self->_debug("ARRAY($k) means distribute over elements");
847 $v->[0] =~ /^-((?:and|or))$/i
848 ? ($v = [ @{$v}[1..$#$v] ], $1)
849 : ($self->{logic} || 'or')
853 map $self->_expand_expr({ $k => $_ }, $this_logic), @$v
856 if (my $literal = is_literal_value($v)) {
858 belch 'Hash-pairs consisting of an empty string with a literal are deprecated, and will be removed in 2.0: use -and => [ $literal ] instead';
861 my ($sql, @bind) = @$literal;
862 if ($self->{bindtype} eq 'columns') {
864 $self->_assert_bindval_matches_bindtype($_);
867 return +{ -literal => [ $self->_quote($k).' '.$sql, @bind ] };
873 my ($self, $expr) = @_;
874 my ($k, $v, @rest) = %$expr;
876 if (my $meth = $self->{node_types}{$k}) {
877 return $self->$meth($v);
879 die "notreached: $k";
883 my ($self, $where, $logic) = @_;
885 #print STDERR Data::Dumper::Concise::Dumper([ $where, $logic ]);
887 # Special case: top level simple string treated as literal
889 my $where_exp = (ref($where)
890 ? $self->_expand_expr($where, $logic)
891 : { -literal => [ $where ] });
893 #print STDERR Data::Dumper::Concise::Dumper([ EXP => $where_exp ]);
895 # dispatch on appropriate method according to refkind of $where
896 # my $method = $self->_METHOD_FOR_refkind("_where", $where_exp);
898 # my ($sql, @bind) = $self->$method($where_exp, $logic);
900 my ($sql, @bind) = defined($where_exp) ? $self->_render_expr($where_exp) : (undef);
902 # DBIx::Class used to call _recurse_where in scalar context
903 # something else might too...
905 return ($sql, @bind);
908 belch "Calling _recurse_where in scalar context is deprecated and will go away before 2.0";
914 my ($self, $ident) = @_;
916 return $self->_convert($self->_quote($ident));
920 my ($self, $value) = @_;
922 return ($self->_convert('?'), $self->_bindtype(undef, $value));
925 my %unop_postfix = map +($_ => 1),
926 'is null', 'is not null',
934 my ($self, $args) = @_;
935 my ($left, $low, $high) = @$args;
936 my ($rhsql, @rhbind) = do {
938 puke "Single arg to between must be a literal"
939 unless $low->{-literal};
942 my ($l, $h) = map [ $self->_render_expr($_) ], $low, $high;
943 (join(' ', $l->[0], $self->_sqlcase('and'), $h->[0]),
944 @{$l}[1..$#$l], @{$h}[1..$#$h])
947 my ($lhsql, @lhbind) = $self->_render_expr($left);
949 join(' ', '(', $lhsql, $self->_sqlcase($op), $rhsql, ')'),
953 }), 'between', 'not between'),
957 my ($self, $args) = @_;
958 my ($lhs, $rhs) = @$args;
961 my ($sql, @bind) = $self->_render_expr($_);
962 push @in_bind, @bind;
965 my ($lhsql, @lbind) = $self->_render_expr($lhs);
967 $lhsql.' '.$self->_sqlcase($op).' ( '
978 my ($op, @args) = @$v;
979 $op =~ s/^-// if length($op) > 1;
981 if (my $h = $special{$op}) {
982 return $self->$h(\@args);
984 my $us = List::Util::first { $op =~ $_->{regex} } @{$self->{special_ops}};
985 if ($us and @args > 1) {
986 puke "Special op '${op}' requires first value to be identifier"
987 unless my ($k) = map $_->{-ident}, grep ref($_) eq 'HASH', $args[0];
988 return $self->${\($us->{handler})}($k, $op, $args[1]);
990 if (my $us = List::Util::first { $op =~ $_->{regex} } @{$self->{unary_ops}}) {
991 return $self->${\($us->{handler})}($op, $args[0]);
993 my $final_op = $op =~ /^(?:is|not)_/ ? join(' ', split '_', $op) : $op;
994 if (@args == 1 and $op !~ /^(and|or)$/) {
995 my ($expr_sql, @bind) = $self->_render_expr($args[0]);
996 my $op_sql = $self->_sqlcase($final_op);
998 $unop_postfix{lc($final_op)}
999 ? "${expr_sql} ${op_sql}"
1000 : "${op_sql} ${expr_sql}"
1002 return (($op eq 'not' || $us ? '('.$final_sql.')' : $final_sql), @bind);
1004 my @parts = map [ $self->_render_expr($_) ], @args;
1005 my ($final_sql) = map +($op =~ /^(and|or)$/ ? "( ${_} )" : $_), join(
1006 ($final_op eq ',' ? '' : ' ').$self->_sqlcase($final_op).' ',
1011 map @{$_}[1..$#$_], @parts
1018 my ($self, $rest) = @_;
1019 my ($func, @args) = @$rest;
1023 push @arg_sql, shift @x;
1025 } map [ $self->_render_expr($_) ], @args;
1026 return ($self->_sqlcase($func).'('.join(', ', @arg_sql).')', @bind);
1030 my ($self, $bind) = @_;
1031 return ($self->_convert('?'), $self->_bindtype(@$bind));
1034 sub _render_literal {
1035 my ($self, $literal) = @_;
1036 $self->_assert_bindval_matches_bindtype(@{$literal}[1..$#$literal]);
1040 # Some databases (SQLite) treat col IN (1, 2) different from
1041 # col IN ( (1, 2) ). Use this to strip all outer parens while
1042 # adding them back in the corresponding method
1043 sub _open_outer_paren {
1044 my ($self, $sql) = @_;
1046 while (my ($inner) = $sql =~ /^ \s* \( (.*) \) \s* $/xs) {
1048 # there are closing parens inside, need the heavy duty machinery
1049 # to reevaluate the extraction starting from $sql (full reevaluation)
1050 if ($inner =~ /\)/) {
1051 require Text::Balanced;
1053 my (undef, $remainder) = do {
1054 # idiotic design - writes to $@ but *DOES NOT* throw exceptions
1056 Text::Balanced::extract_bracketed($sql, '()', qr/\s*/);
1059 # the entire expression needs to be a balanced bracketed thing
1060 # (after an extract no remainder sans trailing space)
1061 last if defined $remainder and $remainder =~ /\S/;
1071 #======================================================================
1073 #======================================================================
1075 sub _expand_order_by {
1076 my ($self, $arg) = @_;
1078 return unless defined($arg) and not (ref($arg) eq 'ARRAY' and !@$arg);
1080 my $expander = sub {
1081 my ($self, $dir, $expr) = @_;
1082 my @to_expand = ref($expr) eq 'ARRAY' ? @$expr : $expr;
1083 foreach my $arg (@to_expand) {
1087 and grep /^-(asc|desc)$/, keys %$arg
1089 puke "ordering direction hash passed to order by must have exactly one key (-asc or -desc)";
1092 my @exp = map +(defined($dir) ? { -op => [ $dir => $_ ] } : $_),
1093 map $self->_expand_expr($_, undef, -ident),
1094 map ref($_) eq 'ARRAY' ? @$_ : $_, @to_expand;
1095 return (@exp > 1 ? { -op => [ ',', @exp ] } : $exp[0]);
1098 local @{$self->{expand_unary}}{qw(-asc -desc)} = (
1099 sub { shift->$expander(asc => @_) },
1100 sub { shift->$expander(desc => @_) },
1103 return $self->$expander(undef, $arg);
1107 my ($self, $arg) = @_;
1109 return '' unless defined(my $expanded = $self->_expand_order_by($arg));
1111 my ($sql, @bind) = $self->_render_expr($expanded);
1113 my $final_sql = $self->_sqlcase(' order by ').$sql;
1115 return wantarray ? ($final_sql, @bind) : $final_sql;
1118 # _order_by no longer needs to call this so doesn't but DBIC uses it.
1120 sub _order_by_chunks {
1121 my ($self, $arg) = @_;
1123 return () unless defined(my $expanded = $self->_expand_order_by($arg));
1125 return $self->_chunkify_order_by($expanded);
1128 sub _chunkify_order_by {
1129 my ($self, $expanded) = @_;
1131 if (ref() eq 'HASH' and my $op = $_->{-op}) {
1132 if ($op->[0] eq ',') {
1133 return map $self->_chunkify_order_by($_), @{$op}[1..$#$op];
1136 return [ $self->_render_expr($_) ];
1140 #======================================================================
1141 # DATASOURCE (FOR NOW, JUST PLAIN TABLE OR LIST OF TABLES)
1142 #======================================================================
1147 ($self->_render_expr(
1148 $self->_expand_maybe_list_expr($from, undef, -ident)
1153 #======================================================================
1155 #======================================================================
1157 sub _expand_maybe_list_expr {
1158 my ($self, $expr, $logic, $default) = @_;
1160 if (ref($expr) eq 'ARRAY') {
1162 ',', map $self->_expand_expr($_, $logic, $default), @$expr
1169 return $self->_expand_expr($e, $logic, $default);
1172 # highly optimized, as it's called way too often
1174 # my ($self, $label) = @_;
1176 return '' unless defined $_[1];
1177 return ${$_[1]} if ref($_[1]) eq 'SCALAR';
1178 puke 'Identifier cannot be hashref' if ref($_[1]) eq 'HASH';
1180 unless ($_[0]->{quote_char}) {
1181 if (ref($_[1]) eq 'ARRAY') {
1182 return join($_[0]->{name_sep}||'.', @{$_[1]});
1184 $_[0]->_assert_pass_injection_guard($_[1]);
1189 my $qref = ref $_[0]->{quote_char};
1191 !$qref ? ($_[0]->{quote_char}, $_[0]->{quote_char})
1192 : ($qref eq 'ARRAY') ? @{$_[0]->{quote_char}}
1193 : puke "Unsupported quote_char format: $_[0]->{quote_char}";
1195 my $esc = $_[0]->{escape_char} || $r;
1197 # parts containing * are naturally unquoted
1199 $_[0]->{name_sep}||'',
1203 : do { (my $n = $_) =~ s/(\Q$esc\E|\Q$r\E)/$esc$1/g; $l . $n . $r }
1205 (ref($_[1]) eq 'ARRAY'
1209 ? split (/\Q$_[0]->{name_sep}\E/, $_[1] )
1217 # Conversion, if applicable
1219 #my ($self, $arg) = @_;
1220 if ($_[0]->{convert_where}) {
1221 return $_[0]->_sqlcase($_[0]->{convert_where}) .'(' . $_[1] . ')';
1228 #my ($self, $col, @vals) = @_;
1229 # called often - tighten code
1230 return $_[0]->{bindtype} eq 'columns'
1231 ? map {[$_[1], $_]} @_[2 .. $#_]
1236 # Dies if any element of @bind is not in [colname => value] format
1237 # if bindtype is 'columns'.
1238 sub _assert_bindval_matches_bindtype {
1239 # my ($self, @bind) = @_;
1241 if ($self->{bindtype} eq 'columns') {
1243 if (!defined $_ || ref($_) ne 'ARRAY' || @$_ != 2) {
1244 puke "bindtype 'columns' selected, you need to pass: [column_name => bind_value]"
1250 sub _join_sql_clauses {
1251 my ($self, $logic, $clauses_aref, $bind_aref) = @_;
1253 if (@$clauses_aref > 1) {
1254 my $join = " " . $self->_sqlcase($logic) . " ";
1255 my $sql = '( ' . join($join, @$clauses_aref) . ' )';
1256 return ($sql, @$bind_aref);
1258 elsif (@$clauses_aref) {
1259 return ($clauses_aref->[0], @$bind_aref); # no parentheses
1262 return (); # if no SQL, ignore @$bind_aref
1267 # Fix SQL case, if so requested
1269 # LDNOTE: if $self->{case} is true, then it contains 'lower', so we
1270 # don't touch the argument ... crooked logic, but let's not change it!
1271 return $_[0]->{case} ? $_[1] : uc($_[1]);
1275 #======================================================================
1276 # DISPATCHING FROM REFKIND
1277 #======================================================================
1280 my ($self, $data) = @_;
1282 return 'UNDEF' unless defined $data;
1284 # blessed objects are treated like scalars
1285 my $ref = (Scalar::Util::blessed $data) ? '' : ref $data;
1287 return 'SCALAR' unless $ref;
1290 while ($ref eq 'REF') {
1292 $ref = (Scalar::Util::blessed $data) ? '' : ref $data;
1296 return ($ref||'SCALAR') . ('REF' x $n_steps);
1300 my ($self, $data) = @_;
1301 my @try = ($self->_refkind($data));
1302 push @try, 'SCALAR_or_UNDEF' if $try[0] eq 'SCALAR' || $try[0] eq 'UNDEF';
1303 push @try, 'FALLBACK';
1307 sub _METHOD_FOR_refkind {
1308 my ($self, $meth_prefix, $data) = @_;
1311 for (@{$self->_try_refkind($data)}) {
1312 $method = $self->can($meth_prefix."_".$_)
1316 return $method || puke "cannot dispatch on '$meth_prefix' for ".$self->_refkind($data);
1320 sub _SWITCH_refkind {
1321 my ($self, $data, $dispatch_table) = @_;
1324 for (@{$self->_try_refkind($data)}) {
1325 $coderef = $dispatch_table->{$_}
1329 puke "no dispatch entry for ".$self->_refkind($data)
1338 #======================================================================
1339 # VALUES, GENERATE, AUTOLOAD
1340 #======================================================================
1342 # LDNOTE: original code from nwiger, didn't touch code in that section
1343 # I feel the AUTOLOAD stuff should not be the default, it should
1344 # only be activated on explicit demand by user.
1348 my $data = shift || return;
1349 puke "Argument to ", __PACKAGE__, "->values must be a \\%hash"
1350 unless ref $data eq 'HASH';
1353 foreach my $k (sort keys %$data) {
1354 my $v = $data->{$k};
1355 $self->_SWITCH_refkind($v, {
1357 if ($self->{array_datatypes}) { # array datatype
1358 push @all_bind, $self->_bindtype($k, $v);
1360 else { # literal SQL with bind
1361 my ($sql, @bind) = @$v;
1362 $self->_assert_bindval_matches_bindtype(@bind);
1363 push @all_bind, @bind;
1366 ARRAYREFREF => sub { # literal SQL with bind
1367 my ($sql, @bind) = @${$v};
1368 $self->_assert_bindval_matches_bindtype(@bind);
1369 push @all_bind, @bind;
1371 SCALARREF => sub { # literal SQL without bind
1373 SCALAR_or_UNDEF => sub {
1374 push @all_bind, $self->_bindtype($k, $v);
1385 my(@sql, @sqlq, @sqlv);
1389 if ($ref eq 'HASH') {
1390 for my $k (sort keys %$_) {
1393 my $label = $self->_quote($k);
1394 if ($r eq 'ARRAY') {
1395 # literal SQL with bind
1396 my ($sql, @bind) = @$v;
1397 $self->_assert_bindval_matches_bindtype(@bind);
1398 push @sqlq, "$label = $sql";
1400 } elsif ($r eq 'SCALAR') {
1401 # literal SQL without bind
1402 push @sqlq, "$label = $$v";
1404 push @sqlq, "$label = ?";
1405 push @sqlv, $self->_bindtype($k, $v);
1408 push @sql, $self->_sqlcase('set'), join ', ', @sqlq;
1409 } elsif ($ref eq 'ARRAY') {
1410 # unlike insert(), assume these are ONLY the column names, i.e. for SQL
1413 if ($r eq 'ARRAY') { # literal SQL with bind
1414 my ($sql, @bind) = @$v;
1415 $self->_assert_bindval_matches_bindtype(@bind);
1418 } elsif ($r eq 'SCALAR') { # literal SQL without bind
1419 # embedded literal SQL
1426 push @sql, '(' . join(', ', @sqlq) . ')';
1427 } elsif ($ref eq 'SCALAR') {
1431 # strings get case twiddled
1432 push @sql, $self->_sqlcase($_);
1436 my $sql = join ' ', @sql;
1438 # this is pretty tricky
1439 # if ask for an array, return ($stmt, @bind)
1440 # otherwise, s/?/shift @sqlv/ to put it inline
1442 return ($sql, @sqlv);
1444 1 while $sql =~ s/\?/my $d = shift(@sqlv);
1445 ref $d ? $d->[1] : $d/e;
1454 # This allows us to check for a local, then _form, attr
1456 my($name) = $AUTOLOAD =~ /.*::(.+)/;
1457 return $self->generate($name, @_);
1468 SQL::Abstract - Generate SQL from Perl data structures
1474 my $sql = SQL::Abstract->new;
1476 my($stmt, @bind) = $sql->select($source, \@fields, \%where, $order);
1478 my($stmt, @bind) = $sql->insert($table, \%fieldvals || \@values);
1480 my($stmt, @bind) = $sql->update($table, \%fieldvals, \%where);
1482 my($stmt, @bind) = $sql->delete($table, \%where);
1484 # Then, use these in your DBI statements
1485 my $sth = $dbh->prepare($stmt);
1486 $sth->execute(@bind);
1488 # Just generate the WHERE clause
1489 my($stmt, @bind) = $sql->where(\%where, $order);
1491 # Return values in the same order, for hashed queries
1492 # See PERFORMANCE section for more details
1493 my @bind = $sql->values(\%fieldvals);
1497 This module was inspired by the excellent L<DBIx::Abstract>.
1498 However, in using that module I found that what I really wanted
1499 to do was generate SQL, but still retain complete control over my
1500 statement handles and use the DBI interface. So, I set out to
1501 create an abstract SQL generation module.
1503 While based on the concepts used by L<DBIx::Abstract>, there are
1504 several important differences, especially when it comes to WHERE
1505 clauses. I have modified the concepts used to make the SQL easier
1506 to generate from Perl data structures and, IMO, more intuitive.
1507 The underlying idea is for this module to do what you mean, based
1508 on the data structures you provide it. The big advantage is that
1509 you don't have to modify your code every time your data changes,
1510 as this module figures it out.
1512 To begin with, an SQL INSERT is as easy as just specifying a hash
1513 of C<key=value> pairs:
1516 name => 'Jimbo Bobson',
1517 phone => '123-456-7890',
1518 address => '42 Sister Lane',
1519 city => 'St. Louis',
1520 state => 'Louisiana',
1523 The SQL can then be generated with this:
1525 my($stmt, @bind) = $sql->insert('people', \%data);
1527 Which would give you something like this:
1529 $stmt = "INSERT INTO people
1530 (address, city, name, phone, state)
1531 VALUES (?, ?, ?, ?, ?)";
1532 @bind = ('42 Sister Lane', 'St. Louis', 'Jimbo Bobson',
1533 '123-456-7890', 'Louisiana');
1535 These are then used directly in your DBI code:
1537 my $sth = $dbh->prepare($stmt);
1538 $sth->execute(@bind);
1540 =head2 Inserting and Updating Arrays
1542 If your database has array types (like for example Postgres),
1543 activate the special option C<< array_datatypes => 1 >>
1544 when creating the C<SQL::Abstract> object.
1545 Then you may use an arrayref to insert and update database array types:
1547 my $sql = SQL::Abstract->new(array_datatypes => 1);
1549 planets => [qw/Mercury Venus Earth Mars/]
1552 my($stmt, @bind) = $sql->insert('solar_system', \%data);
1556 $stmt = "INSERT INTO solar_system (planets) VALUES (?)"
1558 @bind = (['Mercury', 'Venus', 'Earth', 'Mars']);
1561 =head2 Inserting and Updating SQL
1563 In order to apply SQL functions to elements of your C<%data> you may
1564 specify a reference to an arrayref for the given hash value. For example,
1565 if you need to execute the Oracle C<to_date> function on a value, you can
1566 say something like this:
1570 date_entered => \[ "to_date(?,'MM/DD/YYYY')", "03/02/2003" ],
1573 The first value in the array is the actual SQL. Any other values are
1574 optional and would be included in the bind values array. This gives
1577 my($stmt, @bind) = $sql->insert('people', \%data);
1579 $stmt = "INSERT INTO people (name, date_entered)
1580 VALUES (?, to_date(?,'MM/DD/YYYY'))";
1581 @bind = ('Bill', '03/02/2003');
1583 An UPDATE is just as easy, all you change is the name of the function:
1585 my($stmt, @bind) = $sql->update('people', \%data);
1587 Notice that your C<%data> isn't touched; the module will generate
1588 the appropriately quirky SQL for you automatically. Usually you'll
1589 want to specify a WHERE clause for your UPDATE, though, which is
1590 where handling C<%where> hashes comes in handy...
1592 =head2 Complex where statements
1594 This module can generate pretty complicated WHERE statements
1595 easily. For example, simple C<key=value> pairs are taken to mean
1596 equality, and if you want to see if a field is within a set
1597 of values, you can use an arrayref. Let's say we wanted to
1598 SELECT some data based on this criteria:
1601 requestor => 'inna',
1602 worker => ['nwiger', 'rcwe', 'sfz'],
1603 status => { '!=', 'completed' }
1606 my($stmt, @bind) = $sql->select('tickets', '*', \%where);
1608 The above would give you something like this:
1610 $stmt = "SELECT * FROM tickets WHERE
1611 ( requestor = ? ) AND ( status != ? )
1612 AND ( worker = ? OR worker = ? OR worker = ? )";
1613 @bind = ('inna', 'completed', 'nwiger', 'rcwe', 'sfz');
1615 Which you could then use in DBI code like so:
1617 my $sth = $dbh->prepare($stmt);
1618 $sth->execute(@bind);
1624 The methods are simple. There's one for every major SQL operation,
1625 and a constructor you use first. The arguments are specified in a
1626 similar order for each method (table, then fields, then a where
1627 clause) to try and simplify things.
1629 =head2 new(option => 'value')
1631 The C<new()> function takes a list of options and values, and returns
1632 a new B<SQL::Abstract> object which can then be used to generate SQL
1633 through the methods below. The options accepted are:
1639 If set to 'lower', then SQL will be generated in all lowercase. By
1640 default SQL is generated in "textbook" case meaning something like:
1642 SELECT a_field FROM a_table WHERE some_field LIKE '%someval%'
1644 Any setting other than 'lower' is ignored.
1648 This determines what the default comparison operator is. By default
1649 it is C<=>, meaning that a hash like this:
1651 %where = (name => 'nwiger', email => 'nate@wiger.org');
1653 Will generate SQL like this:
1655 WHERE name = 'nwiger' AND email = 'nate@wiger.org'
1657 However, you may want loose comparisons by default, so if you set
1658 C<cmp> to C<like> you would get SQL such as:
1660 WHERE name like 'nwiger' AND email like 'nate@wiger.org'
1662 You can also override the comparison on an individual basis - see
1663 the huge section on L</"WHERE CLAUSES"> at the bottom.
1665 =item sqltrue, sqlfalse
1667 Expressions for inserting boolean values within SQL statements.
1668 By default these are C<1=1> and C<1=0>. They are used
1669 by the special operators C<-in> and C<-not_in> for generating
1670 correct SQL even when the argument is an empty array (see below).
1674 This determines the default logical operator for multiple WHERE
1675 statements in arrays or hashes. If absent, the default logic is "or"
1676 for arrays, and "and" for hashes. This means that a WHERE
1680 event_date => {'>=', '2/13/99'},
1681 event_date => {'<=', '4/24/03'},
1684 will generate SQL like this:
1686 WHERE event_date >= '2/13/99' OR event_date <= '4/24/03'
1688 This is probably not what you want given this query, though (look
1689 at the dates). To change the "OR" to an "AND", simply specify:
1691 my $sql = SQL::Abstract->new(logic => 'and');
1693 Which will change the above C<WHERE> to:
1695 WHERE event_date >= '2/13/99' AND event_date <= '4/24/03'
1697 The logic can also be changed locally by inserting
1698 a modifier in front of an arrayref:
1700 @where = (-and => [event_date => {'>=', '2/13/99'},
1701 event_date => {'<=', '4/24/03'} ]);
1703 See the L</"WHERE CLAUSES"> section for explanations.
1707 This will automatically convert comparisons using the specified SQL
1708 function for both column and value. This is mostly used with an argument
1709 of C<upper> or C<lower>, so that the SQL will have the effect of
1710 case-insensitive "searches". For example, this:
1712 $sql = SQL::Abstract->new(convert => 'upper');
1713 %where = (keywords => 'MaKe iT CAse inSeNSItive');
1715 Will turn out the following SQL:
1717 WHERE upper(keywords) like upper('MaKe iT CAse inSeNSItive')
1719 The conversion can be C<upper()>, C<lower()>, or any other SQL function
1720 that can be applied symmetrically to fields (actually B<SQL::Abstract> does
1721 not validate this option; it will just pass through what you specify verbatim).
1725 This is a kludge because many databases suck. For example, you can't
1726 just bind values using DBI's C<execute()> for Oracle C<CLOB> or C<BLOB> fields.
1727 Instead, you have to use C<bind_param()>:
1729 $sth->bind_param(1, 'reg data');
1730 $sth->bind_param(2, $lots, {ora_type => ORA_CLOB});
1732 The problem is, B<SQL::Abstract> will normally just return a C<@bind> array,
1733 which loses track of which field each slot refers to. Fear not.
1735 If you specify C<bindtype> in new, you can determine how C<@bind> is returned.
1736 Currently, you can specify either C<normal> (default) or C<columns>. If you
1737 specify C<columns>, you will get an array that looks like this:
1739 my $sql = SQL::Abstract->new(bindtype => 'columns');
1740 my($stmt, @bind) = $sql->insert(...);
1743 [ 'column1', 'value1' ],
1744 [ 'column2', 'value2' ],
1745 [ 'column3', 'value3' ],
1748 You can then iterate through this manually, using DBI's C<bind_param()>.
1750 $sth->prepare($stmt);
1753 my($col, $data) = @$_;
1754 if ($col eq 'details' || $col eq 'comments') {
1755 $sth->bind_param($i, $data, {ora_type => ORA_CLOB});
1756 } elsif ($col eq 'image') {
1757 $sth->bind_param($i, $data, {ora_type => ORA_BLOB});
1759 $sth->bind_param($i, $data);
1763 $sth->execute; # execute without @bind now
1765 Now, why would you still use B<SQL::Abstract> if you have to do this crap?
1766 Basically, the advantage is still that you don't have to care which fields
1767 are or are not included. You could wrap that above C<for> loop in a simple
1768 sub called C<bind_fields()> or something and reuse it repeatedly. You still
1769 get a layer of abstraction over manual SQL specification.
1771 Note that if you set L</bindtype> to C<columns>, the C<\[ $sql, @bind ]>
1772 construct (see L</Literal SQL with placeholders and bind values (subqueries)>)
1773 will expect the bind values in this format.
1777 This is the character that a table or column name will be quoted
1778 with. By default this is an empty string, but you could set it to
1779 the character C<`>, to generate SQL like this:
1781 SELECT `a_field` FROM `a_table` WHERE `some_field` LIKE '%someval%'
1783 Alternatively, you can supply an array ref of two items, the first being the left
1784 hand quote character, and the second the right hand quote character. For
1785 example, you could supply C<['[',']']> for SQL Server 2000 compliant quotes
1786 that generates SQL like this:
1788 SELECT [a_field] FROM [a_table] WHERE [some_field] LIKE '%someval%'
1790 Quoting is useful if you have tables or columns names that are reserved
1791 words in your database's SQL dialect.
1795 This is the character that will be used to escape L</quote_char>s appearing
1796 in an identifier before it has been quoted.
1798 The parameter default in case of a single L</quote_char> character is the quote
1801 When opening-closing-style quoting is used (L</quote_char> is an arrayref)
1802 this parameter defaults to the B<closing (right)> L</quote_char>. Occurrences
1803 of the B<opening (left)> L</quote_char> within the identifier are currently left
1804 untouched. The default for opening-closing-style quotes may change in future
1805 versions, thus you are B<strongly encouraged> to specify the escape character
1810 This is the character that separates a table and column name. It is
1811 necessary to specify this when the C<quote_char> option is selected,
1812 so that tables and column names can be individually quoted like this:
1814 SELECT `table`.`one_field` FROM `table` WHERE `table`.`other_field` = 1
1816 =item injection_guard
1818 A regular expression C<qr/.../> that is applied to any C<-function> and unquoted
1819 column name specified in a query structure. This is a safety mechanism to avoid
1820 injection attacks when mishandling user input e.g.:
1822 my %condition_as_column_value_pairs = get_values_from_user();
1823 $sqla->select( ... , \%condition_as_column_value_pairs );
1825 If the expression matches an exception is thrown. Note that literal SQL
1826 supplied via C<\'...'> or C<\['...']> is B<not> checked in any way.
1828 Defaults to checking for C<;> and the C<GO> keyword (TransactSQL)
1830 =item array_datatypes
1832 When this option is true, arrayrefs in INSERT or UPDATE are
1833 interpreted as array datatypes and are passed directly
1835 When this option is false, arrayrefs are interpreted
1836 as literal SQL, just like refs to arrayrefs
1837 (but this behavior is for backwards compatibility; when writing
1838 new queries, use the "reference to arrayref" syntax
1844 Takes a reference to a list of "special operators"
1845 to extend the syntax understood by L<SQL::Abstract>.
1846 See section L</"SPECIAL OPERATORS"> for details.
1850 Takes a reference to a list of "unary operators"
1851 to extend the syntax understood by L<SQL::Abstract>.
1852 See section L</"UNARY OPERATORS"> for details.
1858 =head2 insert($table, \@values || \%fieldvals, \%options)
1860 This is the simplest function. You simply give it a table name
1861 and either an arrayref of values or hashref of field/value pairs.
1862 It returns an SQL INSERT statement and a list of bind values.
1863 See the sections on L</"Inserting and Updating Arrays"> and
1864 L</"Inserting and Updating SQL"> for information on how to insert
1865 with those data types.
1867 The optional C<\%options> hash reference may contain additional
1868 options to generate the insert SQL. Currently supported options
1875 Takes either a scalar of raw SQL fields, or an array reference of
1876 field names, and adds on an SQL C<RETURNING> statement at the end.
1877 This allows you to return data generated by the insert statement
1878 (such as row IDs) without performing another C<SELECT> statement.
1879 Note, however, this is not part of the SQL standard and may not
1880 be supported by all database engines.
1884 =head2 update($table, \%fieldvals, \%where, \%options)
1886 This takes a table, hashref of field/value pairs, and an optional
1887 hashref L<WHERE clause|/WHERE CLAUSES>. It returns an SQL UPDATE function and a list
1889 See the sections on L</"Inserting and Updating Arrays"> and
1890 L</"Inserting and Updating SQL"> for information on how to insert
1891 with those data types.
1893 The optional C<\%options> hash reference may contain additional
1894 options to generate the update SQL. Currently supported options
1901 See the C<returning> option to
1902 L<insert|/insert($table, \@values || \%fieldvals, \%options)>.
1906 =head2 select($source, $fields, $where, $order)
1908 This returns a SQL SELECT statement and associated list of bind values, as
1909 specified by the arguments:
1915 Specification of the 'FROM' part of the statement.
1916 The argument can be either a plain scalar (interpreted as a table
1917 name, will be quoted), or an arrayref (interpreted as a list
1918 of table names, joined by commas, quoted), or a scalarref
1919 (literal SQL, not quoted).
1923 Specification of the list of fields to retrieve from
1925 The argument can be either an arrayref (interpreted as a list
1926 of field names, will be joined by commas and quoted), or a
1927 plain scalar (literal SQL, not quoted).
1928 Please observe that this API is not as flexible as that of
1929 the first argument C<$source>, for backwards compatibility reasons.
1933 Optional argument to specify the WHERE part of the query.
1934 The argument is most often a hashref, but can also be
1935 an arrayref or plain scalar --
1936 see section L<WHERE clause|/"WHERE CLAUSES"> for details.
1940 Optional argument to specify the ORDER BY part of the query.
1941 The argument can be a scalar, a hashref or an arrayref
1942 -- see section L<ORDER BY clause|/"ORDER BY CLAUSES">
1948 =head2 delete($table, \%where, \%options)
1950 This takes a table name and optional hashref L<WHERE clause|/WHERE CLAUSES>.
1951 It returns an SQL DELETE statement and list of bind values.
1953 The optional C<\%options> hash reference may contain additional
1954 options to generate the delete SQL. Currently supported options
1961 See the C<returning> option to
1962 L<insert|/insert($table, \@values || \%fieldvals, \%options)>.
1966 =head2 where(\%where, $order)
1968 This is used to generate just the WHERE clause. For example,
1969 if you have an arbitrary data structure and know what the
1970 rest of your SQL is going to look like, but want an easy way
1971 to produce a WHERE clause, use this. It returns an SQL WHERE
1972 clause and list of bind values.
1975 =head2 values(\%data)
1977 This just returns the values from the hash C<%data>, in the same
1978 order that would be returned from any of the other above queries.
1979 Using this allows you to markedly speed up your queries if you
1980 are affecting lots of rows. See below under the L</"PERFORMANCE"> section.
1982 =head2 generate($any, 'number', $of, \@data, $struct, \%types)
1984 Warning: This is an experimental method and subject to change.
1986 This returns arbitrarily generated SQL. It's a really basic shortcut.
1987 It will return two different things, depending on return context:
1989 my($stmt, @bind) = $sql->generate('create table', \$table, \@fields);
1990 my $stmt_and_val = $sql->generate('create table', \$table, \@fields);
1992 These would return the following:
1994 # First calling form
1995 $stmt = "CREATE TABLE test (?, ?)";
1996 @bind = (field1, field2);
1998 # Second calling form
1999 $stmt_and_val = "CREATE TABLE test (field1, field2)";
2001 Depending on what you're trying to do, it's up to you to choose the correct
2002 format. In this example, the second form is what you would want.
2006 $sql->generate('alter session', { nls_date_format => 'MM/YY' });
2010 ALTER SESSION SET nls_date_format = 'MM/YY'
2012 You get the idea. Strings get their case twiddled, but everything
2013 else remains verbatim.
2015 =head1 EXPORTABLE FUNCTIONS
2017 =head2 is_plain_value
2019 Determines if the supplied argument is a plain value as understood by this
2024 =item * The value is C<undef>
2026 =item * The value is a non-reference
2028 =item * The value is an object with stringification overloading
2030 =item * The value is of the form C<< { -value => $anything } >>
2034 On failure returns C<undef>, on success returns a B<scalar> reference
2035 to the original supplied argument.
2041 The stringification overloading detection is rather advanced: it takes
2042 into consideration not only the presence of a C<""> overload, but if that
2043 fails also checks for enabled
2044 L<autogenerated versions of C<"">|overload/Magic Autogeneration>, based
2045 on either C<0+> or C<bool>.
2047 Unfortunately testing in the field indicates that this
2048 detection B<< may tickle a latent bug in perl versions before 5.018 >>,
2049 but only when very large numbers of stringifying objects are involved.
2050 At the time of writing ( Sep 2014 ) there is no clear explanation of
2051 the direct cause, nor is there a manageably small test case that reliably
2052 reproduces the problem.
2054 If you encounter any of the following exceptions in B<random places within
2055 your application stack> - this module may be to blame:
2057 Operation "ne": no method found,
2058 left argument in overloaded package <something>,
2059 right argument in overloaded package <something>
2063 Stub found while resolving method "???" overloading """" in package <something>
2065 If you fall victim to the above - please attempt to reduce the problem
2066 to something that could be sent to the L<SQL::Abstract developers
2067 |DBIx::Class/GETTING HELP/SUPPORT>
2068 (either publicly or privately). As a workaround in the meantime you can
2069 set C<$ENV{SQLA_ISVALUE_IGNORE_AUTOGENERATED_STRINGIFICATION}> to a true
2070 value, which will most likely eliminate your problem (at the expense of
2071 not being able to properly detect exotic forms of stringification).
2073 This notice and environment variable will be removed in a future version,
2074 as soon as the underlying problem is found and a reliable workaround is
2079 =head2 is_literal_value
2081 Determines if the supplied argument is a literal value as understood by this
2086 =item * C<\$sql_string>
2088 =item * C<\[ $sql_string, @bind_values ]>
2092 On failure returns C<undef>, on success returns an B<array> reference
2093 containing the unpacked version of the supplied literal SQL and bind values.
2095 =head1 WHERE CLAUSES
2099 This module uses a variation on the idea from L<DBIx::Abstract>. It
2100 is B<NOT>, repeat I<not> 100% compatible. B<The main logic of this
2101 module is that things in arrays are OR'ed, and things in hashes
2104 The easiest way to explain is to show lots of examples. After
2105 each C<%where> hash shown, it is assumed you used:
2107 my($stmt, @bind) = $sql->where(\%where);
2109 However, note that the C<%where> hash can be used directly in any
2110 of the other functions as well, as described above.
2112 =head2 Key-value pairs
2114 So, let's get started. To begin, a simple hash:
2118 status => 'completed'
2121 Is converted to SQL C<key = val> statements:
2123 $stmt = "WHERE user = ? AND status = ?";
2124 @bind = ('nwiger', 'completed');
2126 One common thing I end up doing is having a list of values that
2127 a field can be in. To do this, simply specify a list inside of
2132 status => ['assigned', 'in-progress', 'pending'];
2135 This simple code will create the following:
2137 $stmt = "WHERE user = ? AND ( status = ? OR status = ? OR status = ? )";
2138 @bind = ('nwiger', 'assigned', 'in-progress', 'pending');
2140 A field associated to an empty arrayref will be considered a
2141 logical false and will generate 0=1.
2143 =head2 Tests for NULL values
2145 If the value part is C<undef> then this is converted to SQL <IS NULL>
2154 $stmt = "WHERE user = ? AND status IS NULL";
2157 To test if a column IS NOT NULL:
2161 status => { '!=', undef },
2164 =head2 Specific comparison operators
2166 If you want to specify a different type of operator for your comparison,
2167 you can use a hashref for a given column:
2171 status => { '!=', 'completed' }
2174 Which would generate:
2176 $stmt = "WHERE user = ? AND status != ?";
2177 @bind = ('nwiger', 'completed');
2179 To test against multiple values, just enclose the values in an arrayref:
2181 status => { '=', ['assigned', 'in-progress', 'pending'] };
2183 Which would give you:
2185 "WHERE status = ? OR status = ? OR status = ?"
2188 The hashref can also contain multiple pairs, in which case it is expanded
2189 into an C<AND> of its elements:
2193 status => { '!=', 'completed', -not_like => 'pending%' }
2196 # Or more dynamically, like from a form
2197 $where{user} = 'nwiger';
2198 $where{status}{'!='} = 'completed';
2199 $where{status}{'-not_like'} = 'pending%';
2201 # Both generate this
2202 $stmt = "WHERE user = ? AND status != ? AND status NOT LIKE ?";
2203 @bind = ('nwiger', 'completed', 'pending%');
2206 To get an OR instead, you can combine it with the arrayref idea:
2210 priority => [ { '=', 2 }, { '>', 5 } ]
2213 Which would generate:
2215 $stmt = "WHERE ( priority = ? OR priority > ? ) AND user = ?";
2216 @bind = ('2', '5', 'nwiger');
2218 If you want to include literal SQL (with or without bind values), just use a
2219 scalar reference or reference to an arrayref as the value:
2222 date_entered => { '>' => \["to_date(?, 'MM/DD/YYYY')", "11/26/2008"] },
2223 date_expires => { '<' => \"now()" }
2226 Which would generate:
2228 $stmt = "WHERE date_entered > to_date(?, 'MM/DD/YYYY') AND date_expires < now()";
2229 @bind = ('11/26/2008');
2232 =head2 Logic and nesting operators
2234 In the example above,
2235 there is a subtle trap if you want to say something like
2236 this (notice the C<AND>):
2238 WHERE priority != ? AND priority != ?
2240 Because, in Perl you I<can't> do this:
2242 priority => { '!=' => 2, '!=' => 1 }
2244 As the second C<!=> key will obliterate the first. The solution
2245 is to use the special C<-modifier> form inside an arrayref:
2247 priority => [ -and => {'!=', 2},
2251 Normally, these would be joined by C<OR>, but the modifier tells it
2252 to use C<AND> instead. (Hint: You can use this in conjunction with the
2253 C<logic> option to C<new()> in order to change the way your queries
2254 work by default.) B<Important:> Note that the C<-modifier> goes
2255 B<INSIDE> the arrayref, as an extra first element. This will
2256 B<NOT> do what you think it might:
2258 priority => -and => [{'!=', 2}, {'!=', 1}] # WRONG!
2260 Here is a quick list of equivalencies, since there is some overlap:
2263 status => {'!=', 'completed', 'not like', 'pending%' }
2264 status => [ -and => {'!=', 'completed'}, {'not like', 'pending%'}]
2267 status => {'=', ['assigned', 'in-progress']}
2268 status => [ -or => {'=', 'assigned'}, {'=', 'in-progress'}]
2269 status => [ {'=', 'assigned'}, {'=', 'in-progress'} ]
2273 =head2 Special operators: IN, BETWEEN, etc.
2275 You can also use the hashref format to compare a list of fields using the
2276 C<IN> comparison operator, by specifying the list as an arrayref:
2279 status => 'completed',
2280 reportid => { -in => [567, 2335, 2] }
2283 Which would generate:
2285 $stmt = "WHERE status = ? AND reportid IN (?,?,?)";
2286 @bind = ('completed', '567', '2335', '2');
2288 The reverse operator C<-not_in> generates SQL C<NOT IN> and is used in
2291 If the argument to C<-in> is an empty array, 'sqlfalse' is generated
2292 (by default: C<1=0>). Similarly, C<< -not_in => [] >> generates
2293 'sqltrue' (by default: C<1=1>).
2295 In addition to the array you can supply a chunk of literal sql or
2296 literal sql with bind:
2299 customer => { -in => \[
2300 'SELECT cust_id FROM cust WHERE balance > ?',
2303 status => { -in => \'SELECT status_codes FROM states' },
2309 customer IN ( SELECT cust_id FROM cust WHERE balance > ? )
2310 AND status IN ( SELECT status_codes FROM states )
2314 Finally, if the argument to C<-in> is not a reference, it will be
2315 treated as a single-element array.
2317 Another pair of operators is C<-between> and C<-not_between>,
2318 used with an arrayref of two values:
2322 completion_date => {
2323 -not_between => ['2002-10-01', '2003-02-06']
2329 WHERE user = ? AND completion_date NOT BETWEEN ( ? AND ? )
2331 Just like with C<-in> all plausible combinations of literal SQL
2335 start0 => { -between => [ 1, 2 ] },
2336 start1 => { -between => \["? AND ?", 1, 2] },
2337 start2 => { -between => \"lower(x) AND upper(y)" },
2338 start3 => { -between => [
2340 \["upper(?)", 'stuff' ],
2347 ( start0 BETWEEN ? AND ? )
2348 AND ( start1 BETWEEN ? AND ? )
2349 AND ( start2 BETWEEN lower(x) AND upper(y) )
2350 AND ( start3 BETWEEN lower(x) AND upper(?) )
2352 @bind = (1, 2, 1, 2, 'stuff');
2355 These are the two builtin "special operators"; but the
2356 list can be expanded: see section L</"SPECIAL OPERATORS"> below.
2358 =head2 Unary operators: bool
2360 If you wish to test against boolean columns or functions within your
2361 database you can use the C<-bool> and C<-not_bool> operators. For
2362 example to test the column C<is_user> being true and the column
2363 C<is_enabled> being false you would use:-
2367 -not_bool => 'is_enabled',
2372 WHERE is_user AND NOT is_enabled
2374 If a more complex combination is required, testing more conditions,
2375 then you should use the and/or operators:-
2380 -not_bool => { two=> { -rlike => 'bar' } },
2381 -not_bool => { three => [ { '=', 2 }, { '>', 5 } ] },
2392 (NOT ( three = ? OR three > ? ))
2395 =head2 Nested conditions, -and/-or prefixes
2397 So far, we've seen how multiple conditions are joined with a top-level
2398 C<AND>. We can change this by putting the different conditions we want in
2399 hashes and then putting those hashes in an array. For example:
2404 status => { -like => ['pending%', 'dispatched'] },
2408 status => 'unassigned',
2412 This data structure would create the following:
2414 $stmt = "WHERE ( user = ? AND ( status LIKE ? OR status LIKE ? ) )
2415 OR ( user = ? AND status = ? ) )";
2416 @bind = ('nwiger', 'pending', 'dispatched', 'robot', 'unassigned');
2419 Clauses in hashrefs or arrayrefs can be prefixed with an C<-and> or C<-or>
2420 to change the logic inside:
2426 -and => [ workhrs => {'>', 20}, geo => 'ASIA' ],
2427 -or => { workhrs => {'<', 50}, geo => 'EURO' },
2434 $stmt = "WHERE ( user = ?
2435 AND ( ( workhrs > ? AND geo = ? )
2436 OR ( workhrs < ? OR geo = ? ) ) )";
2437 @bind = ('nwiger', '20', 'ASIA', '50', 'EURO');
2439 =head3 Algebraic inconsistency, for historical reasons
2441 C<Important note>: when connecting several conditions, the C<-and->|C<-or>
2442 operator goes C<outside> of the nested structure; whereas when connecting
2443 several constraints on one column, the C<-and> operator goes
2444 C<inside> the arrayref. Here is an example combining both features:
2447 -and => [a => 1, b => 2],
2448 -or => [c => 3, d => 4],
2449 e => [-and => {-like => 'foo%'}, {-like => '%bar'} ]
2454 WHERE ( ( ( a = ? AND b = ? )
2455 OR ( c = ? OR d = ? )
2456 OR ( e LIKE ? AND e LIKE ? ) ) )
2458 This difference in syntax is unfortunate but must be preserved for
2459 historical reasons. So be careful: the two examples below would
2460 seem algebraically equivalent, but they are not
2463 { -like => 'foo%' },
2464 { -like => '%bar' },
2466 # yields: WHERE ( ( col LIKE ? AND col LIKE ? ) )
2469 { col => { -like => 'foo%' } },
2470 { col => { -like => '%bar' } },
2472 # yields: WHERE ( ( col LIKE ? OR col LIKE ? ) )
2475 =head2 Literal SQL and value type operators
2477 The basic premise of SQL::Abstract is that in WHERE specifications the "left
2478 side" is a column name and the "right side" is a value (normally rendered as
2479 a placeholder). This holds true for both hashrefs and arrayref pairs as you
2480 see in the L</WHERE CLAUSES> examples above. Sometimes it is necessary to
2481 alter this behavior. There are several ways of doing so.
2485 This is a virtual operator that signals the string to its right side is an
2486 identifier (a column name) and not a value. For example to compare two
2487 columns you would write:
2490 priority => { '<', 2 },
2491 requestor => { -ident => 'submitter' },
2496 $stmt = "WHERE priority < ? AND requestor = submitter";
2499 If you are maintaining legacy code you may see a different construct as
2500 described in L</Deprecated usage of Literal SQL>, please use C<-ident> in new
2505 This is a virtual operator that signals that the construct to its right side
2506 is a value to be passed to DBI. This is for example necessary when you want
2507 to write a where clause against an array (for RDBMS that support such
2508 datatypes). For example:
2511 array => { -value => [1, 2, 3] }
2516 $stmt = 'WHERE array = ?';
2517 @bind = ([1, 2, 3]);
2519 Note that if you were to simply say:
2525 the result would probably not be what you wanted:
2527 $stmt = 'WHERE array = ? OR array = ? OR array = ?';
2532 Finally, sometimes only literal SQL will do. To include a random snippet
2533 of SQL verbatim, you specify it as a scalar reference. Consider this only
2534 as a last resort. Usually there is a better way. For example:
2537 priority => { '<', 2 },
2538 requestor => { -in => \'(SELECT name FROM hitmen)' },
2543 $stmt = "WHERE priority < ? AND requestor IN (SELECT name FROM hitmen)"
2546 Note that in this example, you only get one bind parameter back, since
2547 the verbatim SQL is passed as part of the statement.
2551 Never use untrusted input as a literal SQL argument - this is a massive
2552 security risk (there is no way to check literal snippets for SQL
2553 injections and other nastyness). If you need to deal with untrusted input
2554 use literal SQL with placeholders as described next.
2556 =head3 Literal SQL with placeholders and bind values (subqueries)
2558 If the literal SQL to be inserted has placeholders and bind values,
2559 use a reference to an arrayref (yes this is a double reference --
2560 not so common, but perfectly legal Perl). For example, to find a date
2561 in Postgres you can use something like this:
2564 date_column => \[ "= date '2008-09-30' - ?::integer", 10 ]
2569 $stmt = "WHERE ( date_column = date '2008-09-30' - ?::integer )"
2572 Note that you must pass the bind values in the same format as they are returned
2573 by L<where|/where(\%where, $order)>. This means that if you set L</bindtype>
2574 to C<columns>, you must provide the bind values in the
2575 C<< [ column_meta => value ] >> format, where C<column_meta> is an opaque
2576 scalar value; most commonly the column name, but you can use any scalar value
2577 (including references and blessed references), L<SQL::Abstract> will simply
2578 pass it through intact. So if C<bindtype> is set to C<columns> the above
2579 example will look like:
2582 date_column => \[ "= date '2008-09-30' - ?::integer", [ {} => 10 ] ]
2585 Literal SQL is especially useful for nesting parenthesized clauses in the
2586 main SQL query. Here is a first example:
2588 my ($sub_stmt, @sub_bind) = ("SELECT c1 FROM t1 WHERE c2 < ? AND c3 LIKE ?",
2592 bar => \["IN ($sub_stmt)" => @sub_bind],
2597 $stmt = "WHERE (foo = ? AND bar IN (SELECT c1 FROM t1
2598 WHERE c2 < ? AND c3 LIKE ?))";
2599 @bind = (1234, 100, "foo%");
2601 Other subquery operators, like for example C<"E<gt> ALL"> or C<"NOT IN">,
2602 are expressed in the same way. Of course the C<$sub_stmt> and
2603 its associated bind values can be generated through a former call
2606 my ($sub_stmt, @sub_bind)
2607 = $sql->select("t1", "c1", {c2 => {"<" => 100},
2608 c3 => {-like => "foo%"}});
2611 bar => \["> ALL ($sub_stmt)" => @sub_bind],
2614 In the examples above, the subquery was used as an operator on a column;
2615 but the same principle also applies for a clause within the main C<%where>
2616 hash, like an EXISTS subquery:
2618 my ($sub_stmt, @sub_bind)
2619 = $sql->select("t1", "*", {c1 => 1, c2 => \"> t0.c0"});
2620 my %where = ( -and => [
2622 \["EXISTS ($sub_stmt)" => @sub_bind],
2627 $stmt = "WHERE (foo = ? AND EXISTS (SELECT * FROM t1
2628 WHERE c1 = ? AND c2 > t0.c0))";
2632 Observe that the condition on C<c2> in the subquery refers to
2633 column C<t0.c0> of the main query: this is I<not> a bind
2634 value, so we have to express it through a scalar ref.
2635 Writing C<< c2 => {">" => "t0.c0"} >> would have generated
2636 C<< c2 > ? >> with bind value C<"t0.c0"> ... not exactly
2637 what we wanted here.
2639 Finally, here is an example where a subquery is used
2640 for expressing unary negation:
2642 my ($sub_stmt, @sub_bind)
2643 = $sql->where({age => [{"<" => 10}, {">" => 20}]});
2644 $sub_stmt =~ s/^ where //i; # don't want "WHERE" in the subclause
2646 lname => {like => '%son%'},
2647 \["NOT ($sub_stmt)" => @sub_bind],
2652 $stmt = "lname LIKE ? AND NOT ( age < ? OR age > ? )"
2653 @bind = ('%son%', 10, 20)
2655 =head3 Deprecated usage of Literal SQL
2657 Below are some examples of archaic use of literal SQL. It is shown only as
2658 reference for those who deal with legacy code. Each example has a much
2659 better, cleaner and safer alternative that users should opt for in new code.
2665 my %where = ( requestor => \'IS NOT NULL' )
2667 $stmt = "WHERE requestor IS NOT NULL"
2669 This used to be the way of generating NULL comparisons, before the handling
2670 of C<undef> got formalized. For new code please use the superior syntax as
2671 described in L</Tests for NULL values>.
2675 my %where = ( requestor => \'= submitter' )
2677 $stmt = "WHERE requestor = submitter"
2679 This used to be the only way to compare columns. Use the superior L</-ident>
2680 method for all new code. For example an identifier declared in such a way
2681 will be properly quoted if L</quote_char> is properly set, while the legacy
2682 form will remain as supplied.
2686 my %where = ( is_ready => \"", completed => { '>', '2012-12-21' } )
2688 $stmt = "WHERE completed > ? AND is_ready"
2689 @bind = ('2012-12-21')
2691 Using an empty string literal used to be the only way to express a boolean.
2692 For all new code please use the much more readable
2693 L<-bool|/Unary operators: bool> operator.
2699 These pages could go on for a while, since the nesting of the data
2700 structures this module can handle are pretty much unlimited (the
2701 module implements the C<WHERE> expansion as a recursive function
2702 internally). Your best bet is to "play around" with the module a
2703 little to see how the data structures behave, and choose the best
2704 format for your data based on that.
2706 And of course, all the values above will probably be replaced with
2707 variables gotten from forms or the command line. After all, if you
2708 knew everything ahead of time, you wouldn't have to worry about
2709 dynamically-generating SQL and could just hardwire it into your
2712 =head1 ORDER BY CLAUSES
2714 Some functions take an order by clause. This can either be a scalar (just a
2715 column name), a hashref of C<< { -desc => 'col' } >> or C<< { -asc => 'col' }
2716 >>, a scalarref, an arrayref-ref, or an arrayref of any of the previous
2719 Given | Will Generate
2720 ---------------------------------------------------------------
2722 'colA' | ORDER BY colA
2724 [qw/colA colB/] | ORDER BY colA, colB
2726 {-asc => 'colA'} | ORDER BY colA ASC
2728 {-desc => 'colB'} | ORDER BY colB DESC
2730 ['colA', {-asc => 'colB'}] | ORDER BY colA, colB ASC
2732 { -asc => [qw/colA colB/] } | ORDER BY colA ASC, colB ASC
2734 \'colA DESC' | ORDER BY colA DESC
2736 \[ 'FUNC(colA, ?)', $x ] | ORDER BY FUNC(colA, ?)
2737 | /* ...with $x bound to ? */
2740 { -asc => 'colA' }, | colA ASC,
2741 { -desc => [qw/colB/] }, | colB DESC,
2742 { -asc => [qw/colC colD/] },| colC ASC, colD ASC,
2743 \'colE DESC', | colE DESC,
2744 \[ 'FUNC(colF, ?)', $x ], | FUNC(colF, ?)
2745 ] | /* ...with $x bound to ? */
2746 ===============================================================
2750 =head1 SPECIAL OPERATORS
2752 my $sqlmaker = SQL::Abstract->new(special_ops => [
2756 my ($self, $field, $op, $arg) = @_;
2762 handler => 'method_name',
2766 A "special operator" is a SQL syntactic clause that can be
2767 applied to a field, instead of a usual binary operator.
2770 WHERE field IN (?, ?, ?)
2771 WHERE field BETWEEN ? AND ?
2772 WHERE MATCH(field) AGAINST (?, ?)
2774 Special operators IN and BETWEEN are fairly standard and therefore
2775 are builtin within C<SQL::Abstract> (as the overridable methods
2776 C<_where_field_IN> and C<_where_field_BETWEEN>). For other operators,
2777 like the MATCH .. AGAINST example above which is specific to MySQL,
2778 you can write your own operator handlers - supply a C<special_ops>
2779 argument to the C<new> method. That argument takes an arrayref of
2780 operator definitions; each operator definition is a hashref with two
2787 the regular expression to match the operator
2791 Either a coderef or a plain scalar method name. In both cases
2792 the expected return is C<< ($sql, @bind) >>.
2794 When supplied with a method name, it is simply called on the
2795 L<SQL::Abstract> object as:
2797 $self->$method_name($field, $op, $arg)
2801 $field is the LHS of the operator
2802 $op is the part that matched the handler regex
2805 When supplied with a coderef, it is called as:
2807 $coderef->($self, $field, $op, $arg)
2812 For example, here is an implementation
2813 of the MATCH .. AGAINST syntax for MySQL
2815 my $sqlmaker = SQL::Abstract->new(special_ops => [
2817 # special op for MySql MATCH (field) AGAINST(word1, word2, ...)
2818 {regex => qr/^match$/i,
2820 my ($self, $field, $op, $arg) = @_;
2821 $arg = [$arg] if not ref $arg;
2822 my $label = $self->_quote($field);
2823 my ($placeholder) = $self->_convert('?');
2824 my $placeholders = join ", ", (($placeholder) x @$arg);
2825 my $sql = $self->_sqlcase('match') . " ($label) "
2826 . $self->_sqlcase('against') . " ($placeholders) ";
2827 my @bind = $self->_bindtype($field, @$arg);
2828 return ($sql, @bind);
2835 =head1 UNARY OPERATORS
2837 my $sqlmaker = SQL::Abstract->new(unary_ops => [
2841 my ($self, $op, $arg) = @_;
2847 handler => 'method_name',
2851 A "unary operator" is a SQL syntactic clause that can be
2852 applied to a field - the operator goes before the field
2854 You can write your own operator handlers - supply a C<unary_ops>
2855 argument to the C<new> method. That argument takes an arrayref of
2856 operator definitions; each operator definition is a hashref with two
2863 the regular expression to match the operator
2867 Either a coderef or a plain scalar method name. In both cases
2868 the expected return is C<< $sql >>.
2870 When supplied with a method name, it is simply called on the
2871 L<SQL::Abstract> object as:
2873 $self->$method_name($op, $arg)
2877 $op is the part that matched the handler regex
2878 $arg is the RHS or argument of the operator
2880 When supplied with a coderef, it is called as:
2882 $coderef->($self, $op, $arg)
2890 Thanks to some benchmarking by Mark Stosberg, it turns out that
2891 this module is many orders of magnitude faster than using C<DBIx::Abstract>.
2892 I must admit this wasn't an intentional design issue, but it's a
2893 byproduct of the fact that you get to control your C<DBI> handles
2896 To maximize performance, use a code snippet like the following:
2898 # prepare a statement handle using the first row
2899 # and then reuse it for the rest of the rows
2901 for my $href (@array_of_hashrefs) {
2902 $stmt ||= $sql->insert('table', $href);
2903 $sth ||= $dbh->prepare($stmt);
2904 $sth->execute($sql->values($href));
2907 The reason this works is because the keys in your C<$href> are sorted
2908 internally by B<SQL::Abstract>. Thus, as long as your data retains
2909 the same structure, you only have to generate the SQL the first time
2910 around. On subsequent queries, simply use the C<values> function provided
2911 by this module to return your values in the correct order.
2913 However this depends on the values having the same type - if, for
2914 example, the values of a where clause may either have values
2915 (resulting in sql of the form C<column = ?> with a single bind
2916 value), or alternatively the values might be C<undef> (resulting in
2917 sql of the form C<column IS NULL> with no bind value) then the
2918 caching technique suggested will not work.
2922 If you use my C<CGI::FormBuilder> module at all, you'll hopefully
2923 really like this part (I do, at least). Building up a complex query
2924 can be as simple as the following:
2931 use CGI::FormBuilder;
2934 my $form = CGI::FormBuilder->new(...);
2935 my $sql = SQL::Abstract->new;
2937 if ($form->submitted) {
2938 my $field = $form->field;
2939 my $id = delete $field->{id};
2940 my($stmt, @bind) = $sql->update('table', $field, {id => $id});
2943 Of course, you would still have to connect using C<DBI> to run the
2944 query, but the point is that if you make your form look like your
2945 table, the actual query script can be extremely simplistic.
2947 If you're B<REALLY> lazy (I am), check out C<HTML::QuickTable> for
2948 a fast interface to returning and formatting data. I frequently
2949 use these three modules together to write complex database query
2950 apps in under 50 lines.
2952 =head1 HOW TO CONTRIBUTE
2954 Contributions are always welcome, in all usable forms (we especially
2955 welcome documentation improvements). The delivery methods include git-
2956 or unified-diff formatted patches, GitHub pull requests, or plain bug
2957 reports either via RT or the Mailing list. Contributors are generally
2958 granted full access to the official repository after their first several
2959 patches pass successful review.
2961 This project is maintained in a git repository. The code and related tools are
2962 accessible at the following locations:
2966 =item * Official repo: L<git://git.shadowcat.co.uk/dbsrgits/SQL-Abstract.git>
2968 =item * Official gitweb: L<http://git.shadowcat.co.uk/gitweb/gitweb.cgi?p=dbsrgits/SQL-Abstract.git>
2970 =item * GitHub mirror: L<https://github.com/dbsrgits/sql-abstract>
2972 =item * Authorized committers: L<ssh://dbsrgits@git.shadowcat.co.uk/SQL-Abstract.git>
2978 Version 1.50 was a major internal refactoring of C<SQL::Abstract>.
2979 Great care has been taken to preserve the I<published> behavior
2980 documented in previous versions in the 1.* family; however,
2981 some features that were previously undocumented, or behaved
2982 differently from the documentation, had to be changed in order
2983 to clarify the semantics. Hence, client code that was relying
2984 on some dark areas of C<SQL::Abstract> v1.*
2985 B<might behave differently> in v1.50.
2987 The main changes are:
2993 support for literal SQL through the C<< \ [ $sql, @bind ] >> syntax.
2997 support for the { operator => \"..." } construct (to embed literal SQL)
3001 support for the { operator => \["...", @bind] } construct (to embed literal SQL with bind values)
3005 optional support for L<array datatypes|/"Inserting and Updating Arrays">
3009 defensive programming: check arguments
3013 fixed bug with global logic, which was previously implemented
3014 through global variables yielding side-effects. Prior versions would
3015 interpret C<< [ {cond1, cond2}, [cond3, cond4] ] >>
3016 as C<< "(cond1 AND cond2) OR (cond3 AND cond4)" >>.
3017 Now this is interpreted
3018 as C<< "(cond1 AND cond2) OR (cond3 OR cond4)" >>.
3023 fixed semantics of _bindtype on array args
3027 dropped the C<_anoncopy> of the %where tree. No longer necessary,
3028 we just avoid shifting arrays within that tree.
3032 dropped the C<_modlogic> function
3036 =head1 ACKNOWLEDGEMENTS
3038 There are a number of individuals that have really helped out with
3039 this module. Unfortunately, most of them submitted bugs via CPAN
3040 so I have no idea who they are! But the people I do know are:
3042 Ash Berlin (order_by hash term support)
3043 Matt Trout (DBIx::Class support)
3044 Mark Stosberg (benchmarking)
3045 Chas Owens (initial "IN" operator support)
3046 Philip Collins (per-field SQL functions)
3047 Eric Kolve (hashref "AND" support)
3048 Mike Fragassi (enhancements to "BETWEEN" and "LIKE")
3049 Dan Kubb (support for "quote_char" and "name_sep")
3050 Guillermo Roditi (patch to cleanup "IN" and "BETWEEN", fix and tests for _order_by)
3051 Laurent Dami (internal refactoring, extensible list of special operators, literal SQL)
3052 Norbert Buchmuller (support for literal SQL in hashpair, misc. fixes & tests)
3053 Peter Rabbitson (rewrite of SQLA::Test, misc. fixes & tests)
3054 Oliver Charles (support for "RETURNING" after "INSERT")
3060 L<DBIx::Class>, L<DBIx::Abstract>, L<CGI::FormBuilder>, L<HTML::QuickTable>.
3064 Copyright (c) 2001-2007 Nathan Wiger <nwiger@cpan.org>. All Rights Reserved.
3066 This module is actively maintained by Matt Trout <mst@shadowcatsystems.co.uk>
3068 For support, your best bet is to try the C<DBIx::Class> users mailing list.
3069 While not an official support venue, C<DBIx::Class> makes heavy use of
3070 C<SQL::Abstract>, and as such list members there are very familiar with
3071 how to create queries.
3075 This module is free software; you may copy this under the same
3076 terms as perl itself (either the GNU General Public License or
3077 the Artistic License)