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)
10 use warnings FATAL => 'all';
13 use Data::Query::Constants qw(
14 DQ_IDENTIFIER DQ_OPERATOR DQ_VALUE DQ_LITERAL DQ_JOIN DQ_SELECT DQ_ORDER
15 DQ_WHERE DQ_DELETE DQ_UPDATE DQ_INSERT
17 use Data::Query::ExprHelpers qw(perl_scalar_value);
19 #======================================================================
21 #======================================================================
23 our $VERSION = '1.72';
25 # This would confuse some packagers
26 $VERSION = eval $VERSION if $VERSION =~ /_/; # numify for warning-free dev releases
30 # special operators (-in, -between). May be extended/overridden by user.
31 # See section WHERE: BUILTIN SPECIAL OPERATORS below for implementation
32 my @BUILTIN_SPECIAL_OPS = ();
34 # unaryish operators - key maps to handler
35 my @BUILTIN_UNARY_OPS = ();
37 #======================================================================
38 # DEBUGGING AND ERROR REPORTING
39 #======================================================================
42 return unless $_[0]->{debug}; shift; # a little faster
43 my $func = (caller(1))[3];
44 warn "[$func] ", @_, "\n";
48 my($func) = (caller(1))[3];
49 Carp::carp "[$func] Warning: ", @_;
53 my($func) = (caller(1))[3];
54 Carp::croak "[$func] Fatal: ", @_;
58 #======================================================================
60 #======================================================================
64 my $class = ref($self) || $self;
65 my %opt = (ref $_[0] eq 'HASH') ? %{$_[0]} : @_;
67 # choose our case by keeping an option around
68 delete $opt{case} if $opt{case} && $opt{case} ne 'lower';
70 # default logic for interpreting arrayrefs
71 $opt{logic} = $opt{logic} ? uc $opt{logic} : 'OR';
73 # how to return bind vars
74 # LDNOTE: changed nwiger code : why this 'delete' ??
75 # $opt{bindtype} ||= delete($opt{bind_type}) || 'normal';
76 $opt{bindtype} ||= 'normal';
78 # default comparison is "=", but can be overridden
81 # try to recognize which are the 'equality' and 'unequality' ops
82 # (temporary quickfix, should go through a more seasoned API)
83 $opt{equality_op} = qr/^(\Q$opt{cmp}\E|is|(is\s+)?like)$/i;
84 $opt{inequality_op} = qr/^(!=|<>|(is\s+)?not(\s+like)?)$/i;
87 $opt{sqltrue} ||= '1=1';
88 $opt{sqlfalse} ||= '0=1';
91 $opt{special_ops} ||= [];
92 # regexes are applied in order, thus push after user-defines
93 push @{$opt{special_ops}}, @BUILTIN_SPECIAL_OPS;
96 $opt{unary_ops} ||= [];
97 push @{$opt{unary_ops}}, @BUILTIN_UNARY_OPS;
99 # rudimentary saniy-check for user supplied bits treated as functions/operators
100 # If a purported function matches this regular expression, an exception is thrown.
101 # Literal SQL is *NOT* subject to this check, only functions (and column names
102 # when quoting is not in effect)
105 # need to guard against ()'s in column names too, but this will break tons of
106 # hacks... ideas anyone?
107 $opt{injection_guard} ||= qr/
113 $opt{name_sep} ||= '.';
115 $opt{renderer} ||= do {
116 require Data::Query::Renderer::SQL::Naive;
117 my ($always, $chars);
118 for ($opt{quote_char}) {
119 $chars = defined() ? (ref() ? $_ : [$_]) : ['',''];
122 Data::Query::Renderer::SQL::Naive->new({
123 quote_chars => $chars, always_quote => $always,
124 ($opt{case} ? (lc_keywords => 1) : ()), # always 'lower' if it exists
128 return bless \%opt, $class;
132 my ($self, $dq) = @_;
136 my ($sql, @bind) = @{$self->{renderer}->render($dq)};
138 ($self->{bindtype} eq 'normal'
139 ? ($sql, map $_->{value}, @bind)
140 : ($sql, map [ $_->{value_meta}, $_->{value} ], @bind)
146 my ($self, $literal) = @_;
148 ($literal, @bind) = @$literal if ref($literal) eq 'ARRAY';
153 (@bind ? (values => [ $self->_bind_to_dq(@bind) ]) : ()),
158 my ($self, @bind) = @_;
160 $self->{bindtype} eq 'normal'
161 ? map perl_scalar_value($_), @bind
163 $self->_assert_bindval_matches_bindtype(@bind);
164 map perl_scalar_value(reverse @$_), @bind
169 my ($self, $value) = @_;
170 $self->_maybe_convert_dq(perl_scalar_value($value, our $Cur_Col_Meta));
174 my ($self, $ident) = @_;
175 $self->_assert_pass_injection_guard($ident)
176 unless $self->{renderer}{always_quote};
177 $self->_maybe_convert_dq({
178 type => DQ_IDENTIFIER,
179 elements => [ split /\Q$self->{name_sep}/, $ident ],
183 sub _maybe_convert_dq {
184 my ($self, $dq) = @_;
185 if (my $c = $self->{where_convert}) {
188 operator => { 'SQL.Naive' => 'apply' },
190 { type => DQ_IDENTIFIER, elements => [ $self->_sqlcase($c) ] },
200 my ($self, $op, @args) = @_;
201 $self->_assert_pass_injection_guard($op);
204 operator => { 'SQL.Naive' => $op },
209 sub _assert_pass_injection_guard {
210 if ($_[1] =~ $_[0]->{injection_guard}) {
211 my $class = ref $_[0];
212 puke "Possible SQL injection attempt '$_[1]'. If this is indeed a part of the "
213 . "desired SQL use literal SQL ( \'...' or \[ '...' ] ) or supply your own "
214 . "{injection_guard} attribute to ${class}->new()"
219 #======================================================================
221 #======================================================================
225 $self->_render_dq($self->_insert_to_dq(@_));
229 my ($self, $table, $data, $options) = @_;
230 my (@names, @values);
231 if (ref($data) eq 'HASH') {
232 @names = sort keys %$data;
233 foreach my $k (@names) {
234 local our $Cur_Col_Meta = $k;
235 push @values, $self->_mutation_rhs_to_dq($data->{$k});
237 } elsif (ref($data) eq 'ARRAY') {
238 local our $Cur_Col_Meta;
239 @values = map $self->_mutation_rhs_to_dq($_), @$data;
241 die "Not handled yet";
244 if (my $r_source = $options->{returning}) {
246 map +(ref($_) ? $self->_expr_to_dq($_) : $self->_ident_to_dq($_)),
247 (ref($r_source) eq 'ARRAY' ? @$r_source : $r_source),
252 target => $self->_ident_to_dq($table),
253 (@names ? (names => [ map $self->_ident_to_dq($_), @names ]) : ()),
254 values => [ \@values ],
255 ($returning ? (returning => $returning) : ()),
259 sub _mutation_rhs_to_dq {
261 if (ref($v) eq 'ARRAY') {
262 if ($self->{array_datatypes}) {
263 return $self->_value_to_dq($v);
265 $v = \do { my $x = $v };
267 if (ref($v) eq 'HASH') {
268 my ($op, $arg, @rest) = %$v;
270 puke 'Operator calls in update/insert must be in the form { -op => $arg }'
271 if (@rest or not $op =~ /^\-(.+)/);
273 return $self->_expr_to_dq($v);
276 #======================================================================
278 #======================================================================
283 $self->_render_dq($self->_update_to_dq(@_));
287 my ($self, $table, $data, $where) = @_;
289 puke "Unsupported data type specified to \$sql->update"
290 unless ref $data eq 'HASH';
294 foreach my $k (sort keys %$data) {
296 local our $Cur_Col_Meta = $k;
297 push @set, [ $self->_ident_to_dq($k), $self->_mutation_rhs_to_dq($v) ];
302 target => $self->_ident_to_dq($table),
304 where => $self->_where_to_dq($where),
309 #======================================================================
311 #======================================================================
314 my ($self, $table, $where) = @_;
316 my $source_dq = $self->_table_to_dq($table);
318 if (my $where_dq = $self->_where_to_dq($where)) {
331 return $self->_render_dq($self->_select_to_dq(@_));
335 my ($self, $table, $fields, $where, $order) = @_;
338 my $source_dq = $self->_source_to_dq($table, $where);
343 map $self->_ident_to_dq($_),
344 ref($fields) eq 'ARRAY' ? @$fields : $fields
350 $final_dq = $self->_order_by_to_dq($order, undef, $final_dq);
356 #======================================================================
358 #======================================================================
363 $self->_render_dq($self->_delete_to_dq(@_));
367 my ($self, $table, $where) = @_;
370 target => $self->_table_to_dq($table),
371 where => $self->_where_to_dq($where),
376 #======================================================================
378 #======================================================================
382 # Finally, a separate routine just to handle WHERE clauses
384 my ($self, $where, $order) = @_;
390 ($sql, @bind) = $self->_recurse_where($where) if defined($where);
391 $sql = $sql ? $self->_sqlcase(' where ') . "( $sql )" : '';
395 $sql .= $self->_order_by($order);
398 return wantarray ? ($sql, @bind) : $sql;
402 my ($self, $where, $logic) = @_;
404 return $self->_render_dq($self->_where_to_dq($where, $logic));
408 my ($self, $where, $logic) = @_;
410 return undef unless defined($where);
412 # turn the convert misfeature on - only used in WHERE clauses
413 local $self->{where_convert} = $self->{convert};
415 return $self->_expr_to_dq($where, $logic);
419 my ($self, $where, $logic) = @_;
421 if (ref($where) eq 'ARRAY') {
422 return $self->_expr_to_dq_ARRAYREF($where, $logic);
423 } elsif (ref($where) eq 'HASH') {
424 return $self->_expr_to_dq_HASHREF($where, $logic);
426 ref($where) eq 'SCALAR'
427 or (ref($where) eq 'REF' and ref($$where) eq 'ARRAY')
429 return $self->_literal_to_dq($$where);
430 } elsif (!ref($where) or Scalar::Util::blessed($where)) {
431 return $self->_value_to_dq($where);
433 die "Can't handle $where";
436 sub _expr_to_dq_ARRAYREF {
437 my ($self, $where, $logic) = @_;
439 $logic = uc($logic || $self->{logic} || 'OR');
440 $logic eq 'AND' or $logic eq 'OR' or puke "unknown logic: $logic";
442 return unless @$where;
444 my ($first, @rest) = @$where;
446 return $self->_expr_to_dq($first) unless @rest;
450 $self->_where_hashpair_to_dq($first => shift(@rest));
452 $self->_expr_to_dq($first);
456 return $self->_expr_to_dq_ARRAYREF(\@rest, $logic) unless $first_dq;
459 $logic, $first_dq, $self->_expr_to_dq_ARRAYREF(\@rest, $logic)
463 sub _expr_to_dq_HASHREF {
464 my ($self, $where, $logic) = @_;
466 $logic = uc($logic) if $logic;
469 $self->_where_hashpair_to_dq($_ => $where->{$_}, $logic)
472 return $dq[0] unless @dq > 1;
474 my $final = pop(@dq);
476 foreach my $dq (reverse @dq) {
477 $final = $self->_op_to_dq($logic||'AND', $dq, $final);
483 sub _where_to_dq_SCALAR {
484 shift->_value_to_dq(@_);
487 sub _where_op_IDENT {
489 my ($op, $rhs) = splice @_, -2;
491 puke "-$op takes a single scalar argument (a quotable identifier)";
494 # in case we are called as a top level special op (no '=')
497 $_ = $self->_convert($self->_quote($_)) for ($lhs, $rhs);
505 sub _where_op_VALUE {
507 my ($op, $rhs) = splice @_, -2;
509 # in case we are called as a top level special op (no '=')
514 ($lhs || $self->{_nested_func_lhs}),
521 $self->_convert($self->_quote($lhs)) . ' = ' . $self->_convert('?'),
525 $self->_convert('?'),
531 sub _where_hashpair_to_dq {
532 my ($self, $k, $v, $logic) = @_;
534 if ($k =~ /^-(.*)/s) {
536 if ($op eq 'AND' or $op eq 'OR') {
537 return $self->_expr_to_dq($v, $op);
538 } elsif ($op eq 'NEST') {
539 return $self->_expr_to_dq($v);
540 } elsif ($op eq 'NOT') {
541 return $self->_op_to_dq(NOT => $self->_expr_to_dq($v));
542 } elsif ($op eq 'BOOL') {
543 return ref($v) ? $self->_expr_to_dq($v) : $self->_ident_to_dq($v);
544 } elsif ($op eq 'NOT_BOOL') {
545 return $self->_op_to_dq(
546 NOT => ref($v) ? $self->_expr_to_dq($v) : $self->_ident_to_dq($v)
548 } elsif ($op =~ /^(?:AND|OR|NEST)_?\d+/) {
549 die "Use of [and|or|nest]_N modifiers is no longer supported";
552 if (ref($v) eq 'HASH' and keys(%$v) == 1 and (keys %$v)[0] =~ /^-(.*)/s) {
554 my ($inner) = values %$v;
557 (map $self->_expr_to_dq($_),
558 (ref($inner) eq 'ARRAY' ? @$inner : $inner))
561 (map $self->_expr_to_dq($_), (ref($v) eq 'ARRAY' ? @$v : $v))
564 $self->_assert_pass_injection_guard($op);
565 return $self->_op_to_dq(
566 apply => $self->_ident_to_dq($op), @args
570 local our $Cur_Col_Meta = $k;
571 if (ref($v) eq 'ARRAY') {
573 return $self->_literal_to_dq($self->{sqlfalse});
574 } elsif (defined($v->[0]) && $v->[0] =~ /-(and|or)/i) {
575 return $self->_expr_to_dq_ARRAYREF([
576 map +{ $k => $_ }, @{$v}[1..$#$v]
579 return $self->_expr_to_dq_ARRAYREF([
580 map +{ $k => $_ }, @$v
582 } elsif (ref($v) eq 'SCALAR' or (ref($v) eq 'REF' and ref($$v) eq 'ARRAY')) {
586 parts => [ $self->_ident_to_dq($k), $self->_literal_to_dq($$v) ]
589 my ($op, $rhs) = do {
590 if (ref($v) eq 'HASH') {
592 return $self->_expr_to_dq_ARRAYREF([
593 map +{ $k => { $_ => $v->{$_} } }, sort keys %$v
596 my ($op, $value) = %$v;
597 s/^-//, s/_/ /g for $op;
598 if ($op =~ /^(and|or)$/i) {
599 return $self->_expr_to_dq({ $k => $value }, $op);
601 my $special_op = List::Util::first {$op =~ $_->{regex}}
602 @{$self->{special_ops}}
604 return $self->_literal_to_dq(
605 [ $self->${\$special_op->{handler}}($k, $op, $value) ]
607 } elsif ($op =~ /^(?:AND|OR|NEST)_?\d+$/i) {
608 die "Use of [and|or|nest]_N modifiers is no longer supported";
615 if ($op eq 'BETWEEN' or $op eq 'IN' or $op eq 'NOT IN' or $op eq 'NOT BETWEEN') {
616 if (ref($rhs) ne 'ARRAY') {
618 # have to add parens if none present because -in => \"SELECT ..."
619 # got documented. mst hates everything.
620 if (ref($rhs) eq 'SCALAR') {
622 1 while ($x =~ s/\A\s*\((.*)\)\s*\Z/$1/s);
625 my ($x, @rest) = @{$$rhs};
626 1 while ($x =~ s/\A\s*\((.*)\)\s*\Z/$1/s);
627 $rhs = \[ $x, @rest ];
630 return $self->_op_to_dq(
631 $op, $self->_ident_to_dq($k), $self->_literal_to_dq($$rhs)
634 return $self->_literal_to_dq($self->{sqlfalse}) unless @$rhs;
635 return $self->_op_to_dq(
636 $op, $self->_ident_to_dq($k), map $self->_expr_to_dq($_), @$rhs
638 } elsif ($op =~ s/^NOT (?!LIKE)//) {
639 return $self->_where_hashpair_to_dq(-not => { $k => { $op => $rhs } });
640 } elsif (!defined($rhs)) {
642 if ($op eq '=' or $op eq 'LIKE') {
644 } elsif ($op eq '!=') {
647 die "Can't do undef -> NULL transform for operator ${op}";
650 return $self->_op_to_dq($null_op, $self->_ident_to_dq($k));
652 if (ref($rhs) eq 'ARRAY') {
654 return $self->_literal_to_dq(
655 $op eq '!=' ? $self->{sqltrue} : $self->{sqlfalse}
657 } elsif (defined($rhs->[0]) and $rhs->[0] =~ /^-(and|or)$/i) {
658 return $self->_expr_to_dq_ARRAYREF([
659 map +{ $k => { $op => $_ } }, @{$rhs}[1..$#$rhs]
661 } elsif ($op =~ /^-(?:AND|OR|NEST)_?\d+/) {
662 die "Use of [and|or|nest]_N modifiers is no longer supported";
664 return $self->_expr_to_dq_ARRAYREF([
665 map +{ $k => { $op => $_ } }, @$rhs
668 return $self->_op_to_dq(
669 $op, $self->_ident_to_dq($k), $self->_expr_to_dq($rhs)
674 #======================================================================
676 #======================================================================
679 my ($self, $arg) = @_;
680 if (my $dq = $self->_order_by_to_dq($arg)) {
681 # SQLA generates ' ORDER BY foo'. The hilarity.
683 ? do { my @r = $self->_render_dq($dq); $r[0] = ' '.$r[0]; @r }
684 : ' '.$self->_render_dq($dq);
690 sub _order_by_to_dq {
691 my ($self, $arg, $dir, $from) = @_;
697 ($dir ? (direction => $dir) : ()),
698 ($from ? (from => $from) : ()),
702 $dq->{by} = $self->_ident_to_dq($arg);
703 } elsif (ref($arg) eq 'ARRAY') {
705 local our $Order_Inner unless our $Order_Recursing;
706 local $Order_Recursing = 1;
708 foreach my $member (@$arg) {
710 my $next = $self->_order_by_to_dq($member, $dir, $from);
712 $inner->{from} = $next if $inner;
713 $inner = $Order_Inner || $next;
715 $Order_Inner = $inner;
717 } elsif (ref($arg) eq 'REF' and ref($$arg) eq 'ARRAY') {
718 $dq->{by} = $self->_literal_to_dq($$arg);
719 } elsif (ref($arg) eq 'SCALAR') {
720 $dq->{by} = $self->_literal_to_dq($$arg);
721 } elsif (ref($arg) eq 'HASH') {
722 my ($key, $val, @rest) = %$arg;
726 if (@rest or not $key =~ /^-(desc|asc)/i) {
727 puke "hash passed to _order_by must have exactly one key (-desc or -asc)";
730 return $self->_order_by_to_dq($val, $dir, $from);
732 die "Can't handle $arg in _order_by_to_dq";
737 #======================================================================
738 # DATASOURCE (FOR NOW, JUST PLAIN TABLE OR LIST OF TABLES)
739 #======================================================================
742 my ($self, $from) = @_;
743 $self->_render_dq($self->_table_to_dq($from));
747 my ($self, $from) = @_;
748 if (ref($from) eq 'ARRAY') {
749 die "Empty FROM list" unless my @f = @$from;
750 my $dq = $self->_table_to_dq(shift @f);
751 while (my $x = shift @f) {
754 join => [ $dq, $self->_table_to_dq($x) ]
758 } elsif (ref($from) eq 'SCALAR') {
765 $self->_ident_to_dq($from);
770 #======================================================================
772 #======================================================================
774 # highly optimized, as it's called way too often
776 # my ($self, $label) = @_;
778 return '' unless defined $_[1];
779 return ${$_[1]} if ref($_[1]) eq 'SCALAR';
781 unless ($_[0]->{quote_char}) {
782 $_[0]->_assert_pass_injection_guard($_[1]);
786 my $qref = ref $_[0]->{quote_char};
789 ($l, $r) = ( $_[0]->{quote_char}, $_[0]->{quote_char} );
791 elsif ($qref eq 'ARRAY') {
792 ($l, $r) = @{$_[0]->{quote_char}};
795 puke "Unsupported quote_char format: $_[0]->{quote_char}";
798 # parts containing * are naturally unquoted
799 return join( $_[0]->{name_sep}||'', map
800 { $_ eq '*' ? $_ : $l . $_ . $r }
801 ( $_[0]->{name_sep} ? split (/\Q$_[0]->{name_sep}\E/, $_[1] ) : $_[1] )
806 # Conversion, if applicable
808 #my ($self, $arg) = @_;
810 # LDNOTE : modified the previous implementation below because
811 # it was not consistent : the first "return" is always an array,
812 # the second "return" is context-dependent. Anyway, _convert
813 # seems always used with just a single argument, so make it a
815 # return @_ unless $self->{convert};
816 # my $conv = $self->_sqlcase($self->{convert});
817 # my @ret = map { $conv.'('.$_.')' } @_;
818 # return wantarray ? @ret : $ret[0];
819 if ($_[0]->{convert}) {
820 return $_[0]->_sqlcase($_[0]->{convert}) .'(' . $_[1] . ')';
827 #my ($self, $col, @vals) = @_;
829 #LDNOTE : changed original implementation below because it did not make
830 # sense when bindtype eq 'columns' and @vals > 1.
831 # return $self->{bindtype} eq 'columns' ? [ $col, @vals ] : @vals;
833 # called often - tighten code
834 return $_[0]->{bindtype} eq 'columns'
835 ? map {[$_[1], $_]} @_[2 .. $#_]
840 # Dies if any element of @bind is not in [colname => value] format
841 # if bindtype is 'columns'.
842 sub _assert_bindval_matches_bindtype {
843 # my ($self, @bind) = @_;
845 if ($self->{bindtype} eq 'columns') {
847 if (!defined $_ || ref($_) ne 'ARRAY' || @$_ != 2) {
848 puke "bindtype 'columns' selected, you need to pass: [column_name => bind_value]"
854 # Fix SQL case, if so requested
856 # LDNOTE: if $self->{case} is true, then it contains 'lower', so we
857 # don't touch the argument ... crooked logic, but let's not change it!
858 return $_[0]->{case} ? $_[1] : uc($_[1]);
861 #======================================================================
862 # VALUES, GENERATE, AUTOLOAD
863 #======================================================================
865 # LDNOTE: original code from nwiger, didn't touch code in that section
866 # I feel the AUTOLOAD stuff should not be the default, it should
867 # only be activated on explicit demand by user.
871 my $data = shift || return;
872 puke "Argument to ", __PACKAGE__, "->values must be a \\%hash"
873 unless ref $data eq 'HASH';
876 foreach my $k ( sort keys %$data ) {
878 local our $Cur_Col_Meta = $k;
879 my ($sql, @bind) = $self->_render_dq(
880 $self->_mutation_rhs_to_dq($v)
882 push @all_bind, @bind;
891 my(@sql, @sqlq, @sqlv);
895 if ($ref eq 'HASH') {
896 for my $k (sort keys %$_) {
899 my $label = $self->_quote($k);
901 # literal SQL with bind
902 my ($sql, @bind) = @$v;
903 $self->_assert_bindval_matches_bindtype(@bind);
904 push @sqlq, "$label = $sql";
906 } elsif ($r eq 'SCALAR') {
907 # literal SQL without bind
908 push @sqlq, "$label = $$v";
910 push @sqlq, "$label = ?";
911 push @sqlv, $self->_bindtype($k, $v);
914 push @sql, $self->_sqlcase('set'), join ', ', @sqlq;
915 } elsif ($ref eq 'ARRAY') {
916 # unlike insert(), assume these are ONLY the column names, i.e. for SQL
919 if ($r eq 'ARRAY') { # literal SQL with bind
920 my ($sql, @bind) = @$v;
921 $self->_assert_bindval_matches_bindtype(@bind);
924 } elsif ($r eq 'SCALAR') { # literal SQL without bind
925 # embedded literal SQL
932 push @sql, '(' . join(', ', @sqlq) . ')';
933 } elsif ($ref eq 'SCALAR') {
937 # strings get case twiddled
938 push @sql, $self->_sqlcase($_);
942 my $sql = join ' ', @sql;
944 # this is pretty tricky
945 # if ask for an array, return ($stmt, @bind)
946 # otherwise, s/?/shift @sqlv/ to put it inline
948 return ($sql, @sqlv);
950 1 while $sql =~ s/\?/my $d = shift(@sqlv);
951 ref $d ? $d->[1] : $d/e;
960 # # This allows us to check for a local, then _form, attr
962 # my($name) = $AUTOLOAD =~ /.*::(.+)/;
963 # return $self->generate($name, @_);
974 SQL::Abstract - Generate SQL from Perl data structures
980 my $sql = SQL::Abstract->new;
982 my($stmt, @bind) = $sql->select($table, \@fields, \%where, \@order);
984 my($stmt, @bind) = $sql->insert($table, \%fieldvals || \@values);
986 my($stmt, @bind) = $sql->update($table, \%fieldvals, \%where);
988 my($stmt, @bind) = $sql->delete($table, \%where);
990 # Then, use these in your DBI statements
991 my $sth = $dbh->prepare($stmt);
992 $sth->execute(@bind);
994 # Just generate the WHERE clause
995 my($stmt, @bind) = $sql->where(\%where, \@order);
997 # Return values in the same order, for hashed queries
998 # See PERFORMANCE section for more details
999 my @bind = $sql->values(\%fieldvals);
1003 This module was inspired by the excellent L<DBIx::Abstract>.
1004 However, in using that module I found that what I really wanted
1005 to do was generate SQL, but still retain complete control over my
1006 statement handles and use the DBI interface. So, I set out to
1007 create an abstract SQL generation module.
1009 While based on the concepts used by L<DBIx::Abstract>, there are
1010 several important differences, especially when it comes to WHERE
1011 clauses. I have modified the concepts used to make the SQL easier
1012 to generate from Perl data structures and, IMO, more intuitive.
1013 The underlying idea is for this module to do what you mean, based
1014 on the data structures you provide it. The big advantage is that
1015 you don't have to modify your code every time your data changes,
1016 as this module figures it out.
1018 To begin with, an SQL INSERT is as easy as just specifying a hash
1019 of C<key=value> pairs:
1022 name => 'Jimbo Bobson',
1023 phone => '123-456-7890',
1024 address => '42 Sister Lane',
1025 city => 'St. Louis',
1026 state => 'Louisiana',
1029 The SQL can then be generated with this:
1031 my($stmt, @bind) = $sql->insert('people', \%data);
1033 Which would give you something like this:
1035 $stmt = "INSERT INTO people
1036 (address, city, name, phone, state)
1037 VALUES (?, ?, ?, ?, ?)";
1038 @bind = ('42 Sister Lane', 'St. Louis', 'Jimbo Bobson',
1039 '123-456-7890', 'Louisiana');
1041 These are then used directly in your DBI code:
1043 my $sth = $dbh->prepare($stmt);
1044 $sth->execute(@bind);
1046 =head2 Inserting and Updating Arrays
1048 If your database has array types (like for example Postgres),
1049 activate the special option C<< array_datatypes => 1 >>
1050 when creating the C<SQL::Abstract> object.
1051 Then you may use an arrayref to insert and update database array types:
1053 my $sql = SQL::Abstract->new(array_datatypes => 1);
1055 planets => [qw/Mercury Venus Earth Mars/]
1058 my($stmt, @bind) = $sql->insert('solar_system', \%data);
1062 $stmt = "INSERT INTO solar_system (planets) VALUES (?)"
1064 @bind = (['Mercury', 'Venus', 'Earth', 'Mars']);
1067 =head2 Inserting and Updating SQL
1069 In order to apply SQL functions to elements of your C<%data> you may
1070 specify a reference to an arrayref for the given hash value. For example,
1071 if you need to execute the Oracle C<to_date> function on a value, you can
1072 say something like this:
1076 date_entered => \["to_date(?,'MM/DD/YYYY')", "03/02/2003"],
1079 The first value in the array is the actual SQL. Any other values are
1080 optional and would be included in the bind values array. This gives
1083 my($stmt, @bind) = $sql->insert('people', \%data);
1085 $stmt = "INSERT INTO people (name, date_entered)
1086 VALUES (?, to_date(?,'MM/DD/YYYY'))";
1087 @bind = ('Bill', '03/02/2003');
1089 An UPDATE is just as easy, all you change is the name of the function:
1091 my($stmt, @bind) = $sql->update('people', \%data);
1093 Notice that your C<%data> isn't touched; the module will generate
1094 the appropriately quirky SQL for you automatically. Usually you'll
1095 want to specify a WHERE clause for your UPDATE, though, which is
1096 where handling C<%where> hashes comes in handy...
1098 =head2 Complex where statements
1100 This module can generate pretty complicated WHERE statements
1101 easily. For example, simple C<key=value> pairs are taken to mean
1102 equality, and if you want to see if a field is within a set
1103 of values, you can use an arrayref. Let's say we wanted to
1104 SELECT some data based on this criteria:
1107 requestor => 'inna',
1108 worker => ['nwiger', 'rcwe', 'sfz'],
1109 status => { '!=', 'completed' }
1112 my($stmt, @bind) = $sql->select('tickets', '*', \%where);
1114 The above would give you something like this:
1116 $stmt = "SELECT * FROM tickets WHERE
1117 ( requestor = ? ) AND ( status != ? )
1118 AND ( worker = ? OR worker = ? OR worker = ? )";
1119 @bind = ('inna', 'completed', 'nwiger', 'rcwe', 'sfz');
1121 Which you could then use in DBI code like so:
1123 my $sth = $dbh->prepare($stmt);
1124 $sth->execute(@bind);
1130 The functions are simple. There's one for each major SQL operation,
1131 and a constructor you use first. The arguments are specified in a
1132 similar order to each function (table, then fields, then a where
1133 clause) to try and simplify things.
1138 =head2 new(option => 'value')
1140 The C<new()> function takes a list of options and values, and returns
1141 a new B<SQL::Abstract> object which can then be used to generate SQL
1142 through the methods below. The options accepted are:
1148 If set to 'lower', then SQL will be generated in all lowercase. By
1149 default SQL is generated in "textbook" case meaning something like:
1151 SELECT a_field FROM a_table WHERE some_field LIKE '%someval%'
1153 Any setting other than 'lower' is ignored.
1157 This determines what the default comparison operator is. By default
1158 it is C<=>, meaning that a hash like this:
1160 %where = (name => 'nwiger', email => 'nate@wiger.org');
1162 Will generate SQL like this:
1164 WHERE name = 'nwiger' AND email = 'nate@wiger.org'
1166 However, you may want loose comparisons by default, so if you set
1167 C<cmp> to C<like> you would get SQL such as:
1169 WHERE name like 'nwiger' AND email like 'nate@wiger.org'
1171 You can also override the comparsion on an individual basis - see
1172 the huge section on L</"WHERE CLAUSES"> at the bottom.
1174 =item sqltrue, sqlfalse
1176 Expressions for inserting boolean values within SQL statements.
1177 By default these are C<1=1> and C<1=0>. They are used
1178 by the special operators C<-in> and C<-not_in> for generating
1179 correct SQL even when the argument is an empty array (see below).
1183 This determines the default logical operator for multiple WHERE
1184 statements in arrays or hashes. If absent, the default logic is "or"
1185 for arrays, and "and" for hashes. This means that a WHERE
1189 event_date => {'>=', '2/13/99'},
1190 event_date => {'<=', '4/24/03'},
1193 will generate SQL like this:
1195 WHERE event_date >= '2/13/99' OR event_date <= '4/24/03'
1197 This is probably not what you want given this query, though (look
1198 at the dates). To change the "OR" to an "AND", simply specify:
1200 my $sql = SQL::Abstract->new(logic => 'and');
1202 Which will change the above C<WHERE> to:
1204 WHERE event_date >= '2/13/99' AND event_date <= '4/24/03'
1206 The logic can also be changed locally by inserting
1207 a modifier in front of an arrayref :
1209 @where = (-and => [event_date => {'>=', '2/13/99'},
1210 event_date => {'<=', '4/24/03'} ]);
1212 See the L</"WHERE CLAUSES"> section for explanations.
1216 This will automatically convert comparisons using the specified SQL
1217 function for both column and value. This is mostly used with an argument
1218 of C<upper> or C<lower>, so that the SQL will have the effect of
1219 case-insensitive "searches". For example, this:
1221 $sql = SQL::Abstract->new(convert => 'upper');
1222 %where = (keywords => 'MaKe iT CAse inSeNSItive');
1224 Will turn out the following SQL:
1226 WHERE upper(keywords) like upper('MaKe iT CAse inSeNSItive')
1228 The conversion can be C<upper()>, C<lower()>, or any other SQL function
1229 that can be applied symmetrically to fields (actually B<SQL::Abstract> does
1230 not validate this option; it will just pass through what you specify verbatim).
1234 This is a kludge because many databases suck. For example, you can't
1235 just bind values using DBI's C<execute()> for Oracle C<CLOB> or C<BLOB> fields.
1236 Instead, you have to use C<bind_param()>:
1238 $sth->bind_param(1, 'reg data');
1239 $sth->bind_param(2, $lots, {ora_type => ORA_CLOB});
1241 The problem is, B<SQL::Abstract> will normally just return a C<@bind> array,
1242 which loses track of which field each slot refers to. Fear not.
1244 If you specify C<bindtype> in new, you can determine how C<@bind> is returned.
1245 Currently, you can specify either C<normal> (default) or C<columns>. If you
1246 specify C<columns>, you will get an array that looks like this:
1248 my $sql = SQL::Abstract->new(bindtype => 'columns');
1249 my($stmt, @bind) = $sql->insert(...);
1252 [ 'column1', 'value1' ],
1253 [ 'column2', 'value2' ],
1254 [ 'column3', 'value3' ],
1257 You can then iterate through this manually, using DBI's C<bind_param()>.
1259 $sth->prepare($stmt);
1262 my($col, $data) = @$_;
1263 if ($col eq 'details' || $col eq 'comments') {
1264 $sth->bind_param($i, $data, {ora_type => ORA_CLOB});
1265 } elsif ($col eq 'image') {
1266 $sth->bind_param($i, $data, {ora_type => ORA_BLOB});
1268 $sth->bind_param($i, $data);
1272 $sth->execute; # execute without @bind now
1274 Now, why would you still use B<SQL::Abstract> if you have to do this crap?
1275 Basically, the advantage is still that you don't have to care which fields
1276 are or are not included. You could wrap that above C<for> loop in a simple
1277 sub called C<bind_fields()> or something and reuse it repeatedly. You still
1278 get a layer of abstraction over manual SQL specification.
1280 Note that if you set L</bindtype> to C<columns>, the C<\[$sql, @bind]>
1281 construct (see L</Literal SQL with placeholders and bind values (subqueries)>)
1282 will expect the bind values in this format.
1286 This is the character that a table or column name will be quoted
1287 with. By default this is an empty string, but you could set it to
1288 the character C<`>, to generate SQL like this:
1290 SELECT `a_field` FROM `a_table` WHERE `some_field` LIKE '%someval%'
1292 Alternatively, you can supply an array ref of two items, the first being the left
1293 hand quote character, and the second the right hand quote character. For
1294 example, you could supply C<['[',']']> for SQL Server 2000 compliant quotes
1295 that generates SQL like this:
1297 SELECT [a_field] FROM [a_table] WHERE [some_field] LIKE '%someval%'
1299 Quoting is useful if you have tables or columns names that are reserved
1300 words in your database's SQL dialect.
1304 This is the character that separates a table and column name. It is
1305 necessary to specify this when the C<quote_char> option is selected,
1306 so that tables and column names can be individually quoted like this:
1308 SELECT `table`.`one_field` FROM `table` WHERE `table`.`other_field` = 1
1310 =item injection_guard
1312 A regular expression C<qr/.../> that is applied to any C<-function> and unquoted
1313 column name specified in a query structure. This is a safety mechanism to avoid
1314 injection attacks when mishandling user input e.g.:
1316 my %condition_as_column_value_pairs = get_values_from_user();
1317 $sqla->select( ... , \%condition_as_column_value_pairs );
1319 If the expression matches an exception is thrown. Note that literal SQL
1320 supplied via C<\'...'> or C<\['...']> is B<not> checked in any way.
1322 Defaults to checking for C<;> and the C<GO> keyword (TransactSQL)
1324 =item array_datatypes
1326 When this option is true, arrayrefs in INSERT or UPDATE are
1327 interpreted as array datatypes and are passed directly
1329 When this option is false, arrayrefs are interpreted
1330 as literal SQL, just like refs to arrayrefs
1331 (but this behavior is for backwards compatibility; when writing
1332 new queries, use the "reference to arrayref" syntax
1338 Takes a reference to a list of "special operators"
1339 to extend the syntax understood by L<SQL::Abstract>.
1340 See section L</"SPECIAL OPERATORS"> for details.
1344 Takes a reference to a list of "unary operators"
1345 to extend the syntax understood by L<SQL::Abstract>.
1346 See section L</"UNARY OPERATORS"> for details.
1352 =head2 insert($table, \@values || \%fieldvals, \%options)
1354 This is the simplest function. You simply give it a table name
1355 and either an arrayref of values or hashref of field/value pairs.
1356 It returns an SQL INSERT statement and a list of bind values.
1357 See the sections on L</"Inserting and Updating Arrays"> and
1358 L</"Inserting and Updating SQL"> for information on how to insert
1359 with those data types.
1361 The optional C<\%options> hash reference may contain additional
1362 options to generate the insert SQL. Currently supported options
1369 Takes either a scalar of raw SQL fields, or an array reference of
1370 field names, and adds on an SQL C<RETURNING> statement at the end.
1371 This allows you to return data generated by the insert statement
1372 (such as row IDs) without performing another C<SELECT> statement.
1373 Note, however, this is not part of the SQL standard and may not
1374 be supported by all database engines.
1378 =head2 update($table, \%fieldvals, \%where)
1380 This takes a table, hashref of field/value pairs, and an optional
1381 hashref L<WHERE clause|/WHERE CLAUSES>. It returns an SQL UPDATE function and a list
1383 See the sections on L</"Inserting and Updating Arrays"> and
1384 L</"Inserting and Updating SQL"> for information on how to insert
1385 with those data types.
1387 =head2 select($source, $fields, $where, $order)
1389 This returns a SQL SELECT statement and associated list of bind values, as
1390 specified by the arguments :
1396 Specification of the 'FROM' part of the statement.
1397 The argument can be either a plain scalar (interpreted as a table
1398 name, will be quoted), or an arrayref (interpreted as a list
1399 of table names, joined by commas, quoted), or a scalarref
1400 (literal table name, not quoted), or a ref to an arrayref
1401 (list of literal table names, joined by commas, not quoted).
1405 Specification of the list of fields to retrieve from
1407 The argument can be either an arrayref (interpreted as a list
1408 of field names, will be joined by commas and quoted), or a
1409 plain scalar (literal SQL, not quoted).
1410 Please observe that this API is not as flexible as for
1411 the first argument C<$table>, for backwards compatibility reasons.
1415 Optional argument to specify the WHERE part of the query.
1416 The argument is most often a hashref, but can also be
1417 an arrayref or plain scalar --
1418 see section L<WHERE clause|/"WHERE CLAUSES"> for details.
1422 Optional argument to specify the ORDER BY part of the query.
1423 The argument can be a scalar, a hashref or an arrayref
1424 -- see section L<ORDER BY clause|/"ORDER BY CLAUSES">
1430 =head2 delete($table, \%where)
1432 This takes a table name and optional hashref L<WHERE clause|/WHERE CLAUSES>.
1433 It returns an SQL DELETE statement and list of bind values.
1435 =head2 where(\%where, \@order)
1437 This is used to generate just the WHERE clause. For example,
1438 if you have an arbitrary data structure and know what the
1439 rest of your SQL is going to look like, but want an easy way
1440 to produce a WHERE clause, use this. It returns an SQL WHERE
1441 clause and list of bind values.
1444 =head2 values(\%data)
1446 This just returns the values from the hash C<%data>, in the same
1447 order that would be returned from any of the other above queries.
1448 Using this allows you to markedly speed up your queries if you
1449 are affecting lots of rows. See below under the L</"PERFORMANCE"> section.
1451 =head2 generate($any, 'number', $of, \@data, $struct, \%types)
1453 Warning: This is an experimental method and subject to change.
1455 This returns arbitrarily generated SQL. It's a really basic shortcut.
1456 It will return two different things, depending on return context:
1458 my($stmt, @bind) = $sql->generate('create table', \$table, \@fields);
1459 my $stmt_and_val = $sql->generate('create table', \$table, \@fields);
1461 These would return the following:
1463 # First calling form
1464 $stmt = "CREATE TABLE test (?, ?)";
1465 @bind = (field1, field2);
1467 # Second calling form
1468 $stmt_and_val = "CREATE TABLE test (field1, field2)";
1470 Depending on what you're trying to do, it's up to you to choose the correct
1471 format. In this example, the second form is what you would want.
1475 $sql->generate('alter session', { nls_date_format => 'MM/YY' });
1479 ALTER SESSION SET nls_date_format = 'MM/YY'
1481 You get the idea. Strings get their case twiddled, but everything
1482 else remains verbatim.
1484 =head1 WHERE CLAUSES
1488 This module uses a variation on the idea from L<DBIx::Abstract>. It
1489 is B<NOT>, repeat I<not> 100% compatible. B<The main logic of this
1490 module is that things in arrays are OR'ed, and things in hashes
1493 The easiest way to explain is to show lots of examples. After
1494 each C<%where> hash shown, it is assumed you used:
1496 my($stmt, @bind) = $sql->where(\%where);
1498 However, note that the C<%where> hash can be used directly in any
1499 of the other functions as well, as described above.
1501 =head2 Key-value pairs
1503 So, let's get started. To begin, a simple hash:
1507 status => 'completed'
1510 Is converted to SQL C<key = val> statements:
1512 $stmt = "WHERE user = ? AND status = ?";
1513 @bind = ('nwiger', 'completed');
1515 One common thing I end up doing is having a list of values that
1516 a field can be in. To do this, simply specify a list inside of
1521 status => ['assigned', 'in-progress', 'pending'];
1524 This simple code will create the following:
1526 $stmt = "WHERE user = ? AND ( status = ? OR status = ? OR status = ? )";
1527 @bind = ('nwiger', 'assigned', 'in-progress', 'pending');
1529 A field associated to an empty arrayref will be considered a
1530 logical false and will generate 0=1.
1532 =head2 Tests for NULL values
1534 If the value part is C<undef> then this is converted to SQL <IS NULL>
1543 $stmt = "WHERE user = ? AND status IS NULL";
1546 To test if a column IS NOT NULL:
1550 status => { '!=', undef },
1553 =head2 Specific comparison operators
1555 If you want to specify a different type of operator for your comparison,
1556 you can use a hashref for a given column:
1560 status => { '!=', 'completed' }
1563 Which would generate:
1565 $stmt = "WHERE user = ? AND status != ?";
1566 @bind = ('nwiger', 'completed');
1568 To test against multiple values, just enclose the values in an arrayref:
1570 status => { '=', ['assigned', 'in-progress', 'pending'] };
1572 Which would give you:
1574 "WHERE status = ? OR status = ? OR status = ?"
1577 The hashref can also contain multiple pairs, in which case it is expanded
1578 into an C<AND> of its elements:
1582 status => { '!=', 'completed', -not_like => 'pending%' }
1585 # Or more dynamically, like from a form
1586 $where{user} = 'nwiger';
1587 $where{status}{'!='} = 'completed';
1588 $where{status}{'-not_like'} = 'pending%';
1590 # Both generate this
1591 $stmt = "WHERE user = ? AND status != ? AND status NOT LIKE ?";
1592 @bind = ('nwiger', 'completed', 'pending%');
1595 To get an OR instead, you can combine it with the arrayref idea:
1599 priority => [ { '=', 2 }, { '>', 5 } ]
1602 Which would generate:
1604 $stmt = "WHERE ( priority = ? OR priority > ? ) AND user = ?";
1605 @bind = ('2', '5', 'nwiger');
1607 If you want to include literal SQL (with or without bind values), just use a
1608 scalar reference or array reference as the value:
1611 date_entered => { '>' => \["to_date(?, 'MM/DD/YYYY')", "11/26/2008"] },
1612 date_expires => { '<' => \"now()" }
1615 Which would generate:
1617 $stmt = "WHERE date_entered > "to_date(?, 'MM/DD/YYYY') AND date_expires < now()";
1618 @bind = ('11/26/2008');
1621 =head2 Logic and nesting operators
1623 In the example above,
1624 there is a subtle trap if you want to say something like
1625 this (notice the C<AND>):
1627 WHERE priority != ? AND priority != ?
1629 Because, in Perl you I<can't> do this:
1631 priority => { '!=', 2, '!=', 1 }
1633 As the second C<!=> key will obliterate the first. The solution
1634 is to use the special C<-modifier> form inside an arrayref:
1636 priority => [ -and => {'!=', 2},
1640 Normally, these would be joined by C<OR>, but the modifier tells it
1641 to use C<AND> instead. (Hint: You can use this in conjunction with the
1642 C<logic> option to C<new()> in order to change the way your queries
1643 work by default.) B<Important:> Note that the C<-modifier> goes
1644 B<INSIDE> the arrayref, as an extra first element. This will
1645 B<NOT> do what you think it might:
1647 priority => -and => [{'!=', 2}, {'!=', 1}] # WRONG!
1649 Here is a quick list of equivalencies, since there is some overlap:
1652 status => {'!=', 'completed', 'not like', 'pending%' }
1653 status => [ -and => {'!=', 'completed'}, {'not like', 'pending%'}]
1656 status => {'=', ['assigned', 'in-progress']}
1657 status => [ -or => {'=', 'assigned'}, {'=', 'in-progress'}]
1658 status => [ {'=', 'assigned'}, {'=', 'in-progress'} ]
1662 =head2 Special operators : IN, BETWEEN, etc.
1664 You can also use the hashref format to compare a list of fields using the
1665 C<IN> comparison operator, by specifying the list as an arrayref:
1668 status => 'completed',
1669 reportid => { -in => [567, 2335, 2] }
1672 Which would generate:
1674 $stmt = "WHERE status = ? AND reportid IN (?,?,?)";
1675 @bind = ('completed', '567', '2335', '2');
1677 The reverse operator C<-not_in> generates SQL C<NOT IN> and is used in
1680 If the argument to C<-in> is an empty array, 'sqlfalse' is generated
1681 (by default : C<1=0>). Similarly, C<< -not_in => [] >> generates
1682 'sqltrue' (by default : C<1=1>).
1684 In addition to the array you can supply a chunk of literal sql or
1685 literal sql with bind:
1688 customer => { -in => \[
1689 'SELECT cust_id FROM cust WHERE balance > ?',
1692 status => { -in => \'SELECT status_codes FROM states' },
1698 customer IN ( SELECT cust_id FROM cust WHERE balance > ? )
1699 AND status IN ( SELECT status_codes FROM states )
1705 Another pair of operators is C<-between> and C<-not_between>,
1706 used with an arrayref of two values:
1710 completion_date => {
1711 -not_between => ['2002-10-01', '2003-02-06']
1717 WHERE user = ? AND completion_date NOT BETWEEN ( ? AND ? )
1719 Just like with C<-in> all plausible combinations of literal SQL
1723 start0 => { -between => [ 1, 2 ] },
1724 start1 => { -between => \["? AND ?", 1, 2] },
1725 start2 => { -between => \"lower(x) AND upper(y)" },
1726 start3 => { -between => [
1728 \["upper(?)", 'stuff' ],
1735 ( start0 BETWEEN ? AND ? )
1736 AND ( start1 BETWEEN ? AND ? )
1737 AND ( start2 BETWEEN lower(x) AND upper(y) )
1738 AND ( start3 BETWEEN lower(x) AND upper(?) )
1740 @bind = (1, 2, 1, 2, 'stuff');
1743 These are the two builtin "special operators"; but the
1744 list can be expanded : see section L</"SPECIAL OPERATORS"> below.
1746 =head2 Unary operators: bool
1748 If you wish to test against boolean columns or functions within your
1749 database you can use the C<-bool> and C<-not_bool> operators. For
1750 example to test the column C<is_user> being true and the column
1751 C<is_enabled> being false you would use:-
1755 -not_bool => 'is_enabled',
1760 WHERE is_user AND NOT is_enabled
1762 If a more complex combination is required, testing more conditions,
1763 then you should use the and/or operators:-
1770 -not_bool => 'four',
1776 WHERE one AND two AND three AND NOT four
1779 =head2 Nested conditions, -and/-or prefixes
1781 So far, we've seen how multiple conditions are joined with a top-level
1782 C<AND>. We can change this by putting the different conditions we want in
1783 hashes and then putting those hashes in an array. For example:
1788 status => { -like => ['pending%', 'dispatched'] },
1792 status => 'unassigned',
1796 This data structure would create the following:
1798 $stmt = "WHERE ( user = ? AND ( status LIKE ? OR status LIKE ? ) )
1799 OR ( user = ? AND status = ? ) )";
1800 @bind = ('nwiger', 'pending', 'dispatched', 'robot', 'unassigned');
1803 Clauses in hashrefs or arrayrefs can be prefixed with an C<-and> or C<-or>
1804 to change the logic inside :
1810 -and => [ workhrs => {'>', 20}, geo => 'ASIA' ],
1811 -or => { workhrs => {'<', 50}, geo => 'EURO' },
1818 WHERE ( user = ? AND (
1819 ( workhrs > ? AND geo = ? )
1820 OR ( workhrs < ? OR geo = ? )
1823 =head3 Algebraic inconsistency, for historical reasons
1825 C<Important note>: when connecting several conditions, the C<-and->|C<-or>
1826 operator goes C<outside> of the nested structure; whereas when connecting
1827 several constraints on one column, the C<-and> operator goes
1828 C<inside> the arrayref. Here is an example combining both features :
1831 -and => [a => 1, b => 2],
1832 -or => [c => 3, d => 4],
1833 e => [-and => {-like => 'foo%'}, {-like => '%bar'} ]
1838 WHERE ( ( ( a = ? AND b = ? )
1839 OR ( c = ? OR d = ? )
1840 OR ( e LIKE ? AND e LIKE ? ) ) )
1842 This difference in syntax is unfortunate but must be preserved for
1843 historical reasons. So be careful : the two examples below would
1844 seem algebraically equivalent, but they are not
1846 {col => [-and => {-like => 'foo%'}, {-like => '%bar'}]}
1847 # yields : WHERE ( ( col LIKE ? AND col LIKE ? ) )
1849 [-and => {col => {-like => 'foo%'}, {col => {-like => '%bar'}}]]
1850 # yields : WHERE ( ( col LIKE ? OR col LIKE ? ) )
1853 =head2 Literal SQL and value type operators
1855 The basic premise of SQL::Abstract is that in WHERE specifications the "left
1856 side" is a column name and the "right side" is a value (normally rendered as
1857 a placeholder). This holds true for both hashrefs and arrayref pairs as you
1858 see in the L</WHERE CLAUSES> examples above. Sometimes it is necessary to
1859 alter this behavior. There are several ways of doing so.
1863 This is a virtual operator that signals the string to its right side is an
1864 identifier (a column name) and not a value. For example to compare two
1865 columns you would write:
1868 priority => { '<', 2 },
1869 requestor => { -ident => 'submitter' },
1874 $stmt = "WHERE priority < ? AND requestor = submitter";
1877 If you are maintaining legacy code you may see a different construct as
1878 described in L</Deprecated usage of Literal SQL>, please use C<-ident> in new
1883 This is a virtual operator that signals that the construct to its right side
1884 is a value to be passed to DBI. This is for example necessary when you want
1885 to write a where clause against an array (for RDBMS that support such
1886 datatypes). For example:
1889 array => { -value => [1, 2, 3] }
1894 $stmt = 'WHERE array = ?';
1895 @bind = ([1, 2, 3]);
1897 Note that if you were to simply say:
1903 the result would porbably be not what you wanted:
1905 $stmt = 'WHERE array = ? OR array = ? OR array = ?';
1910 Finally, sometimes only literal SQL will do. To include a random snippet
1911 of SQL verbatim, you specify it as a scalar reference. Consider this only
1912 as a last resort. Usually there is a better way. For example:
1915 priority => { '<', 2 },
1916 requestor => { -in => \'(SELECT name FROM hitmen)' },
1921 $stmt = "WHERE priority < ? AND requestor IN (SELECT name FROM hitmen)"
1924 Note that in this example, you only get one bind parameter back, since
1925 the verbatim SQL is passed as part of the statement.
1929 Never use untrusted input as a literal SQL argument - this is a massive
1930 security risk (there is no way to check literal snippets for SQL
1931 injections and other nastyness). If you need to deal with untrusted input
1932 use literal SQL with placeholders as described next.
1934 =head3 Literal SQL with placeholders and bind values (subqueries)
1936 If the literal SQL to be inserted has placeholders and bind values,
1937 use a reference to an arrayref (yes this is a double reference --
1938 not so common, but perfectly legal Perl). For example, to find a date
1939 in Postgres you can use something like this:
1942 date_column => \[q/= date '2008-09-30' - ?::integer/, 10/]
1947 $stmt = "WHERE ( date_column = date '2008-09-30' - ?::integer )"
1950 Note that you must pass the bind values in the same format as they are returned
1951 by L</where>. That means that if you set L</bindtype> to C<columns>, you must
1952 provide the bind values in the C<< [ column_meta => value ] >> format, where
1953 C<column_meta> is an opaque scalar value; most commonly the column name, but
1954 you can use any scalar value (including references and blessed references),
1955 L<SQL::Abstract> will simply pass it through intact. So if C<bindtype> is set
1956 to C<columns> the above example will look like:
1959 date_column => \[q/= date '2008-09-30' - ?::integer/, [ dummy => 10 ]/]
1962 Literal SQL is especially useful for nesting parenthesized clauses in the
1963 main SQL query. Here is a first example :
1965 my ($sub_stmt, @sub_bind) = ("SELECT c1 FROM t1 WHERE c2 < ? AND c3 LIKE ?",
1969 bar => \["IN ($sub_stmt)" => @sub_bind],
1974 $stmt = "WHERE (foo = ? AND bar IN (SELECT c1 FROM t1
1975 WHERE c2 < ? AND c3 LIKE ?))";
1976 @bind = (1234, 100, "foo%");
1978 Other subquery operators, like for example C<"E<gt> ALL"> or C<"NOT IN">,
1979 are expressed in the same way. Of course the C<$sub_stmt> and
1980 its associated bind values can be generated through a former call
1983 my ($sub_stmt, @sub_bind)
1984 = $sql->select("t1", "c1", {c2 => {"<" => 100},
1985 c3 => {-like => "foo%"}});
1988 bar => \["> ALL ($sub_stmt)" => @sub_bind],
1991 In the examples above, the subquery was used as an operator on a column;
1992 but the same principle also applies for a clause within the main C<%where>
1993 hash, like an EXISTS subquery :
1995 my ($sub_stmt, @sub_bind)
1996 = $sql->select("t1", "*", {c1 => 1, c2 => \"> t0.c0"});
1997 my %where = ( -and => [
1999 \["EXISTS ($sub_stmt)" => @sub_bind],
2004 $stmt = "WHERE (foo = ? AND EXISTS (SELECT * FROM t1
2005 WHERE c1 = ? AND c2 > t0.c0))";
2009 Observe that the condition on C<c2> in the subquery refers to
2010 column C<t0.c0> of the main query : this is I<not> a bind
2011 value, so we have to express it through a scalar ref.
2012 Writing C<< c2 => {">" => "t0.c0"} >> would have generated
2013 C<< c2 > ? >> with bind value C<"t0.c0"> ... not exactly
2014 what we wanted here.
2016 Finally, here is an example where a subquery is used
2017 for expressing unary negation:
2019 my ($sub_stmt, @sub_bind)
2020 = $sql->where({age => [{"<" => 10}, {">" => 20}]});
2021 $sub_stmt =~ s/^ where //i; # don't want "WHERE" in the subclause
2023 lname => {like => '%son%'},
2024 \["NOT ($sub_stmt)" => @sub_bind],
2029 $stmt = "lname LIKE ? AND NOT ( age < ? OR age > ? )"
2030 @bind = ('%son%', 10, 20)
2032 =head3 Deprecated usage of Literal SQL
2034 Below are some examples of archaic use of literal SQL. It is shown only as
2035 reference for those who deal with legacy code. Each example has a much
2036 better, cleaner and safer alternative that users should opt for in new code.
2042 my %where = ( requestor => \'IS NOT NULL' )
2044 $stmt = "WHERE requestor IS NOT NULL"
2046 This used to be the way of generating NULL comparisons, before the handling
2047 of C<undef> got formalized. For new code please use the superior syntax as
2048 described in L</Tests for NULL values>.
2052 my %where = ( requestor => \'= submitter' )
2054 $stmt = "WHERE requestor = submitter"
2056 This used to be the only way to compare columns. Use the superior L</-ident>
2057 method for all new code. For example an identifier declared in such a way
2058 will be properly quoted if L</quote_char> is properly set, while the legacy
2059 form will remain as supplied.
2063 my %where = ( is_ready => \"", completed => { '>', '2012-12-21' } )
2065 $stmt = "WHERE completed > ? AND is_ready"
2066 @bind = ('2012-12-21')
2068 Using an empty string literal used to be the only way to express a boolean.
2069 For all new code please use the much more readable
2070 L<-bool|/Unary operators: bool> operator.
2076 These pages could go on for a while, since the nesting of the data
2077 structures this module can handle are pretty much unlimited (the
2078 module implements the C<WHERE> expansion as a recursive function
2079 internally). Your best bet is to "play around" with the module a
2080 little to see how the data structures behave, and choose the best
2081 format for your data based on that.
2083 And of course, all the values above will probably be replaced with
2084 variables gotten from forms or the command line. After all, if you
2085 knew everything ahead of time, you wouldn't have to worry about
2086 dynamically-generating SQL and could just hardwire it into your
2089 =head1 ORDER BY CLAUSES
2091 Some functions take an order by clause. This can either be a scalar (just a
2092 column name,) a hash of C<< { -desc => 'col' } >> or C<< { -asc => 'col' } >>,
2093 or an array of either of the two previous forms. Examples:
2095 Given | Will Generate
2096 ----------------------------------------------------------
2098 \'colA DESC' | ORDER BY colA DESC
2100 'colA' | ORDER BY colA
2102 [qw/colA colB/] | ORDER BY colA, colB
2104 {-asc => 'colA'} | ORDER BY colA ASC
2106 {-desc => 'colB'} | ORDER BY colB DESC
2108 ['colA', {-asc => 'colB'}] | ORDER BY colA, colB ASC
2110 { -asc => [qw/colA colB/] } | ORDER BY colA ASC, colB ASC
2113 { -asc => 'colA' }, | ORDER BY colA ASC, colB DESC,
2114 { -desc => [qw/colB/], | colC ASC, colD ASC
2115 { -asc => [qw/colC colD/],|
2117 ===========================================================
2121 =head1 SPECIAL OPERATORS
2123 my $sqlmaker = SQL::Abstract->new(special_ops => [
2127 my ($self, $field, $op, $arg) = @_;
2133 handler => 'method_name',
2137 A "special operator" is a SQL syntactic clause that can be
2138 applied to a field, instead of a usual binary operator.
2141 WHERE field IN (?, ?, ?)
2142 WHERE field BETWEEN ? AND ?
2143 WHERE MATCH(field) AGAINST (?, ?)
2145 Special operators IN and BETWEEN are fairly standard and therefore
2146 are builtin within C<SQL::Abstract> (as the overridable methods
2147 C<_where_field_IN> and C<_where_field_BETWEEN>). For other operators,
2148 like the MATCH .. AGAINST example above which is specific to MySQL,
2149 you can write your own operator handlers - supply a C<special_ops>
2150 argument to the C<new> method. That argument takes an arrayref of
2151 operator definitions; each operator definition is a hashref with two
2158 the regular expression to match the operator
2162 Either a coderef or a plain scalar method name. In both cases
2163 the expected return is C<< ($sql, @bind) >>.
2165 When supplied with a method name, it is simply called on the
2166 L<SQL::Abstract/> object as:
2168 $self->$method_name ($field, $op, $arg)
2172 $op is the part that matched the handler regex
2173 $field is the LHS of the operator
2176 When supplied with a coderef, it is called as:
2178 $coderef->($self, $field, $op, $arg)
2183 For example, here is an implementation
2184 of the MATCH .. AGAINST syntax for MySQL
2186 my $sqlmaker = SQL::Abstract->new(special_ops => [
2188 # special op for MySql MATCH (field) AGAINST(word1, word2, ...)
2189 {regex => qr/^match$/i,
2191 my ($self, $field, $op, $arg) = @_;
2192 $arg = [$arg] if not ref $arg;
2193 my $label = $self->_quote($field);
2194 my ($placeholder) = $self->_convert('?');
2195 my $placeholders = join ", ", (($placeholder) x @$arg);
2196 my $sql = $self->_sqlcase('match') . " ($label) "
2197 . $self->_sqlcase('against') . " ($placeholders) ";
2198 my @bind = $self->_bindtype($field, @$arg);
2199 return ($sql, @bind);
2206 =head1 UNARY OPERATORS
2208 my $sqlmaker = SQL::Abstract->new(unary_ops => [
2212 my ($self, $op, $arg) = @_;
2218 handler => 'method_name',
2222 A "unary operator" is a SQL syntactic clause that can be
2223 applied to a field - the operator goes before the field
2225 You can write your own operator handlers - supply a C<unary_ops>
2226 argument to the C<new> method. That argument takes an arrayref of
2227 operator definitions; each operator definition is a hashref with two
2234 the regular expression to match the operator
2238 Either a coderef or a plain scalar method name. In both cases
2239 the expected return is C<< $sql >>.
2241 When supplied with a method name, it is simply called on the
2242 L<SQL::Abstract/> object as:
2244 $self->$method_name ($op, $arg)
2248 $op is the part that matched the handler regex
2249 $arg is the RHS or argument of the operator
2251 When supplied with a coderef, it is called as:
2253 $coderef->($self, $op, $arg)
2261 Thanks to some benchmarking by Mark Stosberg, it turns out that
2262 this module is many orders of magnitude faster than using C<DBIx::Abstract>.
2263 I must admit this wasn't an intentional design issue, but it's a
2264 byproduct of the fact that you get to control your C<DBI> handles
2267 To maximize performance, use a code snippet like the following:
2269 # prepare a statement handle using the first row
2270 # and then reuse it for the rest of the rows
2272 for my $href (@array_of_hashrefs) {
2273 $stmt ||= $sql->insert('table', $href);
2274 $sth ||= $dbh->prepare($stmt);
2275 $sth->execute($sql->values($href));
2278 The reason this works is because the keys in your C<$href> are sorted
2279 internally by B<SQL::Abstract>. Thus, as long as your data retains
2280 the same structure, you only have to generate the SQL the first time
2281 around. On subsequent queries, simply use the C<values> function provided
2282 by this module to return your values in the correct order.
2284 However this depends on the values having the same type - if, for
2285 example, the values of a where clause may either have values
2286 (resulting in sql of the form C<column = ?> with a single bind
2287 value), or alternatively the values might be C<undef> (resulting in
2288 sql of the form C<column IS NULL> with no bind value) then the
2289 caching technique suggested will not work.
2293 If you use my C<CGI::FormBuilder> module at all, you'll hopefully
2294 really like this part (I do, at least). Building up a complex query
2295 can be as simple as the following:
2299 use CGI::FormBuilder;
2302 my $form = CGI::FormBuilder->new(...);
2303 my $sql = SQL::Abstract->new;
2305 if ($form->submitted) {
2306 my $field = $form->field;
2307 my $id = delete $field->{id};
2308 my($stmt, @bind) = $sql->update('table', $field, {id => $id});
2311 Of course, you would still have to connect using C<DBI> to run the
2312 query, but the point is that if you make your form look like your
2313 table, the actual query script can be extremely simplistic.
2315 If you're B<REALLY> lazy (I am), check out C<HTML::QuickTable> for
2316 a fast interface to returning and formatting data. I frequently
2317 use these three modules together to write complex database query
2318 apps in under 50 lines.
2324 =item * gitweb: L<http://git.shadowcat.co.uk/gitweb/gitweb.cgi?p=dbsrgits/SQL-Abstract.git>
2326 =item * git: L<git://git.shadowcat.co.uk/dbsrgits/SQL-Abstract.git>
2332 Version 1.50 was a major internal refactoring of C<SQL::Abstract>.
2333 Great care has been taken to preserve the I<published> behavior
2334 documented in previous versions in the 1.* family; however,
2335 some features that were previously undocumented, or behaved
2336 differently from the documentation, had to be changed in order
2337 to clarify the semantics. Hence, client code that was relying
2338 on some dark areas of C<SQL::Abstract> v1.*
2339 B<might behave differently> in v1.50.
2341 The main changes are :
2347 support for literal SQL through the C<< \ [$sql, bind] >> syntax.
2351 support for the { operator => \"..." } construct (to embed literal SQL)
2355 support for the { operator => \["...", @bind] } construct (to embed literal SQL with bind values)
2359 optional support for L<array datatypes|/"Inserting and Updating Arrays">
2363 defensive programming : check arguments
2367 fixed bug with global logic, which was previously implemented
2368 through global variables yielding side-effects. Prior versions would
2369 interpret C<< [ {cond1, cond2}, [cond3, cond4] ] >>
2370 as C<< "(cond1 AND cond2) OR (cond3 AND cond4)" >>.
2371 Now this is interpreted
2372 as C<< "(cond1 AND cond2) OR (cond3 OR cond4)" >>.
2377 fixed semantics of _bindtype on array args
2381 dropped the C<_anoncopy> of the %where tree. No longer necessary,
2382 we just avoid shifting arrays within that tree.
2386 dropped the C<_modlogic> function
2390 =head1 ACKNOWLEDGEMENTS
2392 There are a number of individuals that have really helped out with
2393 this module. Unfortunately, most of them submitted bugs via CPAN
2394 so I have no idea who they are! But the people I do know are:
2396 Ash Berlin (order_by hash term support)
2397 Matt Trout (DBIx::Class support)
2398 Mark Stosberg (benchmarking)
2399 Chas Owens (initial "IN" operator support)
2400 Philip Collins (per-field SQL functions)
2401 Eric Kolve (hashref "AND" support)
2402 Mike Fragassi (enhancements to "BETWEEN" and "LIKE")
2403 Dan Kubb (support for "quote_char" and "name_sep")
2404 Guillermo Roditi (patch to cleanup "IN" and "BETWEEN", fix and tests for _order_by)
2405 Laurent Dami (internal refactoring, extensible list of special operators, literal SQL)
2406 Norbert Buchmuller (support for literal SQL in hashpair, misc. fixes & tests)
2407 Peter Rabbitson (rewrite of SQLA::Test, misc. fixes & tests)
2408 Oliver Charles (support for "RETURNING" after "INSERT")
2414 L<DBIx::Class>, L<DBIx::Abstract>, L<CGI::FormBuilder>, L<HTML::QuickTable>.
2418 Copyright (c) 2001-2007 Nathan Wiger <nwiger@cpan.org>. All Rights Reserved.
2420 This module is actively maintained by Matt Trout <mst@shadowcatsystems.co.uk>
2422 For support, your best bet is to try the C<DBIx::Class> users mailing list.
2423 While not an official support venue, C<DBIx::Class> makes heavy use of
2424 C<SQL::Abstract>, and as such list members there are very familiar with
2425 how to create queries.
2429 This module is free software; you may copy this under the same
2430 terms as perl itself (either the GNU General Public License or
2431 the Artistic License)