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)
14 #======================================================================
16 #======================================================================
18 our $VERSION = '1.72';
20 # This would confuse some packagers
21 $VERSION = eval $VERSION if $VERSION =~ /_/; # numify for warning-free dev releases
25 # special operators (-in, -between). May be extended/overridden by user.
26 # See section WHERE: BUILTIN SPECIAL OPERATORS below for implementation
27 my @BUILTIN_SPECIAL_OPS = (
28 {regex => qr/^ (?: not \s )? between $/ix, handler => '_where_field_BETWEEN'},
29 {regex => qr/^ (?: not \s )? in $/ix, handler => '_where_field_IN'},
30 {regex => qr/^ func $/ix, handler => '_where_field_FUNC'},
31 {regex => qr/^ op $/ix, handler => '_where_op_OP'},
34 # unaryish operators - key maps to handler
35 my @BUILTIN_UNARY_OPS = (
36 # the digits are backcompat stuff
37 { regex => qr/^ and (?: [_\s]? \d+ )? $/xi, handler => '_where_op_ANDOR' },
38 { regex => qr/^ or (?: [_\s]? \d+ )? $/xi, handler => '_where_op_ANDOR' },
39 { regex => qr/^ nest (?: [_\s]? \d+ )? $/xi, handler => '_where_op_NEST' },
40 { regex => qr/^ (?: not \s )? bool $/xi, handler => '_where_op_BOOL' },
41 { regex => qr/^ func $/ix, handler => '_where_op_FUNC' },
42 { regex => qr/^ op $/ix, handler => '_where_op_OP' },
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($func) = (caller(1))[3];
57 carp "[$func] Warning: ", @_;
61 my($func) = (caller(1))[3];
62 croak "[$func] Fatal: ", @_;
66 #======================================================================
68 #======================================================================
72 my $class = ref($self) || $self;
73 my %opt = (ref $_[0] eq 'HASH') ? %{$_[0]} : @_;
75 # choose our case by keeping an option around
76 delete $opt{case} if $opt{case} && $opt{case} ne 'lower';
78 # default logic for interpreting arrayrefs
79 $opt{logic} = $opt{logic} ? uc $opt{logic} : 'OR';
81 # how to return bind vars
82 # LDNOTE: changed nwiger code : why this 'delete' ??
83 # $opt{bindtype} ||= delete($opt{bind_type}) || 'normal';
84 $opt{bindtype} ||= 'normal';
86 # default comparison is "=", but can be overridden
89 # try to recognize which are the 'equality' and 'unequality' ops
90 # (temporary quickfix, should go through a more seasoned API)
91 $opt{equality_op} = qr/^(\Q$opt{cmp}\E|is|(is\s+)?like)$/i;
92 $opt{inequality_op} = qr/^(!=|<>|(is\s+)?not(\s+like)?)$/i;
95 $opt{sqltrue} ||= '1=1';
96 $opt{sqlfalse} ||= '0=1';
99 $opt{special_ops} ||= [];
100 # regexes are applied in order, thus push after user-defines
101 push @{$opt{special_ops}}, @BUILTIN_SPECIAL_OPS;
104 $opt{unary_ops} ||= [];
105 push @{$opt{unary_ops}}, @BUILTIN_UNARY_OPS;
107 # rudimentary saniy-check for user supplied bits treated as functions/operators
108 # If a purported function matches this regular expression, an exception is thrown.
109 # Literal SQL is *NOT* subject to this check, only functions (and column names
110 # when quoting is not in effect)
113 # need to guard against ()'s in column names too, but this will break tons of
114 # hacks... ideas anyone?
115 $opt{injection_guard} ||= qr/
121 return bless \%opt, $class;
125 sub _assert_pass_injection_guard {
126 if ($_[1] =~ $_[0]->{injection_guard}) {
127 my $class = ref $_[0];
128 puke "Possible SQL injection attempt '$_[1]'. If this is indeed a part of the "
129 . "desired SQL use literal SQL ( \'...' or \[ '...' ] ) or supply your own "
130 . "{injection_guard} attribute to ${class}->new()"
135 #======================================================================
137 #======================================================================
141 my $table = $self->_table(shift);
142 my $data = shift || return;
145 my $method = $self->_METHOD_FOR_refkind("_insert", $data);
146 my ($sql, @bind) = $self->$method($data);
147 $sql = join " ", $self->_sqlcase('insert into'), $table, $sql;
149 if ($options->{returning}) {
150 my ($s, @b) = $self->_insert_returning ($options);
155 return wantarray ? ($sql, @bind) : $sql;
158 sub _insert_returning {
159 my ($self, $options) = @_;
161 my $f = $options->{returning};
163 my $fieldlist = $self->_SWITCH_refkind($f, {
164 ARRAYREF => sub {join ', ', map { $self->_quote($_) } @$f;},
165 SCALAR => sub {$self->_quote($f)},
166 SCALARREF => sub {$$f},
168 return $self->_sqlcase(' returning ') . $fieldlist;
171 sub _insert_HASHREF { # explicit list of fields and then values
172 my ($self, $data) = @_;
174 my @fields = sort keys %$data;
176 my ($sql, @bind) = $self->_insert_values($data);
179 $_ = $self->_quote($_) foreach @fields;
180 $sql = "( ".join(", ", @fields).") ".$sql;
182 return ($sql, @bind);
185 sub _insert_ARRAYREF { # just generate values(?,?) part (no list of fields)
186 my ($self, $data) = @_;
188 # no names (arrayref) so can't generate bindtype
189 $self->{bindtype} ne 'columns'
190 or belch "can't do 'columns' bindtype when called with arrayref";
192 # fold the list of values into a hash of column name - value pairs
193 # (where the column names are artificially generated, and their
194 # lexicographical ordering keep the ordering of the original list)
195 my $i = "a"; # incremented values will be in lexicographical order
196 my $data_in_hash = { map { ($i++ => $_) } @$data };
198 return $self->_insert_values($data_in_hash);
201 sub _insert_ARRAYREFREF { # literal SQL with bind
202 my ($self, $data) = @_;
204 my ($sql, @bind) = @${$data};
205 $self->_assert_bindval_matches_bindtype(@bind);
207 return ($sql, @bind);
211 sub _insert_SCALARREF { # literal SQL without bind
212 my ($self, $data) = @_;
218 my ($self, $data) = @_;
220 my (@values, @all_bind);
221 foreach my $column (sort keys %$data) {
222 my $v = $data->{$column};
224 $self->_SWITCH_refkind($v, {
227 if ($self->{array_datatypes}) { # if array datatype are activated
229 push @all_bind, $self->_bindtype($column, $v);
231 else { # else literal SQL with bind
232 my ($sql, @bind) = @$v;
233 $self->_assert_bindval_matches_bindtype(@bind);
235 push @all_bind, @bind;
239 ARRAYREFREF => sub { # literal SQL with bind
240 my ($sql, @bind) = @${$v};
241 $self->_assert_bindval_matches_bindtype(@bind);
243 push @all_bind, @bind;
246 # THINK : anything useful to do with a HASHREF ?
247 HASHREF => sub { # (nothing, but old SQLA passed it through)
248 #TODO in SQLA >= 2.0 it will die instead
249 belch "HASH ref as bind value in insert is not supported";
251 push @all_bind, $self->_bindtype($column, $v);
254 SCALARREF => sub { # literal SQL without bind
258 SCALAR_or_UNDEF => sub {
260 push @all_bind, $self->_bindtype($column, $v);
267 my $sql = $self->_sqlcase('values')." ( ".join(", ", @values)." )";
268 return ($sql, @all_bind);
273 #======================================================================
275 #======================================================================
280 my $table = $self->_table(shift);
281 my $data = shift || return;
284 # first build the 'SET' part of the sql statement
285 my (@set, @all_bind);
286 puke "Unsupported data type specified to \$sql->update"
287 unless ref $data eq 'HASH';
289 for my $k (sort keys %$data) {
292 my $label = $self->_quote($k);
294 $self->_SWITCH_refkind($v, {
296 if ($self->{array_datatypes}) { # array datatype
297 push @set, "$label = ?";
298 push @all_bind, $self->_bindtype($k, $v);
300 else { # literal SQL with bind
301 my ($sql, @bind) = @$v;
302 $self->_assert_bindval_matches_bindtype(@bind);
303 push @set, "$label = $sql";
304 push @all_bind, @bind;
307 ARRAYREFREF => sub { # literal SQL with bind
308 my ($sql, @bind) = @${$v};
309 $self->_assert_bindval_matches_bindtype(@bind);
310 push @set, "$label = $sql";
311 push @all_bind, @bind;
313 SCALARREF => sub { # literal SQL without bind
314 push @set, "$label = $$v";
317 my ($op, $arg, @rest) = %$v;
319 puke 'Operator calls in update must be in the form { -op => $arg }'
320 if (@rest or not $op =~ /^\-(.+)/);
322 local $self->{_nested_func_lhs} = $k;
323 my ($sql, @bind) = $self->_where_unary_op ($1, $arg);
325 push @set, "$label = $sql";
326 push @all_bind, @bind;
328 SCALAR_or_UNDEF => sub {
329 push @set, "$label = ?";
330 push @all_bind, $self->_bindtype($k, $v);
336 my $sql = $self->_sqlcase('update') . " $table " . $self->_sqlcase('set ')
340 my($where_sql, @where_bind) = $self->where($where);
342 push @all_bind, @where_bind;
345 return wantarray ? ($sql, @all_bind) : $sql;
351 #======================================================================
353 #======================================================================
358 my $table = $self->_table(shift);
359 my $fields = shift || '*';
363 my($where_sql, @bind) = $self->where($where, $order);
365 my $f = (ref $fields eq 'ARRAY') ? join ', ', map { $self->_quote($_) } @$fields
367 my $sql = join(' ', $self->_sqlcase('select'), $f,
368 $self->_sqlcase('from'), $table)
371 return wantarray ? ($sql, @bind) : $sql;
374 #======================================================================
376 #======================================================================
381 my $table = $self->_table(shift);
385 my($where_sql, @bind) = $self->where($where);
386 my $sql = $self->_sqlcase('delete from') . " $table" . $where_sql;
388 return wantarray ? ($sql, @bind) : $sql;
392 #======================================================================
394 #======================================================================
398 # Finally, a separate routine just to handle WHERE clauses
400 my ($self, $where, $order) = @_;
403 my ($sql, @bind) = $self->_recurse_where($where);
404 $sql = $sql ? $self->_sqlcase(' where ') . "( $sql )" : '';
408 $sql .= $self->_order_by($order);
411 return wantarray ? ($sql, @bind) : $sql;
416 my ($self, $where, $logic) = @_;
418 # dispatch on appropriate method according to refkind of $where
419 my $method = $self->_METHOD_FOR_refkind("_where", $where);
421 my ($sql, @bind) = $self->$method($where, $logic);
423 # DBIx::Class directly calls _recurse_where in scalar context, so
424 # we must implement it, even if not in the official API
425 return wantarray ? ($sql, @bind) : $sql;
430 #======================================================================
431 # WHERE: top-level ARRAYREF
432 #======================================================================
435 sub _where_ARRAYREF {
436 my ($self, $where, $logic) = @_;
438 $logic = uc($logic || $self->{logic});
439 $logic eq 'AND' or $logic eq 'OR' or puke "unknown logic: $logic";
441 my @clauses = @$where;
443 my (@sql_clauses, @all_bind);
444 # need to use while() so can shift() for pairs
445 while (my $el = shift @clauses) {
447 # switch according to kind of $el and get corresponding ($sql, @bind)
448 my ($sql, @bind) = $self->_SWITCH_refkind($el, {
450 # skip empty elements, otherwise get invalid trailing AND stuff
451 ARRAYREF => sub {$self->_recurse_where($el) if @$el},
455 $self->_assert_bindval_matches_bindtype(@b);
459 HASHREF => sub {$self->_recurse_where($el, 'and') if %$el},
460 # LDNOTE : previous SQLA code for hashrefs was creating a dirty
461 # side-effect: the first hashref within an array would change
462 # the global logic to 'AND'. So [ {cond1, cond2}, [cond3, cond4] ]
463 # was interpreted as "(cond1 AND cond2) OR (cond3 AND cond4)",
464 # whereas it should be "(cond1 AND cond2) OR (cond3 OR cond4)".
466 SCALARREF => sub { ($$el); },
468 SCALAR => sub {# top-level arrayref with scalars, recurse in pairs
469 $self->_recurse_where({$el => shift(@clauses)})},
471 UNDEF => sub {puke "not supported : UNDEF in arrayref" },
475 push @sql_clauses, $sql;
476 push @all_bind, @bind;
480 return $self->_join_sql_clauses($logic, \@sql_clauses, \@all_bind);
483 #======================================================================
484 # WHERE: top-level ARRAYREFREF
485 #======================================================================
487 sub _where_ARRAYREFREF {
488 my ($self, $where) = @_;
489 my ($sql, @bind) = @$$where;
490 $self->_assert_bindval_matches_bindtype(@bind);
491 return ($sql, @bind);
494 #======================================================================
495 # WHERE: top-level HASHREF
496 #======================================================================
499 my ($self, $where) = @_;
500 my (@sql_clauses, @all_bind);
502 for my $k (sort keys %$where) {
503 my $v = $where->{$k};
505 # ($k => $v) is either a special unary op or a regular hashpair
506 my ($sql, @bind) = do {
508 # put the operator in canonical form
510 $op = substr $op, 1; # remove initial dash
511 $op =~ s/^\s+|\s+$//g;# remove leading/trailing space
512 $op =~ s/\s+/ /g; # compress whitespace
514 # so that -not_foo works correctly
515 $op =~ s/^not_/NOT /i;
517 $self->_debug("Unary OP(-$op) within hashref, recursing...");
518 my ($s, @b) = $self->_where_unary_op ($op, $v);
520 # top level vs nested
521 # we assume that handled unary ops will take care of their ()s
523 List::Util::first {$op =~ $_->{regex}} @{$self->{unary_ops}}
525 defined($self->{_nested_func_lhs}) && ($self->{_nested_func_lhs} eq $k)
530 my $method = $self->_METHOD_FOR_refkind("_where_hashpair", $v);
531 $self->$method($k, $v);
535 push @sql_clauses, $sql;
536 push @all_bind, @bind;
539 return $self->_join_sql_clauses('and', \@sql_clauses, \@all_bind);
542 sub _where_unary_op {
543 my ($self, $op, $rhs) = @_;
545 if (my $op_entry = List::Util::first {$op =~ $_->{regex}} @{$self->{unary_ops}}) {
546 my $handler = $op_entry->{handler};
548 if (not ref $handler) {
549 if ($op =~ s/ [_\s]? \d+ $//x ) {
550 belch 'Use of [and|or|nest]_N modifiers is deprecated and will be removed in SQLA v2.0. '
551 . "You probably wanted ...-and => [ -$op => COND1, -$op => COND2 ... ]";
553 return $self->$handler ($op, $rhs);
555 elsif (ref $handler eq 'CODE') {
556 return $handler->($self, $op, $rhs);
559 puke "Illegal handler for operator $op - expecting a method name or a coderef";
563 $self->debug("Generic unary OP: $op - recursing as function");
565 $self->_assert_pass_injection_guard($op);
567 my ($sql, @bind) = $self->_SWITCH_refkind ($rhs, {
569 puke "Illegal use of top-level '$op'"
570 unless $self->{_nested_func_lhs};
573 $self->_convert('?'),
574 $self->_bindtype($self->{_nested_func_lhs}, $rhs)
578 $self->_recurse_where ($rhs)
582 $sql = sprintf ('%s %s',
583 $self->_sqlcase($op),
587 return ($sql, @bind);
590 sub _where_op_ANDOR {
591 my ($self, $op, $v) = @_;
593 $self->_SWITCH_refkind($v, {
595 return $self->_where_ARRAYREF($v, $op);
599 return ( $op =~ /^or/i )
600 ? $self->_where_ARRAYREF( [ map { $_ => $v->{$_} } ( sort keys %$v ) ], $op )
601 : $self->_where_HASHREF($v);
605 puke "-$op => \\\$scalar makes little sense, use " .
607 ? '[ \$scalar, \%rest_of_conditions ] instead'
608 : '-and => [ \$scalar, \%rest_of_conditions ] instead'
613 puke "-$op => \\[...] makes little sense, use " .
615 ? '[ \[...], \%rest_of_conditions ] instead'
616 : '-and => [ \[...], \%rest_of_conditions ] instead'
620 SCALAR => sub { # permissively interpreted as SQL
621 puke "-$op => \$value makes little sense, use -bool => \$value instead";
625 puke "-$op => undef not supported";
631 my ($self, $op, $v) = @_;
633 $self->_SWITCH_refkind($v, {
635 SCALAR => sub { # permissively interpreted as SQL
636 belch "literal SQL should be -nest => \\'scalar' "
637 . "instead of -nest => 'scalar' ";
642 puke "-$op => undef not supported";
646 $self->_recurse_where ($v);
654 my ($self, $op, $v) = @_;
656 my ($s, @b) = $self->_SWITCH_refkind($v, {
657 SCALAR => sub { # interpreted as SQL column
658 $self->_convert($self->_quote($v));
662 puke "-$op => undef not supported";
666 $self->_recurse_where ($v);
670 $s = "(NOT $s)" if $op =~ /^not/i;
675 sub _where_hashpair_ARRAYREF {
676 my ($self, $k, $v) = @_;
679 my @v = @$v; # need copy because of shift below
680 $self->_debug("ARRAY($k) means distribute over elements");
682 # put apart first element if it is an operator (-and, -or)
684 (defined $v[0] && $v[0] =~ /^ - (?: AND|OR ) $/ix)
688 my @distributed = map { {$k => $_} } @v;
691 $self->_debug("OP($op) reinjected into the distributed array");
692 unshift @distributed, $op;
695 my $logic = $op ? substr($op, 1) : '';
697 return $self->_recurse_where(\@distributed, $logic);
700 # LDNOTE : not sure of this one. What does "distribute over nothing" mean?
701 $self->_debug("empty ARRAY($k) means 0=1");
702 return ($self->{sqlfalse});
706 sub _where_hashpair_HASHREF {
707 my ($self, $k, $v, $logic) = @_;
710 local $self->{_nested_func_lhs} = $self->{_nested_func_lhs};
712 my ($all_sql, @all_bind);
714 for my $orig_op (sort keys %$v) {
715 my $val = $v->{$orig_op};
717 # put the operator in canonical form
720 # FIXME - we need to phase out dash-less ops
721 $op =~ s/^-//; # remove possible initial dash
722 $op =~ s/^\s+|\s+$//g;# remove leading/trailing space
723 $op =~ s/\s+/ /g; # compress whitespace
725 $self->_assert_pass_injection_guard($op);
727 # so that -not_foo works correctly
728 $op =~ s/^not_/NOT /i;
732 # CASE: col-value logic modifiers
733 if ( $orig_op =~ /^ \- (and|or) $/xi ) {
734 ($sql, @bind) = $self->_where_hashpair_HASHREF($k, $val, $1);
736 # CASE: special operators like -in or -between
737 elsif ( my $special_op = List::Util::first {$op =~ $_->{regex}} @{$self->{special_ops}} ) {
738 my $handler = $special_op->{handler};
740 puke "No handler supplied for special operator $orig_op";
742 elsif (not ref $handler) {
743 ($sql, @bind) = $self->$handler ($k, $op, $val);
745 elsif (ref $handler eq 'CODE') {
746 ($sql, @bind) = $handler->($self, $k, $op, $val);
749 puke "Illegal handler for special operator $orig_op - expecting a method name or a coderef";
753 $self->_SWITCH_refkind($val, {
755 ARRAYREF => sub { # CASE: col => {op => \@vals}
756 ($sql, @bind) = $self->_where_field_op_ARRAYREF($k, $op, $val);
759 ARRAYREFREF => sub { # CASE: col => {op => \[$sql, @bind]} (literal SQL with bind)
760 my ($sub_sql, @sub_bind) = @$$val;
761 $self->_assert_bindval_matches_bindtype(@sub_bind);
762 $sql = join ' ', $self->_convert($self->_quote($k)),
763 $self->_sqlcase($op),
768 UNDEF => sub { # CASE: col => {op => undef} : sql "IS (NOT)? NULL"
769 my $is = ($op =~ $self->{equality_op}) ? 'is' :
770 ($op =~ $self->{inequality_op}) ? 'is not' :
771 puke "unexpected operator '$orig_op' with undef operand";
772 $sql = $self->_quote($k) . $self->_sqlcase(" $is null");
775 FALLBACK => sub { # CASE: col => {op/func => $stuff}
777 # retain for proper column type bind
778 $self->{_nested_func_lhs} ||= $k;
780 ($sql, @bind) = $self->_where_unary_op ($op, $val);
783 $self->_convert($self->_quote($k)),
784 $self->{_nested_func_lhs} eq $k ? $sql : "($sql)", # top level vs nested
790 ($all_sql) = (defined $all_sql and $all_sql) ? $self->_join_sql_clauses($logic, [$all_sql, $sql], []) : $sql;
791 push @all_bind, @bind;
793 return ($all_sql, @all_bind);
798 sub _where_field_op_ARRAYREF {
799 my ($self, $k, $op, $vals) = @_;
801 my @vals = @$vals; #always work on a copy
804 $self->_debug(sprintf '%s means multiple elements: [ %s ]',
806 join (', ', map { defined $_ ? "'$_'" : 'NULL' } @vals ),
809 # see if the first element is an -and/-or op
811 if (defined $vals[0] && $vals[0] =~ /^ - ( AND|OR ) $/ix) {
816 # distribute $op over each remaining member of @vals, append logic if exists
817 return $self->_recurse_where([map { {$k => {$op, $_}} } @vals], $logic);
819 # LDNOTE : had planned to change the distribution logic when
820 # $op =~ $self->{inequality_op}, because of Morgan laws :
821 # with {field => {'!=' => [22, 33]}}, it would be ridiculous to generate
822 # WHERE field != 22 OR field != 33 : the user probably means
823 # WHERE field != 22 AND field != 33.
824 # To do this, replace the above to roughly :
825 # my $logic = ($op =~ $self->{inequality_op}) ? 'AND' : 'OR';
826 # return $self->_recurse_where([map { {$k => {$op, $_}} } @vals], $logic);
830 # try to DWIM on equality operators
831 # LDNOTE : not 100% sure this is the correct thing to do ...
832 return ($self->{sqlfalse}) if $op =~ $self->{equality_op};
833 return ($self->{sqltrue}) if $op =~ $self->{inequality_op};
836 puke "operator '$op' applied on an empty array (field '$k')";
841 sub _where_hashpair_SCALARREF {
842 my ($self, $k, $v) = @_;
843 $self->_debug("SCALAR($k) means literal SQL: $$v");
844 my $sql = $self->_quote($k) . " " . $$v;
848 # literal SQL with bind
849 sub _where_hashpair_ARRAYREFREF {
850 my ($self, $k, $v) = @_;
851 $self->_debug("REF($k) means literal SQL: @${$v}");
852 my ($sql, @bind) = @$$v;
853 $self->_assert_bindval_matches_bindtype(@bind);
854 $sql = $self->_quote($k) . " " . $sql;
855 return ($sql, @bind );
858 # literal SQL without bind
859 sub _where_hashpair_SCALAR {
860 my ($self, $k, $v) = @_;
861 $self->_debug("NOREF($k) means simple key=val: $k $self->{cmp} $v");
862 my $sql = join ' ', $self->_convert($self->_quote($k)),
863 $self->_sqlcase($self->{cmp}),
864 $self->_convert('?');
865 my @bind = $self->_bindtype($k, $v);
866 return ( $sql, @bind);
870 sub _where_hashpair_UNDEF {
871 my ($self, $k, $v) = @_;
872 $self->_debug("UNDEF($k) means IS NULL");
873 my $sql = $self->_quote($k) . $self->_sqlcase(' is null');
877 #======================================================================
878 # WHERE: TOP-LEVEL OTHERS (SCALARREF, SCALAR, UNDEF)
879 #======================================================================
882 sub _where_SCALARREF {
883 my ($self, $where) = @_;
886 $self->_debug("SCALAR(*top) means literal SQL: $$where");
892 my ($self, $where) = @_;
895 $self->_debug("NOREF(*top) means literal SQL: $where");
906 #======================================================================
907 # WHERE: BUILTIN SPECIAL OPERATORS (-in, -between)
908 #======================================================================
911 sub _where_field_BETWEEN {
912 my ($self, $k, $op, $vals) = @_;
914 my ($label, $and, $placeholder);
915 $label = $self->_convert($self->_quote($k));
916 $and = ' ' . $self->_sqlcase('and') . ' ';
917 $placeholder = $self->_convert('?');
918 $op = $self->_sqlcase($op);
920 my ($clause, @bind) = $self->_SWITCH_refkind($vals, {
922 my ($s, @b) = @$$vals;
923 $self->_assert_bindval_matches_bindtype(@b);
930 puke "special op 'between' accepts an arrayref with exactly two values"
933 my (@all_sql, @all_bind);
934 foreach my $val (@$vals) {
935 my ($sql, @bind) = $self->_SWITCH_refkind($val, {
937 return ($placeholder, $self->_bindtype($k, $val) );
943 my ($sql, @bind) = @$$val;
944 $self->_assert_bindval_matches_bindtype(@bind);
945 return ($sql, @bind);
948 my ($func, $arg, @rest) = %$val;
949 puke ("Only simple { -func => arg } functions accepted as sub-arguments to BETWEEN")
950 if (@rest or $func !~ /^ \- (.+)/x);
951 local $self->{_nested_func_lhs} = $k;
952 $self->_where_unary_op ($1 => $arg);
956 push @all_bind, @bind;
960 (join $and, @all_sql),
965 puke "special op 'between' accepts an arrayref with two values, or a single literal scalarref/arrayref-ref";
969 my $sql = "( $label $op $clause )";
973 sub _where_field_FUNC {
974 my ($self, $k, $op, $vals) = @_;
976 return $self->_where_generic_FUNC($k,$vals);
980 my ($self, $k, $vals) = @_;
982 return $self->_where_generic_FUNC('', $vals);
985 sub _where_generic_FUNC {
986 my ($self, $k, $vals) = @_;
988 my $label = $self->_convert($self->_quote($k));
989 my $placeholder = $self->_convert('?');
991 puke '-func must be an array' unless ref $vals eq 'ARRAY';
992 puke 'first arg for -func must be a scalar' unless !ref $vals->[0];
994 my ($func,@rest_of_vals) = @$vals;
996 $self->_assert_pass_injection_guard($func);
998 my (@all_sql, @all_bind);
999 foreach my $val (@rest_of_vals) {
1000 my ($sql, @bind) = $self->_SWITCH_refkind($val, {
1002 return ($placeholder, $self->_bindtype($k, $val) );
1007 ARRAYREFREF => sub {
1008 my ($sql, @bind) = @$$val;
1009 $self->_assert_bindval_matches_bindtype(@bind);
1010 return ($sql, @bind);
1013 $self->_recurse_where( $val );
1016 push @all_sql, $sql;
1017 push @all_bind, @bind;
1020 my ($clause, @bind) = ("$func(" . (join ",", @all_sql) . ")", @all_bind);
1022 my $sql = $k ? "( $label = $clause )" : "( $clause )";
1023 return ($sql, @bind)
1032 # $_[1] gets set to "op" ?
1037 # $_[2] gets set to "op" ?
1041 my $label = $self->_convert($self->_quote($k));
1042 my $placeholder = $self->_convert('?');
1044 puke '-op must be an array' unless ref $vals eq 'ARRAY';
1045 puke 'first arg for -op must be a scalar' unless !ref $vals->[0];
1047 my ($op, @rest_of_vals) = @$vals;
1049 $self->_assert_pass_injection_guard($op);
1051 my (@all_sql, @all_bind);
1052 foreach my $val (@rest_of_vals) {
1053 my ($sql, @bind) = $self->_SWITCH_refkind($val, {
1055 return ($placeholder, $self->_bindtype($k, $val) );
1060 ARRAYREFREF => sub {
1061 my ($sql, @bind) = @$$val;
1062 $self->_assert_bindval_matches_bindtype(@bind);
1063 return ($sql, @bind);
1066 $self->_recurse_where( $val );
1069 push @all_sql, $sql;
1070 push @all_bind, @bind;
1073 my ($clause, @bind) = ((join " $op ", @all_sql), @all_bind);
1075 my $sql = $k ? "( $label = $clause )" : "( $clause )";
1076 return ($sql, @bind)
1079 sub _where_field_IN {
1080 my ($self, $k, $op, $vals) = @_;
1082 # backwards compatibility : if scalar, force into an arrayref
1083 $vals = [$vals] if defined $vals && ! ref $vals;
1085 my ($label) = $self->_convert($self->_quote($k));
1086 my ($placeholder) = $self->_convert('?');
1087 $op = $self->_sqlcase($op);
1089 my ($sql, @bind) = $self->_SWITCH_refkind($vals, {
1090 ARRAYREF => sub { # list of choices
1091 if (@$vals) { # nonempty list
1092 my (@all_sql, @all_bind);
1094 for my $val (@$vals) {
1095 my ($sql, @bind) = $self->_SWITCH_refkind($val, {
1097 return ($placeholder, $val);
1102 ARRAYREFREF => sub {
1103 my ($sql, @bind) = @$$val;
1104 $self->_assert_bindval_matches_bindtype(@bind);
1105 return ($sql, @bind);
1108 my ($func, $arg, @rest) = %$val;
1109 puke ("Only simple { -func => arg } functions accepted as sub-arguments to IN")
1110 if (@rest or $func !~ /^ \- (.+)/x);
1111 local $self->{_nested_func_lhs} = $k;
1112 $self->_where_unary_op ($1 => $arg);
1115 return $self->_sqlcase('null');
1118 push @all_sql, $sql;
1119 push @all_bind, @bind;
1123 sprintf ('%s %s ( %s )',
1126 join (', ', @all_sql)
1128 $self->_bindtype($k, @all_bind),
1131 else { # empty list : some databases won't understand "IN ()", so DWIM
1132 my $sql = ($op =~ /\bnot\b/i) ? $self->{sqltrue} : $self->{sqlfalse};
1137 SCALARREF => sub { # literal SQL
1138 my $sql = $self->_open_outer_paren ($$vals);
1139 return ("$label $op ( $sql )");
1141 ARRAYREFREF => sub { # literal SQL with bind
1142 my ($sql, @bind) = @$$vals;
1143 $self->_assert_bindval_matches_bindtype(@bind);
1144 $sql = $self->_open_outer_paren ($sql);
1145 return ("$label $op ( $sql )", @bind);
1149 puke "special op 'in' requires an arrayref (or scalarref/arrayref-ref)";
1153 return ($sql, @bind);
1156 # Some databases (SQLite) treat col IN (1, 2) different from
1157 # col IN ( (1, 2) ). Use this to strip all outer parens while
1158 # adding them back in the corresponding method
1159 sub _open_outer_paren {
1160 my ($self, $sql) = @_;
1161 $sql = $1 while $sql =~ /^ \s* \( (.*) \) \s* $/xs;
1166 #======================================================================
1168 #======================================================================
1171 my ($self, $arg) = @_;
1174 for my $c ($self->_order_by_chunks ($arg) ) {
1175 $self->_SWITCH_refkind ($c, {
1176 SCALAR => sub { push @sql, $c },
1177 ARRAYREF => sub { push @sql, shift @$c; push @bind, @$c },
1183 $self->_sqlcase(' order by'),
1189 return wantarray ? ($sql, @bind) : $sql;
1192 sub _order_by_chunks {
1193 my ($self, $arg) = @_;
1195 return $self->_SWITCH_refkind($arg, {
1198 map { $self->_order_by_chunks ($_ ) } @$arg;
1201 ARRAYREFREF => sub {
1202 my ($s, @b) = @$$arg;
1203 $self->_assert_bindval_matches_bindtype(@b);
1207 SCALAR => sub {$self->_quote($arg)},
1209 UNDEF => sub {return () },
1211 SCALARREF => sub {$$arg}, # literal SQL, no quoting
1214 # get first pair in hash
1215 my ($key, $val, @rest) = %$arg;
1217 return () unless $key;
1219 if ( @rest or not $key =~ /^-(desc|asc)/i ) {
1220 puke "hash passed to _order_by must have exactly one key (-desc or -asc)";
1226 for my $c ($self->_order_by_chunks ($val)) {
1229 $self->_SWITCH_refkind ($c, {
1234 ($sql, @bind) = @$c;
1238 $sql = $sql . ' ' . $self->_sqlcase($direction);
1240 push @ret, [ $sql, @bind];
1249 #======================================================================
1250 # DATASOURCE (FOR NOW, JUST PLAIN TABLE OR LIST OF TABLES)
1251 #======================================================================
1256 $self->_SWITCH_refkind($from, {
1257 ARRAYREF => sub {join ', ', map { $self->_quote($_) } @$from;},
1258 SCALAR => sub {$self->_quote($from)},
1259 SCALARREF => sub {$$from},
1260 ARRAYREFREF => sub {join ', ', @$from;},
1265 #======================================================================
1267 #======================================================================
1269 # highly optimized, as it's called way too often
1271 # my ($self, $label) = @_;
1273 return '' unless defined $_[1];
1274 return ${$_[1]} if ref($_[1]) eq 'SCALAR';
1276 unless ($_[0]->{quote_char}) {
1277 $_[0]->_assert_pass_injection_guard($_[1]);
1281 my $qref = ref $_[0]->{quote_char};
1284 ($l, $r) = ( $_[0]->{quote_char}, $_[0]->{quote_char} );
1286 elsif ($qref eq 'ARRAY') {
1287 ($l, $r) = @{$_[0]->{quote_char}};
1290 puke "Unsupported quote_char format: $_[0]->{quote_char}";
1293 # parts containing * are naturally unquoted
1294 return join( $_[0]->{name_sep}||'', map
1295 { $_ eq '*' ? $_ : $l . $_ . $r }
1296 ( $_[0]->{name_sep} ? split (/\Q$_[0]->{name_sep}\E/, $_[1] ) : $_[1] )
1301 # Conversion, if applicable
1303 #my ($self, $arg) = @_;
1305 # LDNOTE : modified the previous implementation below because
1306 # it was not consistent : the first "return" is always an array,
1307 # the second "return" is context-dependent. Anyway, _convert
1308 # seems always used with just a single argument, so make it a
1310 # return @_ unless $self->{convert};
1311 # my $conv = $self->_sqlcase($self->{convert});
1312 # my @ret = map { $conv.'('.$_.')' } @_;
1313 # return wantarray ? @ret : $ret[0];
1314 if ($_[0]->{convert}) {
1315 return $_[0]->_sqlcase($_[0]->{convert}) .'(' . $_[1] . ')';
1322 #my ($self, $col, @vals) = @_;
1324 #LDNOTE : changed original implementation below because it did not make
1325 # sense when bindtype eq 'columns' and @vals > 1.
1326 # return $self->{bindtype} eq 'columns' ? [ $col, @vals ] : @vals;
1328 # called often - tighten code
1329 return $_[0]->{bindtype} eq 'columns'
1330 ? map {[$_[1], $_]} @_[2 .. $#_]
1335 # Dies if any element of @bind is not in [colname => value] format
1336 # if bindtype is 'columns'.
1337 sub _assert_bindval_matches_bindtype {
1338 # my ($self, @bind) = @_;
1340 if ($self->{bindtype} eq 'columns') {
1342 if (!defined $_ || ref($_) ne 'ARRAY' || @$_ != 2) {
1343 puke "bindtype 'columns' selected, you need to pass: [column_name => bind_value]"
1349 sub _join_sql_clauses {
1350 my ($self, $logic, $clauses_aref, $bind_aref) = @_;
1352 if (@$clauses_aref > 1) {
1353 my $join = " " . $self->_sqlcase($logic) . " ";
1354 my $sql = '( ' . join($join, @$clauses_aref) . ' )';
1355 return ($sql, @$bind_aref);
1357 elsif (@$clauses_aref) {
1358 return ($clauses_aref->[0], @$bind_aref); # no parentheses
1361 return (); # if no SQL, ignore @$bind_aref
1366 # Fix SQL case, if so requested
1368 # LDNOTE: if $self->{case} is true, then it contains 'lower', so we
1369 # don't touch the argument ... crooked logic, but let's not change it!
1370 return $_[0]->{case} ? $_[1] : uc($_[1]);
1374 #======================================================================
1375 # DISPATCHING FROM REFKIND
1376 #======================================================================
1379 my ($self, $data) = @_;
1381 return 'UNDEF' unless defined $data;
1383 # blessed objects are treated like scalars
1384 my $ref = (Scalar::Util::blessed $data) ? '' : ref $data;
1386 return 'SCALAR' unless $ref;
1389 while ($ref eq 'REF') {
1391 $ref = (Scalar::Util::blessed $data) ? '' : ref $data;
1395 return ($ref||'SCALAR') . ('REF' x $n_steps);
1399 my ($self, $data) = @_;
1400 my @try = ($self->_refkind($data));
1401 push @try, 'SCALAR_or_UNDEF' if $try[0] eq 'SCALAR' || $try[0] eq 'UNDEF';
1402 push @try, 'FALLBACK';
1406 sub _METHOD_FOR_refkind {
1407 my ($self, $meth_prefix, $data) = @_;
1410 for (@{$self->_try_refkind($data)}) {
1411 $method = $self->can($meth_prefix."_".$_)
1415 return $method || puke "cannot dispatch on '$meth_prefix' for ".$self->_refkind($data);
1419 sub _SWITCH_refkind {
1420 my ($self, $data, $dispatch_table) = @_;
1423 for (@{$self->_try_refkind($data)}) {
1424 $coderef = $dispatch_table->{$_}
1428 puke "no dispatch entry for ".$self->_refkind($data)
1437 #======================================================================
1438 # VALUES, GENERATE, AUTOLOAD
1439 #======================================================================
1441 # LDNOTE: original code from nwiger, didn't touch code in that section
1442 # I feel the AUTOLOAD stuff should not be the default, it should
1443 # only be activated on explicit demand by user.
1447 my $data = shift || return;
1448 puke "Argument to ", __PACKAGE__, "->values must be a \\%hash"
1449 unless ref $data eq 'HASH';
1452 foreach my $k ( sort keys %$data ) {
1453 my $v = $data->{$k};
1454 $self->_SWITCH_refkind($v, {
1456 if ($self->{array_datatypes}) { # array datatype
1457 push @all_bind, $self->_bindtype($k, $v);
1459 else { # literal SQL with bind
1460 my ($sql, @bind) = @$v;
1461 $self->_assert_bindval_matches_bindtype(@bind);
1462 push @all_bind, @bind;
1465 ARRAYREFREF => sub { # literal SQL with bind
1466 my ($sql, @bind) = @${$v};
1467 $self->_assert_bindval_matches_bindtype(@bind);
1468 push @all_bind, @bind;
1470 SCALARREF => sub { # literal SQL without bind
1472 SCALAR_or_UNDEF => sub {
1473 push @all_bind, $self->_bindtype($k, $v);
1484 my(@sql, @sqlq, @sqlv);
1488 if ($ref eq 'HASH') {
1489 for my $k (sort keys %$_) {
1492 my $label = $self->_quote($k);
1493 if ($r eq 'ARRAY') {
1494 # literal SQL with bind
1495 my ($sql, @bind) = @$v;
1496 $self->_assert_bindval_matches_bindtype(@bind);
1497 push @sqlq, "$label = $sql";
1499 } elsif ($r eq 'SCALAR') {
1500 # literal SQL without bind
1501 push @sqlq, "$label = $$v";
1503 push @sqlq, "$label = ?";
1504 push @sqlv, $self->_bindtype($k, $v);
1507 push @sql, $self->_sqlcase('set'), join ', ', @sqlq;
1508 } elsif ($ref eq 'ARRAY') {
1509 # unlike insert(), assume these are ONLY the column names, i.e. for SQL
1512 if ($r eq 'ARRAY') { # literal SQL with bind
1513 my ($sql, @bind) = @$v;
1514 $self->_assert_bindval_matches_bindtype(@bind);
1517 } elsif ($r eq 'SCALAR') { # literal SQL without bind
1518 # embedded literal SQL
1525 push @sql, '(' . join(', ', @sqlq) . ')';
1526 } elsif ($ref eq 'SCALAR') {
1530 # strings get case twiddled
1531 push @sql, $self->_sqlcase($_);
1535 my $sql = join ' ', @sql;
1537 # this is pretty tricky
1538 # if ask for an array, return ($stmt, @bind)
1539 # otherwise, s/?/shift @sqlv/ to put it inline
1541 return ($sql, @sqlv);
1543 1 while $sql =~ s/\?/my $d = shift(@sqlv);
1544 ref $d ? $d->[1] : $d/e;
1553 # This allows us to check for a local, then _form, attr
1555 my($name) = $AUTOLOAD =~ /.*::(.+)/;
1556 return $self->generate($name, @_);
1567 SQL::Abstract - Generate SQL from Perl data structures
1573 my $sql = SQL::Abstract->new;
1575 my($stmt, @bind) = $sql->select($table, \@fields, \%where, \@order);
1577 my($stmt, @bind) = $sql->insert($table, \%fieldvals || \@values);
1579 my($stmt, @bind) = $sql->update($table, \%fieldvals, \%where);
1581 my($stmt, @bind) = $sql->delete($table, \%where);
1583 # Then, use these in your DBI statements
1584 my $sth = $dbh->prepare($stmt);
1585 $sth->execute(@bind);
1587 # Just generate the WHERE clause
1588 my($stmt, @bind) = $sql->where(\%where, \@order);
1590 # Return values in the same order, for hashed queries
1591 # See PERFORMANCE section for more details
1592 my @bind = $sql->values(\%fieldvals);
1596 This module was inspired by the excellent L<DBIx::Abstract>.
1597 However, in using that module I found that what I really wanted
1598 to do was generate SQL, but still retain complete control over my
1599 statement handles and use the DBI interface. So, I set out to
1600 create an abstract SQL generation module.
1602 While based on the concepts used by L<DBIx::Abstract>, there are
1603 several important differences, especially when it comes to WHERE
1604 clauses. I have modified the concepts used to make the SQL easier
1605 to generate from Perl data structures and, IMO, more intuitive.
1606 The underlying idea is for this module to do what you mean, based
1607 on the data structures you provide it. The big advantage is that
1608 you don't have to modify your code every time your data changes,
1609 as this module figures it out.
1611 To begin with, an SQL INSERT is as easy as just specifying a hash
1612 of C<key=value> pairs:
1615 name => 'Jimbo Bobson',
1616 phone => '123-456-7890',
1617 address => '42 Sister Lane',
1618 city => 'St. Louis',
1619 state => 'Louisiana',
1622 The SQL can then be generated with this:
1624 my($stmt, @bind) = $sql->insert('people', \%data);
1626 Which would give you something like this:
1628 $stmt = "INSERT INTO people
1629 (address, city, name, phone, state)
1630 VALUES (?, ?, ?, ?, ?)";
1631 @bind = ('42 Sister Lane', 'St. Louis', 'Jimbo Bobson',
1632 '123-456-7890', 'Louisiana');
1634 These are then used directly in your DBI code:
1636 my $sth = $dbh->prepare($stmt);
1637 $sth->execute(@bind);
1639 =head2 Inserting and Updating Arrays
1641 If your database has array types (like for example Postgres),
1642 activate the special option C<< array_datatypes => 1 >>
1643 when creating the C<SQL::Abstract> object.
1644 Then you may use an arrayref to insert and update database array types:
1646 my $sql = SQL::Abstract->new(array_datatypes => 1);
1648 planets => [qw/Mercury Venus Earth Mars/]
1651 my($stmt, @bind) = $sql->insert('solar_system', \%data);
1655 $stmt = "INSERT INTO solar_system (planets) VALUES (?)"
1657 @bind = (['Mercury', 'Venus', 'Earth', 'Mars']);
1660 =head2 Inserting and Updating SQL
1662 In order to apply SQL functions to elements of your C<%data> you may
1663 specify a reference to an arrayref for the given hash value. For example,
1664 if you need to execute the Oracle C<to_date> function on a value, you can
1665 say something like this:
1669 date_entered => \["to_date(?,'MM/DD/YYYY')", "03/02/2003"],
1672 The first value in the array is the actual SQL. Any other values are
1673 optional and would be included in the bind values array. This gives
1676 my($stmt, @bind) = $sql->insert('people', \%data);
1678 $stmt = "INSERT INTO people (name, date_entered)
1679 VALUES (?, to_date(?,'MM/DD/YYYY'))";
1680 @bind = ('Bill', '03/02/2003');
1682 An UPDATE is just as easy, all you change is the name of the function:
1684 my($stmt, @bind) = $sql->update('people', \%data);
1686 Notice that your C<%data> isn't touched; the module will generate
1687 the appropriately quirky SQL for you automatically. Usually you'll
1688 want to specify a WHERE clause for your UPDATE, though, which is
1689 where handling C<%where> hashes comes in handy...
1691 =head2 Complex where statements
1693 This module can generate pretty complicated WHERE statements
1694 easily. For example, simple C<key=value> pairs are taken to mean
1695 equality, and if you want to see if a field is within a set
1696 of values, you can use an arrayref. Let's say we wanted to
1697 SELECT some data based on this criteria:
1700 requestor => 'inna',
1701 worker => ['nwiger', 'rcwe', 'sfz'],
1702 status => { '!=', 'completed' }
1705 my($stmt, @bind) = $sql->select('tickets', '*', \%where);
1707 The above would give you something like this:
1709 $stmt = "SELECT * FROM tickets WHERE
1710 ( requestor = ? ) AND ( status != ? )
1711 AND ( worker = ? OR worker = ? OR worker = ? )";
1712 @bind = ('inna', 'completed', 'nwiger', 'rcwe', 'sfz');
1714 Which you could then use in DBI code like so:
1716 my $sth = $dbh->prepare($stmt);
1717 $sth->execute(@bind);
1723 The functions are simple. There's one for each major SQL operation,
1724 and a constructor you use first. The arguments are specified in a
1725 similar order to each function (table, then fields, then a where
1726 clause) to try and simplify things.
1731 =head2 new(option => 'value')
1733 The C<new()> function takes a list of options and values, and returns
1734 a new B<SQL::Abstract> object which can then be used to generate SQL
1735 through the methods below. The options accepted are:
1741 If set to 'lower', then SQL will be generated in all lowercase. By
1742 default SQL is generated in "textbook" case meaning something like:
1744 SELECT a_field FROM a_table WHERE some_field LIKE '%someval%'
1746 Any setting other than 'lower' is ignored.
1750 This determines what the default comparison operator is. By default
1751 it is C<=>, meaning that a hash like this:
1753 %where = (name => 'nwiger', email => 'nate@wiger.org');
1755 Will generate SQL like this:
1757 WHERE name = 'nwiger' AND email = 'nate@wiger.org'
1759 However, you may want loose comparisons by default, so if you set
1760 C<cmp> to C<like> you would get SQL such as:
1762 WHERE name like 'nwiger' AND email like 'nate@wiger.org'
1764 You can also override the comparsion on an individual basis - see
1765 the huge section on L</"WHERE CLAUSES"> at the bottom.
1767 =item sqltrue, sqlfalse
1769 Expressions for inserting boolean values within SQL statements.
1770 By default these are C<1=1> and C<1=0>. They are used
1771 by the special operators C<-in> and C<-not_in> for generating
1772 correct SQL even when the argument is an empty array (see below).
1776 This determines the default logical operator for multiple WHERE
1777 statements in arrays or hashes. If absent, the default logic is "or"
1778 for arrays, and "and" for hashes. This means that a WHERE
1782 event_date => {'>=', '2/13/99'},
1783 event_date => {'<=', '4/24/03'},
1786 will generate SQL like this:
1788 WHERE event_date >= '2/13/99' OR event_date <= '4/24/03'
1790 This is probably not what you want given this query, though (look
1791 at the dates). To change the "OR" to an "AND", simply specify:
1793 my $sql = SQL::Abstract->new(logic => 'and');
1795 Which will change the above C<WHERE> to:
1797 WHERE event_date >= '2/13/99' AND event_date <= '4/24/03'
1799 The logic can also be changed locally by inserting
1800 a modifier in front of an arrayref :
1802 @where = (-and => [event_date => {'>=', '2/13/99'},
1803 event_date => {'<=', '4/24/03'} ]);
1805 See the L</"WHERE CLAUSES"> section for explanations.
1809 This will automatically convert comparisons using the specified SQL
1810 function for both column and value. This is mostly used with an argument
1811 of C<upper> or C<lower>, so that the SQL will have the effect of
1812 case-insensitive "searches". For example, this:
1814 $sql = SQL::Abstract->new(convert => 'upper');
1815 %where = (keywords => 'MaKe iT CAse inSeNSItive');
1817 Will turn out the following SQL:
1819 WHERE upper(keywords) like upper('MaKe iT CAse inSeNSItive')
1821 The conversion can be C<upper()>, C<lower()>, or any other SQL function
1822 that can be applied symmetrically to fields (actually B<SQL::Abstract> does
1823 not validate this option; it will just pass through what you specify verbatim).
1827 This is a kludge because many databases suck. For example, you can't
1828 just bind values using DBI's C<execute()> for Oracle C<CLOB> or C<BLOB> fields.
1829 Instead, you have to use C<bind_param()>:
1831 $sth->bind_param(1, 'reg data');
1832 $sth->bind_param(2, $lots, {ora_type => ORA_CLOB});
1834 The problem is, B<SQL::Abstract> will normally just return a C<@bind> array,
1835 which loses track of which field each slot refers to. Fear not.
1837 If you specify C<bindtype> in new, you can determine how C<@bind> is returned.
1838 Currently, you can specify either C<normal> (default) or C<columns>. If you
1839 specify C<columns>, you will get an array that looks like this:
1841 my $sql = SQL::Abstract->new(bindtype => 'columns');
1842 my($stmt, @bind) = $sql->insert(...);
1845 [ 'column1', 'value1' ],
1846 [ 'column2', 'value2' ],
1847 [ 'column3', 'value3' ],
1850 You can then iterate through this manually, using DBI's C<bind_param()>.
1852 $sth->prepare($stmt);
1855 my($col, $data) = @$_;
1856 if ($col eq 'details' || $col eq 'comments') {
1857 $sth->bind_param($i, $data, {ora_type => ORA_CLOB});
1858 } elsif ($col eq 'image') {
1859 $sth->bind_param($i, $data, {ora_type => ORA_BLOB});
1861 $sth->bind_param($i, $data);
1865 $sth->execute; # execute without @bind now
1867 Now, why would you still use B<SQL::Abstract> if you have to do this crap?
1868 Basically, the advantage is still that you don't have to care which fields
1869 are or are not included. You could wrap that above C<for> loop in a simple
1870 sub called C<bind_fields()> or something and reuse it repeatedly. You still
1871 get a layer of abstraction over manual SQL specification.
1873 Note that if you set L</bindtype> to C<columns>, the C<\[$sql, @bind]>
1874 construct (see L</Literal SQL with placeholders and bind values (subqueries)>)
1875 will expect the bind values in this format.
1879 This is the character that a table or column name will be quoted
1880 with. By default this is an empty string, but you could set it to
1881 the character C<`>, to generate SQL like this:
1883 SELECT `a_field` FROM `a_table` WHERE `some_field` LIKE '%someval%'
1885 Alternatively, you can supply an array ref of two items, the first being the left
1886 hand quote character, and the second the right hand quote character. For
1887 example, you could supply C<['[',']']> for SQL Server 2000 compliant quotes
1888 that generates SQL like this:
1890 SELECT [a_field] FROM [a_table] WHERE [some_field] LIKE '%someval%'
1892 Quoting is useful if you have tables or columns names that are reserved
1893 words in your database's SQL dialect.
1897 This is the character that separates a table and column name. It is
1898 necessary to specify this when the C<quote_char> option is selected,
1899 so that tables and column names can be individually quoted like this:
1901 SELECT `table`.`one_field` FROM `table` WHERE `table`.`other_field` = 1
1903 =item injection_guard
1905 A regular expression C<qr/.../> that is applied to any C<-function> and unquoted
1906 column name specified in a query structure. This is a safety mechanism to avoid
1907 injection attacks when mishandling user input e.g.:
1909 my %condition_as_column_value_pairs = get_values_from_user();
1910 $sqla->select( ... , \%condition_as_column_value_pairs );
1912 If the expression matches an exception is thrown. Note that literal SQL
1913 supplied via C<\'...'> or C<\['...']> is B<not> checked in any way.
1915 Defaults to checking for C<;> and the C<GO> keyword (TransactSQL)
1917 =item array_datatypes
1919 When this option is true, arrayrefs in INSERT or UPDATE are
1920 interpreted as array datatypes and are passed directly
1922 When this option is false, arrayrefs are interpreted
1923 as literal SQL, just like refs to arrayrefs
1924 (but this behavior is for backwards compatibility; when writing
1925 new queries, use the "reference to arrayref" syntax
1931 Takes a reference to a list of "special operators"
1932 to extend the syntax understood by L<SQL::Abstract>.
1933 See section L</"SPECIAL OPERATORS"> for details.
1937 Takes a reference to a list of "unary operators"
1938 to extend the syntax understood by L<SQL::Abstract>.
1939 See section L</"UNARY OPERATORS"> for details.
1945 =head2 insert($table, \@values || \%fieldvals, \%options)
1947 This is the simplest function. You simply give it a table name
1948 and either an arrayref of values or hashref of field/value pairs.
1949 It returns an SQL INSERT statement and a list of bind values.
1950 See the sections on L</"Inserting and Updating Arrays"> and
1951 L</"Inserting and Updating SQL"> for information on how to insert
1952 with those data types.
1954 The optional C<\%options> hash reference may contain additional
1955 options to generate the insert SQL. Currently supported options
1962 Takes either a scalar of raw SQL fields, or an array reference of
1963 field names, and adds on an SQL C<RETURNING> statement at the end.
1964 This allows you to return data generated by the insert statement
1965 (such as row IDs) without performing another C<SELECT> statement.
1966 Note, however, this is not part of the SQL standard and may not
1967 be supported by all database engines.
1971 =head2 update($table, \%fieldvals, \%where)
1973 This takes a table, hashref of field/value pairs, and an optional
1974 hashref L<WHERE clause|/WHERE CLAUSES>. It returns an SQL UPDATE function and a list
1976 See the sections on L</"Inserting and Updating Arrays"> and
1977 L</"Inserting and Updating SQL"> for information on how to insert
1978 with those data types.
1980 =head2 select($source, $fields, $where, $order)
1982 This returns a SQL SELECT statement and associated list of bind values, as
1983 specified by the arguments :
1989 Specification of the 'FROM' part of the statement.
1990 The argument can be either a plain scalar (interpreted as a table
1991 name, will be quoted), or an arrayref (interpreted as a list
1992 of table names, joined by commas, quoted), or a scalarref
1993 (literal table name, not quoted), or a ref to an arrayref
1994 (list of literal table names, joined by commas, not quoted).
1998 Specification of the list of fields to retrieve from
2000 The argument can be either an arrayref (interpreted as a list
2001 of field names, will be joined by commas and quoted), or a
2002 plain scalar (literal SQL, not quoted).
2003 Please observe that this API is not as flexible as for
2004 the first argument C<$table>, for backwards compatibility reasons.
2008 Optional argument to specify the WHERE part of the query.
2009 The argument is most often a hashref, but can also be
2010 an arrayref or plain scalar --
2011 see section L<WHERE clause|/"WHERE CLAUSES"> for details.
2015 Optional argument to specify the ORDER BY part of the query.
2016 The argument can be a scalar, a hashref or an arrayref
2017 -- see section L<ORDER BY clause|/"ORDER BY CLAUSES">
2023 =head2 delete($table, \%where)
2025 This takes a table name and optional hashref L<WHERE clause|/WHERE CLAUSES>.
2026 It returns an SQL DELETE statement and list of bind values.
2028 =head2 where(\%where, \@order)
2030 This is used to generate just the WHERE clause. For example,
2031 if you have an arbitrary data structure and know what the
2032 rest of your SQL is going to look like, but want an easy way
2033 to produce a WHERE clause, use this. It returns an SQL WHERE
2034 clause and list of bind values.
2037 =head2 values(\%data)
2039 This just returns the values from the hash C<%data>, in the same
2040 order that would be returned from any of the other above queries.
2041 Using this allows you to markedly speed up your queries if you
2042 are affecting lots of rows. See below under the L</"PERFORMANCE"> section.
2044 =head2 generate($any, 'number', $of, \@data, $struct, \%types)
2046 Warning: This is an experimental method and subject to change.
2048 This returns arbitrarily generated SQL. It's a really basic shortcut.
2049 It will return two different things, depending on return context:
2051 my($stmt, @bind) = $sql->generate('create table', \$table, \@fields);
2052 my $stmt_and_val = $sql->generate('create table', \$table, \@fields);
2054 These would return the following:
2056 # First calling form
2057 $stmt = "CREATE TABLE test (?, ?)";
2058 @bind = (field1, field2);
2060 # Second calling form
2061 $stmt_and_val = "CREATE TABLE test (field1, field2)";
2063 Depending on what you're trying to do, it's up to you to choose the correct
2064 format. In this example, the second form is what you would want.
2068 $sql->generate('alter session', { nls_date_format => 'MM/YY' });
2072 ALTER SESSION SET nls_date_format = 'MM/YY'
2074 You get the idea. Strings get their case twiddled, but everything
2075 else remains verbatim.
2080 =head1 WHERE CLAUSES
2084 This module uses a variation on the idea from L<DBIx::Abstract>. It
2085 is B<NOT>, repeat I<not> 100% compatible. B<The main logic of this
2086 module is that things in arrays are OR'ed, and things in hashes
2089 The easiest way to explain is to show lots of examples. After
2090 each C<%where> hash shown, it is assumed you used:
2092 my($stmt, @bind) = $sql->where(\%where);
2094 However, note that the C<%where> hash can be used directly in any
2095 of the other functions as well, as described above.
2097 =head2 Key-value pairs
2099 So, let's get started. To begin, a simple hash:
2103 status => 'completed'
2106 Is converted to SQL C<key = val> statements:
2108 $stmt = "WHERE user = ? AND status = ?";
2109 @bind = ('nwiger', 'completed');
2111 One common thing I end up doing is having a list of values that
2112 a field can be in. To do this, simply specify a list inside of
2117 status => ['assigned', 'in-progress', 'pending'];
2120 This simple code will create the following:
2122 $stmt = "WHERE user = ? AND ( status = ? OR status = ? OR status = ? )";
2123 @bind = ('nwiger', 'assigned', 'in-progress', 'pending');
2125 A field associated to an empty arrayref will be considered a
2126 logical false and will generate 0=1.
2128 =head2 Tests for NULL values
2130 If the value part is C<undef> then this is converted to SQL <IS NULL>
2139 $stmt = "WHERE user = ? AND status IS NULL";
2142 =head2 Specific comparison operators
2144 If you want to specify a different type of operator for your comparison,
2145 you can use a hashref for a given column:
2149 status => { '!=', 'completed' }
2152 Which would generate:
2154 $stmt = "WHERE user = ? AND status != ?";
2155 @bind = ('nwiger', 'completed');
2157 To test against multiple values, just enclose the values in an arrayref:
2159 status => { '=', ['assigned', 'in-progress', 'pending'] };
2161 Which would give you:
2163 "WHERE status = ? OR status = ? OR status = ?"
2166 The hashref can also contain multiple pairs, in which case it is expanded
2167 into an C<AND> of its elements:
2171 status => { '!=', 'completed', -not_like => 'pending%' }
2174 # Or more dynamically, like from a form
2175 $where{user} = 'nwiger';
2176 $where{status}{'!='} = 'completed';
2177 $where{status}{'-not_like'} = 'pending%';
2179 # Both generate this
2180 $stmt = "WHERE user = ? AND status != ? AND status NOT LIKE ?";
2181 @bind = ('nwiger', 'completed', 'pending%');
2184 To get an OR instead, you can combine it with the arrayref idea:
2188 priority => [ {'=', 2}, {'!=', 1} ]
2191 Which would generate:
2193 $stmt = "WHERE user = ? AND priority = ? OR priority != ?";
2194 @bind = ('nwiger', '2', '1');
2196 If you want to include literal SQL (with or without bind values), just use a
2197 scalar reference or array reference as the value:
2200 date_entered => { '>' => \["to_date(?, 'MM/DD/YYYY')", "11/26/2008"] },
2201 date_expires => { '<' => \"now()" }
2204 Which would generate:
2206 $stmt = "WHERE date_entered > "to_date(?, 'MM/DD/YYYY') AND date_expires < now()";
2207 @bind = ('11/26/2008');
2210 =head2 Logic and nesting operators
2212 In the example above,
2213 there is a subtle trap if you want to say something like
2214 this (notice the C<AND>):
2216 WHERE priority != ? AND priority != ?
2218 Because, in Perl you I<can't> do this:
2220 priority => { '!=', 2, '!=', 1 }
2222 As the second C<!=> key will obliterate the first. The solution
2223 is to use the special C<-modifier> form inside an arrayref:
2225 priority => [ -and => {'!=', 2},
2229 Normally, these would be joined by C<OR>, but the modifier tells it
2230 to use C<AND> instead. (Hint: You can use this in conjunction with the
2231 C<logic> option to C<new()> in order to change the way your queries
2232 work by default.) B<Important:> Note that the C<-modifier> goes
2233 B<INSIDE> the arrayref, as an extra first element. This will
2234 B<NOT> do what you think it might:
2236 priority => -and => [{'!=', 2}, {'!=', 1}] # WRONG!
2238 Here is a quick list of equivalencies, since there is some overlap:
2241 status => {'!=', 'completed', 'not like', 'pending%' }
2242 status => [ -and => {'!=', 'completed'}, {'not like', 'pending%'}]
2245 status => {'=', ['assigned', 'in-progress']}
2246 status => [ -or => {'=', 'assigned'}, {'=', 'in-progress'}]
2247 status => [ {'=', 'assigned'}, {'=', 'in-progress'} ]
2251 =head2 Special operators : IN, BETWEEN, etc.
2253 You can also use the hashref format to compare a list of fields using the
2254 C<IN> comparison operator, by specifying the list as an arrayref:
2257 status => 'completed',
2258 reportid => { -in => [567, 2335, 2] }
2261 Which would generate:
2263 $stmt = "WHERE status = ? AND reportid IN (?,?,?)";
2264 @bind = ('completed', '567', '2335', '2');
2266 The reverse operator C<-not_in> generates SQL C<NOT IN> and is used in
2269 If the argument to C<-in> is an empty array, 'sqlfalse' is generated
2270 (by default : C<1=0>). Similarly, C<< -not_in => [] >> generates
2271 'sqltrue' (by default : C<1=1>).
2273 In addition to the array you can supply a chunk of literal sql or
2274 literal sql with bind:
2277 customer => { -in => \[
2278 'SELECT cust_id FROM cust WHERE balance > ?',
2281 status => { -in => \'SELECT status_codes FROM states' },
2287 customer IN ( SELECT cust_id FROM cust WHERE balance > ? )
2288 AND status IN ( SELECT status_codes FROM states )
2294 Another pair of operators is C<-between> and C<-not_between>,
2295 used with an arrayref of two values:
2299 completion_date => {
2300 -not_between => ['2002-10-01', '2003-02-06']
2306 WHERE user = ? AND completion_date NOT BETWEEN ( ? AND ? )
2308 Just like with C<-in> all plausible combinations of literal SQL
2312 start0 => { -between => [ 1, 2 ] },
2313 start1 => { -between => \["? AND ?", 1, 2] },
2314 start2 => { -between => \"lower(x) AND upper(y)" },
2315 start3 => { -between => [
2317 \["upper(?)", 'stuff' ],
2324 ( start0 BETWEEN ? AND ? )
2325 AND ( start1 BETWEEN ? AND ? )
2326 AND ( start2 BETWEEN lower(x) AND upper(y) )
2327 AND ( start3 BETWEEN lower(x) AND upper(?) )
2329 @bind = (1, 2, 1, 2, 'stuff');
2332 These are the two builtin "special operators"; but the
2333 list can be expanded : see section L</"SPECIAL OPERATORS"> below.
2335 Another operator is C<-func> that allows you to call SQL functions with
2336 arguments. It receives an array reference containing the function name
2337 as the 0th argument and the other arguments being its parameters. For example:
2340 -func => ['substr', 'Hello', 50, 5],
2345 $stmt = "WHERE (substr(?,?,?))";
2346 @bind = ("Hello", 50, 5);
2348 Yet another operator is C<-op> that allows you to use SQL operators. It
2349 receives an array reference containing the operator 0th argument and the other
2350 arguments being its operands. For example:
2353 foo => { -op => ['+', \'bar', 50, 5] },
2358 $stmt = "WHERE (foo = bar + ? + ?)";
2361 =head2 Unary operators: bool
2363 If you wish to test against boolean columns or functions within your
2364 database you can use the C<-bool> and C<-not_bool> operators. For
2365 example to test the column C<is_user> being true and the column
2366 C<is_enabled> being false you would use:-
2370 -not_bool => 'is_enabled',
2375 WHERE is_user AND NOT is_enabled
2377 If a more complex combination is required, testing more conditions,
2378 then you should use the and/or operators:-
2385 -not_bool => 'four',
2391 WHERE one AND two AND three AND NOT four
2394 =head2 Nested conditions, -and/-or prefixes
2396 So far, we've seen how multiple conditions are joined with a top-level
2397 C<AND>. We can change this by putting the different conditions we want in
2398 hashes and then putting those hashes in an array. For example:
2403 status => { -like => ['pending%', 'dispatched'] },
2407 status => 'unassigned',
2411 This data structure would create the following:
2413 $stmt = "WHERE ( user = ? AND ( status LIKE ? OR status LIKE ? ) )
2414 OR ( user = ? AND status = ? ) )";
2415 @bind = ('nwiger', 'pending', 'dispatched', 'robot', 'unassigned');
2418 Clauses in hashrefs or arrayrefs can be prefixed with an C<-and> or C<-or>
2419 to change the logic inside :
2425 -and => [ workhrs => {'>', 20}, geo => 'ASIA' ],
2426 -or => { workhrs => {'<', 50}, geo => 'EURO' },
2433 WHERE ( user = ? AND (
2434 ( workhrs > ? AND geo = ? )
2435 OR ( workhrs < ? OR geo = ? )
2438 =head2 Algebraic inconsistency, for historical reasons
2440 C<Important note>: when connecting several conditions, the C<-and->|C<-or>
2441 operator goes C<outside> of the nested structure; whereas when connecting
2442 several constraints on one column, the C<-and> operator goes
2443 C<inside> the arrayref. Here is an example combining both features :
2446 -and => [a => 1, b => 2],
2447 -or => [c => 3, d => 4],
2448 e => [-and => {-like => 'foo%'}, {-like => '%bar'} ]
2453 WHERE ( ( ( a = ? AND b = ? )
2454 OR ( c = ? OR d = ? )
2455 OR ( e LIKE ? AND e LIKE ? ) ) )
2457 This difference in syntax is unfortunate but must be preserved for
2458 historical reasons. So be careful : the two examples below would
2459 seem algebraically equivalent, but they are not
2461 {col => [-and => {-like => 'foo%'}, {-like => '%bar'}]}
2462 # yields : WHERE ( ( col LIKE ? AND col LIKE ? ) )
2464 [-and => {col => {-like => 'foo%'}, {col => {-like => '%bar'}}]]
2465 # yields : WHERE ( ( col LIKE ? OR col LIKE ? ) )
2470 Finally, sometimes only literal SQL will do. If you want to include
2471 literal SQL verbatim, you can specify it as a scalar reference, namely:
2473 my $inn = 'is Not Null';
2475 priority => { '<', 2 },
2481 $stmt = "WHERE priority < ? AND requestor is Not Null";
2484 Note that in this example, you only get one bind parameter back, since
2485 the verbatim SQL is passed as part of the statement.
2487 Of course, just to prove a point, the above can also be accomplished
2491 priority => { '<', 2 },
2492 requestor => { '!=', undef },
2498 Conditions on boolean columns can be expressed in the same way, passing
2499 a reference to an empty string, however using liternal SQL in this way
2500 is deprecated - the preferred method is to use the boolean operators -
2501 see L</"Unary operators: bool"> :
2504 priority => { '<', 2 },
2510 $stmt = "WHERE priority < ? AND is_ready";
2513 Literal SQL is also the only way to compare 2 columns to one another:
2516 priority => { '<', 2 },
2517 requestor => \'= submittor'
2522 $stmt = "WHERE priority < ? AND requestor = submitter";
2525 =head2 Literal SQL with placeholders and bind values (subqueries)
2527 If the literal SQL to be inserted has placeholders and bind values,
2528 use a reference to an arrayref (yes this is a double reference --
2529 not so common, but perfectly legal Perl). For example, to find a date
2530 in Postgres you can use something like this:
2533 date_column => \[q/= date '2008-09-30' - ?::integer/, 10/]
2538 $stmt = "WHERE ( date_column = date '2008-09-30' - ?::integer )"
2541 Note that you must pass the bind values in the same format as they are returned
2542 by L</where>. That means that if you set L</bindtype> to C<columns>, you must
2543 provide the bind values in the C<< [ column_meta => value ] >> format, where
2544 C<column_meta> is an opaque scalar value; most commonly the column name, but
2545 you can use any scalar value (including references and blessed references),
2546 L<SQL::Abstract> will simply pass it through intact. So if C<bindtype> is set
2547 to C<columns> the above example will look like:
2550 date_column => \[q/= date '2008-09-30' - ?::integer/, [ dummy => 10 ]/]
2553 Literal SQL is especially useful for nesting parenthesized clauses in the
2554 main SQL query. Here is a first example :
2556 my ($sub_stmt, @sub_bind) = ("SELECT c1 FROM t1 WHERE c2 < ? AND c3 LIKE ?",
2560 bar => \["IN ($sub_stmt)" => @sub_bind],
2565 $stmt = "WHERE (foo = ? AND bar IN (SELECT c1 FROM t1
2566 WHERE c2 < ? AND c3 LIKE ?))";
2567 @bind = (1234, 100, "foo%");
2569 Other subquery operators, like for example C<"E<gt> ALL"> or C<"NOT IN">,
2570 are expressed in the same way. Of course the C<$sub_stmt> and
2571 its associated bind values can be generated through a former call
2574 my ($sub_stmt, @sub_bind)
2575 = $sql->select("t1", "c1", {c2 => {"<" => 100},
2576 c3 => {-like => "foo%"}});
2579 bar => \["> ALL ($sub_stmt)" => @sub_bind],
2582 In the examples above, the subquery was used as an operator on a column;
2583 but the same principle also applies for a clause within the main C<%where>
2584 hash, like an EXISTS subquery :
2586 my ($sub_stmt, @sub_bind)
2587 = $sql->select("t1", "*", {c1 => 1, c2 => \"> t0.c0"});
2588 my %where = ( -and => [
2590 \["EXISTS ($sub_stmt)" => @sub_bind],
2595 $stmt = "WHERE (foo = ? AND EXISTS (SELECT * FROM t1
2596 WHERE c1 = ? AND c2 > t0.c0))";
2600 Observe that the condition on C<c2> in the subquery refers to
2601 column C<t0.c0> of the main query : this is I<not> a bind
2602 value, so we have to express it through a scalar ref.
2603 Writing C<< c2 => {">" => "t0.c0"} >> would have generated
2604 C<< c2 > ? >> with bind value C<"t0.c0"> ... not exactly
2605 what we wanted here.
2607 Finally, here is an example where a subquery is used
2608 for expressing unary negation:
2610 my ($sub_stmt, @sub_bind)
2611 = $sql->where({age => [{"<" => 10}, {">" => 20}]});
2612 $sub_stmt =~ s/^ where //i; # don't want "WHERE" in the subclause
2614 lname => {like => '%son%'},
2615 \["NOT ($sub_stmt)" => @sub_bind],
2620 $stmt = "lname LIKE ? AND NOT ( age < ? OR age > ? )"
2621 @bind = ('%son%', 10, 20)
2627 These pages could go on for a while, since the nesting of the data
2628 structures this module can handle are pretty much unlimited (the
2629 module implements the C<WHERE> expansion as a recursive function
2630 internally). Your best bet is to "play around" with the module a
2631 little to see how the data structures behave, and choose the best
2632 format for your data based on that.
2634 And of course, all the values above will probably be replaced with
2635 variables gotten from forms or the command line. After all, if you
2636 knew everything ahead of time, you wouldn't have to worry about
2637 dynamically-generating SQL and could just hardwire it into your
2643 =head1 ORDER BY CLAUSES
2645 Some functions take an order by clause. This can either be a scalar (just a
2646 column name,) a hash of C<< { -desc => 'col' } >> or C<< { -asc => 'col' } >>,
2647 or an array of either of the two previous forms. Examples:
2649 Given | Will Generate
2650 ----------------------------------------------------------
2652 \'colA DESC' | ORDER BY colA DESC
2654 'colA' | ORDER BY colA
2656 [qw/colA colB/] | ORDER BY colA, colB
2658 {-asc => 'colA'} | ORDER BY colA ASC
2660 {-desc => 'colB'} | ORDER BY colB DESC
2662 ['colA', {-asc => 'colB'}] | ORDER BY colA, colB ASC
2664 { -asc => [qw/colA colB/] } | ORDER BY colA ASC, colB ASC
2667 { -asc => 'colA' }, | ORDER BY colA ASC, colB DESC,
2668 { -desc => [qw/colB/], | colC ASC, colD ASC
2669 { -asc => [qw/colC colD/],|
2671 ===========================================================
2675 =head1 SPECIAL OPERATORS
2677 my $sqlmaker = SQL::Abstract->new(special_ops => [
2681 my ($self, $field, $op, $arg) = @_;
2687 handler => 'method_name',
2691 A "special operator" is a SQL syntactic clause that can be
2692 applied to a field, instead of a usual binary operator.
2695 WHERE field IN (?, ?, ?)
2696 WHERE field BETWEEN ? AND ?
2697 WHERE MATCH(field) AGAINST (?, ?)
2699 Special operators IN and BETWEEN are fairly standard and therefore
2700 are builtin within C<SQL::Abstract> (as the overridable methods
2701 C<_where_field_IN> and C<_where_field_BETWEEN>). For other operators,
2702 like the MATCH .. AGAINST example above which is specific to MySQL,
2703 you can write your own operator handlers - supply a C<special_ops>
2704 argument to the C<new> method. That argument takes an arrayref of
2705 operator definitions; each operator definition is a hashref with two
2712 the regular expression to match the operator
2716 Either a coderef or a plain scalar method name. In both cases
2717 the expected return is C<< ($sql, @bind) >>.
2719 When supplied with a method name, it is simply called on the
2720 L<SQL::Abstract/> object as:
2722 $self->$method_name ($field, $op, $arg)
2726 $op is the part that matched the handler regex
2727 $field is the LHS of the operator
2730 When supplied with a coderef, it is called as:
2732 $coderef->($self, $field, $op, $arg)
2737 For example, here is an implementation
2738 of the MATCH .. AGAINST syntax for MySQL
2740 my $sqlmaker = SQL::Abstract->new(special_ops => [
2742 # special op for MySql MATCH (field) AGAINST(word1, word2, ...)
2743 {regex => qr/^match$/i,
2745 my ($self, $field, $op, $arg) = @_;
2746 $arg = [$arg] if not ref $arg;
2747 my $label = $self->_quote($field);
2748 my ($placeholder) = $self->_convert('?');
2749 my $placeholders = join ", ", (($placeholder) x @$arg);
2750 my $sql = $self->_sqlcase('match') . " ($label) "
2751 . $self->_sqlcase('against') . " ($placeholders) ";
2752 my @bind = $self->_bindtype($field, @$arg);
2753 return ($sql, @bind);
2760 =head1 UNARY OPERATORS
2762 my $sqlmaker = SQL::Abstract->new(unary_ops => [
2766 my ($self, $op, $arg) = @_;
2772 handler => 'method_name',
2776 A "unary operator" is a SQL syntactic clause that can be
2777 applied to a field - the operator goes before the field
2779 You can write your own operator handlers - supply a C<unary_ops>
2780 argument to the C<new> method. That argument takes an arrayref of
2781 operator definitions; each operator definition is a hashref with two
2788 the regular expression to match the operator
2792 Either a coderef or a plain scalar method name. In both cases
2793 the expected return is C<< $sql >>.
2795 When supplied with a method name, it is simply called on the
2796 L<SQL::Abstract/> object as:
2798 $self->$method_name ($op, $arg)
2802 $op is the part that matched the handler regex
2803 $arg is the RHS or argument of the operator
2805 When supplied with a coderef, it is called as:
2807 $coderef->($self, $op, $arg)
2815 Thanks to some benchmarking by Mark Stosberg, it turns out that
2816 this module is many orders of magnitude faster than using C<DBIx::Abstract>.
2817 I must admit this wasn't an intentional design issue, but it's a
2818 byproduct of the fact that you get to control your C<DBI> handles
2821 To maximize performance, use a code snippet like the following:
2823 # prepare a statement handle using the first row
2824 # and then reuse it for the rest of the rows
2826 for my $href (@array_of_hashrefs) {
2827 $stmt ||= $sql->insert('table', $href);
2828 $sth ||= $dbh->prepare($stmt);
2829 $sth->execute($sql->values($href));
2832 The reason this works is because the keys in your C<$href> are sorted
2833 internally by B<SQL::Abstract>. Thus, as long as your data retains
2834 the same structure, you only have to generate the SQL the first time
2835 around. On subsequent queries, simply use the C<values> function provided
2836 by this module to return your values in the correct order.
2838 However this depends on the values having the same type - if, for
2839 example, the values of a where clause may either have values
2840 (resulting in sql of the form C<column = ?> with a single bind
2841 value), or alternatively the values might be C<undef> (resulting in
2842 sql of the form C<column IS NULL> with no bind value) then the
2843 caching technique suggested will not work.
2847 If you use my C<CGI::FormBuilder> module at all, you'll hopefully
2848 really like this part (I do, at least). Building up a complex query
2849 can be as simple as the following:
2853 use CGI::FormBuilder;
2856 my $form = CGI::FormBuilder->new(...);
2857 my $sql = SQL::Abstract->new;
2859 if ($form->submitted) {
2860 my $field = $form->field;
2861 my $id = delete $field->{id};
2862 my($stmt, @bind) = $sql->update('table', $field, {id => $id});
2865 Of course, you would still have to connect using C<DBI> to run the
2866 query, but the point is that if you make your form look like your
2867 table, the actual query script can be extremely simplistic.
2869 If you're B<REALLY> lazy (I am), check out C<HTML::QuickTable> for
2870 a fast interface to returning and formatting data. I frequently
2871 use these three modules together to write complex database query
2872 apps in under 50 lines.
2878 =item * gitweb: L<http://git.shadowcat.co.uk/gitweb/gitweb.cgi?p=dbsrgits/DBIx-Class.git>
2880 =item * git: L<git://git.shadowcat.co.uk/dbsrgits/DBIx-Class.git>
2886 Version 1.50 was a major internal refactoring of C<SQL::Abstract>.
2887 Great care has been taken to preserve the I<published> behavior
2888 documented in previous versions in the 1.* family; however,
2889 some features that were previously undocumented, or behaved
2890 differently from the documentation, had to be changed in order
2891 to clarify the semantics. Hence, client code that was relying
2892 on some dark areas of C<SQL::Abstract> v1.*
2893 B<might behave differently> in v1.50.
2895 The main changes are :
2901 support for literal SQL through the C<< \ [$sql, bind] >> syntax.
2905 support for the { operator => \"..." } construct (to embed literal SQL)
2909 support for the { operator => \["...", @bind] } construct (to embed literal SQL with bind values)
2913 optional support for L<array datatypes|/"Inserting and Updating Arrays">
2917 defensive programming : check arguments
2921 fixed bug with global logic, which was previously implemented
2922 through global variables yielding side-effects. Prior versions would
2923 interpret C<< [ {cond1, cond2}, [cond3, cond4] ] >>
2924 as C<< "(cond1 AND cond2) OR (cond3 AND cond4)" >>.
2925 Now this is interpreted
2926 as C<< "(cond1 AND cond2) OR (cond3 OR cond4)" >>.
2931 fixed semantics of _bindtype on array args
2935 dropped the C<_anoncopy> of the %where tree. No longer necessary,
2936 we just avoid shifting arrays within that tree.
2940 dropped the C<_modlogic> function
2946 =head1 ACKNOWLEDGEMENTS
2948 There are a number of individuals that have really helped out with
2949 this module. Unfortunately, most of them submitted bugs via CPAN
2950 so I have no idea who they are! But the people I do know are:
2952 Ash Berlin (order_by hash term support)
2953 Matt Trout (DBIx::Class support)
2954 Mark Stosberg (benchmarking)
2955 Chas Owens (initial "IN" operator support)
2956 Philip Collins (per-field SQL functions)
2957 Eric Kolve (hashref "AND" support)
2958 Mike Fragassi (enhancements to "BETWEEN" and "LIKE")
2959 Dan Kubb (support for "quote_char" and "name_sep")
2960 Guillermo Roditi (patch to cleanup "IN" and "BETWEEN", fix and tests for _order_by)
2961 Laurent Dami (internal refactoring, extensible list of special operators, literal SQL)
2962 Norbert Buchmuller (support for literal SQL in hashpair, misc. fixes & tests)
2963 Peter Rabbitson (rewrite of SQLA::Test, misc. fixes & tests)
2964 Oliver Charles (support for "RETURNING" after "INSERT")
2970 L<DBIx::Class>, L<DBIx::Abstract>, L<CGI::FormBuilder>, L<HTML::QuickTable>.
2974 Copyright (c) 2001-2007 Nathan Wiger <nwiger@cpan.org>. All Rights Reserved.
2976 This module is actively maintained by Matt Trout <mst@shadowcatsystems.co.uk>
2978 For support, your best bet is to try the C<DBIx::Class> users mailing list.
2979 While not an official support venue, C<DBIx::Class> makes heavy use of
2980 C<SQL::Abstract>, and as such list members there are very familiar with
2981 how to create queries.
2985 This module is free software; you may copy this under the same
2986 terms as perl itself (either the GNU General Public License or
2987 the Artistic License)