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 my $method = $self->_METHOD_FOR_refkind("_where_hashpair", $val);
1014 $self->$method('', $val);
1017 push @all_sql, $sql;
1018 push @all_bind, @bind;
1021 my ($clause, @bind) = ("$func(" . (join ",", @all_sql) . ")", @all_bind);
1023 my $sql = $k ? "( $label = $clause )" : "( $clause )";
1024 return ($sql, @bind)
1033 # $_[1] gets set to "op"
1038 # $_[2] gets set to "op"
1042 my $label = $self->_convert($self->_quote($k));
1043 my $placeholder = $self->_convert('?');
1045 puke 'argument to -op must be an arrayref' unless ref $vals eq 'ARRAY';
1046 puke 'first arg for -op must be a scalar' unless !ref $vals->[0];
1048 my ($op, @rest_of_vals) = @$vals;
1050 $self->_assert_pass_injection_guard($op);
1052 my (@all_sql, @all_bind);
1053 foreach my $val (@rest_of_vals) {
1054 my ($sql, @bind) = $self->_SWITCH_refkind($val, {
1056 return ($placeholder, $self->_bindtype($k, $val) );
1061 ARRAYREFREF => sub {
1062 my ($sql, @bind) = @$$val;
1063 $self->_assert_bindval_matches_bindtype(@bind);
1064 return ($sql, @bind);
1067 my $method = $self->_METHOD_FOR_refkind("_where_hashpair", $val);
1068 $self->$method('', $val);
1071 push @all_sql, $sql;
1072 push @all_bind, @bind;
1075 my ($clause, @bind) = ((join " $op ", @all_sql), @all_bind);
1077 my $sql = $k ? "( $label = $clause )" : "( $clause )";
1078 return ($sql, @bind)
1081 sub _where_field_IN {
1082 my ($self, $k, $op, $vals) = @_;
1084 # backwards compatibility : if scalar, force into an arrayref
1085 $vals = [$vals] if defined $vals && ! ref $vals;
1087 my ($label) = $self->_convert($self->_quote($k));
1088 my ($placeholder) = $self->_convert('?');
1089 $op = $self->_sqlcase($op);
1091 my ($sql, @bind) = $self->_SWITCH_refkind($vals, {
1092 ARRAYREF => sub { # list of choices
1093 if (@$vals) { # nonempty list
1094 my (@all_sql, @all_bind);
1096 for my $val (@$vals) {
1097 my ($sql, @bind) = $self->_SWITCH_refkind($val, {
1099 return ($placeholder, $val);
1104 ARRAYREFREF => sub {
1105 my ($sql, @bind) = @$$val;
1106 $self->_assert_bindval_matches_bindtype(@bind);
1107 return ($sql, @bind);
1110 my ($func, $arg, @rest) = %$val;
1111 puke ("Only simple { -func => arg } functions accepted as sub-arguments to IN")
1112 if (@rest or $func !~ /^ \- (.+)/x);
1113 local $self->{_nested_func_lhs} = $k;
1114 $self->_where_unary_op ($1 => $arg);
1117 return $self->_sqlcase('null');
1120 push @all_sql, $sql;
1121 push @all_bind, @bind;
1125 sprintf ('%s %s ( %s )',
1128 join (', ', @all_sql)
1130 $self->_bindtype($k, @all_bind),
1133 else { # empty list : some databases won't understand "IN ()", so DWIM
1134 my $sql = ($op =~ /\bnot\b/i) ? $self->{sqltrue} : $self->{sqlfalse};
1139 SCALARREF => sub { # literal SQL
1140 my $sql = $self->_open_outer_paren ($$vals);
1141 return ("$label $op ( $sql )");
1143 ARRAYREFREF => sub { # literal SQL with bind
1144 my ($sql, @bind) = @$$vals;
1145 $self->_assert_bindval_matches_bindtype(@bind);
1146 $sql = $self->_open_outer_paren ($sql);
1147 return ("$label $op ( $sql )", @bind);
1151 puke "special op 'in' requires an arrayref (or scalarref/arrayref-ref)";
1155 return ($sql, @bind);
1158 # Some databases (SQLite) treat col IN (1, 2) different from
1159 # col IN ( (1, 2) ). Use this to strip all outer parens while
1160 # adding them back in the corresponding method
1161 sub _open_outer_paren {
1162 my ($self, $sql) = @_;
1163 $sql = $1 while $sql =~ /^ \s* \( (.*) \) \s* $/xs;
1168 #======================================================================
1170 #======================================================================
1173 my ($self, $arg) = @_;
1176 for my $c ($self->_order_by_chunks ($arg) ) {
1177 $self->_SWITCH_refkind ($c, {
1178 SCALAR => sub { push @sql, $c },
1179 ARRAYREF => sub { push @sql, shift @$c; push @bind, @$c },
1185 $self->_sqlcase(' order by'),
1191 return wantarray ? ($sql, @bind) : $sql;
1194 sub _order_by_chunks {
1195 my ($self, $arg) = @_;
1197 return $self->_SWITCH_refkind($arg, {
1200 map { $self->_order_by_chunks ($_ ) } @$arg;
1203 ARRAYREFREF => sub {
1204 my ($s, @b) = @$$arg;
1205 $self->_assert_bindval_matches_bindtype(@b);
1209 SCALAR => sub {$self->_quote($arg)},
1211 UNDEF => sub {return () },
1213 SCALARREF => sub {$$arg}, # literal SQL, no quoting
1216 # get first pair in hash
1217 my ($key, $val, @rest) = %$arg;
1219 return () unless $key;
1221 if ( @rest or not $key =~ /^-(desc|asc)/i ) {
1222 puke "hash passed to _order_by must have exactly one key (-desc or -asc)";
1228 for my $c ($self->_order_by_chunks ($val)) {
1231 $self->_SWITCH_refkind ($c, {
1236 ($sql, @bind) = @$c;
1240 $sql = $sql . ' ' . $self->_sqlcase($direction);
1242 push @ret, [ $sql, @bind];
1251 #======================================================================
1252 # DATASOURCE (FOR NOW, JUST PLAIN TABLE OR LIST OF TABLES)
1253 #======================================================================
1258 $self->_SWITCH_refkind($from, {
1259 ARRAYREF => sub {join ', ', map { $self->_quote($_) } @$from;},
1260 SCALAR => sub {$self->_quote($from)},
1261 SCALARREF => sub {$$from},
1262 ARRAYREFREF => sub {join ', ', @$from;},
1267 #======================================================================
1269 #======================================================================
1271 # highly optimized, as it's called way too often
1273 # my ($self, $label) = @_;
1275 return '' unless defined $_[1];
1276 return ${$_[1]} if ref($_[1]) eq 'SCALAR';
1278 unless ($_[0]->{quote_char}) {
1279 $_[0]->_assert_pass_injection_guard($_[1]);
1283 my $qref = ref $_[0]->{quote_char};
1286 ($l, $r) = ( $_[0]->{quote_char}, $_[0]->{quote_char} );
1288 elsif ($qref eq 'ARRAY') {
1289 ($l, $r) = @{$_[0]->{quote_char}};
1292 puke "Unsupported quote_char format: $_[0]->{quote_char}";
1295 # parts containing * are naturally unquoted
1296 return join( $_[0]->{name_sep}||'', map
1297 { $_ eq '*' ? $_ : $l . $_ . $r }
1298 ( $_[0]->{name_sep} ? split (/\Q$_[0]->{name_sep}\E/, $_[1] ) : $_[1] )
1303 # Conversion, if applicable
1305 #my ($self, $arg) = @_;
1307 # LDNOTE : modified the previous implementation below because
1308 # it was not consistent : the first "return" is always an array,
1309 # the second "return" is context-dependent. Anyway, _convert
1310 # seems always used with just a single argument, so make it a
1312 # return @_ unless $self->{convert};
1313 # my $conv = $self->_sqlcase($self->{convert});
1314 # my @ret = map { $conv.'('.$_.')' } @_;
1315 # return wantarray ? @ret : $ret[0];
1316 if ($_[0]->{convert}) {
1317 return $_[0]->_sqlcase($_[0]->{convert}) .'(' . $_[1] . ')';
1324 #my ($self, $col, @vals) = @_;
1326 #LDNOTE : changed original implementation below because it did not make
1327 # sense when bindtype eq 'columns' and @vals > 1.
1328 # return $self->{bindtype} eq 'columns' ? [ $col, @vals ] : @vals;
1330 # called often - tighten code
1331 return $_[0]->{bindtype} eq 'columns'
1332 ? map {[$_[1], $_]} @_[2 .. $#_]
1337 # Dies if any element of @bind is not in [colname => value] format
1338 # if bindtype is 'columns'.
1339 sub _assert_bindval_matches_bindtype {
1340 # my ($self, @bind) = @_;
1342 if ($self->{bindtype} eq 'columns') {
1344 if (!defined $_ || ref($_) ne 'ARRAY' || @$_ != 2) {
1345 puke "bindtype 'columns' selected, you need to pass: [column_name => bind_value]"
1351 sub _join_sql_clauses {
1352 my ($self, $logic, $clauses_aref, $bind_aref) = @_;
1354 if (@$clauses_aref > 1) {
1355 my $join = " " . $self->_sqlcase($logic) . " ";
1356 my $sql = '( ' . join($join, @$clauses_aref) . ' )';
1357 return ($sql, @$bind_aref);
1359 elsif (@$clauses_aref) {
1360 return ($clauses_aref->[0], @$bind_aref); # no parentheses
1363 return (); # if no SQL, ignore @$bind_aref
1368 # Fix SQL case, if so requested
1370 # LDNOTE: if $self->{case} is true, then it contains 'lower', so we
1371 # don't touch the argument ... crooked logic, but let's not change it!
1372 return $_[0]->{case} ? $_[1] : uc($_[1]);
1376 #======================================================================
1377 # DISPATCHING FROM REFKIND
1378 #======================================================================
1381 my ($self, $data) = @_;
1383 return 'UNDEF' unless defined $data;
1385 # blessed objects are treated like scalars
1386 my $ref = (Scalar::Util::blessed $data) ? '' : ref $data;
1388 return 'SCALAR' unless $ref;
1391 while ($ref eq 'REF') {
1393 $ref = (Scalar::Util::blessed $data) ? '' : ref $data;
1397 return ($ref||'SCALAR') . ('REF' x $n_steps);
1401 my ($self, $data) = @_;
1402 my @try = ($self->_refkind($data));
1403 push @try, 'SCALAR_or_UNDEF' if $try[0] eq 'SCALAR' || $try[0] eq 'UNDEF';
1404 push @try, 'FALLBACK';
1408 sub _METHOD_FOR_refkind {
1409 my ($self, $meth_prefix, $data) = @_;
1412 for (@{$self->_try_refkind($data)}) {
1413 $method = $self->can($meth_prefix."_".$_)
1417 return $method || puke "cannot dispatch on '$meth_prefix' for ".$self->_refkind($data);
1421 sub _SWITCH_refkind {
1422 my ($self, $data, $dispatch_table) = @_;
1425 for (@{$self->_try_refkind($data)}) {
1426 $coderef = $dispatch_table->{$_}
1430 puke "no dispatch entry for ".$self->_refkind($data)
1439 #======================================================================
1440 # VALUES, GENERATE, AUTOLOAD
1441 #======================================================================
1443 # LDNOTE: original code from nwiger, didn't touch code in that section
1444 # I feel the AUTOLOAD stuff should not be the default, it should
1445 # only be activated on explicit demand by user.
1449 my $data = shift || return;
1450 puke "Argument to ", __PACKAGE__, "->values must be a \\%hash"
1451 unless ref $data eq 'HASH';
1454 foreach my $k ( sort keys %$data ) {
1455 my $v = $data->{$k};
1456 $self->_SWITCH_refkind($v, {
1458 if ($self->{array_datatypes}) { # array datatype
1459 push @all_bind, $self->_bindtype($k, $v);
1461 else { # literal SQL with bind
1462 my ($sql, @bind) = @$v;
1463 $self->_assert_bindval_matches_bindtype(@bind);
1464 push @all_bind, @bind;
1467 ARRAYREFREF => sub { # literal SQL with bind
1468 my ($sql, @bind) = @${$v};
1469 $self->_assert_bindval_matches_bindtype(@bind);
1470 push @all_bind, @bind;
1472 SCALARREF => sub { # literal SQL without bind
1474 SCALAR_or_UNDEF => sub {
1475 push @all_bind, $self->_bindtype($k, $v);
1486 my(@sql, @sqlq, @sqlv);
1490 if ($ref eq 'HASH') {
1491 for my $k (sort keys %$_) {
1494 my $label = $self->_quote($k);
1495 if ($r eq 'ARRAY') {
1496 # literal SQL with bind
1497 my ($sql, @bind) = @$v;
1498 $self->_assert_bindval_matches_bindtype(@bind);
1499 push @sqlq, "$label = $sql";
1501 } elsif ($r eq 'SCALAR') {
1502 # literal SQL without bind
1503 push @sqlq, "$label = $$v";
1505 push @sqlq, "$label = ?";
1506 push @sqlv, $self->_bindtype($k, $v);
1509 push @sql, $self->_sqlcase('set'), join ', ', @sqlq;
1510 } elsif ($ref eq 'ARRAY') {
1511 # unlike insert(), assume these are ONLY the column names, i.e. for SQL
1514 if ($r eq 'ARRAY') { # literal SQL with bind
1515 my ($sql, @bind) = @$v;
1516 $self->_assert_bindval_matches_bindtype(@bind);
1519 } elsif ($r eq 'SCALAR') { # literal SQL without bind
1520 # embedded literal SQL
1527 push @sql, '(' . join(', ', @sqlq) . ')';
1528 } elsif ($ref eq 'SCALAR') {
1532 # strings get case twiddled
1533 push @sql, $self->_sqlcase($_);
1537 my $sql = join ' ', @sql;
1539 # this is pretty tricky
1540 # if ask for an array, return ($stmt, @bind)
1541 # otherwise, s/?/shift @sqlv/ to put it inline
1543 return ($sql, @sqlv);
1545 1 while $sql =~ s/\?/my $d = shift(@sqlv);
1546 ref $d ? $d->[1] : $d/e;
1555 # This allows us to check for a local, then _form, attr
1557 my($name) = $AUTOLOAD =~ /.*::(.+)/;
1558 return $self->generate($name, @_);
1569 SQL::Abstract - Generate SQL from Perl data structures
1575 my $sql = SQL::Abstract->new;
1577 my($stmt, @bind) = $sql->select($table, \@fields, \%where, \@order);
1579 my($stmt, @bind) = $sql->insert($table, \%fieldvals || \@values);
1581 my($stmt, @bind) = $sql->update($table, \%fieldvals, \%where);
1583 my($stmt, @bind) = $sql->delete($table, \%where);
1585 # Then, use these in your DBI statements
1586 my $sth = $dbh->prepare($stmt);
1587 $sth->execute(@bind);
1589 # Just generate the WHERE clause
1590 my($stmt, @bind) = $sql->where(\%where, \@order);
1592 # Return values in the same order, for hashed queries
1593 # See PERFORMANCE section for more details
1594 my @bind = $sql->values(\%fieldvals);
1598 This module was inspired by the excellent L<DBIx::Abstract>.
1599 However, in using that module I found that what I really wanted
1600 to do was generate SQL, but still retain complete control over my
1601 statement handles and use the DBI interface. So, I set out to
1602 create an abstract SQL generation module.
1604 While based on the concepts used by L<DBIx::Abstract>, there are
1605 several important differences, especially when it comes to WHERE
1606 clauses. I have modified the concepts used to make the SQL easier
1607 to generate from Perl data structures and, IMO, more intuitive.
1608 The underlying idea is for this module to do what you mean, based
1609 on the data structures you provide it. The big advantage is that
1610 you don't have to modify your code every time your data changes,
1611 as this module figures it out.
1613 To begin with, an SQL INSERT is as easy as just specifying a hash
1614 of C<key=value> pairs:
1617 name => 'Jimbo Bobson',
1618 phone => '123-456-7890',
1619 address => '42 Sister Lane',
1620 city => 'St. Louis',
1621 state => 'Louisiana',
1624 The SQL can then be generated with this:
1626 my($stmt, @bind) = $sql->insert('people', \%data);
1628 Which would give you something like this:
1630 $stmt = "INSERT INTO people
1631 (address, city, name, phone, state)
1632 VALUES (?, ?, ?, ?, ?)";
1633 @bind = ('42 Sister Lane', 'St. Louis', 'Jimbo Bobson',
1634 '123-456-7890', 'Louisiana');
1636 These are then used directly in your DBI code:
1638 my $sth = $dbh->prepare($stmt);
1639 $sth->execute(@bind);
1641 =head2 Inserting and Updating Arrays
1643 If your database has array types (like for example Postgres),
1644 activate the special option C<< array_datatypes => 1 >>
1645 when creating the C<SQL::Abstract> object.
1646 Then you may use an arrayref to insert and update database array types:
1648 my $sql = SQL::Abstract->new(array_datatypes => 1);
1650 planets => [qw/Mercury Venus Earth Mars/]
1653 my($stmt, @bind) = $sql->insert('solar_system', \%data);
1657 $stmt = "INSERT INTO solar_system (planets) VALUES (?)"
1659 @bind = (['Mercury', 'Venus', 'Earth', 'Mars']);
1662 =head2 Inserting and Updating SQL
1664 In order to apply SQL functions to elements of your C<%data> you may
1665 specify a reference to an arrayref for the given hash value. For example,
1666 if you need to execute the Oracle C<to_date> function on a value, you can
1667 say something like this:
1671 date_entered => \["to_date(?,'MM/DD/YYYY')", "03/02/2003"],
1674 The first value in the array is the actual SQL. Any other values are
1675 optional and would be included in the bind values array. This gives
1678 my($stmt, @bind) = $sql->insert('people', \%data);
1680 $stmt = "INSERT INTO people (name, date_entered)
1681 VALUES (?, to_date(?,'MM/DD/YYYY'))";
1682 @bind = ('Bill', '03/02/2003');
1684 An UPDATE is just as easy, all you change is the name of the function:
1686 my($stmt, @bind) = $sql->update('people', \%data);
1688 Notice that your C<%data> isn't touched; the module will generate
1689 the appropriately quirky SQL for you automatically. Usually you'll
1690 want to specify a WHERE clause for your UPDATE, though, which is
1691 where handling C<%where> hashes comes in handy...
1693 =head2 Complex where statements
1695 This module can generate pretty complicated WHERE statements
1696 easily. For example, simple C<key=value> pairs are taken to mean
1697 equality, and if you want to see if a field is within a set
1698 of values, you can use an arrayref. Let's say we wanted to
1699 SELECT some data based on this criteria:
1702 requestor => 'inna',
1703 worker => ['nwiger', 'rcwe', 'sfz'],
1704 status => { '!=', 'completed' }
1707 my($stmt, @bind) = $sql->select('tickets', '*', \%where);
1709 The above would give you something like this:
1711 $stmt = "SELECT * FROM tickets WHERE
1712 ( requestor = ? ) AND ( status != ? )
1713 AND ( worker = ? OR worker = ? OR worker = ? )";
1714 @bind = ('inna', 'completed', 'nwiger', 'rcwe', 'sfz');
1716 Which you could then use in DBI code like so:
1718 my $sth = $dbh->prepare($stmt);
1719 $sth->execute(@bind);
1725 The functions are simple. There's one for each major SQL operation,
1726 and a constructor you use first. The arguments are specified in a
1727 similar order to each function (table, then fields, then a where
1728 clause) to try and simplify things.
1733 =head2 new(option => 'value')
1735 The C<new()> function takes a list of options and values, and returns
1736 a new B<SQL::Abstract> object which can then be used to generate SQL
1737 through the methods below. The options accepted are:
1743 If set to 'lower', then SQL will be generated in all lowercase. By
1744 default SQL is generated in "textbook" case meaning something like:
1746 SELECT a_field FROM a_table WHERE some_field LIKE '%someval%'
1748 Any setting other than 'lower' is ignored.
1752 This determines what the default comparison operator is. By default
1753 it is C<=>, meaning that a hash like this:
1755 %where = (name => 'nwiger', email => 'nate@wiger.org');
1757 Will generate SQL like this:
1759 WHERE name = 'nwiger' AND email = 'nate@wiger.org'
1761 However, you may want loose comparisons by default, so if you set
1762 C<cmp> to C<like> you would get SQL such as:
1764 WHERE name like 'nwiger' AND email like 'nate@wiger.org'
1766 You can also override the comparsion on an individual basis - see
1767 the huge section on L</"WHERE CLAUSES"> at the bottom.
1769 =item sqltrue, sqlfalse
1771 Expressions for inserting boolean values within SQL statements.
1772 By default these are C<1=1> and C<1=0>. They are used
1773 by the special operators C<-in> and C<-not_in> for generating
1774 correct SQL even when the argument is an empty array (see below).
1778 This determines the default logical operator for multiple WHERE
1779 statements in arrays or hashes. If absent, the default logic is "or"
1780 for arrays, and "and" for hashes. This means that a WHERE
1784 event_date => {'>=', '2/13/99'},
1785 event_date => {'<=', '4/24/03'},
1788 will generate SQL like this:
1790 WHERE event_date >= '2/13/99' OR event_date <= '4/24/03'
1792 This is probably not what you want given this query, though (look
1793 at the dates). To change the "OR" to an "AND", simply specify:
1795 my $sql = SQL::Abstract->new(logic => 'and');
1797 Which will change the above C<WHERE> to:
1799 WHERE event_date >= '2/13/99' AND event_date <= '4/24/03'
1801 The logic can also be changed locally by inserting
1802 a modifier in front of an arrayref :
1804 @where = (-and => [event_date => {'>=', '2/13/99'},
1805 event_date => {'<=', '4/24/03'} ]);
1807 See the L</"WHERE CLAUSES"> section for explanations.
1811 This will automatically convert comparisons using the specified SQL
1812 function for both column and value. This is mostly used with an argument
1813 of C<upper> or C<lower>, so that the SQL will have the effect of
1814 case-insensitive "searches". For example, this:
1816 $sql = SQL::Abstract->new(convert => 'upper');
1817 %where = (keywords => 'MaKe iT CAse inSeNSItive');
1819 Will turn out the following SQL:
1821 WHERE upper(keywords) like upper('MaKe iT CAse inSeNSItive')
1823 The conversion can be C<upper()>, C<lower()>, or any other SQL function
1824 that can be applied symmetrically to fields (actually B<SQL::Abstract> does
1825 not validate this option; it will just pass through what you specify verbatim).
1829 This is a kludge because many databases suck. For example, you can't
1830 just bind values using DBI's C<execute()> for Oracle C<CLOB> or C<BLOB> fields.
1831 Instead, you have to use C<bind_param()>:
1833 $sth->bind_param(1, 'reg data');
1834 $sth->bind_param(2, $lots, {ora_type => ORA_CLOB});
1836 The problem is, B<SQL::Abstract> will normally just return a C<@bind> array,
1837 which loses track of which field each slot refers to. Fear not.
1839 If you specify C<bindtype> in new, you can determine how C<@bind> is returned.
1840 Currently, you can specify either C<normal> (default) or C<columns>. If you
1841 specify C<columns>, you will get an array that looks like this:
1843 my $sql = SQL::Abstract->new(bindtype => 'columns');
1844 my($stmt, @bind) = $sql->insert(...);
1847 [ 'column1', 'value1' ],
1848 [ 'column2', 'value2' ],
1849 [ 'column3', 'value3' ],
1852 You can then iterate through this manually, using DBI's C<bind_param()>.
1854 $sth->prepare($stmt);
1857 my($col, $data) = @$_;
1858 if ($col eq 'details' || $col eq 'comments') {
1859 $sth->bind_param($i, $data, {ora_type => ORA_CLOB});
1860 } elsif ($col eq 'image') {
1861 $sth->bind_param($i, $data, {ora_type => ORA_BLOB});
1863 $sth->bind_param($i, $data);
1867 $sth->execute; # execute without @bind now
1869 Now, why would you still use B<SQL::Abstract> if you have to do this crap?
1870 Basically, the advantage is still that you don't have to care which fields
1871 are or are not included. You could wrap that above C<for> loop in a simple
1872 sub called C<bind_fields()> or something and reuse it repeatedly. You still
1873 get a layer of abstraction over manual SQL specification.
1875 Note that if you set L</bindtype> to C<columns>, the C<\[$sql, @bind]>
1876 construct (see L</Literal SQL with placeholders and bind values (subqueries)>)
1877 will expect the bind values in this format.
1881 This is the character that a table or column name will be quoted
1882 with. By default this is an empty string, but you could set it to
1883 the character C<`>, to generate SQL like this:
1885 SELECT `a_field` FROM `a_table` WHERE `some_field` LIKE '%someval%'
1887 Alternatively, you can supply an array ref of two items, the first being the left
1888 hand quote character, and the second the right hand quote character. For
1889 example, you could supply C<['[',']']> for SQL Server 2000 compliant quotes
1890 that generates SQL like this:
1892 SELECT [a_field] FROM [a_table] WHERE [some_field] LIKE '%someval%'
1894 Quoting is useful if you have tables or columns names that are reserved
1895 words in your database's SQL dialect.
1899 This is the character that separates a table and column name. It is
1900 necessary to specify this when the C<quote_char> option is selected,
1901 so that tables and column names can be individually quoted like this:
1903 SELECT `table`.`one_field` FROM `table` WHERE `table`.`other_field` = 1
1905 =item injection_guard
1907 A regular expression C<qr/.../> that is applied to any C<-function> and unquoted
1908 column name specified in a query structure. This is a safety mechanism to avoid
1909 injection attacks when mishandling user input e.g.:
1911 my %condition_as_column_value_pairs = get_values_from_user();
1912 $sqla->select( ... , \%condition_as_column_value_pairs );
1914 If the expression matches an exception is thrown. Note that literal SQL
1915 supplied via C<\'...'> or C<\['...']> is B<not> checked in any way.
1917 Defaults to checking for C<;> and the C<GO> keyword (TransactSQL)
1919 =item array_datatypes
1921 When this option is true, arrayrefs in INSERT or UPDATE are
1922 interpreted as array datatypes and are passed directly
1924 When this option is false, arrayrefs are interpreted
1925 as literal SQL, just like refs to arrayrefs
1926 (but this behavior is for backwards compatibility; when writing
1927 new queries, use the "reference to arrayref" syntax
1933 Takes a reference to a list of "special operators"
1934 to extend the syntax understood by L<SQL::Abstract>.
1935 See section L</"SPECIAL OPERATORS"> for details.
1939 Takes a reference to a list of "unary operators"
1940 to extend the syntax understood by L<SQL::Abstract>.
1941 See section L</"UNARY OPERATORS"> for details.
1947 =head2 insert($table, \@values || \%fieldvals, \%options)
1949 This is the simplest function. You simply give it a table name
1950 and either an arrayref of values or hashref of field/value pairs.
1951 It returns an SQL INSERT statement and a list of bind values.
1952 See the sections on L</"Inserting and Updating Arrays"> and
1953 L</"Inserting and Updating SQL"> for information on how to insert
1954 with those data types.
1956 The optional C<\%options> hash reference may contain additional
1957 options to generate the insert SQL. Currently supported options
1964 Takes either a scalar of raw SQL fields, or an array reference of
1965 field names, and adds on an SQL C<RETURNING> statement at the end.
1966 This allows you to return data generated by the insert statement
1967 (such as row IDs) without performing another C<SELECT> statement.
1968 Note, however, this is not part of the SQL standard and may not
1969 be supported by all database engines.
1973 =head2 update($table, \%fieldvals, \%where)
1975 This takes a table, hashref of field/value pairs, and an optional
1976 hashref L<WHERE clause|/WHERE CLAUSES>. It returns an SQL UPDATE function and a list
1978 See the sections on L</"Inserting and Updating Arrays"> and
1979 L</"Inserting and Updating SQL"> for information on how to insert
1980 with those data types.
1982 =head2 select($source, $fields, $where, $order)
1984 This returns a SQL SELECT statement and associated list of bind values, as
1985 specified by the arguments :
1991 Specification of the 'FROM' part of the statement.
1992 The argument can be either a plain scalar (interpreted as a table
1993 name, will be quoted), or an arrayref (interpreted as a list
1994 of table names, joined by commas, quoted), or a scalarref
1995 (literal table name, not quoted), or a ref to an arrayref
1996 (list of literal table names, joined by commas, not quoted).
2000 Specification of the list of fields to retrieve from
2002 The argument can be either an arrayref (interpreted as a list
2003 of field names, will be joined by commas and quoted), or a
2004 plain scalar (literal SQL, not quoted).
2005 Please observe that this API is not as flexible as for
2006 the first argument C<$table>, for backwards compatibility reasons.
2010 Optional argument to specify the WHERE part of the query.
2011 The argument is most often a hashref, but can also be
2012 an arrayref or plain scalar --
2013 see section L<WHERE clause|/"WHERE CLAUSES"> for details.
2017 Optional argument to specify the ORDER BY part of the query.
2018 The argument can be a scalar, a hashref or an arrayref
2019 -- see section L<ORDER BY clause|/"ORDER BY CLAUSES">
2025 =head2 delete($table, \%where)
2027 This takes a table name and optional hashref L<WHERE clause|/WHERE CLAUSES>.
2028 It returns an SQL DELETE statement and list of bind values.
2030 =head2 where(\%where, \@order)
2032 This is used to generate just the WHERE clause. For example,
2033 if you have an arbitrary data structure and know what the
2034 rest of your SQL is going to look like, but want an easy way
2035 to produce a WHERE clause, use this. It returns an SQL WHERE
2036 clause and list of bind values.
2039 =head2 values(\%data)
2041 This just returns the values from the hash C<%data>, in the same
2042 order that would be returned from any of the other above queries.
2043 Using this allows you to markedly speed up your queries if you
2044 are affecting lots of rows. See below under the L</"PERFORMANCE"> section.
2046 =head2 generate($any, 'number', $of, \@data, $struct, \%types)
2048 Warning: This is an experimental method and subject to change.
2050 This returns arbitrarily generated SQL. It's a really basic shortcut.
2051 It will return two different things, depending on return context:
2053 my($stmt, @bind) = $sql->generate('create table', \$table, \@fields);
2054 my $stmt_and_val = $sql->generate('create table', \$table, \@fields);
2056 These would return the following:
2058 # First calling form
2059 $stmt = "CREATE TABLE test (?, ?)";
2060 @bind = (field1, field2);
2062 # Second calling form
2063 $stmt_and_val = "CREATE TABLE test (field1, field2)";
2065 Depending on what you're trying to do, it's up to you to choose the correct
2066 format. In this example, the second form is what you would want.
2070 $sql->generate('alter session', { nls_date_format => 'MM/YY' });
2074 ALTER SESSION SET nls_date_format = 'MM/YY'
2076 You get the idea. Strings get their case twiddled, but everything
2077 else remains verbatim.
2082 =head1 WHERE CLAUSES
2086 This module uses a variation on the idea from L<DBIx::Abstract>. It
2087 is B<NOT>, repeat I<not> 100% compatible. B<The main logic of this
2088 module is that things in arrays are OR'ed, and things in hashes
2091 The easiest way to explain is to show lots of examples. After
2092 each C<%where> hash shown, it is assumed you used:
2094 my($stmt, @bind) = $sql->where(\%where);
2096 However, note that the C<%where> hash can be used directly in any
2097 of the other functions as well, as described above.
2099 =head2 Key-value pairs
2101 So, let's get started. To begin, a simple hash:
2105 status => 'completed'
2108 Is converted to SQL C<key = val> statements:
2110 $stmt = "WHERE user = ? AND status = ?";
2111 @bind = ('nwiger', 'completed');
2113 One common thing I end up doing is having a list of values that
2114 a field can be in. To do this, simply specify a list inside of
2119 status => ['assigned', 'in-progress', 'pending'];
2122 This simple code will create the following:
2124 $stmt = "WHERE user = ? AND ( status = ? OR status = ? OR status = ? )";
2125 @bind = ('nwiger', 'assigned', 'in-progress', 'pending');
2127 A field associated to an empty arrayref will be considered a
2128 logical false and will generate 0=1.
2130 =head2 Tests for NULL values
2132 If the value part is C<undef> then this is converted to SQL <IS NULL>
2141 $stmt = "WHERE user = ? AND status IS NULL";
2144 =head2 Specific comparison operators
2146 If you want to specify a different type of operator for your comparison,
2147 you can use a hashref for a given column:
2151 status => { '!=', 'completed' }
2154 Which would generate:
2156 $stmt = "WHERE user = ? AND status != ?";
2157 @bind = ('nwiger', 'completed');
2159 To test against multiple values, just enclose the values in an arrayref:
2161 status => { '=', ['assigned', 'in-progress', 'pending'] };
2163 Which would give you:
2165 "WHERE status = ? OR status = ? OR status = ?"
2168 The hashref can also contain multiple pairs, in which case it is expanded
2169 into an C<AND> of its elements:
2173 status => { '!=', 'completed', -not_like => 'pending%' }
2176 # Or more dynamically, like from a form
2177 $where{user} = 'nwiger';
2178 $where{status}{'!='} = 'completed';
2179 $where{status}{'-not_like'} = 'pending%';
2181 # Both generate this
2182 $stmt = "WHERE user = ? AND status != ? AND status NOT LIKE ?";
2183 @bind = ('nwiger', 'completed', 'pending%');
2186 To get an OR instead, you can combine it with the arrayref idea:
2190 priority => [ {'=', 2}, {'!=', 1} ]
2193 Which would generate:
2195 $stmt = "WHERE user = ? AND priority = ? OR priority != ?";
2196 @bind = ('nwiger', '2', '1');
2198 If you want to include literal SQL (with or without bind values), just use a
2199 scalar reference or array reference as the value:
2202 date_entered => { '>' => \["to_date(?, 'MM/DD/YYYY')", "11/26/2008"] },
2203 date_expires => { '<' => \"now()" }
2206 Which would generate:
2208 $stmt = "WHERE date_entered > "to_date(?, 'MM/DD/YYYY') AND date_expires < now()";
2209 @bind = ('11/26/2008');
2212 =head2 Logic and nesting operators
2214 In the example above,
2215 there is a subtle trap if you want to say something like
2216 this (notice the C<AND>):
2218 WHERE priority != ? AND priority != ?
2220 Because, in Perl you I<can't> do this:
2222 priority => { '!=', 2, '!=', 1 }
2224 As the second C<!=> key will obliterate the first. The solution
2225 is to use the special C<-modifier> form inside an arrayref:
2227 priority => [ -and => {'!=', 2},
2231 Normally, these would be joined by C<OR>, but the modifier tells it
2232 to use C<AND> instead. (Hint: You can use this in conjunction with the
2233 C<logic> option to C<new()> in order to change the way your queries
2234 work by default.) B<Important:> Note that the C<-modifier> goes
2235 B<INSIDE> the arrayref, as an extra first element. This will
2236 B<NOT> do what you think it might:
2238 priority => -and => [{'!=', 2}, {'!=', 1}] # WRONG!
2240 Here is a quick list of equivalencies, since there is some overlap:
2243 status => {'!=', 'completed', 'not like', 'pending%' }
2244 status => [ -and => {'!=', 'completed'}, {'not like', 'pending%'}]
2247 status => {'=', ['assigned', 'in-progress']}
2248 status => [ -or => {'=', 'assigned'}, {'=', 'in-progress'}]
2249 status => [ {'=', 'assigned'}, {'=', 'in-progress'} ]
2253 =head2 Special operators : IN, BETWEEN, etc.
2255 You can also use the hashref format to compare a list of fields using the
2256 C<IN> comparison operator, by specifying the list as an arrayref:
2259 status => 'completed',
2260 reportid => { -in => [567, 2335, 2] }
2263 Which would generate:
2265 $stmt = "WHERE status = ? AND reportid IN (?,?,?)";
2266 @bind = ('completed', '567', '2335', '2');
2268 The reverse operator C<-not_in> generates SQL C<NOT IN> and is used in
2271 If the argument to C<-in> is an empty array, 'sqlfalse' is generated
2272 (by default : C<1=0>). Similarly, C<< -not_in => [] >> generates
2273 'sqltrue' (by default : C<1=1>).
2275 In addition to the array you can supply a chunk of literal sql or
2276 literal sql with bind:
2279 customer => { -in => \[
2280 'SELECT cust_id FROM cust WHERE balance > ?',
2283 status => { -in => \'SELECT status_codes FROM states' },
2289 customer IN ( SELECT cust_id FROM cust WHERE balance > ? )
2290 AND status IN ( SELECT status_codes FROM states )
2296 Another pair of operators is C<-between> and C<-not_between>,
2297 used with an arrayref of two values:
2301 completion_date => {
2302 -not_between => ['2002-10-01', '2003-02-06']
2308 WHERE user = ? AND completion_date NOT BETWEEN ( ? AND ? )
2310 Just like with C<-in> all plausible combinations of literal SQL
2314 start0 => { -between => [ 1, 2 ] },
2315 start1 => { -between => \["? AND ?", 1, 2] },
2316 start2 => { -between => \"lower(x) AND upper(y)" },
2317 start3 => { -between => [
2319 \["upper(?)", 'stuff' ],
2326 ( start0 BETWEEN ? AND ? )
2327 AND ( start1 BETWEEN ? AND ? )
2328 AND ( start2 BETWEEN lower(x) AND upper(y) )
2329 AND ( start3 BETWEEN lower(x) AND upper(?) )
2331 @bind = (1, 2, 1, 2, 'stuff');
2334 These are the two builtin "special operators"; but the
2335 list can be expanded : see section L</"SPECIAL OPERATORS"> below.
2337 Another operator is C<-func> that allows you to call SQL functions with
2338 arguments. It receives an array reference containing the function name
2339 as the 0th argument and the other arguments being its parameters. For example:
2342 -func => ['substr', 'Hello', 50, 5],
2347 $stmt = "WHERE (substr(?,?,?))";
2348 @bind = ("Hello", 50, 5);
2350 Yet another operator is C<-op> that allows you to use SQL operators. It
2351 receives an array reference containing the operator 0th argument and the other
2352 arguments being its operands. For example:
2355 foo => { -op => ['+', \'bar', 50, 5] },
2360 $stmt = "WHERE (foo = bar + ? + ?)";
2363 =head2 Unary operators: bool
2365 If you wish to test against boolean columns or functions within your
2366 database you can use the C<-bool> and C<-not_bool> operators. For
2367 example to test the column C<is_user> being true and the column
2368 C<is_enabled> being false you would use:-
2372 -not_bool => 'is_enabled',
2377 WHERE is_user AND NOT is_enabled
2379 If a more complex combination is required, testing more conditions,
2380 then you should use the and/or operators:-
2387 -not_bool => 'four',
2393 WHERE one AND two AND three AND NOT four
2396 =head2 Nested conditions, -and/-or prefixes
2398 So far, we've seen how multiple conditions are joined with a top-level
2399 C<AND>. We can change this by putting the different conditions we want in
2400 hashes and then putting those hashes in an array. For example:
2405 status => { -like => ['pending%', 'dispatched'] },
2409 status => 'unassigned',
2413 This data structure would create the following:
2415 $stmt = "WHERE ( user = ? AND ( status LIKE ? OR status LIKE ? ) )
2416 OR ( user = ? AND status = ? ) )";
2417 @bind = ('nwiger', 'pending', 'dispatched', 'robot', 'unassigned');
2420 Clauses in hashrefs or arrayrefs can be prefixed with an C<-and> or C<-or>
2421 to change the logic inside :
2427 -and => [ workhrs => {'>', 20}, geo => 'ASIA' ],
2428 -or => { workhrs => {'<', 50}, geo => 'EURO' },
2435 WHERE ( user = ? AND (
2436 ( workhrs > ? AND geo = ? )
2437 OR ( workhrs < ? OR geo = ? )
2440 =head2 Algebraic inconsistency, for historical reasons
2442 C<Important note>: when connecting several conditions, the C<-and->|C<-or>
2443 operator goes C<outside> of the nested structure; whereas when connecting
2444 several constraints on one column, the C<-and> operator goes
2445 C<inside> the arrayref. Here is an example combining both features :
2448 -and => [a => 1, b => 2],
2449 -or => [c => 3, d => 4],
2450 e => [-and => {-like => 'foo%'}, {-like => '%bar'} ]
2455 WHERE ( ( ( a = ? AND b = ? )
2456 OR ( c = ? OR d = ? )
2457 OR ( e LIKE ? AND e LIKE ? ) ) )
2459 This difference in syntax is unfortunate but must be preserved for
2460 historical reasons. So be careful : the two examples below would
2461 seem algebraically equivalent, but they are not
2463 {col => [-and => {-like => 'foo%'}, {-like => '%bar'}]}
2464 # yields : WHERE ( ( col LIKE ? AND col LIKE ? ) )
2466 [-and => {col => {-like => 'foo%'}, {col => {-like => '%bar'}}]]
2467 # yields : WHERE ( ( col LIKE ? OR col LIKE ? ) )
2472 Finally, sometimes only literal SQL will do. If you want to include
2473 literal SQL verbatim, you can specify it as a scalar reference, namely:
2475 my $inn = 'is Not Null';
2477 priority => { '<', 2 },
2483 $stmt = "WHERE priority < ? AND requestor is Not Null";
2486 Note that in this example, you only get one bind parameter back, since
2487 the verbatim SQL is passed as part of the statement.
2489 Of course, just to prove a point, the above can also be accomplished
2493 priority => { '<', 2 },
2494 requestor => { '!=', undef },
2500 Conditions on boolean columns can be expressed in the same way, passing
2501 a reference to an empty string, however using liternal SQL in this way
2502 is deprecated - the preferred method is to use the boolean operators -
2503 see L</"Unary operators: bool"> :
2506 priority => { '<', 2 },
2512 $stmt = "WHERE priority < ? AND is_ready";
2515 Literal SQL is also the only way to compare 2 columns to one another:
2518 priority => { '<', 2 },
2519 requestor => \'= submittor'
2524 $stmt = "WHERE priority < ? AND requestor = submitter";
2527 =head2 Literal SQL with placeholders and bind values (subqueries)
2529 If the literal SQL to be inserted has placeholders and bind values,
2530 use a reference to an arrayref (yes this is a double reference --
2531 not so common, but perfectly legal Perl). For example, to find a date
2532 in Postgres you can use something like this:
2535 date_column => \[q/= date '2008-09-30' - ?::integer/, 10/]
2540 $stmt = "WHERE ( date_column = date '2008-09-30' - ?::integer )"
2543 Note that you must pass the bind values in the same format as they are returned
2544 by L</where>. That means that if you set L</bindtype> to C<columns>, you must
2545 provide the bind values in the C<< [ column_meta => value ] >> format, where
2546 C<column_meta> is an opaque scalar value; most commonly the column name, but
2547 you can use any scalar value (including references and blessed references),
2548 L<SQL::Abstract> will simply pass it through intact. So if C<bindtype> is set
2549 to C<columns> the above example will look like:
2552 date_column => \[q/= date '2008-09-30' - ?::integer/, [ dummy => 10 ]/]
2555 Literal SQL is especially useful for nesting parenthesized clauses in the
2556 main SQL query. Here is a first example :
2558 my ($sub_stmt, @sub_bind) = ("SELECT c1 FROM t1 WHERE c2 < ? AND c3 LIKE ?",
2562 bar => \["IN ($sub_stmt)" => @sub_bind],
2567 $stmt = "WHERE (foo = ? AND bar IN (SELECT c1 FROM t1
2568 WHERE c2 < ? AND c3 LIKE ?))";
2569 @bind = (1234, 100, "foo%");
2571 Other subquery operators, like for example C<"E<gt> ALL"> or C<"NOT IN">,
2572 are expressed in the same way. Of course the C<$sub_stmt> and
2573 its associated bind values can be generated through a former call
2576 my ($sub_stmt, @sub_bind)
2577 = $sql->select("t1", "c1", {c2 => {"<" => 100},
2578 c3 => {-like => "foo%"}});
2581 bar => \["> ALL ($sub_stmt)" => @sub_bind],
2584 In the examples above, the subquery was used as an operator on a column;
2585 but the same principle also applies for a clause within the main C<%where>
2586 hash, like an EXISTS subquery :
2588 my ($sub_stmt, @sub_bind)
2589 = $sql->select("t1", "*", {c1 => 1, c2 => \"> t0.c0"});
2590 my %where = ( -and => [
2592 \["EXISTS ($sub_stmt)" => @sub_bind],
2597 $stmt = "WHERE (foo = ? AND EXISTS (SELECT * FROM t1
2598 WHERE c1 = ? AND c2 > t0.c0))";
2602 Observe that the condition on C<c2> in the subquery refers to
2603 column C<t0.c0> of the main query : this is I<not> a bind
2604 value, so we have to express it through a scalar ref.
2605 Writing C<< c2 => {">" => "t0.c0"} >> would have generated
2606 C<< c2 > ? >> with bind value C<"t0.c0"> ... not exactly
2607 what we wanted here.
2609 Finally, here is an example where a subquery is used
2610 for expressing unary negation:
2612 my ($sub_stmt, @sub_bind)
2613 = $sql->where({age => [{"<" => 10}, {">" => 20}]});
2614 $sub_stmt =~ s/^ where //i; # don't want "WHERE" in the subclause
2616 lname => {like => '%son%'},
2617 \["NOT ($sub_stmt)" => @sub_bind],
2622 $stmt = "lname LIKE ? AND NOT ( age < ? OR age > ? )"
2623 @bind = ('%son%', 10, 20)
2629 These pages could go on for a while, since the nesting of the data
2630 structures this module can handle are pretty much unlimited (the
2631 module implements the C<WHERE> expansion as a recursive function
2632 internally). Your best bet is to "play around" with the module a
2633 little to see how the data structures behave, and choose the best
2634 format for your data based on that.
2636 And of course, all the values above will probably be replaced with
2637 variables gotten from forms or the command line. After all, if you
2638 knew everything ahead of time, you wouldn't have to worry about
2639 dynamically-generating SQL and could just hardwire it into your
2645 =head1 ORDER BY CLAUSES
2647 Some functions take an order by clause. This can either be a scalar (just a
2648 column name,) a hash of C<< { -desc => 'col' } >> or C<< { -asc => 'col' } >>,
2649 or an array of either of the two previous forms. Examples:
2651 Given | Will Generate
2652 ----------------------------------------------------------
2654 \'colA DESC' | ORDER BY colA DESC
2656 'colA' | ORDER BY colA
2658 [qw/colA colB/] | ORDER BY colA, colB
2660 {-asc => 'colA'} | ORDER BY colA ASC
2662 {-desc => 'colB'} | ORDER BY colB DESC
2664 ['colA', {-asc => 'colB'}] | ORDER BY colA, colB ASC
2666 { -asc => [qw/colA colB/] } | ORDER BY colA ASC, colB ASC
2669 { -asc => 'colA' }, | ORDER BY colA ASC, colB DESC,
2670 { -desc => [qw/colB/], | colC ASC, colD ASC
2671 { -asc => [qw/colC colD/],|
2673 ===========================================================
2677 =head1 SPECIAL OPERATORS
2679 my $sqlmaker = SQL::Abstract->new(special_ops => [
2683 my ($self, $field, $op, $arg) = @_;
2689 handler => 'method_name',
2693 A "special operator" is a SQL syntactic clause that can be
2694 applied to a field, instead of a usual binary operator.
2697 WHERE field IN (?, ?, ?)
2698 WHERE field BETWEEN ? AND ?
2699 WHERE MATCH(field) AGAINST (?, ?)
2701 Special operators IN and BETWEEN are fairly standard and therefore
2702 are builtin within C<SQL::Abstract> (as the overridable methods
2703 C<_where_field_IN> and C<_where_field_BETWEEN>). For other operators,
2704 like the MATCH .. AGAINST example above which is specific to MySQL,
2705 you can write your own operator handlers - supply a C<special_ops>
2706 argument to the C<new> method. That argument takes an arrayref of
2707 operator definitions; each operator definition is a hashref with two
2714 the regular expression to match the operator
2718 Either a coderef or a plain scalar method name. In both cases
2719 the expected return is C<< ($sql, @bind) >>.
2721 When supplied with a method name, it is simply called on the
2722 L<SQL::Abstract/> object as:
2724 $self->$method_name ($field, $op, $arg)
2728 $op is the part that matched the handler regex
2729 $field is the LHS of the operator
2732 When supplied with a coderef, it is called as:
2734 $coderef->($self, $field, $op, $arg)
2739 For example, here is an implementation
2740 of the MATCH .. AGAINST syntax for MySQL
2742 my $sqlmaker = SQL::Abstract->new(special_ops => [
2744 # special op for MySql MATCH (field) AGAINST(word1, word2, ...)
2745 {regex => qr/^match$/i,
2747 my ($self, $field, $op, $arg) = @_;
2748 $arg = [$arg] if not ref $arg;
2749 my $label = $self->_quote($field);
2750 my ($placeholder) = $self->_convert('?');
2751 my $placeholders = join ", ", (($placeholder) x @$arg);
2752 my $sql = $self->_sqlcase('match') . " ($label) "
2753 . $self->_sqlcase('against') . " ($placeholders) ";
2754 my @bind = $self->_bindtype($field, @$arg);
2755 return ($sql, @bind);
2762 =head1 UNARY OPERATORS
2764 my $sqlmaker = SQL::Abstract->new(unary_ops => [
2768 my ($self, $op, $arg) = @_;
2774 handler => 'method_name',
2778 A "unary operator" is a SQL syntactic clause that can be
2779 applied to a field - the operator goes before the field
2781 You can write your own operator handlers - supply a C<unary_ops>
2782 argument to the C<new> method. That argument takes an arrayref of
2783 operator definitions; each operator definition is a hashref with two
2790 the regular expression to match the operator
2794 Either a coderef or a plain scalar method name. In both cases
2795 the expected return is C<< $sql >>.
2797 When supplied with a method name, it is simply called on the
2798 L<SQL::Abstract/> object as:
2800 $self->$method_name ($op, $arg)
2804 $op is the part that matched the handler regex
2805 $arg is the RHS or argument of the operator
2807 When supplied with a coderef, it is called as:
2809 $coderef->($self, $op, $arg)
2817 Thanks to some benchmarking by Mark Stosberg, it turns out that
2818 this module is many orders of magnitude faster than using C<DBIx::Abstract>.
2819 I must admit this wasn't an intentional design issue, but it's a
2820 byproduct of the fact that you get to control your C<DBI> handles
2823 To maximize performance, use a code snippet like the following:
2825 # prepare a statement handle using the first row
2826 # and then reuse it for the rest of the rows
2828 for my $href (@array_of_hashrefs) {
2829 $stmt ||= $sql->insert('table', $href);
2830 $sth ||= $dbh->prepare($stmt);
2831 $sth->execute($sql->values($href));
2834 The reason this works is because the keys in your C<$href> are sorted
2835 internally by B<SQL::Abstract>. Thus, as long as your data retains
2836 the same structure, you only have to generate the SQL the first time
2837 around. On subsequent queries, simply use the C<values> function provided
2838 by this module to return your values in the correct order.
2840 However this depends on the values having the same type - if, for
2841 example, the values of a where clause may either have values
2842 (resulting in sql of the form C<column = ?> with a single bind
2843 value), or alternatively the values might be C<undef> (resulting in
2844 sql of the form C<column IS NULL> with no bind value) then the
2845 caching technique suggested will not work.
2849 If you use my C<CGI::FormBuilder> module at all, you'll hopefully
2850 really like this part (I do, at least). Building up a complex query
2851 can be as simple as the following:
2855 use CGI::FormBuilder;
2858 my $form = CGI::FormBuilder->new(...);
2859 my $sql = SQL::Abstract->new;
2861 if ($form->submitted) {
2862 my $field = $form->field;
2863 my $id = delete $field->{id};
2864 my($stmt, @bind) = $sql->update('table', $field, {id => $id});
2867 Of course, you would still have to connect using C<DBI> to run the
2868 query, but the point is that if you make your form look like your
2869 table, the actual query script can be extremely simplistic.
2871 If you're B<REALLY> lazy (I am), check out C<HTML::QuickTable> for
2872 a fast interface to returning and formatting data. I frequently
2873 use these three modules together to write complex database query
2874 apps in under 50 lines.
2880 =item * gitweb: L<http://git.shadowcat.co.uk/gitweb/gitweb.cgi?p=dbsrgits/DBIx-Class.git>
2882 =item * git: L<git://git.shadowcat.co.uk/dbsrgits/DBIx-Class.git>
2888 Version 1.50 was a major internal refactoring of C<SQL::Abstract>.
2889 Great care has been taken to preserve the I<published> behavior
2890 documented in previous versions in the 1.* family; however,
2891 some features that were previously undocumented, or behaved
2892 differently from the documentation, had to be changed in order
2893 to clarify the semantics. Hence, client code that was relying
2894 on some dark areas of C<SQL::Abstract> v1.*
2895 B<might behave differently> in v1.50.
2897 The main changes are :
2903 support for literal SQL through the C<< \ [$sql, bind] >> syntax.
2907 support for the { operator => \"..." } construct (to embed literal SQL)
2911 support for the { operator => \["...", @bind] } construct (to embed literal SQL with bind values)
2915 optional support for L<array datatypes|/"Inserting and Updating Arrays">
2919 defensive programming : check arguments
2923 fixed bug with global logic, which was previously implemented
2924 through global variables yielding side-effects. Prior versions would
2925 interpret C<< [ {cond1, cond2}, [cond3, cond4] ] >>
2926 as C<< "(cond1 AND cond2) OR (cond3 AND cond4)" >>.
2927 Now this is interpreted
2928 as C<< "(cond1 AND cond2) OR (cond3 OR cond4)" >>.
2933 fixed semantics of _bindtype on array args
2937 dropped the C<_anoncopy> of the %where tree. No longer necessary,
2938 we just avoid shifting arrays within that tree.
2942 dropped the C<_modlogic> function
2948 =head1 ACKNOWLEDGEMENTS
2950 There are a number of individuals that have really helped out with
2951 this module. Unfortunately, most of them submitted bugs via CPAN
2952 so I have no idea who they are! But the people I do know are:
2954 Ash Berlin (order_by hash term support)
2955 Matt Trout (DBIx::Class support)
2956 Mark Stosberg (benchmarking)
2957 Chas Owens (initial "IN" operator support)
2958 Philip Collins (per-field SQL functions)
2959 Eric Kolve (hashref "AND" support)
2960 Mike Fragassi (enhancements to "BETWEEN" and "LIKE")
2961 Dan Kubb (support for "quote_char" and "name_sep")
2962 Guillermo Roditi (patch to cleanup "IN" and "BETWEEN", fix and tests for _order_by)
2963 Laurent Dami (internal refactoring, extensible list of special operators, literal SQL)
2964 Norbert Buchmuller (support for literal SQL in hashpair, misc. fixes & tests)
2965 Peter Rabbitson (rewrite of SQLA::Test, misc. fixes & tests)
2966 Oliver Charles (support for "RETURNING" after "INSERT")
2972 L<DBIx::Class>, L<DBIx::Abstract>, L<CGI::FormBuilder>, L<HTML::QuickTable>.
2976 Copyright (c) 2001-2007 Nathan Wiger <nwiger@cpan.org>. All Rights Reserved.
2978 This module is actively maintained by Matt Trout <mst@shadowcatsystems.co.uk>
2980 For support, your best bet is to try the C<DBIx::Class> users mailing list.
2981 While not an official support venue, C<DBIx::Class> makes heavy use of
2982 C<SQL::Abstract>, and as such list members there are very familiar with
2983 how to create queries.
2987 This module is free software; you may copy this under the same
2988 terms as perl itself (either the GNU General Public License or
2989 the Artistic License)