1 package SQL::Abstract; # see doc at end of file
3 # LDNOTE : this code is heavy refactoring from original SQLA.
4 # Several design decisions will need discussion during
5 # the test / diffusion / acceptance phase; those are marked with flag
6 # 'LDNOTE' (note by laurent.dami AT free.fr)
11 use List::Util qw/first/;
12 use Scalar::Util qw/blessed/;
14 #======================================================================
16 #======================================================================
18 our $VERSION = '1.58';
20 # This would confuse some packagers
21 #$VERSION = eval $VERSION; # numify for warning-free dev releases
25 # special operators (-in, -between). May be extended/overridden by user.
26 # See section WHERE: BUILTIN SPECIAL OPERATORS below for implementation
27 my @BUILTIN_SPECIAL_OPS = (
28 {regex => qr/^(not )?between$/i, handler => '_where_field_BETWEEN'},
29 {regex => qr/^(not )?in$/i, handler => '_where_field_IN'},
32 # unaryish operators - key maps to handler
33 my @BUILTIN_UNARY_OPS = (
34 # the digits are backcompat stuff
35 { regex => qr/^and (?: \s? \d+ )? $/xi, handler => '_where_op_ANDOR' },
36 { regex => qr/^or (?: \s? \d+ )? $/xi, handler => '_where_op_ANDOR' },
37 { regex => qr/^nest (?: \s? \d+ )? $/xi, handler => '_where_op_NEST' },
38 { regex => qr/^ (?: not \s )? bool $/xi, handler => '_where_op_BOOL' },
41 #======================================================================
42 # DEBUGGING AND ERROR REPORTING
43 #======================================================================
46 return unless $_[0]->{debug}; shift; # a little faster
47 my $func = (caller(1))[3];
48 warn "[$func] ", @_, "\n";
52 my($func) = (caller(1))[3];
53 carp "[$func] Warning: ", @_;
57 my($func) = (caller(1))[3];
58 croak "[$func] Fatal: ", @_;
62 #======================================================================
64 #======================================================================
68 my $class = ref($self) || $self;
69 my %opt = (ref $_[0] eq 'HASH') ? %{$_[0]} : @_;
71 # choose our case by keeping an option around
72 delete $opt{case} if $opt{case} && $opt{case} ne 'lower';
74 # default logic for interpreting arrayrefs
75 $opt{logic} = $opt{logic} ? uc $opt{logic} : 'OR';
77 # how to return bind vars
78 # LDNOTE: changed nwiger code : why this 'delete' ??
79 # $opt{bindtype} ||= delete($opt{bind_type}) || 'normal';
80 $opt{bindtype} ||= 'normal';
82 # default comparison is "=", but can be overridden
85 # try to recognize which are the 'equality' and 'unequality' ops
86 # (temporary quickfix, should go through a more seasoned API)
87 $opt{equality_op} = qr/^(\Q$opt{cmp}\E|is|(is\s+)?like)$/i;
88 $opt{inequality_op} = qr/^(!=|<>|(is\s+)?not(\s+like)?)$/i;
91 $opt{sqltrue} ||= '1=1';
92 $opt{sqlfalse} ||= '0=1';
95 $opt{special_ops} ||= [];
96 push @{$opt{special_ops}}, @BUILTIN_SPECIAL_OPS;
99 $opt{unary_ops} ||= [];
100 push @{$opt{unary_ops}}, @BUILTIN_UNARY_OPS;
102 return bless \%opt, $class;
107 #======================================================================
109 #======================================================================
113 my $table = $self->_table(shift);
114 my $data = shift || return;
116 my $method = $self->_METHOD_FOR_refkind("_insert", $data);
117 my ($sql, @bind) = $self->$method($data);
118 $sql = join " ", $self->_sqlcase('insert into'), $table, $sql;
119 return wantarray ? ($sql, @bind) : $sql;
122 sub _insert_HASHREF { # explicit list of fields and then values
123 my ($self, $data) = @_;
125 my @fields = sort keys %$data;
127 my ($sql, @bind) = $self->_insert_values($data);
130 $_ = $self->_quote($_) foreach @fields;
131 $sql = "( ".join(", ", @fields).") ".$sql;
133 return ($sql, @bind);
136 sub _insert_ARRAYREF { # just generate values(?,?) part (no list of fields)
137 my ($self, $data) = @_;
139 # no names (arrayref) so can't generate bindtype
140 $self->{bindtype} ne 'columns'
141 or belch "can't do 'columns' bindtype when called with arrayref";
143 # fold the list of values into a hash of column name - value pairs
144 # (where the column names are artificially generated, and their
145 # lexicographical ordering keep the ordering of the original list)
146 my $i = "a"; # incremented values will be in lexicographical order
147 my $data_in_hash = { map { ($i++ => $_) } @$data };
149 return $self->_insert_values($data_in_hash);
152 sub _insert_ARRAYREFREF { # literal SQL with bind
153 my ($self, $data) = @_;
155 my ($sql, @bind) = @${$data};
156 $self->_assert_bindval_matches_bindtype(@bind);
158 return ($sql, @bind);
162 sub _insert_SCALARREF { # literal SQL without bind
163 my ($self, $data) = @_;
169 my ($self, $data) = @_;
171 my (@values, @all_bind);
172 foreach my $column (sort keys %$data) {
173 my $v = $data->{$column};
175 $self->_SWITCH_refkind($v, {
178 if ($self->{array_datatypes}) { # if array datatype are activated
180 push @all_bind, $self->_bindtype($column, $v);
182 else { # else literal SQL with bind
183 my ($sql, @bind) = @$v;
184 $self->_assert_bindval_matches_bindtype(@bind);
186 push @all_bind, @bind;
190 ARRAYREFREF => sub { # literal SQL with bind
191 my ($sql, @bind) = @${$v};
192 $self->_assert_bindval_matches_bindtype(@bind);
194 push @all_bind, @bind;
197 # THINK : anything useful to do with a HASHREF ?
198 HASHREF => sub { # (nothing, but old SQLA passed it through)
199 #TODO in SQLA >= 2.0 it will die instead
200 belch "HASH ref as bind value in insert is not supported";
202 push @all_bind, $self->_bindtype($column, $v);
205 SCALARREF => sub { # literal SQL without bind
209 SCALAR_or_UNDEF => sub {
211 push @all_bind, $self->_bindtype($column, $v);
218 my $sql = $self->_sqlcase('values')." ( ".join(", ", @values)." )";
219 return ($sql, @all_bind);
224 #======================================================================
226 #======================================================================
231 my $table = $self->_table(shift);
232 my $data = shift || return;
235 # first build the 'SET' part of the sql statement
236 my (@set, @all_bind);
237 puke "Unsupported data type specified to \$sql->update"
238 unless ref $data eq 'HASH';
240 for my $k (sort keys %$data) {
243 my $label = $self->_quote($k);
245 $self->_SWITCH_refkind($v, {
247 if ($self->{array_datatypes}) { # array datatype
248 push @set, "$label = ?";
249 push @all_bind, $self->_bindtype($k, $v);
251 else { # literal SQL with bind
252 my ($sql, @bind) = @$v;
253 $self->_assert_bindval_matches_bindtype(@bind);
254 push @set, "$label = $sql";
255 push @all_bind, @bind;
258 ARRAYREFREF => sub { # literal SQL with bind
259 my ($sql, @bind) = @${$v};
260 $self->_assert_bindval_matches_bindtype(@bind);
261 push @set, "$label = $sql";
262 push @all_bind, @bind;
264 SCALARREF => sub { # literal SQL without bind
265 push @set, "$label = $$v";
267 SCALAR_or_UNDEF => sub {
268 push @set, "$label = ?";
269 push @all_bind, $self->_bindtype($k, $v);
275 my $sql = $self->_sqlcase('update') . " $table " . $self->_sqlcase('set ')
279 my($where_sql, @where_bind) = $self->where($where);
281 push @all_bind, @where_bind;
284 return wantarray ? ($sql, @all_bind) : $sql;
290 #======================================================================
292 #======================================================================
297 my $table = $self->_table(shift);
298 my $fields = shift || '*';
302 my($where_sql, @bind) = $self->where($where, $order);
304 my $f = (ref $fields eq 'ARRAY') ? join ', ', map { $self->_quote($_) } @$fields
306 my $sql = join(' ', $self->_sqlcase('select'), $f,
307 $self->_sqlcase('from'), $table)
310 return wantarray ? ($sql, @bind) : $sql;
313 #======================================================================
315 #======================================================================
320 my $table = $self->_table(shift);
324 my($where_sql, @bind) = $self->where($where);
325 my $sql = $self->_sqlcase('delete from') . " $table" . $where_sql;
327 return wantarray ? ($sql, @bind) : $sql;
331 #======================================================================
333 #======================================================================
337 # Finally, a separate routine just to handle WHERE clauses
339 my ($self, $where, $order) = @_;
342 my ($sql, @bind) = $self->_recurse_where($where);
343 $sql = $sql ? $self->_sqlcase(' where ') . "( $sql )" : '';
347 $sql .= $self->_order_by($order);
350 return wantarray ? ($sql, @bind) : $sql;
355 my ($self, $where, $logic) = @_;
357 # dispatch on appropriate method according to refkind of $where
358 my $method = $self->_METHOD_FOR_refkind("_where", $where);
361 my ($sql, @bind) = $self->$method($where, $logic);
363 # DBIx::Class directly calls _recurse_where in scalar context, so
364 # we must implement it, even if not in the official API
365 return wantarray ? ($sql, @bind) : $sql;
370 #======================================================================
371 # WHERE: top-level ARRAYREF
372 #======================================================================
375 sub _where_ARRAYREF {
376 my ($self, $where, $logic) = @_;
378 $logic = uc($logic || $self->{logic});
379 $logic eq 'AND' or $logic eq 'OR' or puke "unknown logic: $logic";
381 my @clauses = @$where;
383 my (@sql_clauses, @all_bind);
384 # need to use while() so can shift() for pairs
385 while (my $el = shift @clauses) {
387 # switch according to kind of $el and get corresponding ($sql, @bind)
388 my ($sql, @bind) = $self->_SWITCH_refkind($el, {
390 # skip empty elements, otherwise get invalid trailing AND stuff
391 ARRAYREF => sub {$self->_recurse_where($el) if @$el},
393 ARRAYREFREF => sub { @{${$el}} if @{${$el}}},
395 HASHREF => sub {$self->_recurse_where($el, 'and') if %$el},
396 # LDNOTE : previous SQLA code for hashrefs was creating a dirty
397 # side-effect: the first hashref within an array would change
398 # the global logic to 'AND'. So [ {cond1, cond2}, [cond3, cond4] ]
399 # was interpreted as "(cond1 AND cond2) OR (cond3 AND cond4)",
400 # whereas it should be "(cond1 AND cond2) OR (cond3 OR cond4)".
402 SCALARREF => sub { ($$el); },
404 SCALAR => sub {# top-level arrayref with scalars, recurse in pairs
405 $self->_recurse_where({$el => shift(@clauses)})},
407 UNDEF => sub {puke "not supported : UNDEF in arrayref" },
411 push @sql_clauses, $sql;
412 push @all_bind, @bind;
416 return $self->_join_sql_clauses($logic, \@sql_clauses, \@all_bind);
419 #======================================================================
420 # WHERE: top-level ARRAYREFREF
421 #======================================================================
423 sub _where_ARRAYREFREF {
424 my ($self, $where) = @_;
425 my ($sql, @bind) = @{${$where}};
427 return ($sql, @bind);
430 #======================================================================
431 # WHERE: top-level HASHREF
432 #======================================================================
435 my ($self, $where) = @_;
436 my (@sql_clauses, @all_bind);
438 for my $k (sort keys %$where) {
439 my $v = $where->{$k};
441 # ($k => $v) is either a special op or a regular hashpair
442 my ($sql, @bind) = ($k =~ /^(-.+)/) ? $self->_where_op_in_hash($1, $v)
444 my $method = $self->_METHOD_FOR_refkind("_where_hashpair", $v);
445 $self->$method($k, $v);
448 push @sql_clauses, $sql;
449 push @all_bind, @bind;
452 return $self->_join_sql_clauses('and', \@sql_clauses, \@all_bind);
456 sub _where_op_in_hash {
457 my ($self, $orig_op, $v) = @_;
459 # put the operator in canonical form
461 $op =~ s/^-//; # remove initial dash
462 $op =~ s/[_\t ]+/ /g; # underscores and whitespace become single spaces
463 $op =~ s/^\s+|\s+$//g;# remove leading/trailing space
465 $self->_debug("OP(-$op) within hashref, recursing...");
467 my $op_entry = first {$op =~ $_->{regex}} @{$self->{unary_ops}};
468 my $handler = $op_entry->{handler};
470 puke "unknown operator: $orig_op";
472 elsif (not ref $handler) {
473 if ($op =~ s/\s?\d+$//) {
474 belch 'Use of [and|or|nest]_N modifiers is deprecated and will be removed in SQLA v2.0. '
475 . "You probably wanted ...-and => [ -$op => COND1, -$op => COND2 ... ]";
477 return $self->$handler ($op, $v);
479 elsif (ref $handler eq 'CODE') {
480 return $handler->($self, $op, $v);
483 puke "Illegal handler for operator $orig_op - expecting a method name or a coderef";
487 sub _where_op_ANDOR {
488 my ($self, $op, $v) = @_;
490 $self->_SWITCH_refkind($v, {
492 return $self->_where_ARRAYREF($v, $op);
496 return ( $op =~ /^or/i )
497 ? $self->_where_ARRAYREF( [ map { $_ => $v->{$_} } ( sort keys %$v ) ], $op )
498 : $self->_where_HASHREF($v);
502 puke "-$op => \\\$scalar not supported, use -nest => ...";
506 puke "-$op => \\[..] not supported, use -nest => ...";
509 SCALAR => sub { # permissively interpreted as SQL
510 puke "-$op => 'scalar' not supported, use -nest => \\'scalar'";
514 puke "-$op => undef not supported";
520 my ($self, $op, $v) = @_;
522 $self->_SWITCH_refkind($v, {
525 return $self->_where_ARRAYREF($v, '');
529 return $self->_where_HASHREF($v);
532 SCALARREF => sub { # literal SQL
536 ARRAYREFREF => sub { # literal SQL
540 SCALAR => sub { # permissively interpreted as SQL
541 belch "literal SQL should be -nest => \\'scalar' "
542 . "instead of -nest => 'scalar' ";
547 puke "-$op => undef not supported";
554 my ($self, $op, $v) = @_;
556 my ( $prefix, $suffix ) = ( $op =~ /\bnot\b/i )
559 $self->_SWITCH_refkind($v, {
561 my ( $sql, @bind ) = $self->_where_ARRAYREF($v, '');
562 return ( ($prefix . $sql . $suffix), @bind );
566 my ( $sql, @bind ) = @{ ${$v} };
567 return ( ($prefix . $sql . $suffix), @bind );
571 my ( $sql, @bind ) = $self->_where_HASHREF($v);
572 return ( ($prefix . $sql . $suffix), @bind );
575 SCALARREF => sub { # literal SQL
576 return ($prefix . $$v . $suffix);
579 SCALAR => sub { # interpreted as SQL column
580 return ($prefix . $self->_convert($self->_quote($v)) . $suffix);
584 puke "-$op => undef not supported";
590 sub _where_hashpair_ARRAYREF {
591 my ($self, $k, $v) = @_;
594 my @v = @$v; # need copy because of shift below
595 $self->_debug("ARRAY($k) means distribute over elements");
597 # put apart first element if it is an operator (-and, -or)
599 (defined $v[0] && $v[0] =~ /^ - (?: AND|OR ) $/ix)
603 my @distributed = map { {$k => $_} } @v;
606 $self->_debug("OP($op) reinjected into the distributed array");
607 unshift @distributed, $op;
610 my $logic = $op ? substr($op, 1) : '';
612 return $self->_recurse_where(\@distributed, $logic);
615 # LDNOTE : not sure of this one. What does "distribute over nothing" mean?
616 $self->_debug("empty ARRAY($k) means 0=1");
617 return ($self->{sqlfalse});
621 sub _where_hashpair_HASHREF {
622 my ($self, $k, $v, $logic) = @_;
625 my ($all_sql, @all_bind);
627 for my $orig_op (sort keys %$v) {
628 my $val = $v->{$orig_op};
630 # put the operator in canonical form
632 $op =~ s/^-//; # remove initial dash
633 $op =~ s/[_\t ]+/ /g; # underscores and whitespace become single spaces
634 $op =~ s/^\s+|\s+$//g;# remove leading/trailing space
638 # CASE: special operators like -in or -between
639 my $special_op = first {$op =~ $_->{regex}} @{$self->{special_ops}};
641 my $handler = $special_op->{handler};
643 puke "No handler supplied for special operator $orig_op";
645 elsif (not ref $handler) {
646 ($sql, @bind) = $self->$handler ($k, $op, $val);
648 elsif (ref $handler eq 'CODE') {
649 ($sql, @bind) = $handler->($self, $k, $op, $val);
652 puke "Illegal handler for special operator $orig_op - expecting a method name or a coderef";
656 $self->_SWITCH_refkind($val, {
658 ARRAYREF => sub { # CASE: col => {op => \@vals}
659 ($sql, @bind) = $self->_where_field_op_ARRAYREF($k, $op, $val);
662 SCALARREF => sub { # CASE: col => {op => \$scalar} (literal SQL without bind)
663 $sql = join ' ', $self->_convert($self->_quote($k)),
664 $self->_sqlcase($op),
668 ARRAYREFREF => sub { # CASE: col => {op => \[$sql, @bind]} (literal SQL with bind)
669 my ($sub_sql, @sub_bind) = @$$val;
670 $self->_assert_bindval_matches_bindtype(@sub_bind);
671 $sql = join ' ', $self->_convert($self->_quote($k)),
672 $self->_sqlcase($op),
678 ($sql, @bind) = $self->_where_hashpair_HASHREF($k, $val, $op);
681 UNDEF => sub { # CASE: col => {op => undef} : sql "IS (NOT)? NULL"
682 my $is = ($op =~ $self->{equality_op}) ? 'is' :
683 ($op =~ $self->{inequality_op}) ? 'is not' :
684 puke "unexpected operator '$orig_op' with undef operand";
685 $sql = $self->_quote($k) . $self->_sqlcase(" $is null");
688 FALLBACK => sub { # CASE: col => {op => $scalar}
689 $sql = join ' ', $self->_convert($self->_quote($k)),
690 $self->_sqlcase($op),
691 $self->_convert('?');
692 @bind = $self->_bindtype($k, $val);
697 ($all_sql) = (defined $all_sql and $all_sql) ? $self->_join_sql_clauses($logic, [$all_sql, $sql], []) : $sql;
698 push @all_bind, @bind;
700 return ($all_sql, @all_bind);
705 sub _where_field_op_ARRAYREF {
706 my ($self, $k, $op, $vals) = @_;
708 my @vals = @$vals; #always work on a copy
711 $self->_debug(sprintf '%s means multiple elements: [ %s ]',
713 join (', ', map { defined $_ ? "'$_'" : 'NULL' } @vals ),
716 # see if the first element is an -and/-or op
718 if (defined $vals[0] && $vals[0] =~ /^ - ( AND|OR ) $/ix) {
723 # distribute $op over each remaining member of @vals, append logic if exists
724 return $self->_recurse_where([map { {$k => {$op, $_}} } @vals], $logic);
726 # LDNOTE : had planned to change the distribution logic when
727 # $op =~ $self->{inequality_op}, because of Morgan laws :
728 # with {field => {'!=' => [22, 33]}}, it would be ridiculous to generate
729 # WHERE field != 22 OR field != 33 : the user probably means
730 # WHERE field != 22 AND field != 33.
731 # To do this, replace the above to roughly :
732 # my $logic = ($op =~ $self->{inequality_op}) ? 'AND' : 'OR';
733 # return $self->_recurse_where([map { {$k => {$op, $_}} } @vals], $logic);
737 # try to DWIM on equality operators
738 # LDNOTE : not 100% sure this is the correct thing to do ...
739 return ($self->{sqlfalse}) if $op =~ $self->{equality_op};
740 return ($self->{sqltrue}) if $op =~ $self->{inequality_op};
743 puke "operator '$op' applied on an empty array (field '$k')";
748 sub _where_hashpair_SCALARREF {
749 my ($self, $k, $v) = @_;
750 $self->_debug("SCALAR($k) means literal SQL: $$v");
751 my $sql = $self->_quote($k) . " " . $$v;
755 # literal SQL with bind
756 sub _where_hashpair_ARRAYREFREF {
757 my ($self, $k, $v) = @_;
758 $self->_debug("REF($k) means literal SQL: @${$v}");
759 my ($sql, @bind) = @${$v};
760 $self->_assert_bindval_matches_bindtype(@bind);
761 $sql = $self->_quote($k) . " " . $sql;
762 return ($sql, @bind );
765 # literal SQL without bind
766 sub _where_hashpair_SCALAR {
767 my ($self, $k, $v) = @_;
768 $self->_debug("NOREF($k) means simple key=val: $k $self->{cmp} $v");
769 my $sql = join ' ', $self->_convert($self->_quote($k)),
770 $self->_sqlcase($self->{cmp}),
771 $self->_convert('?');
772 my @bind = $self->_bindtype($k, $v);
773 return ( $sql, @bind);
777 sub _where_hashpair_UNDEF {
778 my ($self, $k, $v) = @_;
779 $self->_debug("UNDEF($k) means IS NULL");
780 my $sql = $self->_quote($k) . $self->_sqlcase(' is null');
784 #======================================================================
785 # WHERE: TOP-LEVEL OTHERS (SCALARREF, SCALAR, UNDEF)
786 #======================================================================
789 sub _where_SCALARREF {
790 my ($self, $where) = @_;
793 $self->_debug("SCALAR(*top) means literal SQL: $$where");
799 my ($self, $where) = @_;
802 $self->_debug("NOREF(*top) means literal SQL: $where");
813 #======================================================================
814 # WHERE: BUILTIN SPECIAL OPERATORS (-in, -between)
815 #======================================================================
818 sub _where_field_BETWEEN {
819 my ($self, $k, $op, $vals) = @_;
821 my ($label, $and, $placeholder);
822 $label = $self->_convert($self->_quote($k));
823 $and = ' ' . $self->_sqlcase('and') . ' ';
824 $placeholder = $self->_convert('?');
825 $op = $self->_sqlcase($op);
827 my ($clause, @bind) = $self->_SWITCH_refkind($vals, {
835 puke "special op 'between' accepts an arrayref with exactly two values"
838 my (@all_sql, @all_bind);
839 foreach my $val (@$vals) {
840 my ($sql, @bind) = $self->_SWITCH_refkind($val, {
842 return ($placeholder, ($val));
845 return ($self->_convert($$val), ());
848 my ($sql, @bind) = @$$val;
849 return ($self->_convert($sql), @bind);
853 push @all_bind, @bind;
857 (join $and, @all_sql),
858 $self->_bindtype($k, @all_bind),
862 puke "special op 'between' accepts an arrayref with two values, or a single literal scalarref/arrayref-ref";
866 my $sql = "( $label $op $clause )";
871 sub _where_field_IN {
872 my ($self, $k, $op, $vals) = @_;
874 # backwards compatibility : if scalar, force into an arrayref
875 $vals = [$vals] if defined $vals && ! ref $vals;
877 my ($label) = $self->_convert($self->_quote($k));
878 my ($placeholder) = $self->_convert('?');
879 $op = $self->_sqlcase($op);
881 my ($sql, @bind) = $self->_SWITCH_refkind($vals, {
882 ARRAYREF => sub { # list of choices
883 if (@$vals) { # nonempty list
884 my $placeholders = join ", ", (($placeholder) x @$vals);
885 my $sql = "$label $op ( $placeholders )";
886 my @bind = $self->_bindtype($k, @$vals);
888 return ($sql, @bind);
890 else { # empty list : some databases won't understand "IN ()", so DWIM
891 my $sql = ($op =~ /\bnot\b/i) ? $self->{sqltrue} : $self->{sqlfalse};
896 ARRAYREFREF => sub { # literal SQL with bind
897 my ($sql, @bind) = @$$vals;
898 $self->_assert_bindval_matches_bindtype(@bind);
899 return ("$label $op ( $sql )", @bind);
903 puke "special op 'in' requires an arrayref (or arrayref-ref)";
907 return ($sql, @bind);
911 #======================================================================
913 #======================================================================
916 my ($self, $arg) = @_;
919 for my $c ($self->_order_by_chunks ($arg) ) {
920 $self->_SWITCH_refkind ($c, {
921 SCALAR => sub { push @sql, $c },
922 ARRAYREF => sub { push @sql, shift @$c; push @bind, @$c },
928 $self->_sqlcase(' order by'),
934 return wantarray ? ($sql, @bind) : $sql;
937 sub _order_by_chunks {
938 my ($self, $arg) = @_;
940 return $self->_SWITCH_refkind($arg, {
943 map { $self->_order_by_chunks ($_ ) } @$arg;
946 ARRAYREFREF => sub { [ @$$arg ] },
948 SCALAR => sub {$self->_quote($arg)},
950 UNDEF => sub {return () },
952 SCALARREF => sub {$$arg}, # literal SQL, no quoting
955 # get first pair in hash
956 my ($key, $val) = each %$arg;
958 return () unless $key;
960 if ( (keys %$arg) > 1 or not $key =~ /^-(desc|asc)/i ) {
961 puke "hash passed to _order_by must have exactly one key (-desc or -asc)";
967 for my $c ($self->_order_by_chunks ($val)) {
970 $self->_SWITCH_refkind ($c, {
979 $sql = $sql . ' ' . $self->_sqlcase($direction);
981 push @ret, [ $sql, @bind];
990 #======================================================================
991 # DATASOURCE (FOR NOW, JUST PLAIN TABLE OR LIST OF TABLES)
992 #======================================================================
997 $self->_SWITCH_refkind($from, {
998 ARRAYREF => sub {join ', ', map { $self->_quote($_) } @$from;},
999 SCALAR => sub {$self->_quote($from)},
1000 SCALARREF => sub {$$from},
1001 ARRAYREFREF => sub {join ', ', @$from;},
1006 #======================================================================
1008 #======================================================================
1014 $label or puke "can't quote an empty label";
1016 # left and right quote characters
1017 my ($ql, $qr, @other) = $self->_SWITCH_refkind($self->{quote_char}, {
1018 SCALAR => sub {($self->{quote_char}, $self->{quote_char})},
1019 ARRAYREF => sub {@{$self->{quote_char}}},
1023 or puke "quote_char must be an arrayref of 2 values";
1025 # no quoting if no quoting chars
1026 $ql or return $label;
1028 # no quoting for literal SQL
1029 return $$label if ref($label) eq 'SCALAR';
1031 # separate table / column (if applicable)
1032 my $sep = $self->{name_sep} || '';
1033 my @to_quote = $sep ? split /\Q$sep\E/, $label : ($label);
1035 # do the quoting, except for "*" or for `table`.*
1036 my @quoted = map { $_ eq '*' ? $_: $ql.$_.$qr} @to_quote;
1038 # reassemble and return.
1039 return join $sep, @quoted;
1043 # Conversion, if applicable
1045 my ($self, $arg) = @_;
1047 # LDNOTE : modified the previous implementation below because
1048 # it was not consistent : the first "return" is always an array,
1049 # the second "return" is context-dependent. Anyway, _convert
1050 # seems always used with just a single argument, so make it a
1052 # return @_ unless $self->{convert};
1053 # my $conv = $self->_sqlcase($self->{convert});
1054 # my @ret = map { $conv.'('.$_.')' } @_;
1055 # return wantarray ? @ret : $ret[0];
1056 if ($self->{convert}) {
1057 my $conv = $self->_sqlcase($self->{convert});
1058 $arg = $conv.'('.$arg.')';
1066 my($col, @vals) = @_;
1068 #LDNOTE : changed original implementation below because it did not make
1069 # sense when bindtype eq 'columns' and @vals > 1.
1070 # return $self->{bindtype} eq 'columns' ? [ $col, @vals ] : @vals;
1072 return $self->{bindtype} eq 'columns' ? map {[$col, $_]} @vals : @vals;
1075 # Dies if any element of @bind is not in [colname => value] format
1076 # if bindtype is 'columns'.
1077 sub _assert_bindval_matches_bindtype {
1078 my ($self, @bind) = @_;
1080 if ($self->{bindtype} eq 'columns') {
1081 foreach my $val (@bind) {
1082 if (!defined $val || ref($val) ne 'ARRAY' || @$val != 2) {
1083 die "bindtype 'columns' selected, you need to pass: [column_name => bind_value]"
1089 sub _join_sql_clauses {
1090 my ($self, $logic, $clauses_aref, $bind_aref) = @_;
1092 if (@$clauses_aref > 1) {
1093 my $join = " " . $self->_sqlcase($logic) . " ";
1094 my $sql = '( ' . join($join, @$clauses_aref) . ' )';
1095 return ($sql, @$bind_aref);
1097 elsif (@$clauses_aref) {
1098 return ($clauses_aref->[0], @$bind_aref); # no parentheses
1101 return (); # if no SQL, ignore @$bind_aref
1106 # Fix SQL case, if so requested
1110 # LDNOTE: if $self->{case} is true, then it contains 'lower', so we
1111 # don't touch the argument ... crooked logic, but let's not change it!
1112 return $self->{case} ? $_[0] : uc($_[0]);
1116 #======================================================================
1117 # DISPATCHING FROM REFKIND
1118 #======================================================================
1121 my ($self, $data) = @_;
1127 # blessed objects are treated like scalars
1128 $ref = (blessed $data) ? '' : ref $data;
1129 $n_steps += 1 if $ref;
1130 last if $ref ne 'REF';
1134 my $base = $ref || (defined $data ? 'SCALAR' : 'UNDEF');
1136 return $base . ('REF' x $n_steps);
1142 my ($self, $data) = @_;
1143 my @try = ($self->_refkind($data));
1144 push @try, 'SCALAR_or_UNDEF' if $try[0] eq 'SCALAR' || $try[0] eq 'UNDEF';
1145 push @try, 'FALLBACK';
1149 sub _METHOD_FOR_refkind {
1150 my ($self, $meth_prefix, $data) = @_;
1151 my $method = first {$_} map {$self->can($meth_prefix."_".$_)}
1152 $self->_try_refkind($data)
1153 or puke "cannot dispatch on '$meth_prefix' for ".$self->_refkind($data);
1158 sub _SWITCH_refkind {
1159 my ($self, $data, $dispatch_table) = @_;
1161 my $coderef = first {$_} map {$dispatch_table->{$_}}
1162 $self->_try_refkind($data)
1163 or puke "no dispatch entry for ".$self->_refkind($data);
1170 #======================================================================
1171 # VALUES, GENERATE, AUTOLOAD
1172 #======================================================================
1174 # LDNOTE: original code from nwiger, didn't touch code in that section
1175 # I feel the AUTOLOAD stuff should not be the default, it should
1176 # only be activated on explicit demand by user.
1180 my $data = shift || return;
1181 puke "Argument to ", __PACKAGE__, "->values must be a \\%hash"
1182 unless ref $data eq 'HASH';
1185 foreach my $k ( sort keys %$data ) {
1186 my $v = $data->{$k};
1187 $self->_SWITCH_refkind($v, {
1189 if ($self->{array_datatypes}) { # array datatype
1190 push @all_bind, $self->_bindtype($k, $v);
1192 else { # literal SQL with bind
1193 my ($sql, @bind) = @$v;
1194 $self->_assert_bindval_matches_bindtype(@bind);
1195 push @all_bind, @bind;
1198 ARRAYREFREF => sub { # literal SQL with bind
1199 my ($sql, @bind) = @${$v};
1200 $self->_assert_bindval_matches_bindtype(@bind);
1201 push @all_bind, @bind;
1203 SCALARREF => sub { # literal SQL without bind
1205 SCALAR_or_UNDEF => sub {
1206 push @all_bind, $self->_bindtype($k, $v);
1217 my(@sql, @sqlq, @sqlv);
1221 if ($ref eq 'HASH') {
1222 for my $k (sort keys %$_) {
1225 my $label = $self->_quote($k);
1226 if ($r eq 'ARRAY') {
1227 # literal SQL with bind
1228 my ($sql, @bind) = @$v;
1229 $self->_assert_bindval_matches_bindtype(@bind);
1230 push @sqlq, "$label = $sql";
1232 } elsif ($r eq 'SCALAR') {
1233 # literal SQL without bind
1234 push @sqlq, "$label = $$v";
1236 push @sqlq, "$label = ?";
1237 push @sqlv, $self->_bindtype($k, $v);
1240 push @sql, $self->_sqlcase('set'), join ', ', @sqlq;
1241 } elsif ($ref eq 'ARRAY') {
1242 # unlike insert(), assume these are ONLY the column names, i.e. for SQL
1245 if ($r eq 'ARRAY') { # literal SQL with bind
1246 my ($sql, @bind) = @$v;
1247 $self->_assert_bindval_matches_bindtype(@bind);
1250 } elsif ($r eq 'SCALAR') { # literal SQL without bind
1251 # embedded literal SQL
1258 push @sql, '(' . join(', ', @sqlq) . ')';
1259 } elsif ($ref eq 'SCALAR') {
1263 # strings get case twiddled
1264 push @sql, $self->_sqlcase($_);
1268 my $sql = join ' ', @sql;
1270 # this is pretty tricky
1271 # if ask for an array, return ($stmt, @bind)
1272 # otherwise, s/?/shift @sqlv/ to put it inline
1274 return ($sql, @sqlv);
1276 1 while $sql =~ s/\?/my $d = shift(@sqlv);
1277 ref $d ? $d->[1] : $d/e;
1286 # This allows us to check for a local, then _form, attr
1288 my($name) = $AUTOLOAD =~ /.*::(.+)/;
1289 return $self->generate($name, @_);
1300 SQL::Abstract - Generate SQL from Perl data structures
1306 my $sql = SQL::Abstract->new;
1308 my($stmt, @bind) = $sql->select($table, \@fields, \%where, \@order);
1310 my($stmt, @bind) = $sql->insert($table, \%fieldvals || \@values);
1312 my($stmt, @bind) = $sql->update($table, \%fieldvals, \%where);
1314 my($stmt, @bind) = $sql->delete($table, \%where);
1316 # Then, use these in your DBI statements
1317 my $sth = $dbh->prepare($stmt);
1318 $sth->execute(@bind);
1320 # Just generate the WHERE clause
1321 my($stmt, @bind) = $sql->where(\%where, \@order);
1323 # Return values in the same order, for hashed queries
1324 # See PERFORMANCE section for more details
1325 my @bind = $sql->values(\%fieldvals);
1329 This module was inspired by the excellent L<DBIx::Abstract>.
1330 However, in using that module I found that what I really wanted
1331 to do was generate SQL, but still retain complete control over my
1332 statement handles and use the DBI interface. So, I set out to
1333 create an abstract SQL generation module.
1335 While based on the concepts used by L<DBIx::Abstract>, there are
1336 several important differences, especially when it comes to WHERE
1337 clauses. I have modified the concepts used to make the SQL easier
1338 to generate from Perl data structures and, IMO, more intuitive.
1339 The underlying idea is for this module to do what you mean, based
1340 on the data structures you provide it. The big advantage is that
1341 you don't have to modify your code every time your data changes,
1342 as this module figures it out.
1344 To begin with, an SQL INSERT is as easy as just specifying a hash
1345 of C<key=value> pairs:
1348 name => 'Jimbo Bobson',
1349 phone => '123-456-7890',
1350 address => '42 Sister Lane',
1351 city => 'St. Louis',
1352 state => 'Louisiana',
1355 The SQL can then be generated with this:
1357 my($stmt, @bind) = $sql->insert('people', \%data);
1359 Which would give you something like this:
1361 $stmt = "INSERT INTO people
1362 (address, city, name, phone, state)
1363 VALUES (?, ?, ?, ?, ?)";
1364 @bind = ('42 Sister Lane', 'St. Louis', 'Jimbo Bobson',
1365 '123-456-7890', 'Louisiana');
1367 These are then used directly in your DBI code:
1369 my $sth = $dbh->prepare($stmt);
1370 $sth->execute(@bind);
1372 =head2 Inserting and Updating Arrays
1374 If your database has array types (like for example Postgres),
1375 activate the special option C<< array_datatypes => 1 >>
1376 when creating the C<SQL::Abstract> object.
1377 Then you may use an arrayref to insert and update database array types:
1379 my $sql = SQL::Abstract->new(array_datatypes => 1);
1381 planets => [qw/Mercury Venus Earth Mars/]
1384 my($stmt, @bind) = $sql->insert('solar_system', \%data);
1388 $stmt = "INSERT INTO solar_system (planets) VALUES (?)"
1390 @bind = (['Mercury', 'Venus', 'Earth', 'Mars']);
1393 =head2 Inserting and Updating SQL
1395 In order to apply SQL functions to elements of your C<%data> you may
1396 specify a reference to an arrayref for the given hash value. For example,
1397 if you need to execute the Oracle C<to_date> function on a value, you can
1398 say something like this:
1402 date_entered => \["to_date(?,'MM/DD/YYYY')", "03/02/2003"],
1405 The first value in the array is the actual SQL. Any other values are
1406 optional and would be included in the bind values array. This gives
1409 my($stmt, @bind) = $sql->insert('people', \%data);
1411 $stmt = "INSERT INTO people (name, date_entered)
1412 VALUES (?, to_date(?,'MM/DD/YYYY'))";
1413 @bind = ('Bill', '03/02/2003');
1415 An UPDATE is just as easy, all you change is the name of the function:
1417 my($stmt, @bind) = $sql->update('people', \%data);
1419 Notice that your C<%data> isn't touched; the module will generate
1420 the appropriately quirky SQL for you automatically. Usually you'll
1421 want to specify a WHERE clause for your UPDATE, though, which is
1422 where handling C<%where> hashes comes in handy...
1424 =head2 Complex where statements
1426 This module can generate pretty complicated WHERE statements
1427 easily. For example, simple C<key=value> pairs are taken to mean
1428 equality, and if you want to see if a field is within a set
1429 of values, you can use an arrayref. Let's say we wanted to
1430 SELECT some data based on this criteria:
1433 requestor => 'inna',
1434 worker => ['nwiger', 'rcwe', 'sfz'],
1435 status => { '!=', 'completed' }
1438 my($stmt, @bind) = $sql->select('tickets', '*', \%where);
1440 The above would give you something like this:
1442 $stmt = "SELECT * FROM tickets WHERE
1443 ( requestor = ? ) AND ( status != ? )
1444 AND ( worker = ? OR worker = ? OR worker = ? )";
1445 @bind = ('inna', 'completed', 'nwiger', 'rcwe', 'sfz');
1447 Which you could then use in DBI code like so:
1449 my $sth = $dbh->prepare($stmt);
1450 $sth->execute(@bind);
1456 The functions are simple. There's one for each major SQL operation,
1457 and a constructor you use first. The arguments are specified in a
1458 similar order to each function (table, then fields, then a where
1459 clause) to try and simplify things.
1464 =head2 new(option => 'value')
1466 The C<new()> function takes a list of options and values, and returns
1467 a new B<SQL::Abstract> object which can then be used to generate SQL
1468 through the methods below. The options accepted are:
1474 If set to 'lower', then SQL will be generated in all lowercase. By
1475 default SQL is generated in "textbook" case meaning something like:
1477 SELECT a_field FROM a_table WHERE some_field LIKE '%someval%'
1479 Any setting other than 'lower' is ignored.
1483 This determines what the default comparison operator is. By default
1484 it is C<=>, meaning that a hash like this:
1486 %where = (name => 'nwiger', email => 'nate@wiger.org');
1488 Will generate SQL like this:
1490 WHERE name = 'nwiger' AND email = 'nate@wiger.org'
1492 However, you may want loose comparisons by default, so if you set
1493 C<cmp> to C<like> you would get SQL such as:
1495 WHERE name like 'nwiger' AND email like 'nate@wiger.org'
1497 You can also override the comparsion on an individual basis - see
1498 the huge section on L</"WHERE CLAUSES"> at the bottom.
1500 =item sqltrue, sqlfalse
1502 Expressions for inserting boolean values within SQL statements.
1503 By default these are C<1=1> and C<1=0>. They are used
1504 by the special operators C<-in> and C<-not_in> for generating
1505 correct SQL even when the argument is an empty array (see below).
1509 This determines the default logical operator for multiple WHERE
1510 statements in arrays or hashes. If absent, the default logic is "or"
1511 for arrays, and "and" for hashes. This means that a WHERE
1515 event_date => {'>=', '2/13/99'},
1516 event_date => {'<=', '4/24/03'},
1519 will generate SQL like this:
1521 WHERE event_date >= '2/13/99' OR event_date <= '4/24/03'
1523 This is probably not what you want given this query, though (look
1524 at the dates). To change the "OR" to an "AND", simply specify:
1526 my $sql = SQL::Abstract->new(logic => 'and');
1528 Which will change the above C<WHERE> to:
1530 WHERE event_date >= '2/13/99' AND event_date <= '4/24/03'
1532 The logic can also be changed locally by inserting
1533 a modifier in front of an arrayref :
1535 @where = (-and => [event_date => {'>=', '2/13/99'},
1536 event_date => {'<=', '4/24/03'} ]);
1538 See the L</"WHERE CLAUSES"> section for explanations.
1542 This will automatically convert comparisons using the specified SQL
1543 function for both column and value. This is mostly used with an argument
1544 of C<upper> or C<lower>, so that the SQL will have the effect of
1545 case-insensitive "searches". For example, this:
1547 $sql = SQL::Abstract->new(convert => 'upper');
1548 %where = (keywords => 'MaKe iT CAse inSeNSItive');
1550 Will turn out the following SQL:
1552 WHERE upper(keywords) like upper('MaKe iT CAse inSeNSItive')
1554 The conversion can be C<upper()>, C<lower()>, or any other SQL function
1555 that can be applied symmetrically to fields (actually B<SQL::Abstract> does
1556 not validate this option; it will just pass through what you specify verbatim).
1560 This is a kludge because many databases suck. For example, you can't
1561 just bind values using DBI's C<execute()> for Oracle C<CLOB> or C<BLOB> fields.
1562 Instead, you have to use C<bind_param()>:
1564 $sth->bind_param(1, 'reg data');
1565 $sth->bind_param(2, $lots, {ora_type => ORA_CLOB});
1567 The problem is, B<SQL::Abstract> will normally just return a C<@bind> array,
1568 which loses track of which field each slot refers to. Fear not.
1570 If you specify C<bindtype> in new, you can determine how C<@bind> is returned.
1571 Currently, you can specify either C<normal> (default) or C<columns>. If you
1572 specify C<columns>, you will get an array that looks like this:
1574 my $sql = SQL::Abstract->new(bindtype => 'columns');
1575 my($stmt, @bind) = $sql->insert(...);
1578 [ 'column1', 'value1' ],
1579 [ 'column2', 'value2' ],
1580 [ 'column3', 'value3' ],
1583 You can then iterate through this manually, using DBI's C<bind_param()>.
1585 $sth->prepare($stmt);
1588 my($col, $data) = @$_;
1589 if ($col eq 'details' || $col eq 'comments') {
1590 $sth->bind_param($i, $data, {ora_type => ORA_CLOB});
1591 } elsif ($col eq 'image') {
1592 $sth->bind_param($i, $data, {ora_type => ORA_BLOB});
1594 $sth->bind_param($i, $data);
1598 $sth->execute; # execute without @bind now
1600 Now, why would you still use B<SQL::Abstract> if you have to do this crap?
1601 Basically, the advantage is still that you don't have to care which fields
1602 are or are not included. You could wrap that above C<for> loop in a simple
1603 sub called C<bind_fields()> or something and reuse it repeatedly. You still
1604 get a layer of abstraction over manual SQL specification.
1606 Note that if you set L</bindtype> to C<columns>, the C<\[$sql, @bind]>
1607 construct (see L</Literal SQL with placeholders and bind values (subqueries)>)
1608 will expect the bind values in this format.
1612 This is the character that a table or column name will be quoted
1613 with. By default this is an empty string, but you could set it to
1614 the character C<`>, to generate SQL like this:
1616 SELECT `a_field` FROM `a_table` WHERE `some_field` LIKE '%someval%'
1618 Alternatively, you can supply an array ref of two items, the first being the left
1619 hand quote character, and the second the right hand quote character. For
1620 example, you could supply C<['[',']']> for SQL Server 2000 compliant quotes
1621 that generates SQL like this:
1623 SELECT [a_field] FROM [a_table] WHERE [some_field] LIKE '%someval%'
1625 Quoting is useful if you have tables or columns names that are reserved
1626 words in your database's SQL dialect.
1630 This is the character that separates a table and column name. It is
1631 necessary to specify this when the C<quote_char> option is selected,
1632 so that tables and column names can be individually quoted like this:
1634 SELECT `table`.`one_field` FROM `table` WHERE `table`.`other_field` = 1
1636 =item array_datatypes
1638 When this option is true, arrayrefs in INSERT or UPDATE are
1639 interpreted as array datatypes and are passed directly
1641 When this option is false, arrayrefs are interpreted
1642 as literal SQL, just like refs to arrayrefs
1643 (but this behavior is for backwards compatibility; when writing
1644 new queries, use the "reference to arrayref" syntax
1650 Takes a reference to a list of "special operators"
1651 to extend the syntax understood by L<SQL::Abstract>.
1652 See section L</"SPECIAL OPERATORS"> for details.
1656 Takes a reference to a list of "unary operators"
1657 to extend the syntax understood by L<SQL::Abstract>.
1658 See section L</"UNARY OPERATORS"> for details.
1664 =head2 insert($table, \@values || \%fieldvals)
1666 This is the simplest function. You simply give it a table name
1667 and either an arrayref of values or hashref of field/value pairs.
1668 It returns an SQL INSERT statement and a list of bind values.
1669 See the sections on L</"Inserting and Updating Arrays"> and
1670 L</"Inserting and Updating SQL"> for information on how to insert
1671 with those data types.
1673 =head2 update($table, \%fieldvals, \%where)
1675 This takes a table, hashref of field/value pairs, and an optional
1676 hashref L<WHERE clause|/WHERE CLAUSES>. It returns an SQL UPDATE function and a list
1678 See the sections on L</"Inserting and Updating Arrays"> and
1679 L</"Inserting and Updating SQL"> for information on how to insert
1680 with those data types.
1682 =head2 select($source, $fields, $where, $order)
1684 This returns a SQL SELECT statement and associated list of bind values, as
1685 specified by the arguments :
1691 Specification of the 'FROM' part of the statement.
1692 The argument can be either a plain scalar (interpreted as a table
1693 name, will be quoted), or an arrayref (interpreted as a list
1694 of table names, joined by commas, quoted), or a scalarref
1695 (literal table name, not quoted), or a ref to an arrayref
1696 (list of literal table names, joined by commas, not quoted).
1700 Specification of the list of fields to retrieve from
1702 The argument can be either an arrayref (interpreted as a list
1703 of field names, will be joined by commas and quoted), or a
1704 plain scalar (literal SQL, not quoted).
1705 Please observe that this API is not as flexible as for
1706 the first argument C<$table>, for backwards compatibility reasons.
1710 Optional argument to specify the WHERE part of the query.
1711 The argument is most often a hashref, but can also be
1712 an arrayref or plain scalar --
1713 see section L<WHERE clause|/"WHERE CLAUSES"> for details.
1717 Optional argument to specify the ORDER BY part of the query.
1718 The argument can be a scalar, a hashref or an arrayref
1719 -- see section L<ORDER BY clause|/"ORDER BY CLAUSES">
1725 =head2 delete($table, \%where)
1727 This takes a table name and optional hashref L<WHERE clause|/WHERE CLAUSES>.
1728 It returns an SQL DELETE statement and list of bind values.
1730 =head2 where(\%where, \@order)
1732 This is used to generate just the WHERE clause. For example,
1733 if you have an arbitrary data structure and know what the
1734 rest of your SQL is going to look like, but want an easy way
1735 to produce a WHERE clause, use this. It returns an SQL WHERE
1736 clause and list of bind values.
1739 =head2 values(\%data)
1741 This just returns the values from the hash C<%data>, in the same
1742 order that would be returned from any of the other above queries.
1743 Using this allows you to markedly speed up your queries if you
1744 are affecting lots of rows. See below under the L</"PERFORMANCE"> section.
1746 =head2 generate($any, 'number', $of, \@data, $struct, \%types)
1748 Warning: This is an experimental method and subject to change.
1750 This returns arbitrarily generated SQL. It's a really basic shortcut.
1751 It will return two different things, depending on return context:
1753 my($stmt, @bind) = $sql->generate('create table', \$table, \@fields);
1754 my $stmt_and_val = $sql->generate('create table', \$table, \@fields);
1756 These would return the following:
1758 # First calling form
1759 $stmt = "CREATE TABLE test (?, ?)";
1760 @bind = (field1, field2);
1762 # Second calling form
1763 $stmt_and_val = "CREATE TABLE test (field1, field2)";
1765 Depending on what you're trying to do, it's up to you to choose the correct
1766 format. In this example, the second form is what you would want.
1770 $sql->generate('alter session', { nls_date_format => 'MM/YY' });
1774 ALTER SESSION SET nls_date_format = 'MM/YY'
1776 You get the idea. Strings get their case twiddled, but everything
1777 else remains verbatim.
1782 =head1 WHERE CLAUSES
1786 This module uses a variation on the idea from L<DBIx::Abstract>. It
1787 is B<NOT>, repeat I<not> 100% compatible. B<The main logic of this
1788 module is that things in arrays are OR'ed, and things in hashes
1791 The easiest way to explain is to show lots of examples. After
1792 each C<%where> hash shown, it is assumed you used:
1794 my($stmt, @bind) = $sql->where(\%where);
1796 However, note that the C<%where> hash can be used directly in any
1797 of the other functions as well, as described above.
1799 =head2 Key-value pairs
1801 So, let's get started. To begin, a simple hash:
1805 status => 'completed'
1808 Is converted to SQL C<key = val> statements:
1810 $stmt = "WHERE user = ? AND status = ?";
1811 @bind = ('nwiger', 'completed');
1813 One common thing I end up doing is having a list of values that
1814 a field can be in. To do this, simply specify a list inside of
1819 status => ['assigned', 'in-progress', 'pending'];
1822 This simple code will create the following:
1824 $stmt = "WHERE user = ? AND ( status = ? OR status = ? OR status = ? )";
1825 @bind = ('nwiger', 'assigned', 'in-progress', 'pending');
1827 A field associated to an empty arrayref will be considered a
1828 logical false and will generate 0=1.
1830 =head2 Specific comparison operators
1832 If you want to specify a different type of operator for your comparison,
1833 you can use a hashref for a given column:
1837 status => { '!=', 'completed' }
1840 Which would generate:
1842 $stmt = "WHERE user = ? AND status != ?";
1843 @bind = ('nwiger', 'completed');
1845 To test against multiple values, just enclose the values in an arrayref:
1847 status => { '=', ['assigned', 'in-progress', 'pending'] };
1849 Which would give you:
1851 "WHERE status = ? OR status = ? OR status = ?"
1854 The hashref can also contain multiple pairs, in which case it is expanded
1855 into an C<AND> of its elements:
1859 status => { '!=', 'completed', -not_like => 'pending%' }
1862 # Or more dynamically, like from a form
1863 $where{user} = 'nwiger';
1864 $where{status}{'!='} = 'completed';
1865 $where{status}{'-not_like'} = 'pending%';
1867 # Both generate this
1868 $stmt = "WHERE user = ? AND status != ? AND status NOT LIKE ?";
1869 @bind = ('nwiger', 'completed', 'pending%');
1872 To get an OR instead, you can combine it with the arrayref idea:
1876 priority => [ {'=', 2}, {'!=', 1} ]
1879 Which would generate:
1881 $stmt = "WHERE user = ? AND priority = ? OR priority != ?";
1882 @bind = ('nwiger', '2', '1');
1884 If you want to include literal SQL (with or without bind values), just use a
1885 scalar reference or array reference as the value:
1888 date_entered => { '>' => \["to_date(?, 'MM/DD/YYYY')", "11/26/2008"] },
1889 date_expires => { '<' => \"now()" }
1892 Which would generate:
1894 $stmt = "WHERE date_entered > "to_date(?, 'MM/DD/YYYY') AND date_expires < now()";
1895 @bind = ('11/26/2008');
1898 =head2 Logic and nesting operators
1900 In the example above,
1901 there is a subtle trap if you want to say something like
1902 this (notice the C<AND>):
1904 WHERE priority != ? AND priority != ?
1906 Because, in Perl you I<can't> do this:
1908 priority => { '!=', 2, '!=', 1 }
1910 As the second C<!=> key will obliterate the first. The solution
1911 is to use the special C<-modifier> form inside an arrayref:
1913 priority => [ -and => {'!=', 2},
1917 Normally, these would be joined by C<OR>, but the modifier tells it
1918 to use C<AND> instead. (Hint: You can use this in conjunction with the
1919 C<logic> option to C<new()> in order to change the way your queries
1920 work by default.) B<Important:> Note that the C<-modifier> goes
1921 B<INSIDE> the arrayref, as an extra first element. This will
1922 B<NOT> do what you think it might:
1924 priority => -and => [{'!=', 2}, {'!=', 1}] # WRONG!
1926 Here is a quick list of equivalencies, since there is some overlap:
1929 status => {'!=', 'completed', 'not like', 'pending%' }
1930 status => [ -and => {'!=', 'completed'}, {'not like', 'pending%'}]
1933 status => {'=', ['assigned', 'in-progress']}
1934 status => [ -or => {'=', 'assigned'}, {'=', 'in-progress'}]
1935 status => [ {'=', 'assigned'}, {'=', 'in-progress'} ]
1939 =head2 Special operators : IN, BETWEEN, etc.
1941 You can also use the hashref format to compare a list of fields using the
1942 C<IN> comparison operator, by specifying the list as an arrayref:
1945 status => 'completed',
1946 reportid => { -in => [567, 2335, 2] }
1949 Which would generate:
1951 $stmt = "WHERE status = ? AND reportid IN (?,?,?)";
1952 @bind = ('completed', '567', '2335', '2');
1954 The reverse operator C<-not_in> generates SQL C<NOT IN> and is used in
1957 If the argument to C<-in> is an empty array, 'sqlfalse' is generated
1958 (by default : C<1=0>). Similarly, C<< -not_in => [] >> generates
1959 'sqltrue' (by default : C<1=1>).
1963 Another pair of operators is C<-between> and C<-not_between>,
1964 used with an arrayref of two values:
1968 completion_date => {
1969 -not_between => ['2002-10-01', '2003-02-06']
1975 WHERE user = ? AND completion_date NOT BETWEEN ( ? AND ? )
1977 These are the two builtin "special operators"; but the
1978 list can be expanded : see section L</"SPECIAL OPERATORS"> below.
1980 =head2 Unary operators: bool
1982 If you wish to test against boolean columns or functions within your
1983 database you can use the C<-bool> and C<-not_bool> operators. For
1984 example to test the column C<is_user> being true and the column
1985 <is_enabled> being false you would use:-
1989 -not_bool => 'is_enabled',
1994 WHERE is_user AND NOT is_enabled
1996 If a more complex combination is required, testing more conditions,
1997 then you should use the and/or operators:-
2004 -not_bool => 'four',
2010 WHERE one AND two AND three AND NOT four
2013 =head2 Nested conditions, -and/-or prefixes
2015 So far, we've seen how multiple conditions are joined with a top-level
2016 C<AND>. We can change this by putting the different conditions we want in
2017 hashes and then putting those hashes in an array. For example:
2022 status => { -like => ['pending%', 'dispatched'] },
2026 status => 'unassigned',
2030 This data structure would create the following:
2032 $stmt = "WHERE ( user = ? AND ( status LIKE ? OR status LIKE ? ) )
2033 OR ( user = ? AND status = ? ) )";
2034 @bind = ('nwiger', 'pending', 'dispatched', 'robot', 'unassigned');
2037 There is also a special C<-nest>
2038 operator which adds an additional set of parens, to create a subquery.
2039 For example, to get something like this:
2041 $stmt = "WHERE user = ? AND ( workhrs > ? OR geo = ? )";
2042 @bind = ('nwiger', '20', 'ASIA');
2048 -nest => [ workhrs => {'>', 20}, geo => 'ASIA' ],
2052 Finally, clauses in hashrefs or arrayrefs can be
2053 prefixed with an C<-and> or C<-or> to change the logic
2060 -and => [workhrs => {'>', 20}, geo => 'ASIA' ],
2061 -and => [workhrs => {'<', 50}, geo => 'EURO' ]
2068 WHERE ( user = ? AND
2069 ( ( workhrs > ? AND geo = ? )
2070 OR ( workhrs < ? AND geo = ? ) ) )
2073 =head2 Algebraic inconsistency, for historical reasons
2075 C<Important note>: when connecting several conditions, the C<-and->|C<-or>
2076 operator goes C<outside> of the nested structure; whereas when connecting
2077 several constraints on one column, the C<-and> operator goes
2078 C<inside> the arrayref. Here is an example combining both features :
2081 -and => [a => 1, b => 2],
2082 -or => [c => 3, d => 4],
2083 e => [-and => {-like => 'foo%'}, {-like => '%bar'} ]
2088 WHERE ( ( ( a = ? AND b = ? )
2089 OR ( c = ? OR d = ? )
2090 OR ( e LIKE ? AND e LIKE ? ) ) )
2092 This difference in syntax is unfortunate but must be preserved for
2093 historical reasons. So be careful : the two examples below would
2094 seem algebraically equivalent, but they are not
2096 {col => [-and => {-like => 'foo%'}, {-like => '%bar'}]}
2097 # yields : WHERE ( ( col LIKE ? AND col LIKE ? ) )
2099 [-and => {col => {-like => 'foo%'}, {col => {-like => '%bar'}}]]
2100 # yields : WHERE ( ( col LIKE ? OR col LIKE ? ) )
2105 Finally, sometimes only literal SQL will do. If you want to include
2106 literal SQL verbatim, you can specify it as a scalar reference, namely:
2108 my $inn = 'is Not Null';
2110 priority => { '<', 2 },
2116 $stmt = "WHERE priority < ? AND requestor is Not Null";
2119 Note that in this example, you only get one bind parameter back, since
2120 the verbatim SQL is passed as part of the statement.
2122 Of course, just to prove a point, the above can also be accomplished
2126 priority => { '<', 2 },
2127 requestor => { '!=', undef },
2133 Conditions on boolean columns can be expressed in the same way, passing
2134 a reference to an empty string, however using liternal SQL in this way
2135 is deprecated - the preferred method is to use the boolean operators -
2136 see L</"Unary operators: bool"> :
2139 priority => { '<', 2 },
2145 $stmt = "WHERE priority < ? AND is_ready";
2149 =head2 Literal SQL with placeholders and bind values (subqueries)
2151 If the literal SQL to be inserted has placeholders and bind values,
2152 use a reference to an arrayref (yes this is a double reference --
2153 not so common, but perfectly legal Perl). For example, to find a date
2154 in Postgres you can use something like this:
2157 date_column => \[q/= date '2008-09-30' - ?::integer/, 10/]
2162 $stmt = "WHERE ( date_column = date '2008-09-30' - ?::integer )"
2165 Note that you must pass the bind values in the same format as they are returned
2166 by L</where>. That means that if you set L</bindtype> to C<columns>, you must
2167 provide the bind values in the C<< [ column_meta => value ] >> format, where
2168 C<column_meta> is an opaque scalar value; most commonly the column name, but
2169 you can use any scalar value (including references and blessed references),
2170 L<SQL::Abstract> will simply pass it through intact. So if C<bindtype> is set
2171 to C<columns> the above example will look like:
2174 date_column => \[q/= date '2008-09-30' - ?::integer/, [ dummy => 10 ]/]
2177 Literal SQL is especially useful for nesting parenthesized clauses in the
2178 main SQL query. Here is a first example :
2180 my ($sub_stmt, @sub_bind) = ("SELECT c1 FROM t1 WHERE c2 < ? AND c3 LIKE ?",
2184 bar => \["IN ($sub_stmt)" => @sub_bind],
2189 $stmt = "WHERE (foo = ? AND bar IN (SELECT c1 FROM t1
2190 WHERE c2 < ? AND c3 LIKE ?))";
2191 @bind = (1234, 100, "foo%");
2193 Other subquery operators, like for example C<"E<gt> ALL"> or C<"NOT IN">,
2194 are expressed in the same way. Of course the C<$sub_stmt> and
2195 its associated bind values can be generated through a former call
2198 my ($sub_stmt, @sub_bind)
2199 = $sql->select("t1", "c1", {c2 => {"<" => 100},
2200 c3 => {-like => "foo%"}});
2203 bar => \["> ALL ($sub_stmt)" => @sub_bind],
2206 In the examples above, the subquery was used as an operator on a column;
2207 but the same principle also applies for a clause within the main C<%where>
2208 hash, like an EXISTS subquery :
2210 my ($sub_stmt, @sub_bind)
2211 = $sql->select("t1", "*", {c1 => 1, c2 => \"> t0.c0"});
2214 -nest => \["EXISTS ($sub_stmt)" => @sub_bind],
2219 $stmt = "WHERE (foo = ? AND EXISTS (SELECT * FROM t1
2220 WHERE c1 = ? AND c2 > t0.c0))";
2224 Observe that the condition on C<c2> in the subquery refers to
2225 column C<t0.c0> of the main query : this is I<not> a bind
2226 value, so we have to express it through a scalar ref.
2227 Writing C<< c2 => {">" => "t0.c0"} >> would have generated
2228 C<< c2 > ? >> with bind value C<"t0.c0"> ... not exactly
2229 what we wanted here.
2231 Another use of the subquery technique is when some SQL clauses need
2232 parentheses, as it often occurs with some proprietary SQL extensions
2233 like for example fulltext expressions, geospatial expressions,
2234 NATIVE clauses, etc. Here is an example of a fulltext query in MySQL :
2237 -nest => \["MATCH (col1, col2) AGAINST (?)" => qw/apples/]
2240 Finally, here is an example where a subquery is used
2241 for expressing unary negation:
2243 my ($sub_stmt, @sub_bind)
2244 = $sql->where({age => [{"<" => 10}, {">" => 20}]});
2245 $sub_stmt =~ s/^ where //i; # don't want "WHERE" in the subclause
2247 lname => {like => '%son%'},
2248 -nest => \["NOT ($sub_stmt)" => @sub_bind],
2253 $stmt = "lname LIKE ? AND NOT ( age < ? OR age > ? )"
2254 @bind = ('%son%', 10, 20)
2260 These pages could go on for a while, since the nesting of the data
2261 structures this module can handle are pretty much unlimited (the
2262 module implements the C<WHERE> expansion as a recursive function
2263 internally). Your best bet is to "play around" with the module a
2264 little to see how the data structures behave, and choose the best
2265 format for your data based on that.
2267 And of course, all the values above will probably be replaced with
2268 variables gotten from forms or the command line. After all, if you
2269 knew everything ahead of time, you wouldn't have to worry about
2270 dynamically-generating SQL and could just hardwire it into your
2276 =head1 ORDER BY CLAUSES
2278 Some functions take an order by clause. This can either be a scalar (just a
2279 column name,) a hash of C<< { -desc => 'col' } >> or C<< { -asc => 'col' } >>,
2280 or an array of either of the two previous forms. Examples:
2282 Given | Will Generate
2283 ----------------------------------------------------------
2285 \'colA DESC' | ORDER BY colA DESC
2287 'colA' | ORDER BY colA
2289 [qw/colA colB/] | ORDER BY colA, colB
2291 {-asc => 'colA'} | ORDER BY colA ASC
2293 {-desc => 'colB'} | ORDER BY colB DESC
2295 ['colA', {-asc => 'colB'}] | ORDER BY colA, colB ASC
2297 { -asc => [qw/colA colB] } | ORDER BY colA ASC, colB ASC
2300 { -asc => 'colA' }, | ORDER BY colA ASC, colB DESC,
2301 { -desc => [qw/colB/], | colC ASC, colD ASC
2302 { -asc => [qw/colC colD/],|
2304 ===========================================================
2308 =head1 SPECIAL OPERATORS
2310 my $sqlmaker = SQL::Abstract->new(special_ops => [
2314 my ($self, $field, $op, $arg) = @_;
2320 handler => 'method_name',
2324 A "special operator" is a SQL syntactic clause that can be
2325 applied to a field, instead of a usual binary operator.
2328 WHERE field IN (?, ?, ?)
2329 WHERE field BETWEEN ? AND ?
2330 WHERE MATCH(field) AGAINST (?, ?)
2332 Special operators IN and BETWEEN are fairly standard and therefore
2333 are builtin within C<SQL::Abstract> (as the overridable methods
2334 C<_where_field_IN> and C<_where_field_BETWEEN>). For other operators,
2335 like the MATCH .. AGAINST example above which is specific to MySQL,
2336 you can write your own operator handlers - supply a C<special_ops>
2337 argument to the C<new> method. That argument takes an arrayref of
2338 operator definitions; each operator definition is a hashref with two
2345 the regular expression to match the operator
2349 Either a coderef or a plain scalar method name. In both cases
2350 the expected return is C<< ($sql, @bind) >>.
2352 When supplied with a method name, it is simply called on the
2353 L<SQL::Abstract/> object as:
2355 $self->$method_name ($field, $op, $arg)
2359 $op is the part that matched the handler regex
2360 $field is the LHS of the operator
2363 When supplied with a coderef, it is called as:
2365 $coderef->($self, $field, $op, $arg)
2370 For example, here is an implementation
2371 of the MATCH .. AGAINST syntax for MySQL
2373 my $sqlmaker = SQL::Abstract->new(special_ops => [
2375 # special op for MySql MATCH (field) AGAINST(word1, word2, ...)
2376 {regex => qr/^match$/i,
2378 my ($self, $field, $op, $arg) = @_;
2379 $arg = [$arg] if not ref $arg;
2380 my $label = $self->_quote($field);
2381 my ($placeholder) = $self->_convert('?');
2382 my $placeholders = join ", ", (($placeholder) x @$arg);
2383 my $sql = $self->_sqlcase('match') . " ($label) "
2384 . $self->_sqlcase('against') . " ($placeholders) ";
2385 my @bind = $self->_bindtype($field, @$arg);
2386 return ($sql, @bind);
2393 =head1 UNARY OPERATORS
2395 my $sqlmaker = SQL::Abstract->new(unary_ops => [
2399 my ($self, $op, $arg) = @_;
2405 handler => 'method_name',
2409 A "unary operator" is a SQL syntactic clause that can be
2410 applied to a field - the operator goes before the field
2412 You can write your own operator handlers - supply a C<unary_ops>
2413 argument to the C<new> method. That argument takes an arrayref of
2414 operator definitions; each operator definition is a hashref with two
2421 the regular expression to match the operator
2425 Either a coderef or a plain scalar method name. In both cases
2426 the expected return is C<< $sql >>.
2428 When supplied with a method name, it is simply called on the
2429 L<SQL::Abstract/> object as:
2431 $self->$method_name ($op, $arg)
2435 $op is the part that matched the handler regex
2436 $arg is the RHS or argument of the operator
2438 When supplied with a coderef, it is called as:
2440 $coderef->($self, $op, $arg)
2448 Thanks to some benchmarking by Mark Stosberg, it turns out that
2449 this module is many orders of magnitude faster than using C<DBIx::Abstract>.
2450 I must admit this wasn't an intentional design issue, but it's a
2451 byproduct of the fact that you get to control your C<DBI> handles
2454 To maximize performance, use a code snippet like the following:
2456 # prepare a statement handle using the first row
2457 # and then reuse it for the rest of the rows
2459 for my $href (@array_of_hashrefs) {
2460 $stmt ||= $sql->insert('table', $href);
2461 $sth ||= $dbh->prepare($stmt);
2462 $sth->execute($sql->values($href));
2465 The reason this works is because the keys in your C<$href> are sorted
2466 internally by B<SQL::Abstract>. Thus, as long as your data retains
2467 the same structure, you only have to generate the SQL the first time
2468 around. On subsequent queries, simply use the C<values> function provided
2469 by this module to return your values in the correct order.
2474 If you use my C<CGI::FormBuilder> module at all, you'll hopefully
2475 really like this part (I do, at least). Building up a complex query
2476 can be as simple as the following:
2480 use CGI::FormBuilder;
2483 my $form = CGI::FormBuilder->new(...);
2484 my $sql = SQL::Abstract->new;
2486 if ($form->submitted) {
2487 my $field = $form->field;
2488 my $id = delete $field->{id};
2489 my($stmt, @bind) = $sql->update('table', $field, {id => $id});
2492 Of course, you would still have to connect using C<DBI> to run the
2493 query, but the point is that if you make your form look like your
2494 table, the actual query script can be extremely simplistic.
2496 If you're B<REALLY> lazy (I am), check out C<HTML::QuickTable> for
2497 a fast interface to returning and formatting data. I frequently
2498 use these three modules together to write complex database query
2499 apps in under 50 lines.
2504 Version 1.50 was a major internal refactoring of C<SQL::Abstract>.
2505 Great care has been taken to preserve the I<published> behavior
2506 documented in previous versions in the 1.* family; however,
2507 some features that were previously undocumented, or behaved
2508 differently from the documentation, had to be changed in order
2509 to clarify the semantics. Hence, client code that was relying
2510 on some dark areas of C<SQL::Abstract> v1.*
2511 B<might behave differently> in v1.50.
2513 The main changes are :
2519 support for literal SQL through the C<< \ [$sql, bind] >> syntax.
2523 support for the { operator => \"..." } construct (to embed literal SQL)
2527 support for the { operator => \["...", @bind] } construct (to embed literal SQL with bind values)
2531 optional support for L<array datatypes|/"Inserting and Updating Arrays">
2535 defensive programming : check arguments
2539 fixed bug with global logic, which was previously implemented
2540 through global variables yielding side-effects. Prior versions would
2541 interpret C<< [ {cond1, cond2}, [cond3, cond4] ] >>
2542 as C<< "(cond1 AND cond2) OR (cond3 AND cond4)" >>.
2543 Now this is interpreted
2544 as C<< "(cond1 AND cond2) OR (cond3 OR cond4)" >>.
2549 fixed semantics of _bindtype on array args
2553 dropped the C<_anoncopy> of the %where tree. No longer necessary,
2554 we just avoid shifting arrays within that tree.
2558 dropped the C<_modlogic> function
2564 =head1 ACKNOWLEDGEMENTS
2566 There are a number of individuals that have really helped out with
2567 this module. Unfortunately, most of them submitted bugs via CPAN
2568 so I have no idea who they are! But the people I do know are:
2570 Ash Berlin (order_by hash term support)
2571 Matt Trout (DBIx::Class support)
2572 Mark Stosberg (benchmarking)
2573 Chas Owens (initial "IN" operator support)
2574 Philip Collins (per-field SQL functions)
2575 Eric Kolve (hashref "AND" support)
2576 Mike Fragassi (enhancements to "BETWEEN" and "LIKE")
2577 Dan Kubb (support for "quote_char" and "name_sep")
2578 Guillermo Roditi (patch to cleanup "IN" and "BETWEEN", fix and tests for _order_by)
2579 Laurent Dami (internal refactoring, multiple -nest, extensible list of special operators, literal SQL)
2580 Norbert Buchmuller (support for literal SQL in hashpair, misc. fixes & tests)
2581 Peter Rabbitson (rewrite of SQLA::Test, misc. fixes & tests)
2587 L<DBIx::Class>, L<DBIx::Abstract>, L<CGI::FormBuilder>, L<HTML::QuickTable>.
2591 Copyright (c) 2001-2007 Nathan Wiger <nwiger@cpan.org>. All Rights Reserved.
2593 This module is actively maintained by Matt Trout <mst@shadowcatsystems.co.uk>
2595 For support, your best bet is to try the C<DBIx::Class> users mailing list.
2596 While not an official support venue, C<DBIx::Class> makes heavy use of
2597 C<SQL::Abstract>, and as such list members there are very familiar with
2598 how to create queries.
2602 This module is free software; you may copy this under the terms of
2603 the GNU General Public License, or the Artistic License, copies of
2604 which should have accompanied your Perl kit.