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 $VERSION = '1.51';
20 # This would confuse some packagers
21 #$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 #======================================================================
33 # DEBUGGING AND ERROR REPORTING
34 #======================================================================
37 return unless $_[0]->{debug}; shift; # a little faster
38 my $func = (caller(1))[3];
39 warn "[$func] ", @_, "\n";
43 my($func) = (caller(1))[3];
44 carp "[$func] Warning: ", @_;
48 my($func) = (caller(1))[3];
49 croak "[$func] Fatal: ", @_;
53 #======================================================================
55 #======================================================================
59 my $class = ref($self) || $self;
60 my %opt = (ref $_[0] eq 'HASH') ? %{$_[0]} : @_;
62 # choose our case by keeping an option around
63 delete $opt{case} if $opt{case} && $opt{case} ne 'lower';
65 # default logic for interpreting arrayrefs
66 $opt{logic} = $opt{logic} ? uc $opt{logic} : 'OR';
68 # how to return bind vars
69 # LDNOTE: changed nwiger code : why this 'delete' ??
70 # $opt{bindtype} ||= delete($opt{bind_type}) || 'normal';
71 $opt{bindtype} ||= 'normal';
73 # default comparison is "=", but can be overridden
76 # try to recognize which are the 'equality' and 'unequality' ops
77 # (temporary quickfix, should go through a more seasoned API)
78 $opt{equality_op} = qr/^(\Q$opt{cmp}\E|is|(is\s+)?like)$/i;
79 $opt{inequality_op} = qr/^(!=|<>|(is\s+)?not(\s+like)?)$/i;
82 $opt{sqltrue} ||= '1=1';
83 $opt{sqlfalse} ||= '0=1';
86 $opt{special_ops} ||= [];
87 push @{$opt{special_ops}}, @BUILTIN_SPECIAL_OPS;
89 return bless \%opt, $class;
94 #======================================================================
96 #======================================================================
100 my $table = $self->_table(shift);
101 my $data = shift || return;
103 my $method = $self->_METHOD_FOR_refkind("_insert", $data);
104 my ($sql, @bind) = $self->$method($data);
105 $sql = join " ", $self->_sqlcase('insert into'), $table, $sql;
106 return wantarray ? ($sql, @bind) : $sql;
109 sub _insert_HASHREF { # explicit list of fields and then values
110 my ($self, $data) = @_;
112 my @fields = sort keys %$data;
114 my ($sql, @bind) = $self->_insert_values($data);
117 $_ = $self->_quote($_) foreach @fields;
118 $sql = "( ".join(", ", @fields).") ".$sql;
120 return ($sql, @bind);
123 sub _insert_ARRAYREF { # just generate values(?,?) part (no list of fields)
124 my ($self, $data) = @_;
126 # no names (arrayref) so can't generate bindtype
127 $self->{bindtype} ne 'columns'
128 or belch "can't do 'columns' bindtype when called with arrayref";
130 # fold the list of values into a hash of column name - value pairs
131 # (where the column names are artificially generated, and their
132 # lexicographical ordering keep the ordering of the original list)
133 my $i = "a"; # incremented values will be in lexicographical order
134 my $data_in_hash = { map { ($i++ => $_) } @$data };
136 return $self->_insert_values($data_in_hash);
139 sub _insert_ARRAYREFREF { # literal SQL with bind
140 my ($self, $data) = @_;
142 my ($sql, @bind) = @${$data};
143 $self->_assert_bindval_matches_bindtype(@bind);
145 return ($sql, @bind);
149 sub _insert_SCALARREF { # literal SQL without bind
150 my ($self, $data) = @_;
156 my ($self, $data) = @_;
158 my (@values, @all_bind);
159 foreach my $column (sort keys %$data) {
160 my $v = $data->{$column};
162 $self->_SWITCH_refkind($v, {
165 if ($self->{array_datatypes}) { # if array datatype are activated
167 push @all_bind, $self->_bindtype($column, $v);
169 else { # else literal SQL with bind
170 my ($sql, @bind) = @$v;
171 $self->_assert_bindval_matches_bindtype(@bind);
173 push @all_bind, @bind;
177 ARRAYREFREF => sub { # literal SQL with bind
178 my ($sql, @bind) = @${$v};
179 $self->_assert_bindval_matches_bindtype(@bind);
181 push @all_bind, @bind;
184 # THINK : anything useful to do with a HASHREF ?
185 HASHREF => sub { # (nothing, but old SQLA passed it through)
186 #TODO in SQLA >= 2.0 it will die instead
187 belch "HASH ref as bind value in insert is not supported";
189 push @all_bind, $self->_bindtype($column, $v);
192 SCALARREF => sub { # literal SQL without bind
196 SCALAR_or_UNDEF => sub {
198 push @all_bind, $self->_bindtype($column, $v);
205 my $sql = $self->_sqlcase('values')." ( ".join(", ", @values)." )";
206 return ($sql, @all_bind);
211 #======================================================================
213 #======================================================================
218 my $table = $self->_table(shift);
219 my $data = shift || return;
222 # first build the 'SET' part of the sql statement
223 my (@set, @all_bind);
224 puke "Unsupported data type specified to \$sql->update"
225 unless ref $data eq 'HASH';
227 for my $k (sort keys %$data) {
230 my $label = $self->_quote($k);
232 $self->_SWITCH_refkind($v, {
234 if ($self->{array_datatypes}) { # array datatype
235 push @set, "$label = ?";
236 push @all_bind, $self->_bindtype($k, $v);
238 else { # literal SQL with bind
239 my ($sql, @bind) = @$v;
240 $self->_assert_bindval_matches_bindtype(@bind);
241 push @set, "$label = $sql";
242 push @all_bind, @bind;
245 ARRAYREFREF => sub { # literal SQL with bind
246 my ($sql, @bind) = @${$v};
247 $self->_assert_bindval_matches_bindtype(@bind);
248 push @set, "$label = $sql";
249 push @all_bind, @bind;
251 SCALARREF => sub { # literal SQL without bind
252 push @set, "$label = $$v";
254 SCALAR_or_UNDEF => sub {
255 push @set, "$label = ?";
256 push @all_bind, $self->_bindtype($k, $v);
262 my $sql = $self->_sqlcase('update') . " $table " . $self->_sqlcase('set ')
266 my($where_sql, @where_bind) = $self->where($where);
268 push @all_bind, @where_bind;
271 return wantarray ? ($sql, @all_bind) : $sql;
277 #======================================================================
279 #======================================================================
284 my $table = $self->_table(shift);
285 my $fields = shift || '*';
289 my($where_sql, @bind) = $self->where($where, $order);
291 my $f = (ref $fields eq 'ARRAY') ? join ', ', map { $self->_quote($_) } @$fields
293 my $sql = join(' ', $self->_sqlcase('select'), $f,
294 $self->_sqlcase('from'), $table)
297 return wantarray ? ($sql, @bind) : $sql;
300 #======================================================================
302 #======================================================================
307 my $table = $self->_table(shift);
311 my($where_sql, @bind) = $self->where($where);
312 my $sql = $self->_sqlcase('delete from') . " $table" . $where_sql;
314 return wantarray ? ($sql, @bind) : $sql;
318 #======================================================================
320 #======================================================================
324 # Finally, a separate routine just to handle WHERE clauses
326 my ($self, $where, $order) = @_;
329 my ($sql, @bind) = $self->_recurse_where($where);
330 $sql = $sql ? $self->_sqlcase(' where ') . "( $sql )" : '';
334 $sql .= $self->_order_by($order);
337 return wantarray ? ($sql, @bind) : $sql;
342 my ($self, $where, $logic) = @_;
344 # dispatch on appropriate method according to refkind of $where
345 my $method = $self->_METHOD_FOR_refkind("_where", $where);
348 my ($sql, @bind) = $self->$method($where, $logic);
350 # DBIx::Class directly calls _recurse_where in scalar context, so
351 # we must implement it, even if not in the official API
352 return wantarray ? ($sql, @bind) : $sql;
357 #======================================================================
358 # WHERE: top-level ARRAYREF
359 #======================================================================
362 sub _where_ARRAYREF {
363 my ($self, $where, $logic) = @_;
365 $logic = uc($logic || $self->{logic});
366 $logic eq 'AND' or $logic eq 'OR' or puke "unknown logic: $logic";
368 my @clauses = @$where;
370 my (@sql_clauses, @all_bind);
371 # need to use while() so can shift() for pairs
372 while (my $el = shift @clauses) {
374 # switch according to kind of $el and get corresponding ($sql, @bind)
375 my ($sql, @bind) = $self->_SWITCH_refkind($el, {
377 # skip empty elements, otherwise get invalid trailing AND stuff
378 ARRAYREF => sub {$self->_recurse_where($el) if @$el},
380 ARRAYREFREF => sub { @{${$el}} if @{${$el}}},
382 HASHREF => sub {$self->_recurse_where($el, 'and') if %$el},
383 # LDNOTE : previous SQLA code for hashrefs was creating a dirty
384 # side-effect: the first hashref within an array would change
385 # the global logic to 'AND'. So [ {cond1, cond2}, [cond3, cond4] ]
386 # was interpreted as "(cond1 AND cond2) OR (cond3 AND cond4)",
387 # whereas it should be "(cond1 AND cond2) OR (cond3 OR cond4)".
389 SCALARREF => sub { ($$el); },
391 SCALAR => sub {# top-level arrayref with scalars, recurse in pairs
392 $self->_recurse_where({$el => shift(@clauses)})},
394 UNDEF => sub {puke "not supported : UNDEF in arrayref" },
398 push @sql_clauses, $sql;
399 push @all_bind, @bind;
403 return $self->_join_sql_clauses($logic, \@sql_clauses, \@all_bind);
406 #======================================================================
407 # WHERE: top-level ARRAYREFREF
408 #======================================================================
410 sub _where_ARRAYREFREF {
411 my ($self, $where) = @_;
412 my ($sql, @bind) = @{${$where}};
414 return ($sql, @bind);
417 #======================================================================
418 # WHERE: top-level HASHREF
419 #======================================================================
422 my ($self, $where) = @_;
423 my (@sql_clauses, @all_bind);
425 # LDNOTE : don't really know why we need to sort keys
426 for my $k (sort keys %$where) {
427 my $v = $where->{$k};
429 # ($k => $v) is either a special op or a regular hashpair
430 my ($sql, @bind) = ($k =~ /^-(.+)/) ? $self->_where_op_in_hash($1, $v)
432 my $method = $self->_METHOD_FOR_refkind("_where_hashpair", $v);
433 $self->$method($k, $v);
436 push @sql_clauses, $sql;
437 push @all_bind, @bind;
440 return $self->_join_sql_clauses('and', \@sql_clauses, \@all_bind);
444 sub _where_op_in_hash {
445 my ($self, $op_str, $v) = @_;
447 $op_str =~ /^ (AND|OR|NEST) ( \_? \d* ) $/xi
448 or puke "unknown operator: -$op_str";
450 my $op = uc($1); # uppercase, remove trailing digits
452 belch 'Use of [and|or|nest]_N modifiers is deprecated and will be removed in SQLA v2.0. '
453 . "You probably wanted ...-and => [ $op_str => COND1, $op_str => COND2 ... ]";
456 $self->_debug("OP(-$op) within hashref, recursing...");
458 $self->_SWITCH_refkind($v, {
461 return $self->_where_ARRAYREF($v, $op eq 'NEST' ? '' : $op);
466 return $self->_where_ARRAYREF([%$v], 'OR');
469 return $self->_where_HASHREF($v);
473 SCALARREF => sub { # literal SQL
475 or puke "-$op => \\\$scalar not supported, use -nest => ...";
479 ARRAYREFREF => sub { # literal SQL
481 or puke "-$op => \\[..] not supported, use -nest => ...";
485 SCALAR => sub { # permissively interpreted as SQL
487 or puke "-$op => 'scalar' not supported, use -nest => \\'scalar'";
488 belch "literal SQL should be -nest => \\'scalar' "
489 . "instead of -nest => 'scalar' ";
494 puke "-$op => undef not supported";
500 sub _where_hashpair_ARRAYREF {
501 my ($self, $k, $v) = @_;
504 my @v = @$v; # need copy because of shift below
505 $self->_debug("ARRAY($k) means distribute over elements");
507 # put apart first element if it is an operator (-and, -or)
508 my $op = ($v[0] =~ /^ - (?: AND|OR ) $/ix
512 my @distributed = map { {$k => $_} } @v;
515 $self->_debug("OP($op) reinjected into the distributed array");
516 unshift @distributed, $op;
519 my $logic = $op ? substr($op, 1) : '';
521 return $self->_recurse_where(\@distributed, $logic);
524 # LDNOTE : not sure of this one. What does "distribute over nothing" mean?
525 $self->_debug("empty ARRAY($k) means 0=1");
526 return ($self->{sqlfalse});
530 sub _where_hashpair_HASHREF {
531 my ($self, $k, $v) = @_;
533 my (@all_sql, @all_bind);
535 for my $op (sort keys %$v) {
538 # put the operator in canonical form
539 $op =~ s/^-//; # remove initial dash
540 $op =~ tr/_/ /; # underscores become spaces
541 $op =~ s/^\s+//; # no initial space
542 $op =~ s/\s+$//; # no final space
543 $op =~ s/\s+/ /; # multiple spaces become one
547 # CASE: special operators like -in or -between
548 my $special_op = first {$op =~ $_->{regex}} @{$self->{special_ops}};
550 ($sql, @bind) = $special_op->{handler}->($self, $k, $op, $val);
553 $self->_SWITCH_refkind($val, {
555 ARRAYREF => sub { # CASE: col => {op => \@vals}
556 ($sql, @bind) = $self->_where_field_op_ARRAYREF($k, $op, $val);
559 SCALARREF => sub { # CASE: col => {op => \$scalar} (literal SQL without bind)
560 $sql = join ' ', $self->_convert($self->_quote($k)),
561 $self->_sqlcase($op),
565 ARRAYREFREF => sub { # CASE: col => {op => \[$sql, @bind]} (literal SQL with bind)
566 my ($sub_sql, @sub_bind) = @$$val;
567 $self->_assert_bindval_matches_bindtype(@sub_bind);
568 $sql = join ' ', $self->_convert($self->_quote($k)),
569 $self->_sqlcase($op),
574 UNDEF => sub { # CASE: col => {op => undef} : sql "IS (NOT)? NULL"
575 my $is = ($op =~ $self->{equality_op}) ? 'is' :
576 ($op =~ $self->{inequality_op}) ? 'is not' :
577 puke "unexpected operator '$op' with undef operand";
578 $sql = $self->_quote($k) . $self->_sqlcase(" $is null");
581 FALLBACK => sub { # CASE: col => {op => $scalar}
582 $sql = join ' ', $self->_convert($self->_quote($k)),
583 $self->_sqlcase($op),
584 $self->_convert('?');
585 @bind = $self->_bindtype($k, $val);
591 push @all_bind, @bind;
594 return $self->_join_sql_clauses('and', \@all_sql, \@all_bind);
599 sub _where_field_op_ARRAYREF {
600 my ($self, $k, $op, $vals) = @_;
603 $self->_debug("ARRAY($vals) means multiple elements: [ @$vals ]");
605 # LDNOTE : had planned to change the distribution logic when
606 # $op =~ $self->{inequality_op}, because of Morgan laws :
607 # with {field => {'!=' => [22, 33]}}, it would be ridiculous to generate
608 # WHERE field != 22 OR field != 33 : the user probably means
609 # WHERE field != 22 AND field != 33.
610 # To do this, replace the line below by :
611 # my $logic = ($op =~ $self->{inequality_op}) ? 'AND' : 'OR';
612 # return $self->_recurse_where([map { {$k => {$op, $_}} } @$vals], $logic);
614 # distribute $op over each member of @$vals
615 return $self->_recurse_where([map { {$k => {$op, $_}} } @$vals]);
618 # try to DWIM on equality operators
619 # LDNOTE : not 100% sure this is the correct thing to do ...
620 return ($self->{sqlfalse}) if $op =~ $self->{equality_op};
621 return ($self->{sqltrue}) if $op =~ $self->{inequality_op};
624 puke "operator '$op' applied on an empty array (field '$k')";
629 sub _where_hashpair_SCALARREF {
630 my ($self, $k, $v) = @_;
631 $self->_debug("SCALAR($k) means literal SQL: $$v");
632 my $sql = $self->_quote($k) . " " . $$v;
636 # literal SQL with bind
637 sub _where_hashpair_ARRAYREFREF {
638 my ($self, $k, $v) = @_;
639 $self->_debug("REF($k) means literal SQL: @${$v}");
640 my ($sql, @bind) = @${$v};
641 $self->_assert_bindval_matches_bindtype(@bind);
642 $sql = $self->_quote($k) . " " . $sql;
643 return ($sql, @bind );
646 # literal SQL without bind
647 sub _where_hashpair_SCALAR {
648 my ($self, $k, $v) = @_;
649 $self->_debug("NOREF($k) means simple key=val: $k $self->{cmp} $v");
650 my $sql = join ' ', $self->_convert($self->_quote($k)),
651 $self->_sqlcase($self->{cmp}),
652 $self->_convert('?');
653 my @bind = $self->_bindtype($k, $v);
654 return ( $sql, @bind);
658 sub _where_hashpair_UNDEF {
659 my ($self, $k, $v) = @_;
660 $self->_debug("UNDEF($k) means IS NULL");
661 my $sql = $self->_quote($k) . $self->_sqlcase(' is null');
665 #======================================================================
666 # WHERE: TOP-LEVEL OTHERS (SCALARREF, SCALAR, UNDEF)
667 #======================================================================
670 sub _where_SCALARREF {
671 my ($self, $where) = @_;
674 $self->_debug("SCALAR(*top) means literal SQL: $$where");
680 my ($self, $where) = @_;
683 $self->_debug("NOREF(*top) means literal SQL: $where");
694 #======================================================================
695 # WHERE: BUILTIN SPECIAL OPERATORS (-in, -between)
696 #======================================================================
699 sub _where_field_BETWEEN {
700 my ($self, $k, $op, $vals) = @_;
702 (ref $vals eq 'ARRAY' && @$vals == 2) or
703 (ref $vals eq 'REF' && (@$$vals == 1 || @$$vals == 2 || @$$vals == 3))
704 or puke "special op 'between' requires an arrayref of two values (or a scalarref or arrayrefref for literal SQL)";
706 my ($clause, @bind, $label, $and, $placeholder);
707 $label = $self->_convert($self->_quote($k));
708 $and = ' ' . $self->_sqlcase('and') . ' ';
709 $placeholder = $self->_convert('?');
710 $op = $self->_sqlcase($op);
712 if (ref $vals eq 'REF') {
713 ($clause, @bind) = @$$vals;
716 my (@all_sql, @all_bind);
718 foreach my $val (@$vals) {
719 my ($sql, @bind) = $self->_SWITCH_refkind($val, {
721 return ($placeholder, ($val));
724 return ($self->_convert($$val), ());
728 push @all_bind, @bind;
731 $clause = (join $and, @all_sql);
732 @bind = $self->_bindtype($k, @all_bind);
734 my $sql = "( $label $op $clause )";
739 sub _where_field_IN {
740 my ($self, $k, $op, $vals) = @_;
742 # backwards compatibility : if scalar, force into an arrayref
743 $vals = [$vals] if defined $vals && ! ref $vals;
745 my ($label) = $self->_convert($self->_quote($k));
746 my ($placeholder) = $self->_convert('?');
747 $op = $self->_sqlcase($op);
749 my ($sql, @bind) = $self->_SWITCH_refkind($vals, {
750 ARRAYREF => sub { # list of choices
751 if (@$vals) { # nonempty list
752 my $placeholders = join ", ", (($placeholder) x @$vals);
753 my $sql = "$label $op ( $placeholders )";
754 my @bind = $self->_bindtype($k, @$vals);
756 return ($sql, @bind);
758 else { # empty list : some databases won't understand "IN ()", so DWIM
759 my $sql = ($op =~ /\bnot\b/i) ? $self->{sqltrue} : $self->{sqlfalse};
764 ARRAYREFREF => sub { # literal SQL with bind
765 my ($sql, @bind) = @$$vals;
766 $self->_assert_bindval_matches_bindtype(@bind);
767 return ("$label $op ( $sql )", @bind);
771 puke "special op 'in' requires an arrayref (or arrayref-ref)";
775 return ($sql, @bind);
783 #======================================================================
785 #======================================================================
788 my ($self, $arg) = @_;
790 # construct list of ordering instructions
791 my @order = $self->_SWITCH_refkind($arg, {
794 map {$self->_SWITCH_refkind($_, {
795 SCALAR => sub {$self->_quote($_)},
797 SCALARREF => sub {$$_}, # literal SQL, no quoting
798 HASHREF => sub {$self->_order_by_hash($_)}
802 SCALAR => sub {$self->_quote($arg)},
804 SCALARREF => sub {$$arg}, # literal SQL, no quoting
805 HASHREF => sub {$self->_order_by_hash($arg)},
810 my $order = join ', ', @order;
811 return $order ? $self->_sqlcase(' order by')." $order" : '';
816 my ($self, $hash) = @_;
818 # get first pair in hash
819 my ($key, $val) = each %$hash;
821 # check if one pair was found and no other pair in hash
822 $key && !(each %$hash)
823 or puke "hash passed to _order_by must have exactly one key (-desc or -asc)";
825 my ($order) = ($key =~ /^-(desc|asc)/i)
826 or puke "invalid key in _order_by hash : $key";
828 return $self->_quote($val) ." ". $self->_sqlcase($order);
833 #======================================================================
834 # DATASOURCE (FOR NOW, JUST PLAIN TABLE OR LIST OF TABLES)
835 #======================================================================
840 $self->_SWITCH_refkind($from, {
841 ARRAYREF => sub {join ', ', map { $self->_quote($_) } @$from;},
842 SCALAR => sub {$self->_quote($from)},
843 SCALARREF => sub {$$from},
844 ARRAYREFREF => sub {join ', ', @$from;},
849 #======================================================================
851 #======================================================================
857 $label or puke "can't quote an empty label";
859 # left and right quote characters
860 my ($ql, $qr, @other) = $self->_SWITCH_refkind($self->{quote_char}, {
861 SCALAR => sub {($self->{quote_char}, $self->{quote_char})},
862 ARRAYREF => sub {@{$self->{quote_char}}},
866 or puke "quote_char must be an arrayref of 2 values";
868 # no quoting if no quoting chars
869 $ql or return $label;
871 # no quoting for literal SQL
872 return $$label if ref($label) eq 'SCALAR';
874 # separate table / column (if applicable)
875 my $sep = $self->{name_sep} || '';
876 my @to_quote = $sep ? split /\Q$sep\E/, $label : ($label);
878 # do the quoting, except for "*" or for `table`.*
879 my @quoted = map { $_ eq '*' ? $_: $ql.$_.$qr} @to_quote;
881 # reassemble and return.
882 return join $sep, @quoted;
886 # Conversion, if applicable
888 my ($self, $arg) = @_;
890 # LDNOTE : modified the previous implementation below because
891 # it was not consistent : the first "return" is always an array,
892 # the second "return" is context-dependent. Anyway, _convert
893 # seems always used with just a single argument, so make it a
895 # return @_ unless $self->{convert};
896 # my $conv = $self->_sqlcase($self->{convert});
897 # my @ret = map { $conv.'('.$_.')' } @_;
898 # return wantarray ? @ret : $ret[0];
899 if ($self->{convert}) {
900 my $conv = $self->_sqlcase($self->{convert});
901 $arg = $conv.'('.$arg.')';
909 my($col, @vals) = @_;
911 #LDNOTE : changed original implementation below because it did not make
912 # sense when bindtype eq 'columns' and @vals > 1.
913 # return $self->{bindtype} eq 'columns' ? [ $col, @vals ] : @vals;
915 return $self->{bindtype} eq 'columns' ? map {[$col, $_]} @vals : @vals;
918 # Dies if any element of @bind is not in [colname => value] format
919 # if bindtype is 'columns'.
920 sub _assert_bindval_matches_bindtype {
921 my ($self, @bind) = @_;
923 if ($self->{bindtype} eq 'columns') {
924 foreach my $val (@bind) {
925 if (!defined $val || ref($val) ne 'ARRAY' || @$val != 2) {
926 die "bindtype 'columns' selected, you need to pass: [column_name => bind_value]"
932 sub _join_sql_clauses {
933 my ($self, $logic, $clauses_aref, $bind_aref) = @_;
935 if (@$clauses_aref > 1) {
936 my $join = " " . $self->_sqlcase($logic) . " ";
937 my $sql = '( ' . join($join, @$clauses_aref) . ' )';
938 return ($sql, @$bind_aref);
940 elsif (@$clauses_aref) {
941 return ($clauses_aref->[0], @$bind_aref); # no parentheses
944 return (); # if no SQL, ignore @$bind_aref
949 # Fix SQL case, if so requested
953 # LDNOTE: if $self->{case} is true, then it contains 'lower', so we
954 # don't touch the argument ... crooked logic, but let's not change it!
955 return $self->{case} ? $_[0] : uc($_[0]);
959 #======================================================================
960 # DISPATCHING FROM REFKIND
961 #======================================================================
964 my ($self, $data) = @_;
970 # blessed objects are treated like scalars
971 $ref = (blessed $data) ? '' : ref $data;
972 $n_steps += 1 if $ref;
973 last if $ref ne 'REF';
977 my $base = $ref || (defined $data ? 'SCALAR' : 'UNDEF');
979 return $base . ('REF' x $n_steps);
985 my ($self, $data) = @_;
986 my @try = ($self->_refkind($data));
987 push @try, 'SCALAR_or_UNDEF' if $try[0] eq 'SCALAR' || $try[0] eq 'UNDEF';
988 push @try, 'FALLBACK';
992 sub _METHOD_FOR_refkind {
993 my ($self, $meth_prefix, $data) = @_;
994 my $method = first {$_} map {$self->can($meth_prefix."_".$_)}
995 $self->_try_refkind($data)
996 or puke "cannot dispatch on '$meth_prefix' for ".$self->_refkind($data);
1001 sub _SWITCH_refkind {
1002 my ($self, $data, $dispatch_table) = @_;
1004 my $coderef = first {$_} map {$dispatch_table->{$_}}
1005 $self->_try_refkind($data)
1006 or puke "no dispatch entry for ".$self->_refkind($data);
1013 #======================================================================
1014 # VALUES, GENERATE, AUTOLOAD
1015 #======================================================================
1017 # LDNOTE: original code from nwiger, didn't touch code in that section
1018 # I feel the AUTOLOAD stuff should not be the default, it should
1019 # only be activated on explicit demand by user.
1023 my $data = shift || return;
1024 puke "Argument to ", __PACKAGE__, "->values must be a \\%hash"
1025 unless ref $data eq 'HASH';
1028 foreach my $k ( sort keys %$data ) {
1029 my $v = $data->{$k};
1030 $self->_SWITCH_refkind($v, {
1032 if ($self->{array_datatypes}) { # array datatype
1033 push @all_bind, $self->_bindtype($k, $v);
1035 else { # literal SQL with bind
1036 my ($sql, @bind) = @$v;
1037 $self->_assert_bindval_matches_bindtype(@bind);
1038 push @all_bind, @bind;
1041 ARRAYREFREF => sub { # literal SQL with bind
1042 my ($sql, @bind) = @${$v};
1043 $self->_assert_bindval_matches_bindtype(@bind);
1044 push @all_bind, @bind;
1046 SCALARREF => sub { # literal SQL without bind
1048 SCALAR_or_UNDEF => sub {
1049 push @all_bind, $self->_bindtype($k, $v);
1060 my(@sql, @sqlq, @sqlv);
1064 if ($ref eq 'HASH') {
1065 for my $k (sort keys %$_) {
1068 my $label = $self->_quote($k);
1069 if ($r eq 'ARRAY') {
1070 # literal SQL with bind
1071 my ($sql, @bind) = @$v;
1072 $self->_assert_bindval_matches_bindtype(@bind);
1073 push @sqlq, "$label = $sql";
1075 } elsif ($r eq 'SCALAR') {
1076 # literal SQL without bind
1077 push @sqlq, "$label = $$v";
1079 push @sqlq, "$label = ?";
1080 push @sqlv, $self->_bindtype($k, $v);
1083 push @sql, $self->_sqlcase('set'), join ', ', @sqlq;
1084 } elsif ($ref eq 'ARRAY') {
1085 # unlike insert(), assume these are ONLY the column names, i.e. for SQL
1088 if ($r eq 'ARRAY') { # literal SQL with bind
1089 my ($sql, @bind) = @$v;
1090 $self->_assert_bindval_matches_bindtype(@bind);
1093 } elsif ($r eq 'SCALAR') { # literal SQL without bind
1094 # embedded literal SQL
1101 push @sql, '(' . join(', ', @sqlq) . ')';
1102 } elsif ($ref eq 'SCALAR') {
1106 # strings get case twiddled
1107 push @sql, $self->_sqlcase($_);
1111 my $sql = join ' ', @sql;
1113 # this is pretty tricky
1114 # if ask for an array, return ($stmt, @bind)
1115 # otherwise, s/?/shift @sqlv/ to put it inline
1117 return ($sql, @sqlv);
1119 1 while $sql =~ s/\?/my $d = shift(@sqlv);
1120 ref $d ? $d->[1] : $d/e;
1129 # This allows us to check for a local, then _form, attr
1131 my($name) = $AUTOLOAD =~ /.*::(.+)/;
1132 return $self->generate($name, @_);
1143 SQL::Abstract - Generate SQL from Perl data structures
1149 my $sql = SQL::Abstract->new;
1151 my($stmt, @bind) = $sql->select($table, \@fields, \%where, \@order);
1153 my($stmt, @bind) = $sql->insert($table, \%fieldvals || \@values);
1155 my($stmt, @bind) = $sql->update($table, \%fieldvals, \%where);
1157 my($stmt, @bind) = $sql->delete($table, \%where);
1159 # Then, use these in your DBI statements
1160 my $sth = $dbh->prepare($stmt);
1161 $sth->execute(@bind);
1163 # Just generate the WHERE clause
1164 my($stmt, @bind) = $sql->where(\%where, \@order);
1166 # Return values in the same order, for hashed queries
1167 # See PERFORMANCE section for more details
1168 my @bind = $sql->values(\%fieldvals);
1172 This module was inspired by the excellent L<DBIx::Abstract>.
1173 However, in using that module I found that what I really wanted
1174 to do was generate SQL, but still retain complete control over my
1175 statement handles and use the DBI interface. So, I set out to
1176 create an abstract SQL generation module.
1178 While based on the concepts used by L<DBIx::Abstract>, there are
1179 several important differences, especially when it comes to WHERE
1180 clauses. I have modified the concepts used to make the SQL easier
1181 to generate from Perl data structures and, IMO, more intuitive.
1182 The underlying idea is for this module to do what you mean, based
1183 on the data structures you provide it. The big advantage is that
1184 you don't have to modify your code every time your data changes,
1185 as this module figures it out.
1187 To begin with, an SQL INSERT is as easy as just specifying a hash
1188 of C<key=value> pairs:
1191 name => 'Jimbo Bobson',
1192 phone => '123-456-7890',
1193 address => '42 Sister Lane',
1194 city => 'St. Louis',
1195 state => 'Louisiana',
1198 The SQL can then be generated with this:
1200 my($stmt, @bind) = $sql->insert('people', \%data);
1202 Which would give you something like this:
1204 $stmt = "INSERT INTO people
1205 (address, city, name, phone, state)
1206 VALUES (?, ?, ?, ?, ?)";
1207 @bind = ('42 Sister Lane', 'St. Louis', 'Jimbo Bobson',
1208 '123-456-7890', 'Louisiana');
1210 These are then used directly in your DBI code:
1212 my $sth = $dbh->prepare($stmt);
1213 $sth->execute(@bind);
1215 =head2 Inserting and Updating Arrays
1217 If your database has array types (like for example Postgres),
1218 activate the special option C<< array_datatypes => 1 >>
1219 when creating the C<SQL::Abstract> object.
1220 Then you may use an arrayref to insert and update database array types:
1222 my $sql = SQL::Abstract->new(array_datatypes => 1);
1224 planets => [qw/Mercury Venus Earth Mars/]
1227 my($stmt, @bind) = $sql->insert('solar_system', \%data);
1231 $stmt = "INSERT INTO solar_system (planets) VALUES (?)"
1233 @bind = (['Mercury', 'Venus', 'Earth', 'Mars']);
1236 =head2 Inserting and Updating SQL
1238 In order to apply SQL functions to elements of your C<%data> you may
1239 specify a reference to an arrayref for the given hash value. For example,
1240 if you need to execute the Oracle C<to_date> function on a value, you can
1241 say something like this:
1245 date_entered => \["to_date(?,'MM/DD/YYYY')", "03/02/2003"],
1248 The first value in the array is the actual SQL. Any other values are
1249 optional and would be included in the bind values array. This gives
1252 my($stmt, @bind) = $sql->insert('people', \%data);
1254 $stmt = "INSERT INTO people (name, date_entered)
1255 VALUES (?, to_date(?,'MM/DD/YYYY'))";
1256 @bind = ('Bill', '03/02/2003');
1258 An UPDATE is just as easy, all you change is the name of the function:
1260 my($stmt, @bind) = $sql->update('people', \%data);
1262 Notice that your C<%data> isn't touched; the module will generate
1263 the appropriately quirky SQL for you automatically. Usually you'll
1264 want to specify a WHERE clause for your UPDATE, though, which is
1265 where handling C<%where> hashes comes in handy...
1267 =head2 Complex where statements
1269 This module can generate pretty complicated WHERE statements
1270 easily. For example, simple C<key=value> pairs are taken to mean
1271 equality, and if you want to see if a field is within a set
1272 of values, you can use an arrayref. Let's say we wanted to
1273 SELECT some data based on this criteria:
1276 requestor => 'inna',
1277 worker => ['nwiger', 'rcwe', 'sfz'],
1278 status => { '!=', 'completed' }
1281 my($stmt, @bind) = $sql->select('tickets', '*', \%where);
1283 The above would give you something like this:
1285 $stmt = "SELECT * FROM tickets WHERE
1286 ( requestor = ? ) AND ( status != ? )
1287 AND ( worker = ? OR worker = ? OR worker = ? )";
1288 @bind = ('inna', 'completed', 'nwiger', 'rcwe', 'sfz');
1290 Which you could then use in DBI code like so:
1292 my $sth = $dbh->prepare($stmt);
1293 $sth->execute(@bind);
1299 The functions are simple. There's one for each major SQL operation,
1300 and a constructor you use first. The arguments are specified in a
1301 similar order to each function (table, then fields, then a where
1302 clause) to try and simplify things.
1307 =head2 new(option => 'value')
1309 The C<new()> function takes a list of options and values, and returns
1310 a new B<SQL::Abstract> object which can then be used to generate SQL
1311 through the methods below. The options accepted are:
1317 If set to 'lower', then SQL will be generated in all lowercase. By
1318 default SQL is generated in "textbook" case meaning something like:
1320 SELECT a_field FROM a_table WHERE some_field LIKE '%someval%'
1322 Any setting other than 'lower' is ignored.
1326 This determines what the default comparison operator is. By default
1327 it is C<=>, meaning that a hash like this:
1329 %where = (name => 'nwiger', email => 'nate@wiger.org');
1331 Will generate SQL like this:
1333 WHERE name = 'nwiger' AND email = 'nate@wiger.org'
1335 However, you may want loose comparisons by default, so if you set
1336 C<cmp> to C<like> you would get SQL such as:
1338 WHERE name like 'nwiger' AND email like 'nate@wiger.org'
1340 You can also override the comparsion on an individual basis - see
1341 the huge section on L</"WHERE CLAUSES"> at the bottom.
1343 =item sqltrue, sqlfalse
1345 Expressions for inserting boolean values within SQL statements.
1346 By default these are C<1=1> and C<1=0>. They are used
1347 by the special operators C<-in> and C<-not_in> for generating
1348 correct SQL even when the argument is an empty array (see below).
1352 This determines the default logical operator for multiple WHERE
1353 statements in arrays or hashes. If absent, the default logic is "or"
1354 for arrays, and "and" for hashes. This means that a WHERE
1358 event_date => {'>=', '2/13/99'},
1359 event_date => {'<=', '4/24/03'},
1362 will generate SQL like this:
1364 WHERE event_date >= '2/13/99' OR event_date <= '4/24/03'
1366 This is probably not what you want given this query, though (look
1367 at the dates). To change the "OR" to an "AND", simply specify:
1369 my $sql = SQL::Abstract->new(logic => 'and');
1371 Which will change the above C<WHERE> to:
1373 WHERE event_date >= '2/13/99' AND event_date <= '4/24/03'
1375 The logic can also be changed locally by inserting
1376 a modifier in front of an arrayref :
1378 @where = (-and => [event_date => {'>=', '2/13/99'},
1379 event_date => {'<=', '4/24/03'} ]);
1381 See the L</"WHERE CLAUSES"> section for explanations.
1385 This will automatically convert comparisons using the specified SQL
1386 function for both column and value. This is mostly used with an argument
1387 of C<upper> or C<lower>, so that the SQL will have the effect of
1388 case-insensitive "searches". For example, this:
1390 $sql = SQL::Abstract->new(convert => 'upper');
1391 %where = (keywords => 'MaKe iT CAse inSeNSItive');
1393 Will turn out the following SQL:
1395 WHERE upper(keywords) like upper('MaKe iT CAse inSeNSItive')
1397 The conversion can be C<upper()>, C<lower()>, or any other SQL function
1398 that can be applied symmetrically to fields (actually B<SQL::Abstract> does
1399 not validate this option; it will just pass through what you specify verbatim).
1403 This is a kludge because many databases suck. For example, you can't
1404 just bind values using DBI's C<execute()> for Oracle C<CLOB> or C<BLOB> fields.
1405 Instead, you have to use C<bind_param()>:
1407 $sth->bind_param(1, 'reg data');
1408 $sth->bind_param(2, $lots, {ora_type => ORA_CLOB});
1410 The problem is, B<SQL::Abstract> will normally just return a C<@bind> array,
1411 which loses track of which field each slot refers to. Fear not.
1413 If you specify C<bindtype> in new, you can determine how C<@bind> is returned.
1414 Currently, you can specify either C<normal> (default) or C<columns>. If you
1415 specify C<columns>, you will get an array that looks like this:
1417 my $sql = SQL::Abstract->new(bindtype => 'columns');
1418 my($stmt, @bind) = $sql->insert(...);
1421 [ 'column1', 'value1' ],
1422 [ 'column2', 'value2' ],
1423 [ 'column3', 'value3' ],
1426 You can then iterate through this manually, using DBI's C<bind_param()>.
1428 $sth->prepare($stmt);
1431 my($col, $data) = @$_;
1432 if ($col eq 'details' || $col eq 'comments') {
1433 $sth->bind_param($i, $data, {ora_type => ORA_CLOB});
1434 } elsif ($col eq 'image') {
1435 $sth->bind_param($i, $data, {ora_type => ORA_BLOB});
1437 $sth->bind_param($i, $data);
1441 $sth->execute; # execute without @bind now
1443 Now, why would you still use B<SQL::Abstract> if you have to do this crap?
1444 Basically, the advantage is still that you don't have to care which fields
1445 are or are not included. You could wrap that above C<for> loop in a simple
1446 sub called C<bind_fields()> or something and reuse it repeatedly. You still
1447 get a layer of abstraction over manual SQL specification.
1449 Note that if you set L</bindtype> to C<columns>, the C<\[$sql, @bind]>
1450 construct (see L</Literal SQL with placeholders and bind values (subqueries)>)
1451 will expect the bind values in this format.
1455 This is the character that a table or column name will be quoted
1456 with. By default this is an empty string, but you could set it to
1457 the character C<`>, to generate SQL like this:
1459 SELECT `a_field` FROM `a_table` WHERE `some_field` LIKE '%someval%'
1461 Alternatively, you can supply an array ref of two items, the first being the left
1462 hand quote character, and the second the right hand quote character. For
1463 example, you could supply C<['[',']']> for SQL Server 2000 compliant quotes
1464 that generates SQL like this:
1466 SELECT [a_field] FROM [a_table] WHERE [some_field] LIKE '%someval%'
1468 Quoting is useful if you have tables or columns names that are reserved
1469 words in your database's SQL dialect.
1473 This is the character that separates a table and column name. It is
1474 necessary to specify this when the C<quote_char> option is selected,
1475 so that tables and column names can be individually quoted like this:
1477 SELECT `table`.`one_field` FROM `table` WHERE `table`.`other_field` = 1
1479 =item array_datatypes
1481 When this option is true, arrayrefs in INSERT or UPDATE are
1482 interpreted as array datatypes and are passed directly
1484 When this option is false, arrayrefs are interpreted
1485 as literal SQL, just like refs to arrayrefs
1486 (but this behavior is for backwards compatibility; when writing
1487 new queries, use the "reference to arrayref" syntax
1493 Takes a reference to a list of "special operators"
1494 to extend the syntax understood by L<SQL::Abstract>.
1495 See section L</"SPECIAL OPERATORS"> for details.
1501 =head2 insert($table, \@values || \%fieldvals)
1503 This is the simplest function. You simply give it a table name
1504 and either an arrayref of values or hashref of field/value pairs.
1505 It returns an SQL INSERT statement and a list of bind values.
1506 See the sections on L</"Inserting and Updating Arrays"> and
1507 L</"Inserting and Updating SQL"> for information on how to insert
1508 with those data types.
1510 =head2 update($table, \%fieldvals, \%where)
1512 This takes a table, hashref of field/value pairs, and an optional
1513 hashref L<WHERE clause|/WHERE CLAUSES>. It returns an SQL UPDATE function and a list
1515 See the sections on L</"Inserting and Updating Arrays"> and
1516 L</"Inserting and Updating SQL"> for information on how to insert
1517 with those data types.
1519 =head2 select($source, $fields, $where, $order)
1521 This returns a SQL SELECT statement and associated list of bind values, as
1522 specified by the arguments :
1528 Specification of the 'FROM' part of the statement.
1529 The argument can be either a plain scalar (interpreted as a table
1530 name, will be quoted), or an arrayref (interpreted as a list
1531 of table names, joined by commas, quoted), or a scalarref
1532 (literal table name, not quoted), or a ref to an arrayref
1533 (list of literal table names, joined by commas, not quoted).
1537 Specification of the list of fields to retrieve from
1539 The argument can be either an arrayref (interpreted as a list
1540 of field names, will be joined by commas and quoted), or a
1541 plain scalar (literal SQL, not quoted).
1542 Please observe that this API is not as flexible as for
1543 the first argument C<$table>, for backwards compatibility reasons.
1547 Optional argument to specify the WHERE part of the query.
1548 The argument is most often a hashref, but can also be
1549 an arrayref or plain scalar --
1550 see section L<WHERE clause|/"WHERE CLAUSES"> for details.
1554 Optional argument to specify the ORDER BY part of the query.
1555 The argument can be a scalar, a hashref or an arrayref
1556 -- see section L<ORDER BY clause|/"ORDER BY CLAUSES">
1562 =head2 delete($table, \%where)
1564 This takes a table name and optional hashref L<WHERE clause|/WHERE CLAUSES>.
1565 It returns an SQL DELETE statement and list of bind values.
1567 =head2 where(\%where, \@order)
1569 This is used to generate just the WHERE clause. For example,
1570 if you have an arbitrary data structure and know what the
1571 rest of your SQL is going to look like, but want an easy way
1572 to produce a WHERE clause, use this. It returns an SQL WHERE
1573 clause and list of bind values.
1576 =head2 values(\%data)
1578 This just returns the values from the hash C<%data>, in the same
1579 order that would be returned from any of the other above queries.
1580 Using this allows you to markedly speed up your queries if you
1581 are affecting lots of rows. See below under the L</"PERFORMANCE"> section.
1583 =head2 generate($any, 'number', $of, \@data, $struct, \%types)
1585 Warning: This is an experimental method and subject to change.
1587 This returns arbitrarily generated SQL. It's a really basic shortcut.
1588 It will return two different things, depending on return context:
1590 my($stmt, @bind) = $sql->generate('create table', \$table, \@fields);
1591 my $stmt_and_val = $sql->generate('create table', \$table, \@fields);
1593 These would return the following:
1595 # First calling form
1596 $stmt = "CREATE TABLE test (?, ?)";
1597 @bind = (field1, field2);
1599 # Second calling form
1600 $stmt_and_val = "CREATE TABLE test (field1, field2)";
1602 Depending on what you're trying to do, it's up to you to choose the correct
1603 format. In this example, the second form is what you would want.
1607 $sql->generate('alter session', { nls_date_format => 'MM/YY' });
1611 ALTER SESSION SET nls_date_format = 'MM/YY'
1613 You get the idea. Strings get their case twiddled, but everything
1614 else remains verbatim.
1619 =head1 WHERE CLAUSES
1623 This module uses a variation on the idea from L<DBIx::Abstract>. It
1624 is B<NOT>, repeat I<not> 100% compatible. B<The main logic of this
1625 module is that things in arrays are OR'ed, and things in hashes
1628 The easiest way to explain is to show lots of examples. After
1629 each C<%where> hash shown, it is assumed you used:
1631 my($stmt, @bind) = $sql->where(\%where);
1633 However, note that the C<%where> hash can be used directly in any
1634 of the other functions as well, as described above.
1636 =head2 Key-value pairs
1638 So, let's get started. To begin, a simple hash:
1642 status => 'completed'
1645 Is converted to SQL C<key = val> statements:
1647 $stmt = "WHERE user = ? AND status = ?";
1648 @bind = ('nwiger', 'completed');
1650 One common thing I end up doing is having a list of values that
1651 a field can be in. To do this, simply specify a list inside of
1656 status => ['assigned', 'in-progress', 'pending'];
1659 This simple code will create the following:
1661 $stmt = "WHERE user = ? AND ( status = ? OR status = ? OR status = ? )";
1662 @bind = ('nwiger', 'assigned', 'in-progress', 'pending');
1664 A field associated to an empty arrayref will be considered a
1665 logical false and will generate 0=1.
1667 =head2 Specific comparison operators
1669 If you want to specify a different type of operator for your comparison,
1670 you can use a hashref for a given column:
1674 status => { '!=', 'completed' }
1677 Which would generate:
1679 $stmt = "WHERE user = ? AND status != ?";
1680 @bind = ('nwiger', 'completed');
1682 To test against multiple values, just enclose the values in an arrayref:
1684 status => { '=', ['assigned', 'in-progress', 'pending'] };
1686 Which would give you:
1688 "WHERE status = ? OR status = ? OR status = ?"
1691 The hashref can also contain multiple pairs, in which case it is expanded
1692 into an C<AND> of its elements:
1696 status => { '!=', 'completed', -not_like => 'pending%' }
1699 # Or more dynamically, like from a form
1700 $where{user} = 'nwiger';
1701 $where{status}{'!='} = 'completed';
1702 $where{status}{'-not_like'} = 'pending%';
1704 # Both generate this
1705 $stmt = "WHERE user = ? AND status != ? AND status NOT LIKE ?";
1706 @bind = ('nwiger', 'completed', 'pending%');
1709 To get an OR instead, you can combine it with the arrayref idea:
1713 priority => [ {'=', 2}, {'!=', 1} ]
1716 Which would generate:
1718 $stmt = "WHERE user = ? AND priority = ? OR priority != ?";
1719 @bind = ('nwiger', '2', '1');
1721 If you want to include literal SQL (with or without bind values), just use a
1722 scalar reference or array reference as the value:
1725 date_entered => { '>' => \["to_date(?, 'MM/DD/YYYY')", "11/26/2008"] },
1726 date_expires => { '<' => \"now()" }
1729 Which would generate:
1731 $stmt = "WHERE date_entered > "to_date(?, 'MM/DD/YYYY') AND date_expires < now()";
1732 @bind = ('11/26/2008');
1735 =head2 Logic and nesting operators
1737 In the example above,
1738 there is a subtle trap if you want to say something like
1739 this (notice the C<AND>):
1741 WHERE priority != ? AND priority != ?
1743 Because, in Perl you I<can't> do this:
1745 priority => { '!=', 2, '!=', 1 }
1747 As the second C<!=> key will obliterate the first. The solution
1748 is to use the special C<-modifier> form inside an arrayref:
1750 priority => [ -and => {'!=', 2},
1754 Normally, these would be joined by C<OR>, but the modifier tells it
1755 to use C<AND> instead. (Hint: You can use this in conjunction with the
1756 C<logic> option to C<new()> in order to change the way your queries
1757 work by default.) B<Important:> Note that the C<-modifier> goes
1758 B<INSIDE> the arrayref, as an extra first element. This will
1759 B<NOT> do what you think it might:
1761 priority => -and => [{'!=', 2}, {'!=', 1}] # WRONG!
1763 Here is a quick list of equivalencies, since there is some overlap:
1766 status => {'!=', 'completed', 'not like', 'pending%' }
1767 status => [ -and => {'!=', 'completed'}, {'not like', 'pending%'}]
1770 status => {'=', ['assigned', 'in-progress']}
1771 status => [ -or => {'=', 'assigned'}, {'=', 'in-progress'}]
1772 status => [ {'=', 'assigned'}, {'=', 'in-progress'} ]
1776 =head2 Special operators : IN, BETWEEN, etc.
1778 You can also use the hashref format to compare a list of fields using the
1779 C<IN> comparison operator, by specifying the list as an arrayref:
1782 status => 'completed',
1783 reportid => { -in => [567, 2335, 2] }
1786 Which would generate:
1788 $stmt = "WHERE status = ? AND reportid IN (?,?,?)";
1789 @bind = ('completed', '567', '2335', '2');
1791 The reverse operator C<-not_in> generates SQL C<NOT IN> and is used in
1794 If the argument to C<-in> is an empty array, 'sqlfalse' is generated
1795 (by default : C<1=0>). Similarly, C<< -not_in => [] >> generates
1796 'sqltrue' (by default : C<1=1>).
1800 Another pair of operators is C<-between> and C<-not_between>,
1801 used with an arrayref of two values:
1805 completion_date => {
1806 -not_between => ['2002-10-01', '2003-02-06']
1812 WHERE user = ? AND completion_date NOT BETWEEN ( ? AND ? )
1814 These are the two builtin "special operators"; but the
1815 list can be expanded : see section L</"SPECIAL OPERATORS"> below.
1817 =head2 Nested conditions, -and/-or prefixes
1819 So far, we've seen how multiple conditions are joined with a top-level
1820 C<AND>. We can change this by putting the different conditions we want in
1821 hashes and then putting those hashes in an array. For example:
1826 status => { -like => ['pending%', 'dispatched'] },
1830 status => 'unassigned',
1834 This data structure would create the following:
1836 $stmt = "WHERE ( user = ? AND ( status LIKE ? OR status LIKE ? ) )
1837 OR ( user = ? AND status = ? ) )";
1838 @bind = ('nwiger', 'pending', 'dispatched', 'robot', 'unassigned');
1841 There is also a special C<-nest>
1842 operator which adds an additional set of parens, to create a subquery.
1843 For example, to get something like this:
1845 $stmt = "WHERE user = ? AND ( workhrs > ? OR geo = ? )";
1846 @bind = ('nwiger', '20', 'ASIA');
1852 -nest => [ workhrs => {'>', 20}, geo => 'ASIA' ],
1856 Finally, clauses in hashrefs or arrayrefs can be
1857 prefixed with an C<-and> or C<-or> to change the logic
1864 -and => [workhrs => {'>', 20}, geo => 'ASIA' ],
1865 -and => [workhrs => {'<', 50}, geo => 'EURO' ]
1872 WHERE ( user = ? AND
1873 ( ( workhrs > ? AND geo = ? )
1874 OR ( workhrs < ? AND geo = ? ) ) )
1877 =head2 Algebraic inconsistency, for historical reasons
1879 C<Important note>: when connecting several conditions, the C<-and->|C<-or>
1880 operator goes C<outside> of the nested structure; whereas when connecting
1881 several constraints on one column, the C<-and> operator goes
1882 C<inside> the arrayref. Here is an example combining both features :
1885 -and => [a => 1, b => 2],
1886 -or => [c => 3, d => 4],
1887 e => [-and => {-like => 'foo%'}, {-like => '%bar'} ]
1892 WHERE ( ( ( a = ? AND b = ? )
1893 OR ( c = ? OR d = ? )
1894 OR ( e LIKE ? AND e LIKE ? ) ) )
1896 This difference in syntax is unfortunate but must be preserved for
1897 historical reasons. So be careful : the two examples below would
1898 seem algebraically equivalent, but they are not
1900 {col => [-and => {-like => 'foo%'}, {-like => '%bar'}]}
1901 # yields : WHERE ( ( col LIKE ? AND col LIKE ? ) )
1903 [-and => {col => {-like => 'foo%'}, {col => {-like => '%bar'}}]]
1904 # yields : WHERE ( ( col LIKE ? OR col LIKE ? ) )
1909 Finally, sometimes only literal SQL will do. If you want to include
1910 literal SQL verbatim, you can specify it as a scalar reference, namely:
1912 my $inn = 'is Not Null';
1914 priority => { '<', 2 },
1920 $stmt = "WHERE priority < ? AND requestor is Not Null";
1923 Note that in this example, you only get one bind parameter back, since
1924 the verbatim SQL is passed as part of the statement.
1926 Of course, just to prove a point, the above can also be accomplished
1930 priority => { '<', 2 },
1931 requestor => { '!=', undef },
1937 Conditions on boolean columns can be expressed in the
1938 same way, passing a reference to an empty string :
1941 priority => { '<', 2 },
1947 $stmt = "WHERE priority < ? AND is_ready";
1951 =head2 Literal SQL with placeholders and bind values (subqueries)
1953 If the literal SQL to be inserted has placeholders and bind values,
1954 use a reference to an arrayref (yes this is a double reference --
1955 not so common, but perfectly legal Perl). For example, to find a date
1956 in Postgres you can use something like this:
1959 date_column => \[q/= date '2008-09-30' - ?::integer/, 10/]
1964 $stmt = "WHERE ( date_column = date '2008-09-30' - ?::integer )"
1967 Note that you must pass the bind values in the same format as they are returned
1968 by L</where>. That means that if you set L</bindtype> to C<columns>, you must
1969 provide the bind values in the C<< [ column_meta => value ] >> format, where
1970 C<column_meta> is an opaque scalar value; most commonly the column name, but
1971 you can use any scalar value (including references and blessed references),
1972 L<SQL::Abstract> will simply pass it through intact. So if C<bindtype> is set
1973 to C<columns> the above example will look like:
1976 date_column => \[q/= date '2008-09-30' - ?::integer/, [ dummy => 10 ]/]
1979 Literal SQL is especially useful for nesting parenthesized clauses in the
1980 main SQL query. Here is a first example :
1982 my ($sub_stmt, @sub_bind) = ("SELECT c1 FROM t1 WHERE c2 < ? AND c3 LIKE ?",
1986 bar => \["IN ($sub_stmt)" => @sub_bind],
1991 $stmt = "WHERE (foo = ? AND bar IN (SELECT c1 FROM t1
1992 WHERE c2 < ? AND c3 LIKE ?))";
1993 @bind = (1234, 100, "foo%");
1995 Other subquery operators, like for example C<"E<gt> ALL"> or C<"NOT IN">,
1996 are expressed in the same way. Of course the C<$sub_stmt> and
1997 its associated bind values can be generated through a former call
2000 my ($sub_stmt, @sub_bind)
2001 = $sql->select("t1", "c1", {c2 => {"<" => 100},
2002 c3 => {-like => "foo%"}});
2005 bar => \["> ALL ($sub_stmt)" => @sub_bind],
2008 In the examples above, the subquery was used as an operator on a column;
2009 but the same principle also applies for a clause within the main C<%where>
2010 hash, like an EXISTS subquery :
2012 my ($sub_stmt, @sub_bind)
2013 = $sql->select("t1", "*", {c1 => 1, c2 => \"> t0.c0"});
2016 -nest => \["EXISTS ($sub_stmt)" => @sub_bind],
2021 $stmt = "WHERE (foo = ? AND EXISTS (SELECT * FROM t1
2022 WHERE c1 = ? AND c2 > t0.c0))";
2026 Observe that the condition on C<c2> in the subquery refers to
2027 column C<t0.c0> of the main query : this is I<not> a bind
2028 value, so we have to express it through a scalar ref.
2029 Writing C<< c2 => {">" => "t0.c0"} >> would have generated
2030 C<< c2 > ? >> with bind value C<"t0.c0"> ... not exactly
2031 what we wanted here.
2033 Another use of the subquery technique is when some SQL clauses need
2034 parentheses, as it often occurs with some proprietary SQL extensions
2035 like for example fulltext expressions, geospatial expressions,
2036 NATIVE clauses, etc. Here is an example of a fulltext query in MySQL :
2039 -nest => \["MATCH (col1, col2) AGAINST (?)" => qw/apples/]
2042 Finally, here is an example where a subquery is used
2043 for expressing unary negation:
2045 my ($sub_stmt, @sub_bind)
2046 = $sql->where({age => [{"<" => 10}, {">" => 20}]});
2047 $sub_stmt =~ s/^ where //i; # don't want "WHERE" in the subclause
2049 lname => {like => '%son%'},
2050 -nest => \["NOT ($sub_stmt)" => @sub_bind],
2055 $stmt = "lname LIKE ? AND NOT ( age < ? OR age > ? )"
2056 @bind = ('%son%', 10, 20)
2062 These pages could go on for a while, since the nesting of the data
2063 structures this module can handle are pretty much unlimited (the
2064 module implements the C<WHERE> expansion as a recursive function
2065 internally). Your best bet is to "play around" with the module a
2066 little to see how the data structures behave, and choose the best
2067 format for your data based on that.
2069 And of course, all the values above will probably be replaced with
2070 variables gotten from forms or the command line. After all, if you
2071 knew everything ahead of time, you wouldn't have to worry about
2072 dynamically-generating SQL and could just hardwire it into your
2078 =head1 ORDER BY CLAUSES
2080 Some functions take an order by clause. This can either be a scalar (just a
2081 column name,) a hash of C<< { -desc => 'col' } >> or C<< { -asc => 'col' } >>,
2082 or an array of either of the two previous forms. Examples:
2084 Given | Will Generate
2085 ----------------------------------------------------------
2086 \'colA DESC' | ORDER BY colA DESC
2087 'colA' | ORDER BY colA
2088 [qw/colA colB/] | ORDER BY colA, colB
2089 {-asc => 'colA'} | ORDER BY colA ASC
2090 {-desc => 'colB'} | ORDER BY colB DESC
2092 {-asc => 'colA'}, | ORDER BY colA ASC, colB DESC
2095 [colA => {-asc => 'colB'}] | ORDER BY colA, colB ASC
2096 ==========================================================
2100 =head1 SPECIAL OPERATORS
2102 my $sqlmaker = SQL::Abstract->new(special_ops => [
2105 my ($self, $field, $op, $arg) = @_;
2111 A "special operator" is a SQL syntactic clause that can be
2112 applied to a field, instead of a usual binary operator.
2115 WHERE field IN (?, ?, ?)
2116 WHERE field BETWEEN ? AND ?
2117 WHERE MATCH(field) AGAINST (?, ?)
2119 Special operators IN and BETWEEN are fairly standard and therefore
2120 are builtin within C<SQL::Abstract>. For other operators,
2121 like the MATCH .. AGAINST example above which is
2122 specific to MySQL, you can write your own operator handlers :
2123 supply a C<special_ops> argument to the C<new> method.
2124 That argument takes an arrayref of operator definitions;
2125 each operator definition is a hashref with two entries
2131 the regular expression to match the operator
2135 coderef that will be called when meeting that operator
2136 in the input tree. The coderef will be called with
2137 arguments C<< ($self, $field, $op, $arg) >>, and
2138 should return a C<< ($sql, @bind) >> structure.
2142 For example, here is an implementation
2143 of the MATCH .. AGAINST syntax for MySQL
2145 my $sqlmaker = SQL::Abstract->new(special_ops => [
2147 # special op for MySql MATCH (field) AGAINST(word1, word2, ...)
2148 {regex => qr/^match$/i,
2150 my ($self, $field, $op, $arg) = @_;
2151 $arg = [$arg] if not ref $arg;
2152 my $label = $self->_quote($field);
2153 my ($placeholder) = $self->_convert('?');
2154 my $placeholders = join ", ", (($placeholder) x @$arg);
2155 my $sql = $self->_sqlcase('match') . " ($label) "
2156 . $self->_sqlcase('against') . " ($placeholders) ";
2157 my @bind = $self->_bindtype($field, @$arg);
2158 return ($sql, @bind);
2167 Thanks to some benchmarking by Mark Stosberg, it turns out that
2168 this module is many orders of magnitude faster than using C<DBIx::Abstract>.
2169 I must admit this wasn't an intentional design issue, but it's a
2170 byproduct of the fact that you get to control your C<DBI> handles
2173 To maximize performance, use a code snippet like the following:
2175 # prepare a statement handle using the first row
2176 # and then reuse it for the rest of the rows
2178 for my $href (@array_of_hashrefs) {
2179 $stmt ||= $sql->insert('table', $href);
2180 $sth ||= $dbh->prepare($stmt);
2181 $sth->execute($sql->values($href));
2184 The reason this works is because the keys in your C<$href> are sorted
2185 internally by B<SQL::Abstract>. Thus, as long as your data retains
2186 the same structure, you only have to generate the SQL the first time
2187 around. On subsequent queries, simply use the C<values> function provided
2188 by this module to return your values in the correct order.
2193 If you use my C<CGI::FormBuilder> module at all, you'll hopefully
2194 really like this part (I do, at least). Building up a complex query
2195 can be as simple as the following:
2199 use CGI::FormBuilder;
2202 my $form = CGI::FormBuilder->new(...);
2203 my $sql = SQL::Abstract->new;
2205 if ($form->submitted) {
2206 my $field = $form->field;
2207 my $id = delete $field->{id};
2208 my($stmt, @bind) = $sql->update('table', $field, {id => $id});
2211 Of course, you would still have to connect using C<DBI> to run the
2212 query, but the point is that if you make your form look like your
2213 table, the actual query script can be extremely simplistic.
2215 If you're B<REALLY> lazy (I am), check out C<HTML::QuickTable> for
2216 a fast interface to returning and formatting data. I frequently
2217 use these three modules together to write complex database query
2218 apps in under 50 lines.
2223 Version 1.50 was a major internal refactoring of C<SQL::Abstract>.
2224 Great care has been taken to preserve the I<published> behavior
2225 documented in previous versions in the 1.* family; however,
2226 some features that were previously undocumented, or behaved
2227 differently from the documentation, had to be changed in order
2228 to clarify the semantics. Hence, client code that was relying
2229 on some dark areas of C<SQL::Abstract> v1.*
2230 B<might behave differently> in v1.50.
2232 The main changes are :
2238 support for literal SQL through the C<< \ [$sql, bind] >> syntax.
2242 support for the { operator => \"..." } construct (to embed literal SQL)
2246 support for the { operator => \["...", @bind] } construct (to embed literal SQL with bind values)
2250 optional support for L<array datatypes|/"Inserting and Updating Arrays">
2254 defensive programming : check arguments
2258 fixed bug with global logic, which was previously implemented
2259 through global variables yielding side-effects. Prior versions would
2260 interpret C<< [ {cond1, cond2}, [cond3, cond4] ] >>
2261 as C<< "(cond1 AND cond2) OR (cond3 AND cond4)" >>.
2262 Now this is interpreted
2263 as C<< "(cond1 AND cond2) OR (cond3 OR cond4)" >>.
2268 fixed semantics of _bindtype on array args
2272 dropped the C<_anoncopy> of the %where tree. No longer necessary,
2273 we just avoid shifting arrays within that tree.
2277 dropped the C<_modlogic> function
2283 =head1 ACKNOWLEDGEMENTS
2285 There are a number of individuals that have really helped out with
2286 this module. Unfortunately, most of them submitted bugs via CPAN
2287 so I have no idea who they are! But the people I do know are:
2289 Ash Berlin (order_by hash term support)
2290 Matt Trout (DBIx::Class support)
2291 Mark Stosberg (benchmarking)
2292 Chas Owens (initial "IN" operator support)
2293 Philip Collins (per-field SQL functions)
2294 Eric Kolve (hashref "AND" support)
2295 Mike Fragassi (enhancements to "BETWEEN" and "LIKE")
2296 Dan Kubb (support for "quote_char" and "name_sep")
2297 Guillermo Roditi (patch to cleanup "IN" and "BETWEEN", fix and tests for _order_by)
2298 Laurent Dami (internal refactoring, multiple -nest, extensible list of special operators, literal SQL)
2299 Norbert Buchmuller (support for literal SQL in hashpair, misc. fixes & tests)
2305 L<DBIx::Class>, L<DBIx::Abstract>, L<CGI::FormBuilder>, L<HTML::QuickTable>.
2309 Copyright (c) 2001-2007 Nathan Wiger <nwiger@cpan.org>. All Rights Reserved.
2311 This module is actively maintained by Matt Trout <mst@shadowcatsystems.co.uk>
2313 For support, your best bet is to try the C<DBIx::Class> users mailing list.
2314 While not an official support venue, C<DBIx::Class> makes heavy use of
2315 C<SQL::Abstract>, and as such list members there are very familiar with
2316 how to create queries.
2318 This module is free software; you may copy this under the terms of
2319 the GNU General Public License, or the Artistic License, copies of
2320 which should have accompanied your Perl kit.