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)
509 (defined $v[0] && $v[0] =~ /^ - (?: AND|OR ) $/ix)
513 my @distributed = map { {$k => $_} } @v;
516 $self->_debug("OP($op) reinjected into the distributed array");
517 unshift @distributed, $op;
520 my $logic = $op ? substr($op, 1) : '';
522 return $self->_recurse_where(\@distributed, $logic);
525 # LDNOTE : not sure of this one. What does "distribute over nothing" mean?
526 $self->_debug("empty ARRAY($k) means 0=1");
527 return ($self->{sqlfalse});
531 sub _where_hashpair_HASHREF {
532 my ($self, $k, $v, $logic) = @_;
535 my ($all_sql, @all_bind);
537 for my $op (sort keys %$v) {
540 # put the operator in canonical form
541 $op =~ s/^-//; # remove initial dash
542 $op =~ tr/_/ /; # underscores become spaces
543 $op =~ s/^\s+//; # no initial space
544 $op =~ s/\s+$//; # no final space
545 $op =~ s/\s+/ /; # multiple spaces become one
549 # CASE: special operators like -in or -between
550 my $special_op = first {$op =~ $_->{regex}} @{$self->{special_ops}};
552 ($sql, @bind) = $special_op->{handler}->($self, $k, $op, $val);
555 $self->_SWITCH_refkind($val, {
557 ARRAYREF => sub { # CASE: col => {op => \@vals}
558 ($sql, @bind) = $self->_where_field_op_ARRAYREF($k, $op, $val);
561 SCALARREF => sub { # CASE: col => {op => \$scalar} (literal SQL without bind)
562 $sql = join ' ', $self->_convert($self->_quote($k)),
563 $self->_sqlcase($op),
567 ARRAYREFREF => sub { # CASE: col => {op => \[$sql, @bind]} (literal SQL with bind)
568 my ($sub_sql, @sub_bind) = @$$val;
569 $self->_assert_bindval_matches_bindtype(@sub_bind);
570 $sql = join ' ', $self->_convert($self->_quote($k)),
571 $self->_sqlcase($op),
577 ($sql, @bind) = $self->_where_hashpair_HASHREF($k, $val, $op);
580 UNDEF => sub { # CASE: col => {op => undef} : sql "IS (NOT)? NULL"
581 my $is = ($op =~ $self->{equality_op}) ? 'is' :
582 ($op =~ $self->{inequality_op}) ? 'is not' :
583 puke "unexpected operator '$op' with undef operand";
584 $sql = $self->_quote($k) . $self->_sqlcase(" $is null");
587 FALLBACK => sub { # CASE: col => {op => $scalar}
588 $sql = join ' ', $self->_convert($self->_quote($k)),
589 $self->_sqlcase($op),
590 $self->_convert('?');
591 @bind = $self->_bindtype($k, $val);
596 ($all_sql) = (defined $all_sql and $all_sql) ? $self->_join_sql_clauses($logic, [$all_sql, $sql], []) : $sql;
597 push @all_bind, @bind;
599 return ($all_sql, @all_bind);
604 sub _where_field_op_ARRAYREF {
605 my ($self, $k, $op, $vals) = @_;
608 $self->_debug("ARRAY($vals) means multiple elements: [ @$vals ]");
610 # see if the first element is an -and/-or op
612 if ($vals->[0] =~ /^ - ( AND|OR ) $/ix) {
617 # distribute $op over each remaining member of @$vals, append logic if exists
618 return $self->_recurse_where([map { {$k => {$op, $_}} } @$vals], $logic);
620 # LDNOTE : had planned to change the distribution logic when
621 # $op =~ $self->{inequality_op}, because of Morgan laws :
622 # with {field => {'!=' => [22, 33]}}, it would be ridiculous to generate
623 # WHERE field != 22 OR field != 33 : the user probably means
624 # WHERE field != 22 AND field != 33.
625 # To do this, replace the above to roughly :
626 # my $logic = ($op =~ $self->{inequality_op}) ? 'AND' : 'OR';
627 # return $self->_recurse_where([map { {$k => {$op, $_}} } @$vals], $logic);
631 # try to DWIM on equality operators
632 # LDNOTE : not 100% sure this is the correct thing to do ...
633 return ($self->{sqlfalse}) if $op =~ $self->{equality_op};
634 return ($self->{sqltrue}) if $op =~ $self->{inequality_op};
637 puke "operator '$op' applied on an empty array (field '$k')";
642 sub _where_hashpair_SCALARREF {
643 my ($self, $k, $v) = @_;
644 $self->_debug("SCALAR($k) means literal SQL: $$v");
645 my $sql = $self->_quote($k) . " " . $$v;
649 # literal SQL with bind
650 sub _where_hashpair_ARRAYREFREF {
651 my ($self, $k, $v) = @_;
652 $self->_debug("REF($k) means literal SQL: @${$v}");
653 my ($sql, @bind) = @${$v};
654 $self->_assert_bindval_matches_bindtype(@bind);
655 $sql = $self->_quote($k) . " " . $sql;
656 return ($sql, @bind );
659 # literal SQL without bind
660 sub _where_hashpair_SCALAR {
661 my ($self, $k, $v) = @_;
662 $self->_debug("NOREF($k) means simple key=val: $k $self->{cmp} $v");
663 my $sql = join ' ', $self->_convert($self->_quote($k)),
664 $self->_sqlcase($self->{cmp}),
665 $self->_convert('?');
666 my @bind = $self->_bindtype($k, $v);
667 return ( $sql, @bind);
671 sub _where_hashpair_UNDEF {
672 my ($self, $k, $v) = @_;
673 $self->_debug("UNDEF($k) means IS NULL");
674 my $sql = $self->_quote($k) . $self->_sqlcase(' is null');
678 #======================================================================
679 # WHERE: TOP-LEVEL OTHERS (SCALARREF, SCALAR, UNDEF)
680 #======================================================================
683 sub _where_SCALARREF {
684 my ($self, $where) = @_;
687 $self->_debug("SCALAR(*top) means literal SQL: $$where");
693 my ($self, $where) = @_;
696 $self->_debug("NOREF(*top) means literal SQL: $where");
707 #======================================================================
708 # WHERE: BUILTIN SPECIAL OPERATORS (-in, -between)
709 #======================================================================
712 sub _where_field_BETWEEN {
713 my ($self, $k, $op, $vals) = @_;
715 (ref $vals eq 'ARRAY' && @$vals == 2) or
716 (ref $vals eq 'REF' && (@$$vals == 1 || @$$vals == 2 || @$$vals == 3))
717 or puke "special op 'between' requires an arrayref of two values (or a scalarref or arrayrefref for literal SQL)";
719 my ($clause, @bind, $label, $and, $placeholder);
720 $label = $self->_convert($self->_quote($k));
721 $and = ' ' . $self->_sqlcase('and') . ' ';
722 $placeholder = $self->_convert('?');
723 $op = $self->_sqlcase($op);
725 if (ref $vals eq 'REF') {
726 ($clause, @bind) = @$$vals;
729 my (@all_sql, @all_bind);
731 foreach my $val (@$vals) {
732 my ($sql, @bind) = $self->_SWITCH_refkind($val, {
734 return ($placeholder, ($val));
737 return ($self->_convert($$val), ());
741 push @all_bind, @bind;
744 $clause = (join $and, @all_sql);
745 @bind = $self->_bindtype($k, @all_bind);
747 my $sql = "( $label $op $clause )";
752 sub _where_field_IN {
753 my ($self, $k, $op, $vals) = @_;
755 # backwards compatibility : if scalar, force into an arrayref
756 $vals = [$vals] if defined $vals && ! ref $vals;
758 my ($label) = $self->_convert($self->_quote($k));
759 my ($placeholder) = $self->_convert('?');
760 $op = $self->_sqlcase($op);
762 my ($sql, @bind) = $self->_SWITCH_refkind($vals, {
763 ARRAYREF => sub { # list of choices
764 if (@$vals) { # nonempty list
765 my $placeholders = join ", ", (($placeholder) x @$vals);
766 my $sql = "$label $op ( $placeholders )";
767 my @bind = $self->_bindtype($k, @$vals);
769 return ($sql, @bind);
771 else { # empty list : some databases won't understand "IN ()", so DWIM
772 my $sql = ($op =~ /\bnot\b/i) ? $self->{sqltrue} : $self->{sqlfalse};
777 ARRAYREFREF => sub { # literal SQL with bind
778 my ($sql, @bind) = @$$vals;
779 $self->_assert_bindval_matches_bindtype(@bind);
780 return ("$label $op ( $sql )", @bind);
784 puke "special op 'in' requires an arrayref (or arrayref-ref)";
788 return ($sql, @bind);
796 #======================================================================
798 #======================================================================
801 my ($self, $arg) = @_;
803 # construct list of ordering instructions
804 my @order = $self->_SWITCH_refkind($arg, {
807 map {$self->_SWITCH_refkind($_, {
808 SCALAR => sub {$self->_quote($_)},
810 SCALARREF => sub {$$_}, # literal SQL, no quoting
811 HASHREF => sub {$self->_order_by_hash($_)}
815 SCALAR => sub {$self->_quote($arg)},
817 SCALARREF => sub {$$arg}, # literal SQL, no quoting
818 HASHREF => sub {$self->_order_by_hash($arg)},
823 my $order = join ', ', @order;
824 return $order ? $self->_sqlcase(' order by')." $order" : '';
829 my ($self, $hash) = @_;
831 # get first pair in hash
832 my ($key, $val) = each %$hash;
834 # check if one pair was found and no other pair in hash
835 $key && !(each %$hash)
836 or puke "hash passed to _order_by must have exactly one key (-desc or -asc)";
838 my ($order) = ($key =~ /^-(desc|asc)/i)
839 or puke "invalid key in _order_by hash : $key";
841 $val = ref $val eq 'ARRAY' ? $val : [$val];
842 return join ', ', map { $self->_quote($_) . ' ' . $self->_sqlcase($order) } @$val;
847 #======================================================================
848 # DATASOURCE (FOR NOW, JUST PLAIN TABLE OR LIST OF TABLES)
849 #======================================================================
854 $self->_SWITCH_refkind($from, {
855 ARRAYREF => sub {join ', ', map { $self->_quote($_) } @$from;},
856 SCALAR => sub {$self->_quote($from)},
857 SCALARREF => sub {$$from},
858 ARRAYREFREF => sub {join ', ', @$from;},
863 #======================================================================
865 #======================================================================
871 $label or puke "can't quote an empty label";
873 # left and right quote characters
874 my ($ql, $qr, @other) = $self->_SWITCH_refkind($self->{quote_char}, {
875 SCALAR => sub {($self->{quote_char}, $self->{quote_char})},
876 ARRAYREF => sub {@{$self->{quote_char}}},
880 or puke "quote_char must be an arrayref of 2 values";
882 # no quoting if no quoting chars
883 $ql or return $label;
885 # no quoting for literal SQL
886 return $$label if ref($label) eq 'SCALAR';
888 # separate table / column (if applicable)
889 my $sep = $self->{name_sep} || '';
890 my @to_quote = $sep ? split /\Q$sep\E/, $label : ($label);
892 # do the quoting, except for "*" or for `table`.*
893 my @quoted = map { $_ eq '*' ? $_: $ql.$_.$qr} @to_quote;
895 # reassemble and return.
896 return join $sep, @quoted;
900 # Conversion, if applicable
902 my ($self, $arg) = @_;
904 # LDNOTE : modified the previous implementation below because
905 # it was not consistent : the first "return" is always an array,
906 # the second "return" is context-dependent. Anyway, _convert
907 # seems always used with just a single argument, so make it a
909 # return @_ unless $self->{convert};
910 # my $conv = $self->_sqlcase($self->{convert});
911 # my @ret = map { $conv.'('.$_.')' } @_;
912 # return wantarray ? @ret : $ret[0];
913 if ($self->{convert}) {
914 my $conv = $self->_sqlcase($self->{convert});
915 $arg = $conv.'('.$arg.')';
923 my($col, @vals) = @_;
925 #LDNOTE : changed original implementation below because it did not make
926 # sense when bindtype eq 'columns' and @vals > 1.
927 # return $self->{bindtype} eq 'columns' ? [ $col, @vals ] : @vals;
929 return $self->{bindtype} eq 'columns' ? map {[$col, $_]} @vals : @vals;
932 # Dies if any element of @bind is not in [colname => value] format
933 # if bindtype is 'columns'.
934 sub _assert_bindval_matches_bindtype {
935 my ($self, @bind) = @_;
937 if ($self->{bindtype} eq 'columns') {
938 foreach my $val (@bind) {
939 if (!defined $val || ref($val) ne 'ARRAY' || @$val != 2) {
940 die "bindtype 'columns' selected, you need to pass: [column_name => bind_value]"
946 sub _join_sql_clauses {
947 my ($self, $logic, $clauses_aref, $bind_aref) = @_;
949 if (@$clauses_aref > 1) {
950 my $join = " " . $self->_sqlcase($logic) . " ";
951 my $sql = '( ' . join($join, @$clauses_aref) . ' )';
952 return ($sql, @$bind_aref);
954 elsif (@$clauses_aref) {
955 return ($clauses_aref->[0], @$bind_aref); # no parentheses
958 return (); # if no SQL, ignore @$bind_aref
963 # Fix SQL case, if so requested
967 # LDNOTE: if $self->{case} is true, then it contains 'lower', so we
968 # don't touch the argument ... crooked logic, but let's not change it!
969 return $self->{case} ? $_[0] : uc($_[0]);
973 #======================================================================
974 # DISPATCHING FROM REFKIND
975 #======================================================================
978 my ($self, $data) = @_;
984 # blessed objects are treated like scalars
985 $ref = (blessed $data) ? '' : ref $data;
986 $n_steps += 1 if $ref;
987 last if $ref ne 'REF';
991 my $base = $ref || (defined $data ? 'SCALAR' : 'UNDEF');
993 return $base . ('REF' x $n_steps);
999 my ($self, $data) = @_;
1000 my @try = ($self->_refkind($data));
1001 push @try, 'SCALAR_or_UNDEF' if $try[0] eq 'SCALAR' || $try[0] eq 'UNDEF';
1002 push @try, 'FALLBACK';
1006 sub _METHOD_FOR_refkind {
1007 my ($self, $meth_prefix, $data) = @_;
1008 my $method = first {$_} map {$self->can($meth_prefix."_".$_)}
1009 $self->_try_refkind($data)
1010 or puke "cannot dispatch on '$meth_prefix' for ".$self->_refkind($data);
1015 sub _SWITCH_refkind {
1016 my ($self, $data, $dispatch_table) = @_;
1018 my $coderef = first {$_} map {$dispatch_table->{$_}}
1019 $self->_try_refkind($data)
1020 or puke "no dispatch entry for ".$self->_refkind($data);
1027 #======================================================================
1028 # VALUES, GENERATE, AUTOLOAD
1029 #======================================================================
1031 # LDNOTE: original code from nwiger, didn't touch code in that section
1032 # I feel the AUTOLOAD stuff should not be the default, it should
1033 # only be activated on explicit demand by user.
1037 my $data = shift || return;
1038 puke "Argument to ", __PACKAGE__, "->values must be a \\%hash"
1039 unless ref $data eq 'HASH';
1042 foreach my $k ( sort keys %$data ) {
1043 my $v = $data->{$k};
1044 $self->_SWITCH_refkind($v, {
1046 if ($self->{array_datatypes}) { # array datatype
1047 push @all_bind, $self->_bindtype($k, $v);
1049 else { # literal SQL with bind
1050 my ($sql, @bind) = @$v;
1051 $self->_assert_bindval_matches_bindtype(@bind);
1052 push @all_bind, @bind;
1055 ARRAYREFREF => sub { # literal SQL with bind
1056 my ($sql, @bind) = @${$v};
1057 $self->_assert_bindval_matches_bindtype(@bind);
1058 push @all_bind, @bind;
1060 SCALARREF => sub { # literal SQL without bind
1062 SCALAR_or_UNDEF => sub {
1063 push @all_bind, $self->_bindtype($k, $v);
1074 my(@sql, @sqlq, @sqlv);
1078 if ($ref eq 'HASH') {
1079 for my $k (sort keys %$_) {
1082 my $label = $self->_quote($k);
1083 if ($r eq 'ARRAY') {
1084 # literal SQL with bind
1085 my ($sql, @bind) = @$v;
1086 $self->_assert_bindval_matches_bindtype(@bind);
1087 push @sqlq, "$label = $sql";
1089 } elsif ($r eq 'SCALAR') {
1090 # literal SQL without bind
1091 push @sqlq, "$label = $$v";
1093 push @sqlq, "$label = ?";
1094 push @sqlv, $self->_bindtype($k, $v);
1097 push @sql, $self->_sqlcase('set'), join ', ', @sqlq;
1098 } elsif ($ref eq 'ARRAY') {
1099 # unlike insert(), assume these are ONLY the column names, i.e. for SQL
1102 if ($r eq 'ARRAY') { # literal SQL with bind
1103 my ($sql, @bind) = @$v;
1104 $self->_assert_bindval_matches_bindtype(@bind);
1107 } elsif ($r eq 'SCALAR') { # literal SQL without bind
1108 # embedded literal SQL
1115 push @sql, '(' . join(', ', @sqlq) . ')';
1116 } elsif ($ref eq 'SCALAR') {
1120 # strings get case twiddled
1121 push @sql, $self->_sqlcase($_);
1125 my $sql = join ' ', @sql;
1127 # this is pretty tricky
1128 # if ask for an array, return ($stmt, @bind)
1129 # otherwise, s/?/shift @sqlv/ to put it inline
1131 return ($sql, @sqlv);
1133 1 while $sql =~ s/\?/my $d = shift(@sqlv);
1134 ref $d ? $d->[1] : $d/e;
1143 # This allows us to check for a local, then _form, attr
1145 my($name) = $AUTOLOAD =~ /.*::(.+)/;
1146 return $self->generate($name, @_);
1157 SQL::Abstract - Generate SQL from Perl data structures
1163 my $sql = SQL::Abstract->new;
1165 my($stmt, @bind) = $sql->select($table, \@fields, \%where, \@order);
1167 my($stmt, @bind) = $sql->insert($table, \%fieldvals || \@values);
1169 my($stmt, @bind) = $sql->update($table, \%fieldvals, \%where);
1171 my($stmt, @bind) = $sql->delete($table, \%where);
1173 # Then, use these in your DBI statements
1174 my $sth = $dbh->prepare($stmt);
1175 $sth->execute(@bind);
1177 # Just generate the WHERE clause
1178 my($stmt, @bind) = $sql->where(\%where, \@order);
1180 # Return values in the same order, for hashed queries
1181 # See PERFORMANCE section for more details
1182 my @bind = $sql->values(\%fieldvals);
1186 This module was inspired by the excellent L<DBIx::Abstract>.
1187 However, in using that module I found that what I really wanted
1188 to do was generate SQL, but still retain complete control over my
1189 statement handles and use the DBI interface. So, I set out to
1190 create an abstract SQL generation module.
1192 While based on the concepts used by L<DBIx::Abstract>, there are
1193 several important differences, especially when it comes to WHERE
1194 clauses. I have modified the concepts used to make the SQL easier
1195 to generate from Perl data structures and, IMO, more intuitive.
1196 The underlying idea is for this module to do what you mean, based
1197 on the data structures you provide it. The big advantage is that
1198 you don't have to modify your code every time your data changes,
1199 as this module figures it out.
1201 To begin with, an SQL INSERT is as easy as just specifying a hash
1202 of C<key=value> pairs:
1205 name => 'Jimbo Bobson',
1206 phone => '123-456-7890',
1207 address => '42 Sister Lane',
1208 city => 'St. Louis',
1209 state => 'Louisiana',
1212 The SQL can then be generated with this:
1214 my($stmt, @bind) = $sql->insert('people', \%data);
1216 Which would give you something like this:
1218 $stmt = "INSERT INTO people
1219 (address, city, name, phone, state)
1220 VALUES (?, ?, ?, ?, ?)";
1221 @bind = ('42 Sister Lane', 'St. Louis', 'Jimbo Bobson',
1222 '123-456-7890', 'Louisiana');
1224 These are then used directly in your DBI code:
1226 my $sth = $dbh->prepare($stmt);
1227 $sth->execute(@bind);
1229 =head2 Inserting and Updating Arrays
1231 If your database has array types (like for example Postgres),
1232 activate the special option C<< array_datatypes => 1 >>
1233 when creating the C<SQL::Abstract> object.
1234 Then you may use an arrayref to insert and update database array types:
1236 my $sql = SQL::Abstract->new(array_datatypes => 1);
1238 planets => [qw/Mercury Venus Earth Mars/]
1241 my($stmt, @bind) = $sql->insert('solar_system', \%data);
1245 $stmt = "INSERT INTO solar_system (planets) VALUES (?)"
1247 @bind = (['Mercury', 'Venus', 'Earth', 'Mars']);
1250 =head2 Inserting and Updating SQL
1252 In order to apply SQL functions to elements of your C<%data> you may
1253 specify a reference to an arrayref for the given hash value. For example,
1254 if you need to execute the Oracle C<to_date> function on a value, you can
1255 say something like this:
1259 date_entered => \["to_date(?,'MM/DD/YYYY')", "03/02/2003"],
1262 The first value in the array is the actual SQL. Any other values are
1263 optional and would be included in the bind values array. This gives
1266 my($stmt, @bind) = $sql->insert('people', \%data);
1268 $stmt = "INSERT INTO people (name, date_entered)
1269 VALUES (?, to_date(?,'MM/DD/YYYY'))";
1270 @bind = ('Bill', '03/02/2003');
1272 An UPDATE is just as easy, all you change is the name of the function:
1274 my($stmt, @bind) = $sql->update('people', \%data);
1276 Notice that your C<%data> isn't touched; the module will generate
1277 the appropriately quirky SQL for you automatically. Usually you'll
1278 want to specify a WHERE clause for your UPDATE, though, which is
1279 where handling C<%where> hashes comes in handy...
1281 =head2 Complex where statements
1283 This module can generate pretty complicated WHERE statements
1284 easily. For example, simple C<key=value> pairs are taken to mean
1285 equality, and if you want to see if a field is within a set
1286 of values, you can use an arrayref. Let's say we wanted to
1287 SELECT some data based on this criteria:
1290 requestor => 'inna',
1291 worker => ['nwiger', 'rcwe', 'sfz'],
1292 status => { '!=', 'completed' }
1295 my($stmt, @bind) = $sql->select('tickets', '*', \%where);
1297 The above would give you something like this:
1299 $stmt = "SELECT * FROM tickets WHERE
1300 ( requestor = ? ) AND ( status != ? )
1301 AND ( worker = ? OR worker = ? OR worker = ? )";
1302 @bind = ('inna', 'completed', 'nwiger', 'rcwe', 'sfz');
1304 Which you could then use in DBI code like so:
1306 my $sth = $dbh->prepare($stmt);
1307 $sth->execute(@bind);
1313 The functions are simple. There's one for each major SQL operation,
1314 and a constructor you use first. The arguments are specified in a
1315 similar order to each function (table, then fields, then a where
1316 clause) to try and simplify things.
1321 =head2 new(option => 'value')
1323 The C<new()> function takes a list of options and values, and returns
1324 a new B<SQL::Abstract> object which can then be used to generate SQL
1325 through the methods below. The options accepted are:
1331 If set to 'lower', then SQL will be generated in all lowercase. By
1332 default SQL is generated in "textbook" case meaning something like:
1334 SELECT a_field FROM a_table WHERE some_field LIKE '%someval%'
1336 Any setting other than 'lower' is ignored.
1340 This determines what the default comparison operator is. By default
1341 it is C<=>, meaning that a hash like this:
1343 %where = (name => 'nwiger', email => 'nate@wiger.org');
1345 Will generate SQL like this:
1347 WHERE name = 'nwiger' AND email = 'nate@wiger.org'
1349 However, you may want loose comparisons by default, so if you set
1350 C<cmp> to C<like> you would get SQL such as:
1352 WHERE name like 'nwiger' AND email like 'nate@wiger.org'
1354 You can also override the comparsion on an individual basis - see
1355 the huge section on L</"WHERE CLAUSES"> at the bottom.
1357 =item sqltrue, sqlfalse
1359 Expressions for inserting boolean values within SQL statements.
1360 By default these are C<1=1> and C<1=0>. They are used
1361 by the special operators C<-in> and C<-not_in> for generating
1362 correct SQL even when the argument is an empty array (see below).
1366 This determines the default logical operator for multiple WHERE
1367 statements in arrays or hashes. If absent, the default logic is "or"
1368 for arrays, and "and" for hashes. This means that a WHERE
1372 event_date => {'>=', '2/13/99'},
1373 event_date => {'<=', '4/24/03'},
1376 will generate SQL like this:
1378 WHERE event_date >= '2/13/99' OR event_date <= '4/24/03'
1380 This is probably not what you want given this query, though (look
1381 at the dates). To change the "OR" to an "AND", simply specify:
1383 my $sql = SQL::Abstract->new(logic => 'and');
1385 Which will change the above C<WHERE> to:
1387 WHERE event_date >= '2/13/99' AND event_date <= '4/24/03'
1389 The logic can also be changed locally by inserting
1390 a modifier in front of an arrayref :
1392 @where = (-and => [event_date => {'>=', '2/13/99'},
1393 event_date => {'<=', '4/24/03'} ]);
1395 See the L</"WHERE CLAUSES"> section for explanations.
1399 This will automatically convert comparisons using the specified SQL
1400 function for both column and value. This is mostly used with an argument
1401 of C<upper> or C<lower>, so that the SQL will have the effect of
1402 case-insensitive "searches". For example, this:
1404 $sql = SQL::Abstract->new(convert => 'upper');
1405 %where = (keywords => 'MaKe iT CAse inSeNSItive');
1407 Will turn out the following SQL:
1409 WHERE upper(keywords) like upper('MaKe iT CAse inSeNSItive')
1411 The conversion can be C<upper()>, C<lower()>, or any other SQL function
1412 that can be applied symmetrically to fields (actually B<SQL::Abstract> does
1413 not validate this option; it will just pass through what you specify verbatim).
1417 This is a kludge because many databases suck. For example, you can't
1418 just bind values using DBI's C<execute()> for Oracle C<CLOB> or C<BLOB> fields.
1419 Instead, you have to use C<bind_param()>:
1421 $sth->bind_param(1, 'reg data');
1422 $sth->bind_param(2, $lots, {ora_type => ORA_CLOB});
1424 The problem is, B<SQL::Abstract> will normally just return a C<@bind> array,
1425 which loses track of which field each slot refers to. Fear not.
1427 If you specify C<bindtype> in new, you can determine how C<@bind> is returned.
1428 Currently, you can specify either C<normal> (default) or C<columns>. If you
1429 specify C<columns>, you will get an array that looks like this:
1431 my $sql = SQL::Abstract->new(bindtype => 'columns');
1432 my($stmt, @bind) = $sql->insert(...);
1435 [ 'column1', 'value1' ],
1436 [ 'column2', 'value2' ],
1437 [ 'column3', 'value3' ],
1440 You can then iterate through this manually, using DBI's C<bind_param()>.
1442 $sth->prepare($stmt);
1445 my($col, $data) = @$_;
1446 if ($col eq 'details' || $col eq 'comments') {
1447 $sth->bind_param($i, $data, {ora_type => ORA_CLOB});
1448 } elsif ($col eq 'image') {
1449 $sth->bind_param($i, $data, {ora_type => ORA_BLOB});
1451 $sth->bind_param($i, $data);
1455 $sth->execute; # execute without @bind now
1457 Now, why would you still use B<SQL::Abstract> if you have to do this crap?
1458 Basically, the advantage is still that you don't have to care which fields
1459 are or are not included. You could wrap that above C<for> loop in a simple
1460 sub called C<bind_fields()> or something and reuse it repeatedly. You still
1461 get a layer of abstraction over manual SQL specification.
1463 Note that if you set L</bindtype> to C<columns>, the C<\[$sql, @bind]>
1464 construct (see L</Literal SQL with placeholders and bind values (subqueries)>)
1465 will expect the bind values in this format.
1469 This is the character that a table or column name will be quoted
1470 with. By default this is an empty string, but you could set it to
1471 the character C<`>, to generate SQL like this:
1473 SELECT `a_field` FROM `a_table` WHERE `some_field` LIKE '%someval%'
1475 Alternatively, you can supply an array ref of two items, the first being the left
1476 hand quote character, and the second the right hand quote character. For
1477 example, you could supply C<['[',']']> for SQL Server 2000 compliant quotes
1478 that generates SQL like this:
1480 SELECT [a_field] FROM [a_table] WHERE [some_field] LIKE '%someval%'
1482 Quoting is useful if you have tables or columns names that are reserved
1483 words in your database's SQL dialect.
1487 This is the character that separates a table and column name. It is
1488 necessary to specify this when the C<quote_char> option is selected,
1489 so that tables and column names can be individually quoted like this:
1491 SELECT `table`.`one_field` FROM `table` WHERE `table`.`other_field` = 1
1493 =item array_datatypes
1495 When this option is true, arrayrefs in INSERT or UPDATE are
1496 interpreted as array datatypes and are passed directly
1498 When this option is false, arrayrefs are interpreted
1499 as literal SQL, just like refs to arrayrefs
1500 (but this behavior is for backwards compatibility; when writing
1501 new queries, use the "reference to arrayref" syntax
1507 Takes a reference to a list of "special operators"
1508 to extend the syntax understood by L<SQL::Abstract>.
1509 See section L</"SPECIAL OPERATORS"> for details.
1515 =head2 insert($table, \@values || \%fieldvals)
1517 This is the simplest function. You simply give it a table name
1518 and either an arrayref of values or hashref of field/value pairs.
1519 It returns an SQL INSERT statement and a list of bind values.
1520 See the sections on L</"Inserting and Updating Arrays"> and
1521 L</"Inserting and Updating SQL"> for information on how to insert
1522 with those data types.
1524 =head2 update($table, \%fieldvals, \%where)
1526 This takes a table, hashref of field/value pairs, and an optional
1527 hashref L<WHERE clause|/WHERE CLAUSES>. It returns an SQL UPDATE function and a list
1529 See the sections on L</"Inserting and Updating Arrays"> and
1530 L</"Inserting and Updating SQL"> for information on how to insert
1531 with those data types.
1533 =head2 select($source, $fields, $where, $order)
1535 This returns a SQL SELECT statement and associated list of bind values, as
1536 specified by the arguments :
1542 Specification of the 'FROM' part of the statement.
1543 The argument can be either a plain scalar (interpreted as a table
1544 name, will be quoted), or an arrayref (interpreted as a list
1545 of table names, joined by commas, quoted), or a scalarref
1546 (literal table name, not quoted), or a ref to an arrayref
1547 (list of literal table names, joined by commas, not quoted).
1551 Specification of the list of fields to retrieve from
1553 The argument can be either an arrayref (interpreted as a list
1554 of field names, will be joined by commas and quoted), or a
1555 plain scalar (literal SQL, not quoted).
1556 Please observe that this API is not as flexible as for
1557 the first argument C<$table>, for backwards compatibility reasons.
1561 Optional argument to specify the WHERE part of the query.
1562 The argument is most often a hashref, but can also be
1563 an arrayref or plain scalar --
1564 see section L<WHERE clause|/"WHERE CLAUSES"> for details.
1568 Optional argument to specify the ORDER BY part of the query.
1569 The argument can be a scalar, a hashref or an arrayref
1570 -- see section L<ORDER BY clause|/"ORDER BY CLAUSES">
1576 =head2 delete($table, \%where)
1578 This takes a table name and optional hashref L<WHERE clause|/WHERE CLAUSES>.
1579 It returns an SQL DELETE statement and list of bind values.
1581 =head2 where(\%where, \@order)
1583 This is used to generate just the WHERE clause. For example,
1584 if you have an arbitrary data structure and know what the
1585 rest of your SQL is going to look like, but want an easy way
1586 to produce a WHERE clause, use this. It returns an SQL WHERE
1587 clause and list of bind values.
1590 =head2 values(\%data)
1592 This just returns the values from the hash C<%data>, in the same
1593 order that would be returned from any of the other above queries.
1594 Using this allows you to markedly speed up your queries if you
1595 are affecting lots of rows. See below under the L</"PERFORMANCE"> section.
1597 =head2 generate($any, 'number', $of, \@data, $struct, \%types)
1599 Warning: This is an experimental method and subject to change.
1601 This returns arbitrarily generated SQL. It's a really basic shortcut.
1602 It will return two different things, depending on return context:
1604 my($stmt, @bind) = $sql->generate('create table', \$table, \@fields);
1605 my $stmt_and_val = $sql->generate('create table', \$table, \@fields);
1607 These would return the following:
1609 # First calling form
1610 $stmt = "CREATE TABLE test (?, ?)";
1611 @bind = (field1, field2);
1613 # Second calling form
1614 $stmt_and_val = "CREATE TABLE test (field1, field2)";
1616 Depending on what you're trying to do, it's up to you to choose the correct
1617 format. In this example, the second form is what you would want.
1621 $sql->generate('alter session', { nls_date_format => 'MM/YY' });
1625 ALTER SESSION SET nls_date_format = 'MM/YY'
1627 You get the idea. Strings get their case twiddled, but everything
1628 else remains verbatim.
1633 =head1 WHERE CLAUSES
1637 This module uses a variation on the idea from L<DBIx::Abstract>. It
1638 is B<NOT>, repeat I<not> 100% compatible. B<The main logic of this
1639 module is that things in arrays are OR'ed, and things in hashes
1642 The easiest way to explain is to show lots of examples. After
1643 each C<%where> hash shown, it is assumed you used:
1645 my($stmt, @bind) = $sql->where(\%where);
1647 However, note that the C<%where> hash can be used directly in any
1648 of the other functions as well, as described above.
1650 =head2 Key-value pairs
1652 So, let's get started. To begin, a simple hash:
1656 status => 'completed'
1659 Is converted to SQL C<key = val> statements:
1661 $stmt = "WHERE user = ? AND status = ?";
1662 @bind = ('nwiger', 'completed');
1664 One common thing I end up doing is having a list of values that
1665 a field can be in. To do this, simply specify a list inside of
1670 status => ['assigned', 'in-progress', 'pending'];
1673 This simple code will create the following:
1675 $stmt = "WHERE user = ? AND ( status = ? OR status = ? OR status = ? )";
1676 @bind = ('nwiger', 'assigned', 'in-progress', 'pending');
1678 A field associated to an empty arrayref will be considered a
1679 logical false and will generate 0=1.
1681 =head2 Specific comparison operators
1683 If you want to specify a different type of operator for your comparison,
1684 you can use a hashref for a given column:
1688 status => { '!=', 'completed' }
1691 Which would generate:
1693 $stmt = "WHERE user = ? AND status != ?";
1694 @bind = ('nwiger', 'completed');
1696 To test against multiple values, just enclose the values in an arrayref:
1698 status => { '=', ['assigned', 'in-progress', 'pending'] };
1700 Which would give you:
1702 "WHERE status = ? OR status = ? OR status = ?"
1705 The hashref can also contain multiple pairs, in which case it is expanded
1706 into an C<AND> of its elements:
1710 status => { '!=', 'completed', -not_like => 'pending%' }
1713 # Or more dynamically, like from a form
1714 $where{user} = 'nwiger';
1715 $where{status}{'!='} = 'completed';
1716 $where{status}{'-not_like'} = 'pending%';
1718 # Both generate this
1719 $stmt = "WHERE user = ? AND status != ? AND status NOT LIKE ?";
1720 @bind = ('nwiger', 'completed', 'pending%');
1723 To get an OR instead, you can combine it with the arrayref idea:
1727 priority => [ {'=', 2}, {'!=', 1} ]
1730 Which would generate:
1732 $stmt = "WHERE user = ? AND priority = ? OR priority != ?";
1733 @bind = ('nwiger', '2', '1');
1735 If you want to include literal SQL (with or without bind values), just use a
1736 scalar reference or array reference as the value:
1739 date_entered => { '>' => \["to_date(?, 'MM/DD/YYYY')", "11/26/2008"] },
1740 date_expires => { '<' => \"now()" }
1743 Which would generate:
1745 $stmt = "WHERE date_entered > "to_date(?, 'MM/DD/YYYY') AND date_expires < now()";
1746 @bind = ('11/26/2008');
1749 =head2 Logic and nesting operators
1751 In the example above,
1752 there is a subtle trap if you want to say something like
1753 this (notice the C<AND>):
1755 WHERE priority != ? AND priority != ?
1757 Because, in Perl you I<can't> do this:
1759 priority => { '!=', 2, '!=', 1 }
1761 As the second C<!=> key will obliterate the first. The solution
1762 is to use the special C<-modifier> form inside an arrayref:
1764 priority => [ -and => {'!=', 2},
1768 Normally, these would be joined by C<OR>, but the modifier tells it
1769 to use C<AND> instead. (Hint: You can use this in conjunction with the
1770 C<logic> option to C<new()> in order to change the way your queries
1771 work by default.) B<Important:> Note that the C<-modifier> goes
1772 B<INSIDE> the arrayref, as an extra first element. This will
1773 B<NOT> do what you think it might:
1775 priority => -and => [{'!=', 2}, {'!=', 1}] # WRONG!
1777 Here is a quick list of equivalencies, since there is some overlap:
1780 status => {'!=', 'completed', 'not like', 'pending%' }
1781 status => [ -and => {'!=', 'completed'}, {'not like', 'pending%'}]
1784 status => {'=', ['assigned', 'in-progress']}
1785 status => [ -or => {'=', 'assigned'}, {'=', 'in-progress'}]
1786 status => [ {'=', 'assigned'}, {'=', 'in-progress'} ]
1790 =head2 Special operators : IN, BETWEEN, etc.
1792 You can also use the hashref format to compare a list of fields using the
1793 C<IN> comparison operator, by specifying the list as an arrayref:
1796 status => 'completed',
1797 reportid => { -in => [567, 2335, 2] }
1800 Which would generate:
1802 $stmt = "WHERE status = ? AND reportid IN (?,?,?)";
1803 @bind = ('completed', '567', '2335', '2');
1805 The reverse operator C<-not_in> generates SQL C<NOT IN> and is used in
1808 If the argument to C<-in> is an empty array, 'sqlfalse' is generated
1809 (by default : C<1=0>). Similarly, C<< -not_in => [] >> generates
1810 'sqltrue' (by default : C<1=1>).
1814 Another pair of operators is C<-between> and C<-not_between>,
1815 used with an arrayref of two values:
1819 completion_date => {
1820 -not_between => ['2002-10-01', '2003-02-06']
1826 WHERE user = ? AND completion_date NOT BETWEEN ( ? AND ? )
1828 These are the two builtin "special operators"; but the
1829 list can be expanded : see section L</"SPECIAL OPERATORS"> below.
1831 =head2 Nested conditions, -and/-or prefixes
1833 So far, we've seen how multiple conditions are joined with a top-level
1834 C<AND>. We can change this by putting the different conditions we want in
1835 hashes and then putting those hashes in an array. For example:
1840 status => { -like => ['pending%', 'dispatched'] },
1844 status => 'unassigned',
1848 This data structure would create the following:
1850 $stmt = "WHERE ( user = ? AND ( status LIKE ? OR status LIKE ? ) )
1851 OR ( user = ? AND status = ? ) )";
1852 @bind = ('nwiger', 'pending', 'dispatched', 'robot', 'unassigned');
1855 There is also a special C<-nest>
1856 operator which adds an additional set of parens, to create a subquery.
1857 For example, to get something like this:
1859 $stmt = "WHERE user = ? AND ( workhrs > ? OR geo = ? )";
1860 @bind = ('nwiger', '20', 'ASIA');
1866 -nest => [ workhrs => {'>', 20}, geo => 'ASIA' ],
1870 Finally, clauses in hashrefs or arrayrefs can be
1871 prefixed with an C<-and> or C<-or> to change the logic
1878 -and => [workhrs => {'>', 20}, geo => 'ASIA' ],
1879 -and => [workhrs => {'<', 50}, geo => 'EURO' ]
1886 WHERE ( user = ? AND
1887 ( ( workhrs > ? AND geo = ? )
1888 OR ( workhrs < ? AND geo = ? ) ) )
1891 =head2 Algebraic inconsistency, for historical reasons
1893 C<Important note>: when connecting several conditions, the C<-and->|C<-or>
1894 operator goes C<outside> of the nested structure; whereas when connecting
1895 several constraints on one column, the C<-and> operator goes
1896 C<inside> the arrayref. Here is an example combining both features :
1899 -and => [a => 1, b => 2],
1900 -or => [c => 3, d => 4],
1901 e => [-and => {-like => 'foo%'}, {-like => '%bar'} ]
1906 WHERE ( ( ( a = ? AND b = ? )
1907 OR ( c = ? OR d = ? )
1908 OR ( e LIKE ? AND e LIKE ? ) ) )
1910 This difference in syntax is unfortunate but must be preserved for
1911 historical reasons. So be careful : the two examples below would
1912 seem algebraically equivalent, but they are not
1914 {col => [-and => {-like => 'foo%'}, {-like => '%bar'}]}
1915 # yields : WHERE ( ( col LIKE ? AND col LIKE ? ) )
1917 [-and => {col => {-like => 'foo%'}, {col => {-like => '%bar'}}]]
1918 # yields : WHERE ( ( col LIKE ? OR col LIKE ? ) )
1923 Finally, sometimes only literal SQL will do. If you want to include
1924 literal SQL verbatim, you can specify it as a scalar reference, namely:
1926 my $inn = 'is Not Null';
1928 priority => { '<', 2 },
1934 $stmt = "WHERE priority < ? AND requestor is Not Null";
1937 Note that in this example, you only get one bind parameter back, since
1938 the verbatim SQL is passed as part of the statement.
1940 Of course, just to prove a point, the above can also be accomplished
1944 priority => { '<', 2 },
1945 requestor => { '!=', undef },
1951 Conditions on boolean columns can be expressed in the
1952 same way, passing a reference to an empty string :
1955 priority => { '<', 2 },
1961 $stmt = "WHERE priority < ? AND is_ready";
1965 =head2 Literal SQL with placeholders and bind values (subqueries)
1967 If the literal SQL to be inserted has placeholders and bind values,
1968 use a reference to an arrayref (yes this is a double reference --
1969 not so common, but perfectly legal Perl). For example, to find a date
1970 in Postgres you can use something like this:
1973 date_column => \[q/= date '2008-09-30' - ?::integer/, 10/]
1978 $stmt = "WHERE ( date_column = date '2008-09-30' - ?::integer )"
1981 Note that you must pass the bind values in the same format as they are returned
1982 by L</where>. That means that if you set L</bindtype> to C<columns>, you must
1983 provide the bind values in the C<< [ column_meta => value ] >> format, where
1984 C<column_meta> is an opaque scalar value; most commonly the column name, but
1985 you can use any scalar value (including references and blessed references),
1986 L<SQL::Abstract> will simply pass it through intact. So if C<bindtype> is set
1987 to C<columns> the above example will look like:
1990 date_column => \[q/= date '2008-09-30' - ?::integer/, [ dummy => 10 ]/]
1993 Literal SQL is especially useful for nesting parenthesized clauses in the
1994 main SQL query. Here is a first example :
1996 my ($sub_stmt, @sub_bind) = ("SELECT c1 FROM t1 WHERE c2 < ? AND c3 LIKE ?",
2000 bar => \["IN ($sub_stmt)" => @sub_bind],
2005 $stmt = "WHERE (foo = ? AND bar IN (SELECT c1 FROM t1
2006 WHERE c2 < ? AND c3 LIKE ?))";
2007 @bind = (1234, 100, "foo%");
2009 Other subquery operators, like for example C<"E<gt> ALL"> or C<"NOT IN">,
2010 are expressed in the same way. Of course the C<$sub_stmt> and
2011 its associated bind values can be generated through a former call
2014 my ($sub_stmt, @sub_bind)
2015 = $sql->select("t1", "c1", {c2 => {"<" => 100},
2016 c3 => {-like => "foo%"}});
2019 bar => \["> ALL ($sub_stmt)" => @sub_bind],
2022 In the examples above, the subquery was used as an operator on a column;
2023 but the same principle also applies for a clause within the main C<%where>
2024 hash, like an EXISTS subquery :
2026 my ($sub_stmt, @sub_bind)
2027 = $sql->select("t1", "*", {c1 => 1, c2 => \"> t0.c0"});
2030 -nest => \["EXISTS ($sub_stmt)" => @sub_bind],
2035 $stmt = "WHERE (foo = ? AND EXISTS (SELECT * FROM t1
2036 WHERE c1 = ? AND c2 > t0.c0))";
2040 Observe that the condition on C<c2> in the subquery refers to
2041 column C<t0.c0> of the main query : this is I<not> a bind
2042 value, so we have to express it through a scalar ref.
2043 Writing C<< c2 => {">" => "t0.c0"} >> would have generated
2044 C<< c2 > ? >> with bind value C<"t0.c0"> ... not exactly
2045 what we wanted here.
2047 Another use of the subquery technique is when some SQL clauses need
2048 parentheses, as it often occurs with some proprietary SQL extensions
2049 like for example fulltext expressions, geospatial expressions,
2050 NATIVE clauses, etc. Here is an example of a fulltext query in MySQL :
2053 -nest => \["MATCH (col1, col2) AGAINST (?)" => qw/apples/]
2056 Finally, here is an example where a subquery is used
2057 for expressing unary negation:
2059 my ($sub_stmt, @sub_bind)
2060 = $sql->where({age => [{"<" => 10}, {">" => 20}]});
2061 $sub_stmt =~ s/^ where //i; # don't want "WHERE" in the subclause
2063 lname => {like => '%son%'},
2064 -nest => \["NOT ($sub_stmt)" => @sub_bind],
2069 $stmt = "lname LIKE ? AND NOT ( age < ? OR age > ? )"
2070 @bind = ('%son%', 10, 20)
2076 These pages could go on for a while, since the nesting of the data
2077 structures this module can handle are pretty much unlimited (the
2078 module implements the C<WHERE> expansion as a recursive function
2079 internally). Your best bet is to "play around" with the module a
2080 little to see how the data structures behave, and choose the best
2081 format for your data based on that.
2083 And of course, all the values above will probably be replaced with
2084 variables gotten from forms or the command line. After all, if you
2085 knew everything ahead of time, you wouldn't have to worry about
2086 dynamically-generating SQL and could just hardwire it into your
2092 =head1 ORDER BY CLAUSES
2094 Some functions take an order by clause. This can either be a scalar (just a
2095 column name,) a hash of C<< { -desc => 'col' } >> or C<< { -asc => 'col' } >>,
2096 or an array of either of the two previous forms. Examples:
2098 Given | Will Generate
2099 ----------------------------------------------------------
2101 \'colA DESC' | ORDER BY colA DESC
2103 'colA' | ORDER BY colA
2105 [qw/colA colB/] | ORDER BY colA, colB
2107 {-asc => 'colA'} | ORDER BY colA ASC
2109 {-desc => 'colB'} | ORDER BY colB DESC
2111 ['colA', {-asc => 'colB'}] | ORDER BY colA, colB ASC
2113 { -asc => [qw/colA colB] } | ORDER BY colA ASC, colB ASC
2116 { -asc => 'colA' }, | ORDER BY colA ASC, colB DESC,
2117 { -desc => [qw/colB/], | colC ASC, colD ASC
2118 { -asc => [qw/colC colD/],|
2120 ===========================================================
2124 =head1 SPECIAL OPERATORS
2126 my $sqlmaker = SQL::Abstract->new(special_ops => [
2129 my ($self, $field, $op, $arg) = @_;
2135 A "special operator" is a SQL syntactic clause that can be
2136 applied to a field, instead of a usual binary operator.
2139 WHERE field IN (?, ?, ?)
2140 WHERE field BETWEEN ? AND ?
2141 WHERE MATCH(field) AGAINST (?, ?)
2143 Special operators IN and BETWEEN are fairly standard and therefore
2144 are builtin within C<SQL::Abstract>. For other operators,
2145 like the MATCH .. AGAINST example above which is
2146 specific to MySQL, you can write your own operator handlers :
2147 supply a C<special_ops> argument to the C<new> method.
2148 That argument takes an arrayref of operator definitions;
2149 each operator definition is a hashref with two entries
2155 the regular expression to match the operator
2159 coderef that will be called when meeting that operator
2160 in the input tree. The coderef will be called with
2161 arguments C<< ($self, $field, $op, $arg) >>, and
2162 should return a C<< ($sql, @bind) >> structure.
2166 For example, here is an implementation
2167 of the MATCH .. AGAINST syntax for MySQL
2169 my $sqlmaker = SQL::Abstract->new(special_ops => [
2171 # special op for MySql MATCH (field) AGAINST(word1, word2, ...)
2172 {regex => qr/^match$/i,
2174 my ($self, $field, $op, $arg) = @_;
2175 $arg = [$arg] if not ref $arg;
2176 my $label = $self->_quote($field);
2177 my ($placeholder) = $self->_convert('?');
2178 my $placeholders = join ", ", (($placeholder) x @$arg);
2179 my $sql = $self->_sqlcase('match') . " ($label) "
2180 . $self->_sqlcase('against') . " ($placeholders) ";
2181 my @bind = $self->_bindtype($field, @$arg);
2182 return ($sql, @bind);
2191 Thanks to some benchmarking by Mark Stosberg, it turns out that
2192 this module is many orders of magnitude faster than using C<DBIx::Abstract>.
2193 I must admit this wasn't an intentional design issue, but it's a
2194 byproduct of the fact that you get to control your C<DBI> handles
2197 To maximize performance, use a code snippet like the following:
2199 # prepare a statement handle using the first row
2200 # and then reuse it for the rest of the rows
2202 for my $href (@array_of_hashrefs) {
2203 $stmt ||= $sql->insert('table', $href);
2204 $sth ||= $dbh->prepare($stmt);
2205 $sth->execute($sql->values($href));
2208 The reason this works is because the keys in your C<$href> are sorted
2209 internally by B<SQL::Abstract>. Thus, as long as your data retains
2210 the same structure, you only have to generate the SQL the first time
2211 around. On subsequent queries, simply use the C<values> function provided
2212 by this module to return your values in the correct order.
2217 If you use my C<CGI::FormBuilder> module at all, you'll hopefully
2218 really like this part (I do, at least). Building up a complex query
2219 can be as simple as the following:
2223 use CGI::FormBuilder;
2226 my $form = CGI::FormBuilder->new(...);
2227 my $sql = SQL::Abstract->new;
2229 if ($form->submitted) {
2230 my $field = $form->field;
2231 my $id = delete $field->{id};
2232 my($stmt, @bind) = $sql->update('table', $field, {id => $id});
2235 Of course, you would still have to connect using C<DBI> to run the
2236 query, but the point is that if you make your form look like your
2237 table, the actual query script can be extremely simplistic.
2239 If you're B<REALLY> lazy (I am), check out C<HTML::QuickTable> for
2240 a fast interface to returning and formatting data. I frequently
2241 use these three modules together to write complex database query
2242 apps in under 50 lines.
2247 Version 1.50 was a major internal refactoring of C<SQL::Abstract>.
2248 Great care has been taken to preserve the I<published> behavior
2249 documented in previous versions in the 1.* family; however,
2250 some features that were previously undocumented, or behaved
2251 differently from the documentation, had to be changed in order
2252 to clarify the semantics. Hence, client code that was relying
2253 on some dark areas of C<SQL::Abstract> v1.*
2254 B<might behave differently> in v1.50.
2256 The main changes are :
2262 support for literal SQL through the C<< \ [$sql, bind] >> syntax.
2266 support for the { operator => \"..." } construct (to embed literal SQL)
2270 support for the { operator => \["...", @bind] } construct (to embed literal SQL with bind values)
2274 optional support for L<array datatypes|/"Inserting and Updating Arrays">
2278 defensive programming : check arguments
2282 fixed bug with global logic, which was previously implemented
2283 through global variables yielding side-effects. Prior versions would
2284 interpret C<< [ {cond1, cond2}, [cond3, cond4] ] >>
2285 as C<< "(cond1 AND cond2) OR (cond3 AND cond4)" >>.
2286 Now this is interpreted
2287 as C<< "(cond1 AND cond2) OR (cond3 OR cond4)" >>.
2292 fixed semantics of _bindtype on array args
2296 dropped the C<_anoncopy> of the %where tree. No longer necessary,
2297 we just avoid shifting arrays within that tree.
2301 dropped the C<_modlogic> function
2307 =head1 ACKNOWLEDGEMENTS
2309 There are a number of individuals that have really helped out with
2310 this module. Unfortunately, most of them submitted bugs via CPAN
2311 so I have no idea who they are! But the people I do know are:
2313 Ash Berlin (order_by hash term support)
2314 Matt Trout (DBIx::Class support)
2315 Mark Stosberg (benchmarking)
2316 Chas Owens (initial "IN" operator support)
2317 Philip Collins (per-field SQL functions)
2318 Eric Kolve (hashref "AND" support)
2319 Mike Fragassi (enhancements to "BETWEEN" and "LIKE")
2320 Dan Kubb (support for "quote_char" and "name_sep")
2321 Guillermo Roditi (patch to cleanup "IN" and "BETWEEN", fix and tests for _order_by)
2322 Laurent Dami (internal refactoring, multiple -nest, extensible list of special operators, literal SQL)
2323 Norbert Buchmuller (support for literal SQL in hashpair, misc. fixes & tests)
2329 L<DBIx::Class>, L<DBIx::Abstract>, L<CGI::FormBuilder>, L<HTML::QuickTable>.
2333 Copyright (c) 2001-2007 Nathan Wiger <nwiger@cpan.org>. All Rights Reserved.
2335 This module is actively maintained by Matt Trout <mst@shadowcatsystems.co.uk>
2337 For support, your best bet is to try the C<DBIx::Class> users mailing list.
2338 While not an official support venue, C<DBIx::Class> makes heavy use of
2339 C<SQL::Abstract>, and as such list members there are very familiar with
2340 how to create queries.
2342 This module is free software; you may copy this under the terms of
2343 the GNU General Public License, or the Artistic License, copies of
2344 which should have accompanied your Perl kit.