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, $logic) = @_;
534 my ($all_sql, @all_bind);
536 for my $op (sort keys %$v) {
539 # put the operator in canonical form
540 $op =~ s/^-//; # remove initial dash
541 $op =~ tr/_/ /; # underscores become spaces
542 $op =~ s/^\s+//; # no initial space
543 $op =~ s/\s+$//; # no final space
544 $op =~ s/\s+/ /; # multiple spaces become one
548 # CASE: special operators like -in or -between
549 my $special_op = first {$op =~ $_->{regex}} @{$self->{special_ops}};
551 ($sql, @bind) = $special_op->{handler}->($self, $k, $op, $val);
554 $self->_SWITCH_refkind($val, {
556 ARRAYREF => sub { # CASE: col => {op => \@vals}
557 ($sql, @bind) = $self->_where_field_op_ARRAYREF($k, $op, $val);
560 SCALARREF => sub { # CASE: col => {op => \$scalar} (literal SQL without bind)
561 $sql = join ' ', $self->_convert($self->_quote($k)),
562 $self->_sqlcase($op),
566 ARRAYREFREF => sub { # CASE: col => {op => \[$sql, @bind]} (literal SQL with bind)
567 my ($sub_sql, @sub_bind) = @$$val;
568 $self->_assert_bindval_matches_bindtype(@sub_bind);
569 $sql = join ' ', $self->_convert($self->_quote($k)),
570 $self->_sqlcase($op),
576 ($sql, @bind) = $self->_where_hashpair_HASHREF($k, $val, $op);
579 UNDEF => sub { # CASE: col => {op => undef} : sql "IS (NOT)? NULL"
580 my $is = ($op =~ $self->{equality_op}) ? 'is' :
581 ($op =~ $self->{inequality_op}) ? 'is not' :
582 puke "unexpected operator '$op' with undef operand";
583 $sql = $self->_quote($k) . $self->_sqlcase(" $is null");
586 FALLBACK => sub { # CASE: col => {op => $scalar}
587 $sql = join ' ', $self->_convert($self->_quote($k)),
588 $self->_sqlcase($op),
589 $self->_convert('?');
590 @bind = $self->_bindtype($k, $val);
595 ($all_sql) = (defined $all_sql and $all_sql) ? $self->_join_sql_clauses($logic, [$all_sql, $sql], []) : $sql;
596 push @all_bind, @bind;
598 return ($all_sql, @all_bind);
603 sub _where_field_op_ARRAYREF {
604 my ($self, $k, $op, $vals) = @_;
607 $self->_debug("ARRAY($vals) means multiple elements: [ @$vals ]");
609 # LDNOTE : had planned to change the distribution logic when
610 # $op =~ $self->{inequality_op}, because of Morgan laws :
611 # with {field => {'!=' => [22, 33]}}, it would be ridiculous to generate
612 # WHERE field != 22 OR field != 33 : the user probably means
613 # WHERE field != 22 AND field != 33.
614 # To do this, replace the line below by :
615 # my $logic = ($op =~ $self->{inequality_op}) ? 'AND' : 'OR';
616 # return $self->_recurse_where([map { {$k => {$op, $_}} } @$vals], $logic);
618 # distribute $op over each member of @$vals
619 return $self->_recurse_where([map { {$k => {$op, $_}} } @$vals]);
622 # try to DWIM on equality operators
623 # LDNOTE : not 100% sure this is the correct thing to do ...
624 return ($self->{sqlfalse}) if $op =~ $self->{equality_op};
625 return ($self->{sqltrue}) if $op =~ $self->{inequality_op};
628 puke "operator '$op' applied on an empty array (field '$k')";
633 sub _where_hashpair_SCALARREF {
634 my ($self, $k, $v) = @_;
635 $self->_debug("SCALAR($k) means literal SQL: $$v");
636 my $sql = $self->_quote($k) . " " . $$v;
640 # literal SQL with bind
641 sub _where_hashpair_ARRAYREFREF {
642 my ($self, $k, $v) = @_;
643 $self->_debug("REF($k) means literal SQL: @${$v}");
644 my ($sql, @bind) = @${$v};
645 $self->_assert_bindval_matches_bindtype(@bind);
646 $sql = $self->_quote($k) . " " . $sql;
647 return ($sql, @bind );
650 # literal SQL without bind
651 sub _where_hashpair_SCALAR {
652 my ($self, $k, $v) = @_;
653 $self->_debug("NOREF($k) means simple key=val: $k $self->{cmp} $v");
654 my $sql = join ' ', $self->_convert($self->_quote($k)),
655 $self->_sqlcase($self->{cmp}),
656 $self->_convert('?');
657 my @bind = $self->_bindtype($k, $v);
658 return ( $sql, @bind);
662 sub _where_hashpair_UNDEF {
663 my ($self, $k, $v) = @_;
664 $self->_debug("UNDEF($k) means IS NULL");
665 my $sql = $self->_quote($k) . $self->_sqlcase(' is null');
669 #======================================================================
670 # WHERE: TOP-LEVEL OTHERS (SCALARREF, SCALAR, UNDEF)
671 #======================================================================
674 sub _where_SCALARREF {
675 my ($self, $where) = @_;
678 $self->_debug("SCALAR(*top) means literal SQL: $$where");
684 my ($self, $where) = @_;
687 $self->_debug("NOREF(*top) means literal SQL: $where");
698 #======================================================================
699 # WHERE: BUILTIN SPECIAL OPERATORS (-in, -between)
700 #======================================================================
703 sub _where_field_BETWEEN {
704 my ($self, $k, $op, $vals) = @_;
706 (ref $vals eq 'ARRAY' && @$vals == 2) or
707 (ref $vals eq 'REF' && (@$$vals == 1 || @$$vals == 2 || @$$vals == 3))
708 or puke "special op 'between' requires an arrayref of two values (or a scalarref or arrayrefref for literal SQL)";
710 my ($clause, @bind, $label, $and, $placeholder);
711 $label = $self->_convert($self->_quote($k));
712 $and = ' ' . $self->_sqlcase('and') . ' ';
713 $placeholder = $self->_convert('?');
714 $op = $self->_sqlcase($op);
716 if (ref $vals eq 'REF') {
717 ($clause, @bind) = @$$vals;
720 my (@all_sql, @all_bind);
722 foreach my $val (@$vals) {
723 my ($sql, @bind) = $self->_SWITCH_refkind($val, {
725 return ($placeholder, ($val));
728 return ($self->_convert($$val), ());
732 push @all_bind, @bind;
735 $clause = (join $and, @all_sql);
736 @bind = $self->_bindtype($k, @all_bind);
738 my $sql = "( $label $op $clause )";
743 sub _where_field_IN {
744 my ($self, $k, $op, $vals) = @_;
746 # backwards compatibility : if scalar, force into an arrayref
747 $vals = [$vals] if defined $vals && ! ref $vals;
749 my ($label) = $self->_convert($self->_quote($k));
750 my ($placeholder) = $self->_convert('?');
751 $op = $self->_sqlcase($op);
753 my ($sql, @bind) = $self->_SWITCH_refkind($vals, {
754 ARRAYREF => sub { # list of choices
755 if (@$vals) { # nonempty list
756 my $placeholders = join ", ", (($placeholder) x @$vals);
757 my $sql = "$label $op ( $placeholders )";
758 my @bind = $self->_bindtype($k, @$vals);
760 return ($sql, @bind);
762 else { # empty list : some databases won't understand "IN ()", so DWIM
763 my $sql = ($op =~ /\bnot\b/i) ? $self->{sqltrue} : $self->{sqlfalse};
768 ARRAYREFREF => sub { # literal SQL with bind
769 my ($sql, @bind) = @$$vals;
770 $self->_assert_bindval_matches_bindtype(@bind);
771 return ("$label $op ( $sql )", @bind);
775 puke "special op 'in' requires an arrayref (or arrayref-ref)";
779 return ($sql, @bind);
787 #======================================================================
789 #======================================================================
792 my ($self, $arg) = @_;
794 # construct list of ordering instructions
795 my @order = $self->_SWITCH_refkind($arg, {
798 map {$self->_SWITCH_refkind($_, {
799 SCALAR => sub {$self->_quote($_)},
801 SCALARREF => sub {$$_}, # literal SQL, no quoting
802 HASHREF => sub {$self->_order_by_hash($_)}
806 SCALAR => sub {$self->_quote($arg)},
808 SCALARREF => sub {$$arg}, # literal SQL, no quoting
809 HASHREF => sub {$self->_order_by_hash($arg)},
814 my $order = join ', ', @order;
815 return $order ? $self->_sqlcase(' order by')." $order" : '';
820 my ($self, $hash) = @_;
822 # get first pair in hash
823 my ($key, $val) = each %$hash;
825 # check if one pair was found and no other pair in hash
826 $key && !(each %$hash)
827 or puke "hash passed to _order_by must have exactly one key (-desc or -asc)";
829 my ($order) = ($key =~ /^-(desc|asc)/i)
830 or puke "invalid key in _order_by hash : $key";
832 return $self->_quote($val) ." ". $self->_sqlcase($order);
837 #======================================================================
838 # DATASOURCE (FOR NOW, JUST PLAIN TABLE OR LIST OF TABLES)
839 #======================================================================
844 $self->_SWITCH_refkind($from, {
845 ARRAYREF => sub {join ', ', map { $self->_quote($_) } @$from;},
846 SCALAR => sub {$self->_quote($from)},
847 SCALARREF => sub {$$from},
848 ARRAYREFREF => sub {join ', ', @$from;},
853 #======================================================================
855 #======================================================================
861 $label or puke "can't quote an empty label";
863 # left and right quote characters
864 my ($ql, $qr, @other) = $self->_SWITCH_refkind($self->{quote_char}, {
865 SCALAR => sub {($self->{quote_char}, $self->{quote_char})},
866 ARRAYREF => sub {@{$self->{quote_char}}},
870 or puke "quote_char must be an arrayref of 2 values";
872 # no quoting if no quoting chars
873 $ql or return $label;
875 # no quoting for literal SQL
876 return $$label if ref($label) eq 'SCALAR';
878 # separate table / column (if applicable)
879 my $sep = $self->{name_sep} || '';
880 my @to_quote = $sep ? split /\Q$sep\E/, $label : ($label);
882 # do the quoting, except for "*" or for `table`.*
883 my @quoted = map { $_ eq '*' ? $_: $ql.$_.$qr} @to_quote;
885 # reassemble and return.
886 return join $sep, @quoted;
890 # Conversion, if applicable
892 my ($self, $arg) = @_;
894 # LDNOTE : modified the previous implementation below because
895 # it was not consistent : the first "return" is always an array,
896 # the second "return" is context-dependent. Anyway, _convert
897 # seems always used with just a single argument, so make it a
899 # return @_ unless $self->{convert};
900 # my $conv = $self->_sqlcase($self->{convert});
901 # my @ret = map { $conv.'('.$_.')' } @_;
902 # return wantarray ? @ret : $ret[0];
903 if ($self->{convert}) {
904 my $conv = $self->_sqlcase($self->{convert});
905 $arg = $conv.'('.$arg.')';
913 my($col, @vals) = @_;
915 #LDNOTE : changed original implementation below because it did not make
916 # sense when bindtype eq 'columns' and @vals > 1.
917 # return $self->{bindtype} eq 'columns' ? [ $col, @vals ] : @vals;
919 return $self->{bindtype} eq 'columns' ? map {[$col, $_]} @vals : @vals;
922 # Dies if any element of @bind is not in [colname => value] format
923 # if bindtype is 'columns'.
924 sub _assert_bindval_matches_bindtype {
925 my ($self, @bind) = @_;
927 if ($self->{bindtype} eq 'columns') {
928 foreach my $val (@bind) {
929 if (!defined $val || ref($val) ne 'ARRAY' || @$val != 2) {
930 die "bindtype 'columns' selected, you need to pass: [column_name => bind_value]"
936 sub _join_sql_clauses {
937 my ($self, $logic, $clauses_aref, $bind_aref) = @_;
939 if (@$clauses_aref > 1) {
940 my $join = " " . $self->_sqlcase($logic) . " ";
941 my $sql = '( ' . join($join, @$clauses_aref) . ' )';
942 return ($sql, @$bind_aref);
944 elsif (@$clauses_aref) {
945 return ($clauses_aref->[0], @$bind_aref); # no parentheses
948 return (); # if no SQL, ignore @$bind_aref
953 # Fix SQL case, if so requested
957 # LDNOTE: if $self->{case} is true, then it contains 'lower', so we
958 # don't touch the argument ... crooked logic, but let's not change it!
959 return $self->{case} ? $_[0] : uc($_[0]);
963 #======================================================================
964 # DISPATCHING FROM REFKIND
965 #======================================================================
968 my ($self, $data) = @_;
974 # blessed objects are treated like scalars
975 $ref = (blessed $data) ? '' : ref $data;
976 $n_steps += 1 if $ref;
977 last if $ref ne 'REF';
981 my $base = $ref || (defined $data ? 'SCALAR' : 'UNDEF');
983 return $base . ('REF' x $n_steps);
989 my ($self, $data) = @_;
990 my @try = ($self->_refkind($data));
991 push @try, 'SCALAR_or_UNDEF' if $try[0] eq 'SCALAR' || $try[0] eq 'UNDEF';
992 push @try, 'FALLBACK';
996 sub _METHOD_FOR_refkind {
997 my ($self, $meth_prefix, $data) = @_;
998 my $method = first {$_} map {$self->can($meth_prefix."_".$_)}
999 $self->_try_refkind($data)
1000 or puke "cannot dispatch on '$meth_prefix' for ".$self->_refkind($data);
1005 sub _SWITCH_refkind {
1006 my ($self, $data, $dispatch_table) = @_;
1008 my $coderef = first {$_} map {$dispatch_table->{$_}}
1009 $self->_try_refkind($data)
1010 or puke "no dispatch entry for ".$self->_refkind($data);
1017 #======================================================================
1018 # VALUES, GENERATE, AUTOLOAD
1019 #======================================================================
1021 # LDNOTE: original code from nwiger, didn't touch code in that section
1022 # I feel the AUTOLOAD stuff should not be the default, it should
1023 # only be activated on explicit demand by user.
1027 my $data = shift || return;
1028 puke "Argument to ", __PACKAGE__, "->values must be a \\%hash"
1029 unless ref $data eq 'HASH';
1032 foreach my $k ( sort keys %$data ) {
1033 my $v = $data->{$k};
1034 $self->_SWITCH_refkind($v, {
1036 if ($self->{array_datatypes}) { # array datatype
1037 push @all_bind, $self->_bindtype($k, $v);
1039 else { # literal SQL with bind
1040 my ($sql, @bind) = @$v;
1041 $self->_assert_bindval_matches_bindtype(@bind);
1042 push @all_bind, @bind;
1045 ARRAYREFREF => sub { # literal SQL with bind
1046 my ($sql, @bind) = @${$v};
1047 $self->_assert_bindval_matches_bindtype(@bind);
1048 push @all_bind, @bind;
1050 SCALARREF => sub { # literal SQL without bind
1052 SCALAR_or_UNDEF => sub {
1053 push @all_bind, $self->_bindtype($k, $v);
1064 my(@sql, @sqlq, @sqlv);
1068 if ($ref eq 'HASH') {
1069 for my $k (sort keys %$_) {
1072 my $label = $self->_quote($k);
1073 if ($r eq 'ARRAY') {
1074 # literal SQL with bind
1075 my ($sql, @bind) = @$v;
1076 $self->_assert_bindval_matches_bindtype(@bind);
1077 push @sqlq, "$label = $sql";
1079 } elsif ($r eq 'SCALAR') {
1080 # literal SQL without bind
1081 push @sqlq, "$label = $$v";
1083 push @sqlq, "$label = ?";
1084 push @sqlv, $self->_bindtype($k, $v);
1087 push @sql, $self->_sqlcase('set'), join ', ', @sqlq;
1088 } elsif ($ref eq 'ARRAY') {
1089 # unlike insert(), assume these are ONLY the column names, i.e. for SQL
1092 if ($r eq 'ARRAY') { # literal SQL with bind
1093 my ($sql, @bind) = @$v;
1094 $self->_assert_bindval_matches_bindtype(@bind);
1097 } elsif ($r eq 'SCALAR') { # literal SQL without bind
1098 # embedded literal SQL
1105 push @sql, '(' . join(', ', @sqlq) . ')';
1106 } elsif ($ref eq 'SCALAR') {
1110 # strings get case twiddled
1111 push @sql, $self->_sqlcase($_);
1115 my $sql = join ' ', @sql;
1117 # this is pretty tricky
1118 # if ask for an array, return ($stmt, @bind)
1119 # otherwise, s/?/shift @sqlv/ to put it inline
1121 return ($sql, @sqlv);
1123 1 while $sql =~ s/\?/my $d = shift(@sqlv);
1124 ref $d ? $d->[1] : $d/e;
1133 # This allows us to check for a local, then _form, attr
1135 my($name) = $AUTOLOAD =~ /.*::(.+)/;
1136 return $self->generate($name, @_);
1147 SQL::Abstract - Generate SQL from Perl data structures
1153 my $sql = SQL::Abstract->new;
1155 my($stmt, @bind) = $sql->select($table, \@fields, \%where, \@order);
1157 my($stmt, @bind) = $sql->insert($table, \%fieldvals || \@values);
1159 my($stmt, @bind) = $sql->update($table, \%fieldvals, \%where);
1161 my($stmt, @bind) = $sql->delete($table, \%where);
1163 # Then, use these in your DBI statements
1164 my $sth = $dbh->prepare($stmt);
1165 $sth->execute(@bind);
1167 # Just generate the WHERE clause
1168 my($stmt, @bind) = $sql->where(\%where, \@order);
1170 # Return values in the same order, for hashed queries
1171 # See PERFORMANCE section for more details
1172 my @bind = $sql->values(\%fieldvals);
1176 This module was inspired by the excellent L<DBIx::Abstract>.
1177 However, in using that module I found that what I really wanted
1178 to do was generate SQL, but still retain complete control over my
1179 statement handles and use the DBI interface. So, I set out to
1180 create an abstract SQL generation module.
1182 While based on the concepts used by L<DBIx::Abstract>, there are
1183 several important differences, especially when it comes to WHERE
1184 clauses. I have modified the concepts used to make the SQL easier
1185 to generate from Perl data structures and, IMO, more intuitive.
1186 The underlying idea is for this module to do what you mean, based
1187 on the data structures you provide it. The big advantage is that
1188 you don't have to modify your code every time your data changes,
1189 as this module figures it out.
1191 To begin with, an SQL INSERT is as easy as just specifying a hash
1192 of C<key=value> pairs:
1195 name => 'Jimbo Bobson',
1196 phone => '123-456-7890',
1197 address => '42 Sister Lane',
1198 city => 'St. Louis',
1199 state => 'Louisiana',
1202 The SQL can then be generated with this:
1204 my($stmt, @bind) = $sql->insert('people', \%data);
1206 Which would give you something like this:
1208 $stmt = "INSERT INTO people
1209 (address, city, name, phone, state)
1210 VALUES (?, ?, ?, ?, ?)";
1211 @bind = ('42 Sister Lane', 'St. Louis', 'Jimbo Bobson',
1212 '123-456-7890', 'Louisiana');
1214 These are then used directly in your DBI code:
1216 my $sth = $dbh->prepare($stmt);
1217 $sth->execute(@bind);
1219 =head2 Inserting and Updating Arrays
1221 If your database has array types (like for example Postgres),
1222 activate the special option C<< array_datatypes => 1 >>
1223 when creating the C<SQL::Abstract> object.
1224 Then you may use an arrayref to insert and update database array types:
1226 my $sql = SQL::Abstract->new(array_datatypes => 1);
1228 planets => [qw/Mercury Venus Earth Mars/]
1231 my($stmt, @bind) = $sql->insert('solar_system', \%data);
1235 $stmt = "INSERT INTO solar_system (planets) VALUES (?)"
1237 @bind = (['Mercury', 'Venus', 'Earth', 'Mars']);
1240 =head2 Inserting and Updating SQL
1242 In order to apply SQL functions to elements of your C<%data> you may
1243 specify a reference to an arrayref for the given hash value. For example,
1244 if you need to execute the Oracle C<to_date> function on a value, you can
1245 say something like this:
1249 date_entered => \["to_date(?,'MM/DD/YYYY')", "03/02/2003"],
1252 The first value in the array is the actual SQL. Any other values are
1253 optional and would be included in the bind values array. This gives
1256 my($stmt, @bind) = $sql->insert('people', \%data);
1258 $stmt = "INSERT INTO people (name, date_entered)
1259 VALUES (?, to_date(?,'MM/DD/YYYY'))";
1260 @bind = ('Bill', '03/02/2003');
1262 An UPDATE is just as easy, all you change is the name of the function:
1264 my($stmt, @bind) = $sql->update('people', \%data);
1266 Notice that your C<%data> isn't touched; the module will generate
1267 the appropriately quirky SQL for you automatically. Usually you'll
1268 want to specify a WHERE clause for your UPDATE, though, which is
1269 where handling C<%where> hashes comes in handy...
1271 =head2 Complex where statements
1273 This module can generate pretty complicated WHERE statements
1274 easily. For example, simple C<key=value> pairs are taken to mean
1275 equality, and if you want to see if a field is within a set
1276 of values, you can use an arrayref. Let's say we wanted to
1277 SELECT some data based on this criteria:
1280 requestor => 'inna',
1281 worker => ['nwiger', 'rcwe', 'sfz'],
1282 status => { '!=', 'completed' }
1285 my($stmt, @bind) = $sql->select('tickets', '*', \%where);
1287 The above would give you something like this:
1289 $stmt = "SELECT * FROM tickets WHERE
1290 ( requestor = ? ) AND ( status != ? )
1291 AND ( worker = ? OR worker = ? OR worker = ? )";
1292 @bind = ('inna', 'completed', 'nwiger', 'rcwe', 'sfz');
1294 Which you could then use in DBI code like so:
1296 my $sth = $dbh->prepare($stmt);
1297 $sth->execute(@bind);
1303 The functions are simple. There's one for each major SQL operation,
1304 and a constructor you use first. The arguments are specified in a
1305 similar order to each function (table, then fields, then a where
1306 clause) to try and simplify things.
1311 =head2 new(option => 'value')
1313 The C<new()> function takes a list of options and values, and returns
1314 a new B<SQL::Abstract> object which can then be used to generate SQL
1315 through the methods below. The options accepted are:
1321 If set to 'lower', then SQL will be generated in all lowercase. By
1322 default SQL is generated in "textbook" case meaning something like:
1324 SELECT a_field FROM a_table WHERE some_field LIKE '%someval%'
1326 Any setting other than 'lower' is ignored.
1330 This determines what the default comparison operator is. By default
1331 it is C<=>, meaning that a hash like this:
1333 %where = (name => 'nwiger', email => 'nate@wiger.org');
1335 Will generate SQL like this:
1337 WHERE name = 'nwiger' AND email = 'nate@wiger.org'
1339 However, you may want loose comparisons by default, so if you set
1340 C<cmp> to C<like> you would get SQL such as:
1342 WHERE name like 'nwiger' AND email like 'nate@wiger.org'
1344 You can also override the comparsion on an individual basis - see
1345 the huge section on L</"WHERE CLAUSES"> at the bottom.
1347 =item sqltrue, sqlfalse
1349 Expressions for inserting boolean values within SQL statements.
1350 By default these are C<1=1> and C<1=0>. They are used
1351 by the special operators C<-in> and C<-not_in> for generating
1352 correct SQL even when the argument is an empty array (see below).
1356 This determines the default logical operator for multiple WHERE
1357 statements in arrays or hashes. If absent, the default logic is "or"
1358 for arrays, and "and" for hashes. This means that a WHERE
1362 event_date => {'>=', '2/13/99'},
1363 event_date => {'<=', '4/24/03'},
1366 will generate SQL like this:
1368 WHERE event_date >= '2/13/99' OR event_date <= '4/24/03'
1370 This is probably not what you want given this query, though (look
1371 at the dates). To change the "OR" to an "AND", simply specify:
1373 my $sql = SQL::Abstract->new(logic => 'and');
1375 Which will change the above C<WHERE> to:
1377 WHERE event_date >= '2/13/99' AND event_date <= '4/24/03'
1379 The logic can also be changed locally by inserting
1380 a modifier in front of an arrayref :
1382 @where = (-and => [event_date => {'>=', '2/13/99'},
1383 event_date => {'<=', '4/24/03'} ]);
1385 See the L</"WHERE CLAUSES"> section for explanations.
1389 This will automatically convert comparisons using the specified SQL
1390 function for both column and value. This is mostly used with an argument
1391 of C<upper> or C<lower>, so that the SQL will have the effect of
1392 case-insensitive "searches". For example, this:
1394 $sql = SQL::Abstract->new(convert => 'upper');
1395 %where = (keywords => 'MaKe iT CAse inSeNSItive');
1397 Will turn out the following SQL:
1399 WHERE upper(keywords) like upper('MaKe iT CAse inSeNSItive')
1401 The conversion can be C<upper()>, C<lower()>, or any other SQL function
1402 that can be applied symmetrically to fields (actually B<SQL::Abstract> does
1403 not validate this option; it will just pass through what you specify verbatim).
1407 This is a kludge because many databases suck. For example, you can't
1408 just bind values using DBI's C<execute()> for Oracle C<CLOB> or C<BLOB> fields.
1409 Instead, you have to use C<bind_param()>:
1411 $sth->bind_param(1, 'reg data');
1412 $sth->bind_param(2, $lots, {ora_type => ORA_CLOB});
1414 The problem is, B<SQL::Abstract> will normally just return a C<@bind> array,
1415 which loses track of which field each slot refers to. Fear not.
1417 If you specify C<bindtype> in new, you can determine how C<@bind> is returned.
1418 Currently, you can specify either C<normal> (default) or C<columns>. If you
1419 specify C<columns>, you will get an array that looks like this:
1421 my $sql = SQL::Abstract->new(bindtype => 'columns');
1422 my($stmt, @bind) = $sql->insert(...);
1425 [ 'column1', 'value1' ],
1426 [ 'column2', 'value2' ],
1427 [ 'column3', 'value3' ],
1430 You can then iterate through this manually, using DBI's C<bind_param()>.
1432 $sth->prepare($stmt);
1435 my($col, $data) = @$_;
1436 if ($col eq 'details' || $col eq 'comments') {
1437 $sth->bind_param($i, $data, {ora_type => ORA_CLOB});
1438 } elsif ($col eq 'image') {
1439 $sth->bind_param($i, $data, {ora_type => ORA_BLOB});
1441 $sth->bind_param($i, $data);
1445 $sth->execute; # execute without @bind now
1447 Now, why would you still use B<SQL::Abstract> if you have to do this crap?
1448 Basically, the advantage is still that you don't have to care which fields
1449 are or are not included. You could wrap that above C<for> loop in a simple
1450 sub called C<bind_fields()> or something and reuse it repeatedly. You still
1451 get a layer of abstraction over manual SQL specification.
1453 Note that if you set L</bindtype> to C<columns>, the C<\[$sql, @bind]>
1454 construct (see L</Literal SQL with placeholders and bind values (subqueries)>)
1455 will expect the bind values in this format.
1459 This is the character that a table or column name will be quoted
1460 with. By default this is an empty string, but you could set it to
1461 the character C<`>, to generate SQL like this:
1463 SELECT `a_field` FROM `a_table` WHERE `some_field` LIKE '%someval%'
1465 Alternatively, you can supply an array ref of two items, the first being the left
1466 hand quote character, and the second the right hand quote character. For
1467 example, you could supply C<['[',']']> for SQL Server 2000 compliant quotes
1468 that generates SQL like this:
1470 SELECT [a_field] FROM [a_table] WHERE [some_field] LIKE '%someval%'
1472 Quoting is useful if you have tables or columns names that are reserved
1473 words in your database's SQL dialect.
1477 This is the character that separates a table and column name. It is
1478 necessary to specify this when the C<quote_char> option is selected,
1479 so that tables and column names can be individually quoted like this:
1481 SELECT `table`.`one_field` FROM `table` WHERE `table`.`other_field` = 1
1483 =item array_datatypes
1485 When this option is true, arrayrefs in INSERT or UPDATE are
1486 interpreted as array datatypes and are passed directly
1488 When this option is false, arrayrefs are interpreted
1489 as literal SQL, just like refs to arrayrefs
1490 (but this behavior is for backwards compatibility; when writing
1491 new queries, use the "reference to arrayref" syntax
1497 Takes a reference to a list of "special operators"
1498 to extend the syntax understood by L<SQL::Abstract>.
1499 See section L</"SPECIAL OPERATORS"> for details.
1505 =head2 insert($table, \@values || \%fieldvals)
1507 This is the simplest function. You simply give it a table name
1508 and either an arrayref of values or hashref of field/value pairs.
1509 It returns an SQL INSERT statement and a list of bind values.
1510 See the sections on L</"Inserting and Updating Arrays"> and
1511 L</"Inserting and Updating SQL"> for information on how to insert
1512 with those data types.
1514 =head2 update($table, \%fieldvals, \%where)
1516 This takes a table, hashref of field/value pairs, and an optional
1517 hashref L<WHERE clause|/WHERE CLAUSES>. It returns an SQL UPDATE function and a list
1519 See the sections on L</"Inserting and Updating Arrays"> and
1520 L</"Inserting and Updating SQL"> for information on how to insert
1521 with those data types.
1523 =head2 select($source, $fields, $where, $order)
1525 This returns a SQL SELECT statement and associated list of bind values, as
1526 specified by the arguments :
1532 Specification of the 'FROM' part of the statement.
1533 The argument can be either a plain scalar (interpreted as a table
1534 name, will be quoted), or an arrayref (interpreted as a list
1535 of table names, joined by commas, quoted), or a scalarref
1536 (literal table name, not quoted), or a ref to an arrayref
1537 (list of literal table names, joined by commas, not quoted).
1541 Specification of the list of fields to retrieve from
1543 The argument can be either an arrayref (interpreted as a list
1544 of field names, will be joined by commas and quoted), or a
1545 plain scalar (literal SQL, not quoted).
1546 Please observe that this API is not as flexible as for
1547 the first argument C<$table>, for backwards compatibility reasons.
1551 Optional argument to specify the WHERE part of the query.
1552 The argument is most often a hashref, but can also be
1553 an arrayref or plain scalar --
1554 see section L<WHERE clause|/"WHERE CLAUSES"> for details.
1558 Optional argument to specify the ORDER BY part of the query.
1559 The argument can be a scalar, a hashref or an arrayref
1560 -- see section L<ORDER BY clause|/"ORDER BY CLAUSES">
1566 =head2 delete($table, \%where)
1568 This takes a table name and optional hashref L<WHERE clause|/WHERE CLAUSES>.
1569 It returns an SQL DELETE statement and list of bind values.
1571 =head2 where(\%where, \@order)
1573 This is used to generate just the WHERE clause. For example,
1574 if you have an arbitrary data structure and know what the
1575 rest of your SQL is going to look like, but want an easy way
1576 to produce a WHERE clause, use this. It returns an SQL WHERE
1577 clause and list of bind values.
1580 =head2 values(\%data)
1582 This just returns the values from the hash C<%data>, in the same
1583 order that would be returned from any of the other above queries.
1584 Using this allows you to markedly speed up your queries if you
1585 are affecting lots of rows. See below under the L</"PERFORMANCE"> section.
1587 =head2 generate($any, 'number', $of, \@data, $struct, \%types)
1589 Warning: This is an experimental method and subject to change.
1591 This returns arbitrarily generated SQL. It's a really basic shortcut.
1592 It will return two different things, depending on return context:
1594 my($stmt, @bind) = $sql->generate('create table', \$table, \@fields);
1595 my $stmt_and_val = $sql->generate('create table', \$table, \@fields);
1597 These would return the following:
1599 # First calling form
1600 $stmt = "CREATE TABLE test (?, ?)";
1601 @bind = (field1, field2);
1603 # Second calling form
1604 $stmt_and_val = "CREATE TABLE test (field1, field2)";
1606 Depending on what you're trying to do, it's up to you to choose the correct
1607 format. In this example, the second form is what you would want.
1611 $sql->generate('alter session', { nls_date_format => 'MM/YY' });
1615 ALTER SESSION SET nls_date_format = 'MM/YY'
1617 You get the idea. Strings get their case twiddled, but everything
1618 else remains verbatim.
1623 =head1 WHERE CLAUSES
1627 This module uses a variation on the idea from L<DBIx::Abstract>. It
1628 is B<NOT>, repeat I<not> 100% compatible. B<The main logic of this
1629 module is that things in arrays are OR'ed, and things in hashes
1632 The easiest way to explain is to show lots of examples. After
1633 each C<%where> hash shown, it is assumed you used:
1635 my($stmt, @bind) = $sql->where(\%where);
1637 However, note that the C<%where> hash can be used directly in any
1638 of the other functions as well, as described above.
1640 =head2 Key-value pairs
1642 So, let's get started. To begin, a simple hash:
1646 status => 'completed'
1649 Is converted to SQL C<key = val> statements:
1651 $stmt = "WHERE user = ? AND status = ?";
1652 @bind = ('nwiger', 'completed');
1654 One common thing I end up doing is having a list of values that
1655 a field can be in. To do this, simply specify a list inside of
1660 status => ['assigned', 'in-progress', 'pending'];
1663 This simple code will create the following:
1665 $stmt = "WHERE user = ? AND ( status = ? OR status = ? OR status = ? )";
1666 @bind = ('nwiger', 'assigned', 'in-progress', 'pending');
1668 A field associated to an empty arrayref will be considered a
1669 logical false and will generate 0=1.
1671 =head2 Specific comparison operators
1673 If you want to specify a different type of operator for your comparison,
1674 you can use a hashref for a given column:
1678 status => { '!=', 'completed' }
1681 Which would generate:
1683 $stmt = "WHERE user = ? AND status != ?";
1684 @bind = ('nwiger', 'completed');
1686 To test against multiple values, just enclose the values in an arrayref:
1688 status => { '=', ['assigned', 'in-progress', 'pending'] };
1690 Which would give you:
1692 "WHERE status = ? OR status = ? OR status = ?"
1695 The hashref can also contain multiple pairs, in which case it is expanded
1696 into an C<AND> of its elements:
1700 status => { '!=', 'completed', -not_like => 'pending%' }
1703 # Or more dynamically, like from a form
1704 $where{user} = 'nwiger';
1705 $where{status}{'!='} = 'completed';
1706 $where{status}{'-not_like'} = 'pending%';
1708 # Both generate this
1709 $stmt = "WHERE user = ? AND status != ? AND status NOT LIKE ?";
1710 @bind = ('nwiger', 'completed', 'pending%');
1713 To get an OR instead, you can combine it with the arrayref idea:
1717 priority => [ {'=', 2}, {'!=', 1} ]
1720 Which would generate:
1722 $stmt = "WHERE user = ? AND priority = ? OR priority != ?";
1723 @bind = ('nwiger', '2', '1');
1725 If you want to include literal SQL (with or without bind values), just use a
1726 scalar reference or array reference as the value:
1729 date_entered => { '>' => \["to_date(?, 'MM/DD/YYYY')", "11/26/2008"] },
1730 date_expires => { '<' => \"now()" }
1733 Which would generate:
1735 $stmt = "WHERE date_entered > "to_date(?, 'MM/DD/YYYY') AND date_expires < now()";
1736 @bind = ('11/26/2008');
1739 =head2 Logic and nesting operators
1741 In the example above,
1742 there is a subtle trap if you want to say something like
1743 this (notice the C<AND>):
1745 WHERE priority != ? AND priority != ?
1747 Because, in Perl you I<can't> do this:
1749 priority => { '!=', 2, '!=', 1 }
1751 As the second C<!=> key will obliterate the first. The solution
1752 is to use the special C<-modifier> form inside an arrayref:
1754 priority => [ -and => {'!=', 2},
1758 Normally, these would be joined by C<OR>, but the modifier tells it
1759 to use C<AND> instead. (Hint: You can use this in conjunction with the
1760 C<logic> option to C<new()> in order to change the way your queries
1761 work by default.) B<Important:> Note that the C<-modifier> goes
1762 B<INSIDE> the arrayref, as an extra first element. This will
1763 B<NOT> do what you think it might:
1765 priority => -and => [{'!=', 2}, {'!=', 1}] # WRONG!
1767 Here is a quick list of equivalencies, since there is some overlap:
1770 status => {'!=', 'completed', 'not like', 'pending%' }
1771 status => [ -and => {'!=', 'completed'}, {'not like', 'pending%'}]
1774 status => {'=', ['assigned', 'in-progress']}
1775 status => [ -or => {'=', 'assigned'}, {'=', 'in-progress'}]
1776 status => [ {'=', 'assigned'}, {'=', 'in-progress'} ]
1780 =head2 Special operators : IN, BETWEEN, etc.
1782 You can also use the hashref format to compare a list of fields using the
1783 C<IN> comparison operator, by specifying the list as an arrayref:
1786 status => 'completed',
1787 reportid => { -in => [567, 2335, 2] }
1790 Which would generate:
1792 $stmt = "WHERE status = ? AND reportid IN (?,?,?)";
1793 @bind = ('completed', '567', '2335', '2');
1795 The reverse operator C<-not_in> generates SQL C<NOT IN> and is used in
1798 If the argument to C<-in> is an empty array, 'sqlfalse' is generated
1799 (by default : C<1=0>). Similarly, C<< -not_in => [] >> generates
1800 'sqltrue' (by default : C<1=1>).
1804 Another pair of operators is C<-between> and C<-not_between>,
1805 used with an arrayref of two values:
1809 completion_date => {
1810 -not_between => ['2002-10-01', '2003-02-06']
1816 WHERE user = ? AND completion_date NOT BETWEEN ( ? AND ? )
1818 These are the two builtin "special operators"; but the
1819 list can be expanded : see section L</"SPECIAL OPERATORS"> below.
1821 =head2 Nested conditions, -and/-or prefixes
1823 So far, we've seen how multiple conditions are joined with a top-level
1824 C<AND>. We can change this by putting the different conditions we want in
1825 hashes and then putting those hashes in an array. For example:
1830 status => { -like => ['pending%', 'dispatched'] },
1834 status => 'unassigned',
1838 This data structure would create the following:
1840 $stmt = "WHERE ( user = ? AND ( status LIKE ? OR status LIKE ? ) )
1841 OR ( user = ? AND status = ? ) )";
1842 @bind = ('nwiger', 'pending', 'dispatched', 'robot', 'unassigned');
1845 There is also a special C<-nest>
1846 operator which adds an additional set of parens, to create a subquery.
1847 For example, to get something like this:
1849 $stmt = "WHERE user = ? AND ( workhrs > ? OR geo = ? )";
1850 @bind = ('nwiger', '20', 'ASIA');
1856 -nest => [ workhrs => {'>', 20}, geo => 'ASIA' ],
1860 Finally, clauses in hashrefs or arrayrefs can be
1861 prefixed with an C<-and> or C<-or> to change the logic
1868 -and => [workhrs => {'>', 20}, geo => 'ASIA' ],
1869 -and => [workhrs => {'<', 50}, geo => 'EURO' ]
1876 WHERE ( user = ? AND
1877 ( ( workhrs > ? AND geo = ? )
1878 OR ( workhrs < ? AND geo = ? ) ) )
1881 =head2 Algebraic inconsistency, for historical reasons
1883 C<Important note>: when connecting several conditions, the C<-and->|C<-or>
1884 operator goes C<outside> of the nested structure; whereas when connecting
1885 several constraints on one column, the C<-and> operator goes
1886 C<inside> the arrayref. Here is an example combining both features :
1889 -and => [a => 1, b => 2],
1890 -or => [c => 3, d => 4],
1891 e => [-and => {-like => 'foo%'}, {-like => '%bar'} ]
1896 WHERE ( ( ( a = ? AND b = ? )
1897 OR ( c = ? OR d = ? )
1898 OR ( e LIKE ? AND e LIKE ? ) ) )
1900 This difference in syntax is unfortunate but must be preserved for
1901 historical reasons. So be careful : the two examples below would
1902 seem algebraically equivalent, but they are not
1904 {col => [-and => {-like => 'foo%'}, {-like => '%bar'}]}
1905 # yields : WHERE ( ( col LIKE ? AND col LIKE ? ) )
1907 [-and => {col => {-like => 'foo%'}, {col => {-like => '%bar'}}]]
1908 # yields : WHERE ( ( col LIKE ? OR col LIKE ? ) )
1913 Finally, sometimes only literal SQL will do. If you want to include
1914 literal SQL verbatim, you can specify it as a scalar reference, namely:
1916 my $inn = 'is Not Null';
1918 priority => { '<', 2 },
1924 $stmt = "WHERE priority < ? AND requestor is Not Null";
1927 Note that in this example, you only get one bind parameter back, since
1928 the verbatim SQL is passed as part of the statement.
1930 Of course, just to prove a point, the above can also be accomplished
1934 priority => { '<', 2 },
1935 requestor => { '!=', undef },
1941 Conditions on boolean columns can be expressed in the
1942 same way, passing a reference to an empty string :
1945 priority => { '<', 2 },
1951 $stmt = "WHERE priority < ? AND is_ready";
1955 =head2 Literal SQL with placeholders and bind values (subqueries)
1957 If the literal SQL to be inserted has placeholders and bind values,
1958 use a reference to an arrayref (yes this is a double reference --
1959 not so common, but perfectly legal Perl). For example, to find a date
1960 in Postgres you can use something like this:
1963 date_column => \[q/= date '2008-09-30' - ?::integer/, 10/]
1968 $stmt = "WHERE ( date_column = date '2008-09-30' - ?::integer )"
1971 Note that you must pass the bind values in the same format as they are returned
1972 by L</where>. That means that if you set L</bindtype> to C<columns>, you must
1973 provide the bind values in the C<< [ column_meta => value ] >> format, where
1974 C<column_meta> is an opaque scalar value; most commonly the column name, but
1975 you can use any scalar value (including references and blessed references),
1976 L<SQL::Abstract> will simply pass it through intact. So if C<bindtype> is set
1977 to C<columns> the above example will look like:
1980 date_column => \[q/= date '2008-09-30' - ?::integer/, [ dummy => 10 ]/]
1983 Literal SQL is especially useful for nesting parenthesized clauses in the
1984 main SQL query. Here is a first example :
1986 my ($sub_stmt, @sub_bind) = ("SELECT c1 FROM t1 WHERE c2 < ? AND c3 LIKE ?",
1990 bar => \["IN ($sub_stmt)" => @sub_bind],
1995 $stmt = "WHERE (foo = ? AND bar IN (SELECT c1 FROM t1
1996 WHERE c2 < ? AND c3 LIKE ?))";
1997 @bind = (1234, 100, "foo%");
1999 Other subquery operators, like for example C<"E<gt> ALL"> or C<"NOT IN">,
2000 are expressed in the same way. Of course the C<$sub_stmt> and
2001 its associated bind values can be generated through a former call
2004 my ($sub_stmt, @sub_bind)
2005 = $sql->select("t1", "c1", {c2 => {"<" => 100},
2006 c3 => {-like => "foo%"}});
2009 bar => \["> ALL ($sub_stmt)" => @sub_bind],
2012 In the examples above, the subquery was used as an operator on a column;
2013 but the same principle also applies for a clause within the main C<%where>
2014 hash, like an EXISTS subquery :
2016 my ($sub_stmt, @sub_bind)
2017 = $sql->select("t1", "*", {c1 => 1, c2 => \"> t0.c0"});
2020 -nest => \["EXISTS ($sub_stmt)" => @sub_bind],
2025 $stmt = "WHERE (foo = ? AND EXISTS (SELECT * FROM t1
2026 WHERE c1 = ? AND c2 > t0.c0))";
2030 Observe that the condition on C<c2> in the subquery refers to
2031 column C<t0.c0> of the main query : this is I<not> a bind
2032 value, so we have to express it through a scalar ref.
2033 Writing C<< c2 => {">" => "t0.c0"} >> would have generated
2034 C<< c2 > ? >> with bind value C<"t0.c0"> ... not exactly
2035 what we wanted here.
2037 Another use of the subquery technique is when some SQL clauses need
2038 parentheses, as it often occurs with some proprietary SQL extensions
2039 like for example fulltext expressions, geospatial expressions,
2040 NATIVE clauses, etc. Here is an example of a fulltext query in MySQL :
2043 -nest => \["MATCH (col1, col2) AGAINST (?)" => qw/apples/]
2046 Finally, here is an example where a subquery is used
2047 for expressing unary negation:
2049 my ($sub_stmt, @sub_bind)
2050 = $sql->where({age => [{"<" => 10}, {">" => 20}]});
2051 $sub_stmt =~ s/^ where //i; # don't want "WHERE" in the subclause
2053 lname => {like => '%son%'},
2054 -nest => \["NOT ($sub_stmt)" => @sub_bind],
2059 $stmt = "lname LIKE ? AND NOT ( age < ? OR age > ? )"
2060 @bind = ('%son%', 10, 20)
2066 These pages could go on for a while, since the nesting of the data
2067 structures this module can handle are pretty much unlimited (the
2068 module implements the C<WHERE> expansion as a recursive function
2069 internally). Your best bet is to "play around" with the module a
2070 little to see how the data structures behave, and choose the best
2071 format for your data based on that.
2073 And of course, all the values above will probably be replaced with
2074 variables gotten from forms or the command line. After all, if you
2075 knew everything ahead of time, you wouldn't have to worry about
2076 dynamically-generating SQL and could just hardwire it into your
2082 =head1 ORDER BY CLAUSES
2084 Some functions take an order by clause. This can either be a scalar (just a
2085 column name,) a hash of C<< { -desc => 'col' } >> or C<< { -asc => 'col' } >>,
2086 or an array of either of the two previous forms. Examples:
2088 Given | Will Generate
2089 ----------------------------------------------------------
2090 \'colA DESC' | ORDER BY colA DESC
2091 'colA' | ORDER BY colA
2092 [qw/colA colB/] | ORDER BY colA, colB
2093 {-asc => 'colA'} | ORDER BY colA ASC
2094 {-desc => 'colB'} | ORDER BY colB DESC
2096 {-asc => 'colA'}, | ORDER BY colA ASC, colB DESC
2099 [colA => {-asc => 'colB'}] | ORDER BY colA, colB ASC
2100 ==========================================================
2104 =head1 SPECIAL OPERATORS
2106 my $sqlmaker = SQL::Abstract->new(special_ops => [
2109 my ($self, $field, $op, $arg) = @_;
2115 A "special operator" is a SQL syntactic clause that can be
2116 applied to a field, instead of a usual binary operator.
2119 WHERE field IN (?, ?, ?)
2120 WHERE field BETWEEN ? AND ?
2121 WHERE MATCH(field) AGAINST (?, ?)
2123 Special operators IN and BETWEEN are fairly standard and therefore
2124 are builtin within C<SQL::Abstract>. For other operators,
2125 like the MATCH .. AGAINST example above which is
2126 specific to MySQL, you can write your own operator handlers :
2127 supply a C<special_ops> argument to the C<new> method.
2128 That argument takes an arrayref of operator definitions;
2129 each operator definition is a hashref with two entries
2135 the regular expression to match the operator
2139 coderef that will be called when meeting that operator
2140 in the input tree. The coderef will be called with
2141 arguments C<< ($self, $field, $op, $arg) >>, and
2142 should return a C<< ($sql, @bind) >> structure.
2146 For example, here is an implementation
2147 of the MATCH .. AGAINST syntax for MySQL
2149 my $sqlmaker = SQL::Abstract->new(special_ops => [
2151 # special op for MySql MATCH (field) AGAINST(word1, word2, ...)
2152 {regex => qr/^match$/i,
2154 my ($self, $field, $op, $arg) = @_;
2155 $arg = [$arg] if not ref $arg;
2156 my $label = $self->_quote($field);
2157 my ($placeholder) = $self->_convert('?');
2158 my $placeholders = join ", ", (($placeholder) x @$arg);
2159 my $sql = $self->_sqlcase('match') . " ($label) "
2160 . $self->_sqlcase('against') . " ($placeholders) ";
2161 my @bind = $self->_bindtype($field, @$arg);
2162 return ($sql, @bind);
2171 Thanks to some benchmarking by Mark Stosberg, it turns out that
2172 this module is many orders of magnitude faster than using C<DBIx::Abstract>.
2173 I must admit this wasn't an intentional design issue, but it's a
2174 byproduct of the fact that you get to control your C<DBI> handles
2177 To maximize performance, use a code snippet like the following:
2179 # prepare a statement handle using the first row
2180 # and then reuse it for the rest of the rows
2182 for my $href (@array_of_hashrefs) {
2183 $stmt ||= $sql->insert('table', $href);
2184 $sth ||= $dbh->prepare($stmt);
2185 $sth->execute($sql->values($href));
2188 The reason this works is because the keys in your C<$href> are sorted
2189 internally by B<SQL::Abstract>. Thus, as long as your data retains
2190 the same structure, you only have to generate the SQL the first time
2191 around. On subsequent queries, simply use the C<values> function provided
2192 by this module to return your values in the correct order.
2197 If you use my C<CGI::FormBuilder> module at all, you'll hopefully
2198 really like this part (I do, at least). Building up a complex query
2199 can be as simple as the following:
2203 use CGI::FormBuilder;
2206 my $form = CGI::FormBuilder->new(...);
2207 my $sql = SQL::Abstract->new;
2209 if ($form->submitted) {
2210 my $field = $form->field;
2211 my $id = delete $field->{id};
2212 my($stmt, @bind) = $sql->update('table', $field, {id => $id});
2215 Of course, you would still have to connect using C<DBI> to run the
2216 query, but the point is that if you make your form look like your
2217 table, the actual query script can be extremely simplistic.
2219 If you're B<REALLY> lazy (I am), check out C<HTML::QuickTable> for
2220 a fast interface to returning and formatting data. I frequently
2221 use these three modules together to write complex database query
2222 apps in under 50 lines.
2227 Version 1.50 was a major internal refactoring of C<SQL::Abstract>.
2228 Great care has been taken to preserve the I<published> behavior
2229 documented in previous versions in the 1.* family; however,
2230 some features that were previously undocumented, or behaved
2231 differently from the documentation, had to be changed in order
2232 to clarify the semantics. Hence, client code that was relying
2233 on some dark areas of C<SQL::Abstract> v1.*
2234 B<might behave differently> in v1.50.
2236 The main changes are :
2242 support for literal SQL through the C<< \ [$sql, bind] >> syntax.
2246 support for the { operator => \"..." } construct (to embed literal SQL)
2250 support for the { operator => \["...", @bind] } construct (to embed literal SQL with bind values)
2254 optional support for L<array datatypes|/"Inserting and Updating Arrays">
2258 defensive programming : check arguments
2262 fixed bug with global logic, which was previously implemented
2263 through global variables yielding side-effects. Prior versions would
2264 interpret C<< [ {cond1, cond2}, [cond3, cond4] ] >>
2265 as C<< "(cond1 AND cond2) OR (cond3 AND cond4)" >>.
2266 Now this is interpreted
2267 as C<< "(cond1 AND cond2) OR (cond3 OR cond4)" >>.
2272 fixed semantics of _bindtype on array args
2276 dropped the C<_anoncopy> of the %where tree. No longer necessary,
2277 we just avoid shifting arrays within that tree.
2281 dropped the C<_modlogic> function
2287 =head1 ACKNOWLEDGEMENTS
2289 There are a number of individuals that have really helped out with
2290 this module. Unfortunately, most of them submitted bugs via CPAN
2291 so I have no idea who they are! But the people I do know are:
2293 Ash Berlin (order_by hash term support)
2294 Matt Trout (DBIx::Class support)
2295 Mark Stosberg (benchmarking)
2296 Chas Owens (initial "IN" operator support)
2297 Philip Collins (per-field SQL functions)
2298 Eric Kolve (hashref "AND" support)
2299 Mike Fragassi (enhancements to "BETWEEN" and "LIKE")
2300 Dan Kubb (support for "quote_char" and "name_sep")
2301 Guillermo Roditi (patch to cleanup "IN" and "BETWEEN", fix and tests for _order_by)
2302 Laurent Dami (internal refactoring, multiple -nest, extensible list of special operators, literal SQL)
2303 Norbert Buchmuller (support for literal SQL in hashpair, misc. fixes & tests)
2309 L<DBIx::Class>, L<DBIx::Abstract>, L<CGI::FormBuilder>, L<HTML::QuickTable>.
2313 Copyright (c) 2001-2007 Nathan Wiger <nwiger@cpan.org>. All Rights Reserved.
2315 This module is actively maintained by Matt Trout <mst@shadowcatsystems.co.uk>
2317 For support, your best bet is to try the C<DBIx::Class> users mailing list.
2318 While not an official support venue, C<DBIx::Class> makes heavy use of
2319 C<SQL::Abstract>, and as such list members there are very familiar with
2320 how to create queries.
2322 This module is free software; you may copy this under the terms of
2323 the GNU General Public License, or the Artistic License, copies of
2324 which should have accompanied your Perl kit.