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 $VERSION = '1.50';
20 # This would confuse some packagers
21 #$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} = 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, $v) = @_;
447 $op =~ /^(AND|OR|NEST)[_\d]*/i
448 or puke "unknown operator: -$op";
449 $op = uc($1); # uppercase, remove trailing digits
450 $self->_debug("OP(-$op) within hashref, recursing...");
452 $self->_SWITCH_refkind($v, {
455 return $self->_where_ARRAYREF($v, $op eq 'NEST' ? '' : $op);
460 return $self->_where_ARRAYREF([%$v], 'OR');
463 return $self->_where_HASHREF($v);
467 SCALARREF => sub { # literal SQL
469 or puke "-$op => \\\$scalar not supported, use -nest => ...";
473 ARRAYREFREF => sub { # literal SQL
475 or puke "-$op => \\[..] not supported, use -nest => ...";
479 SCALAR => sub { # permissively interpreted as SQL
481 or puke "-$op => 'scalar' not supported, use -nest => \\'scalar'";
482 belch "literal SQL should be -nest => \\'scalar' "
483 . "instead of -nest => 'scalar' ";
488 puke "-$op => undef not supported";
494 sub _where_hashpair_ARRAYREF {
495 my ($self, $k, $v) = @_;
498 my @v = @$v; # need copy because of shift below
499 $self->_debug("ARRAY($k) means distribute over elements");
501 # put apart first element if it is an operator (-and, -or)
502 my $op = $v[0] =~ /^-/ ? shift @v : undef;
503 $self->_debug("OP($op) reinjected into the distributed array") if $op;
505 my @distributed = map { {$k => $_} } @v;
506 unshift @distributed, $op if $op;
507 my $logic = $op ? substr($op, 1) : '';
509 return $self->_recurse_where(\@distributed, $logic);
512 # LDNOTE : not sure of this one. What does "distribute over nothing" mean?
513 $self->_debug("empty ARRAY($k) means 0=1");
514 return ($self->{sqlfalse});
518 sub _where_hashpair_HASHREF {
519 my ($self, $k, $v) = @_;
521 my (@all_sql, @all_bind);
523 for my $op (sort keys %$v) {
526 # put the operator in canonical form
527 $op =~ s/^-//; # remove initial dash
528 $op =~ tr/_/ /; # underscores become spaces
529 $op =~ s/^\s+//; # no initial space
530 $op =~ s/\s+$//; # no final space
531 $op =~ s/\s+/ /; # multiple spaces become one
535 # CASE: special operators like -in or -between
536 my $special_op = first {$op =~ $_->{regex}} @{$self->{special_ops}};
538 ($sql, @bind) = $special_op->{handler}->($self, $k, $op, $val);
541 $self->_SWITCH_refkind($val, {
543 ARRAYREF => sub { # CASE: col => {op => \@vals}
544 ($sql, @bind) = $self->_where_field_op_ARRAYREF($k, $op, $val);
547 SCALARREF => sub { # CASE: col => {op => \$scalar} (literal SQL without bind)
548 $sql = join ' ', $self->_convert($self->_quote($k)),
549 $self->_sqlcase($op),
553 ARRAYREFREF => sub { # CASE: col => {op => \[$sql, @bind]} (literal SQL with bind)
554 my ($sub_sql, @sub_bind) = @$$val;
555 $self->_assert_bindval_matches_bindtype(@sub_bind);
556 $sql = join ' ', $self->_convert($self->_quote($k)),
557 $self->_sqlcase($op),
562 UNDEF => sub { # CASE: col => {op => undef} : sql "IS (NOT)? NULL"
563 my $is = ($op =~ $self->{equality_op}) ? 'is' :
564 ($op =~ $self->{inequality_op}) ? 'is not' :
565 puke "unexpected operator '$op' with undef operand";
566 $sql = $self->_quote($k) . $self->_sqlcase(" $is null");
569 FALLBACK => sub { # CASE: col => {op => $scalar}
570 $sql = join ' ', $self->_convert($self->_quote($k)),
571 $self->_sqlcase($op),
572 $self->_convert('?');
573 @bind = $self->_bindtype($k, $val);
579 push @all_bind, @bind;
582 return $self->_join_sql_clauses('and', \@all_sql, \@all_bind);
587 sub _where_field_op_ARRAYREF {
588 my ($self, $k, $op, $vals) = @_;
591 $self->_debug("ARRAY($vals) means multiple elements: [ @$vals ]");
593 # LDNOTE : had planned to change the distribution logic when
594 # $op =~ $self->{inequality_op}, because of Morgan laws :
595 # with {field => {'!=' => [22, 33]}}, it would be ridiculous to generate
596 # WHERE field != 22 OR field != 33 : the user probably means
597 # WHERE field != 22 AND field != 33.
598 # To do this, replace the line below by :
599 # my $logic = ($op =~ $self->{inequality_op}) ? 'AND' : 'OR';
600 # return $self->_recurse_where([map { {$k => {$op, $_}} } @$vals], $logic);
602 # distribute $op over each member of @$vals
603 return $self->_recurse_where([map { {$k => {$op, $_}} } @$vals]);
606 # try to DWIM on equality operators
607 # LDNOTE : not 100% sure this is the correct thing to do ...
608 return ($self->{sqlfalse}) if $op =~ $self->{equality_op};
609 return ($self->{sqltrue}) if $op =~ $self->{inequality_op};
612 puke "operator '$op' applied on an empty array (field '$k')";
617 sub _where_hashpair_SCALARREF {
618 my ($self, $k, $v) = @_;
619 $self->_debug("SCALAR($k) means literal SQL: $$v");
620 my $sql = $self->_quote($k) . " " . $$v;
624 # literal SQL with bind
625 sub _where_hashpair_ARRAYREFREF {
626 my ($self, $k, $v) = @_;
627 $self->_debug("REF($k) means literal SQL: @${$v}");
628 my ($sql, @bind) = @${$v};
629 $self->_assert_bindval_matches_bindtype(@bind);
630 $sql = $self->_quote($k) . " " . $sql;
631 return ($sql, @bind );
634 # literal SQL without bind
635 sub _where_hashpair_SCALAR {
636 my ($self, $k, $v) = @_;
637 $self->_debug("NOREF($k) means simple key=val: $k $self->{cmp} $v");
638 my $sql = join ' ', $self->_convert($self->_quote($k)),
639 $self->_sqlcase($self->{cmp}),
640 $self->_convert('?');
641 my @bind = $self->_bindtype($k, $v);
642 return ( $sql, @bind);
646 sub _where_hashpair_UNDEF {
647 my ($self, $k, $v) = @_;
648 $self->_debug("UNDEF($k) means IS NULL");
649 my $sql = $self->_quote($k) . $self->_sqlcase(' is null');
653 #======================================================================
654 # WHERE: TOP-LEVEL OTHERS (SCALARREF, SCALAR, UNDEF)
655 #======================================================================
658 sub _where_SCALARREF {
659 my ($self, $where) = @_;
662 $self->_debug("SCALAR(*top) means literal SQL: $$where");
668 my ($self, $where) = @_;
671 $self->_debug("NOREF(*top) means literal SQL: $where");
682 #======================================================================
683 # WHERE: BUILTIN SPECIAL OPERATORS (-in, -between)
684 #======================================================================
687 sub _where_field_BETWEEN {
688 my ($self, $k, $op, $vals) = @_;
690 ref $vals eq 'ARRAY' && @$vals == 2
691 or puke "special op 'between' requires an arrayref of two values";
693 my ($label) = $self->_convert($self->_quote($k));
694 my ($placeholder) = $self->_convert('?');
695 my $and = $self->_sqlcase('and');
696 $op = $self->_sqlcase($op);
698 my $sql = "( $label $op $placeholder $and $placeholder )";
699 my @bind = $self->_bindtype($k, @$vals);
704 sub _where_field_IN {
705 my ($self, $k, $op, $vals) = @_;
707 # backwards compatibility : if scalar, force into an arrayref
708 $vals = [$vals] if defined $vals && ! ref $vals;
710 my ($label) = $self->_convert($self->_quote($k));
711 my ($placeholder) = $self->_convert('?');
712 $op = $self->_sqlcase($op);
714 my ($sql, @bind) = $self->_SWITCH_refkind($vals, {
715 ARRAYREF => sub { # list of choices
716 if (@$vals) { # nonempty list
717 my $placeholders = join ", ", (($placeholder) x @$vals);
718 my $sql = "$label $op ( $placeholders )";
719 my @bind = $self->_bindtype($k, @$vals);
721 return ($sql, @bind);
723 else { # empty list : some databases won't understand "IN ()", so DWIM
724 my $sql = ($op =~ /\bnot\b/i) ? $self->{sqltrue} : $self->{sqlfalse};
729 ARRAYREFREF => sub { # literal SQL with bind
730 my ($sql, @bind) = @$$vals;
731 $self->_assert_bindval_matches_bindtype(@bind);
732 return ("$label $op ( $sql )", @bind);
736 puke "special op 'in' requires an arrayref (or arrayref-ref)";
740 return ($sql, @bind);
748 #======================================================================
750 #======================================================================
753 my ($self, $arg) = @_;
755 # construct list of ordering instructions
756 my @order = $self->_SWITCH_refkind($arg, {
759 map {$self->_SWITCH_refkind($_, {
760 SCALAR => sub {$self->_quote($_)},
762 SCALARREF => sub {$$_}, # literal SQL, no quoting
763 HASHREF => sub {$self->_order_by_hash($_)}
767 SCALAR => sub {$self->_quote($arg)},
769 SCALARREF => sub {$$arg}, # literal SQL, no quoting
770 HASHREF => sub {$self->_order_by_hash($arg)},
775 my $order = join ', ', @order;
776 return $order ? $self->_sqlcase(' order by')." $order" : '';
781 my ($self, $hash) = @_;
783 # get first pair in hash
784 my ($key, $val) = each %$hash;
786 # check if one pair was found and no other pair in hash
787 $key && !(each %$hash)
788 or puke "hash passed to _order_by must have exactly one key (-desc or -asc)";
790 my ($order) = ($key =~ /^-(desc|asc)/i)
791 or puke "invalid key in _order_by hash : $key";
793 return $self->_quote($val) ." ". $self->_sqlcase($order);
798 #======================================================================
799 # DATASOURCE (FOR NOW, JUST PLAIN TABLE OR LIST OF TABLES)
800 #======================================================================
805 $self->_SWITCH_refkind($from, {
806 ARRAYREF => sub {join ', ', map { $self->_quote($_) } @$from;},
807 SCALAR => sub {$self->_quote($from)},
808 SCALARREF => sub {$$from},
809 ARRAYREFREF => sub {join ', ', @$from;},
814 #======================================================================
816 #======================================================================
822 $label or puke "can't quote an empty label";
824 # left and right quote characters
825 my ($ql, $qr, @other) = $self->_SWITCH_refkind($self->{quote_char}, {
826 SCALAR => sub {($self->{quote_char}, $self->{quote_char})},
827 ARRAYREF => sub {@{$self->{quote_char}}},
831 or puke "quote_char must be an arrayref of 2 values";
833 # no quoting if no quoting chars
834 $ql or return $label;
836 # no quoting for literal SQL
837 return $$label if ref($label) eq 'SCALAR';
839 # separate table / column (if applicable)
840 my $sep = $self->{name_sep} || '';
841 my @to_quote = $sep ? split /\Q$sep\E/, $label : ($label);
843 # do the quoting, except for "*" or for `table`.*
844 my @quoted = map { $_ eq '*' ? $_: $ql.$_.$qr} @to_quote;
846 # reassemble and return.
847 return join $sep, @quoted;
851 # Conversion, if applicable
853 my ($self, $arg) = @_;
855 # LDNOTE : modified the previous implementation below because
856 # it was not consistent : the first "return" is always an array,
857 # the second "return" is context-dependent. Anyway, _convert
858 # seems always used with just a single argument, so make it a
860 # return @_ unless $self->{convert};
861 # my $conv = $self->_sqlcase($self->{convert});
862 # my @ret = map { $conv.'('.$_.')' } @_;
863 # return wantarray ? @ret : $ret[0];
864 if ($self->{convert}) {
865 my $conv = $self->_sqlcase($self->{convert});
866 $arg = $conv.'('.$arg.')';
874 my($col, @vals) = @_;
876 #LDNOTE : changed original implementation below because it did not make
877 # sense when bindtype eq 'columns' and @vals > 1.
878 # return $self->{bindtype} eq 'columns' ? [ $col, @vals ] : @vals;
880 return $self->{bindtype} eq 'columns' ? map {[$col, $_]} @vals : @vals;
883 # Dies if any element of @bind is not in [colname => value] format
884 # if bindtype is 'columns'.
885 sub _assert_bindval_matches_bindtype {
886 my ($self, @bind) = @_;
888 if ($self->{bindtype} eq 'columns') {
889 foreach my $val (@bind) {
890 if (!defined $val || ref($val) ne 'ARRAY' || @$val != 2) {
891 die "bindtype 'columns' selected, you need to pass: [column_name => bind_value]"
897 sub _join_sql_clauses {
898 my ($self, $logic, $clauses_aref, $bind_aref) = @_;
900 if (@$clauses_aref > 1) {
901 my $join = " " . $self->_sqlcase($logic) . " ";
902 my $sql = '( ' . join($join, @$clauses_aref) . ' )';
903 return ($sql, @$bind_aref);
905 elsif (@$clauses_aref) {
906 return ($clauses_aref->[0], @$bind_aref); # no parentheses
909 return (); # if no SQL, ignore @$bind_aref
914 # Fix SQL case, if so requested
918 # LDNOTE: if $self->{case} is true, then it contains 'lower', so we
919 # don't touch the argument ... crooked logic, but let's not change it!
920 return $self->{case} ? $_[0] : uc($_[0]);
924 #======================================================================
925 # DISPATCHING FROM REFKIND
926 #======================================================================
929 my ($self, $data) = @_;
935 # blessed objects are treated like scalars
936 $ref = (blessed $data) ? '' : ref $data;
937 $n_steps += 1 if $ref;
938 last if $ref ne 'REF';
942 my $base = $ref || (defined $data ? 'SCALAR' : 'UNDEF');
944 return $base . ('REF' x $n_steps);
950 my ($self, $data) = @_;
951 my @try = ($self->_refkind($data));
952 push @try, 'SCALAR_or_UNDEF' if $try[0] eq 'SCALAR' || $try[0] eq 'UNDEF';
953 push @try, 'FALLBACK';
957 sub _METHOD_FOR_refkind {
958 my ($self, $meth_prefix, $data) = @_;
959 my $method = first {$_} map {$self->can($meth_prefix."_".$_)}
960 $self->_try_refkind($data)
961 or puke "cannot dispatch on '$meth_prefix' for ".$self->_refkind($data);
966 sub _SWITCH_refkind {
967 my ($self, $data, $dispatch_table) = @_;
969 my $coderef = first {$_} map {$dispatch_table->{$_}}
970 $self->_try_refkind($data)
971 or puke "no dispatch entry for ".$self->_refkind($data);
978 #======================================================================
979 # VALUES, GENERATE, AUTOLOAD
980 #======================================================================
982 # LDNOTE: original code from nwiger, didn't touch code in that section
983 # I feel the AUTOLOAD stuff should not be the default, it should
984 # only be activated on explicit demand by user.
988 my $data = shift || return;
989 puke "Argument to ", __PACKAGE__, "->values must be a \\%hash"
990 unless ref $data eq 'HASH';
993 foreach my $k ( sort keys %$data ) {
995 $self->_SWITCH_refkind($v, {
997 if ($self->{array_datatypes}) { # array datatype
998 push @all_bind, $self->_bindtype($k, $v);
1000 else { # literal SQL with bind
1001 my ($sql, @bind) = @$v;
1002 $self->_assert_bindval_matches_bindtype(@bind);
1003 push @all_bind, @bind;
1006 ARRAYREFREF => sub { # literal SQL with bind
1007 my ($sql, @bind) = @${$v};
1008 $self->_assert_bindval_matches_bindtype(@bind);
1009 push @all_bind, @bind;
1011 SCALARREF => sub { # literal SQL without bind
1013 SCALAR_or_UNDEF => sub {
1014 push @all_bind, $self->_bindtype($k, $v);
1025 my(@sql, @sqlq, @sqlv);
1029 if ($ref eq 'HASH') {
1030 for my $k (sort keys %$_) {
1033 my $label = $self->_quote($k);
1034 if ($r eq 'ARRAY') {
1035 # literal SQL with bind
1036 my ($sql, @bind) = @$v;
1037 $self->_assert_bindval_matches_bindtype(@bind);
1038 push @sqlq, "$label = $sql";
1040 } elsif ($r eq 'SCALAR') {
1041 # literal SQL without bind
1042 push @sqlq, "$label = $$v";
1044 push @sqlq, "$label = ?";
1045 push @sqlv, $self->_bindtype($k, $v);
1048 push @sql, $self->_sqlcase('set'), join ', ', @sqlq;
1049 } elsif ($ref eq 'ARRAY') {
1050 # unlike insert(), assume these are ONLY the column names, i.e. for SQL
1053 if ($r eq 'ARRAY') { # literal SQL with bind
1054 my ($sql, @bind) = @$v;
1055 $self->_assert_bindval_matches_bindtype(@bind);
1058 } elsif ($r eq 'SCALAR') { # literal SQL without bind
1059 # embedded literal SQL
1066 push @sql, '(' . join(', ', @sqlq) . ')';
1067 } elsif ($ref eq 'SCALAR') {
1071 # strings get case twiddled
1072 push @sql, $self->_sqlcase($_);
1076 my $sql = join ' ', @sql;
1078 # this is pretty tricky
1079 # if ask for an array, return ($stmt, @bind)
1080 # otherwise, s/?/shift @sqlv/ to put it inline
1082 return ($sql, @sqlv);
1084 1 while $sql =~ s/\?/my $d = shift(@sqlv);
1085 ref $d ? $d->[1] : $d/e;
1094 # This allows us to check for a local, then _form, attr
1096 my($name) = $AUTOLOAD =~ /.*::(.+)/;
1097 return $self->generate($name, @_);
1108 SQL::Abstract - Generate SQL from Perl data structures
1114 my $sql = SQL::Abstract->new;
1116 my($stmt, @bind) = $sql->select($table, \@fields, \%where, \@order);
1118 my($stmt, @bind) = $sql->insert($table, \%fieldvals || \@values);
1120 my($stmt, @bind) = $sql->update($table, \%fieldvals, \%where);
1122 my($stmt, @bind) = $sql->delete($table, \%where);
1124 # Then, use these in your DBI statements
1125 my $sth = $dbh->prepare($stmt);
1126 $sth->execute(@bind);
1128 # Just generate the WHERE clause
1129 my($stmt, @bind) = $sql->where(\%where, \@order);
1131 # Return values in the same order, for hashed queries
1132 # See PERFORMANCE section for more details
1133 my @bind = $sql->values(\%fieldvals);
1137 This module was inspired by the excellent L<DBIx::Abstract>.
1138 However, in using that module I found that what I really wanted
1139 to do was generate SQL, but still retain complete control over my
1140 statement handles and use the DBI interface. So, I set out to
1141 create an abstract SQL generation module.
1143 While based on the concepts used by L<DBIx::Abstract>, there are
1144 several important differences, especially when it comes to WHERE
1145 clauses. I have modified the concepts used to make the SQL easier
1146 to generate from Perl data structures and, IMO, more intuitive.
1147 The underlying idea is for this module to do what you mean, based
1148 on the data structures you provide it. The big advantage is that
1149 you don't have to modify your code every time your data changes,
1150 as this module figures it out.
1152 To begin with, an SQL INSERT is as easy as just specifying a hash
1153 of C<key=value> pairs:
1156 name => 'Jimbo Bobson',
1157 phone => '123-456-7890',
1158 address => '42 Sister Lane',
1159 city => 'St. Louis',
1160 state => 'Louisiana',
1163 The SQL can then be generated with this:
1165 my($stmt, @bind) = $sql->insert('people', \%data);
1167 Which would give you something like this:
1169 $stmt = "INSERT INTO people
1170 (address, city, name, phone, state)
1171 VALUES (?, ?, ?, ?, ?)";
1172 @bind = ('42 Sister Lane', 'St. Louis', 'Jimbo Bobson',
1173 '123-456-7890', 'Louisiana');
1175 These are then used directly in your DBI code:
1177 my $sth = $dbh->prepare($stmt);
1178 $sth->execute(@bind);
1180 =head2 Inserting and Updating Arrays
1182 If your database has array types (like for example Postgres),
1183 activate the special option C<< array_datatypes => 1 >>
1184 when creating the C<SQL::Abstract> object.
1185 Then you may use an arrayref to insert and update database array types:
1187 my $sql = SQL::Abstract->new(array_datatypes => 1);
1189 planets => [qw/Mercury Venus Earth Mars/]
1192 my($stmt, @bind) = $sql->insert('solar_system', \%data);
1196 $stmt = "INSERT INTO solar_system (planets) VALUES (?)"
1198 @bind = (['Mercury', 'Venus', 'Earth', 'Mars']);
1201 =head2 Inserting and Updating SQL
1203 In order to apply SQL functions to elements of your C<%data> you may
1204 specify a reference to an arrayref for the given hash value. For example,
1205 if you need to execute the Oracle C<to_date> function on a value, you can
1206 say something like this:
1210 date_entered => \["to_date(?,'MM/DD/YYYY')", "03/02/2003"],
1213 The first value in the array is the actual SQL. Any other values are
1214 optional and would be included in the bind values array. This gives
1217 my($stmt, @bind) = $sql->insert('people', \%data);
1219 $stmt = "INSERT INTO people (name, date_entered)
1220 VALUES (?, to_date(?,'MM/DD/YYYY'))";
1221 @bind = ('Bill', '03/02/2003');
1223 An UPDATE is just as easy, all you change is the name of the function:
1225 my($stmt, @bind) = $sql->update('people', \%data);
1227 Notice that your C<%data> isn't touched; the module will generate
1228 the appropriately quirky SQL for you automatically. Usually you'll
1229 want to specify a WHERE clause for your UPDATE, though, which is
1230 where handling C<%where> hashes comes in handy...
1232 =head2 Complex where statements
1234 This module can generate pretty complicated WHERE statements
1235 easily. For example, simple C<key=value> pairs are taken to mean
1236 equality, and if you want to see if a field is within a set
1237 of values, you can use an arrayref. Let's say we wanted to
1238 SELECT some data based on this criteria:
1241 requestor => 'inna',
1242 worker => ['nwiger', 'rcwe', 'sfz'],
1243 status => { '!=', 'completed' }
1246 my($stmt, @bind) = $sql->select('tickets', '*', \%where);
1248 The above would give you something like this:
1250 $stmt = "SELECT * FROM tickets WHERE
1251 ( requestor = ? ) AND ( status != ? )
1252 AND ( worker = ? OR worker = ? OR worker = ? )";
1253 @bind = ('inna', 'completed', 'nwiger', 'rcwe', 'sfz');
1255 Which you could then use in DBI code like so:
1257 my $sth = $dbh->prepare($stmt);
1258 $sth->execute(@bind);
1264 The functions are simple. There's one for each major SQL operation,
1265 and a constructor you use first. The arguments are specified in a
1266 similar order to each function (table, then fields, then a where
1267 clause) to try and simplify things.
1272 =head2 new(option => 'value')
1274 The C<new()> function takes a list of options and values, and returns
1275 a new B<SQL::Abstract> object which can then be used to generate SQL
1276 through the methods below. The options accepted are:
1282 If set to 'lower', then SQL will be generated in all lowercase. By
1283 default SQL is generated in "textbook" case meaning something like:
1285 SELECT a_field FROM a_table WHERE some_field LIKE '%someval%'
1287 Any setting other than 'lower' is ignored.
1291 This determines what the default comparison operator is. By default
1292 it is C<=>, meaning that a hash like this:
1294 %where = (name => 'nwiger', email => 'nate@wiger.org');
1296 Will generate SQL like this:
1298 WHERE name = 'nwiger' AND email = 'nate@wiger.org'
1300 However, you may want loose comparisons by default, so if you set
1301 C<cmp> to C<like> you would get SQL such as:
1303 WHERE name like 'nwiger' AND email like 'nate@wiger.org'
1305 You can also override the comparsion on an individual basis - see
1306 the huge section on L</"WHERE CLAUSES"> at the bottom.
1308 =item sqltrue, sqlfalse
1310 Expressions for inserting boolean values within SQL statements.
1311 By default these are C<1=1> and C<1=0>.
1315 This determines the default logical operator for multiple WHERE
1316 statements in arrays or hashes. If absent, the default logic is "or"
1317 for arrays, and "and" for hashes. This means that a WHERE
1321 event_date => {'>=', '2/13/99'},
1322 event_date => {'<=', '4/24/03'},
1325 will generate SQL like this:
1327 WHERE event_date >= '2/13/99' OR event_date <= '4/24/03'
1329 This is probably not what you want given this query, though (look
1330 at the dates). To change the "OR" to an "AND", simply specify:
1332 my $sql = SQL::Abstract->new(logic => 'and');
1334 Which will change the above C<WHERE> to:
1336 WHERE event_date >= '2/13/99' AND event_date <= '4/24/03'
1338 The logic can also be changed locally by inserting
1339 a modifier in front of an arrayref :
1341 @where = (-and => [event_date => {'>=', '2/13/99'},
1342 event_date => {'<=', '4/24/03'} ]);
1344 See the L</"WHERE CLAUSES"> section for explanations.
1348 This will automatically convert comparisons using the specified SQL
1349 function for both column and value. This is mostly used with an argument
1350 of C<upper> or C<lower>, so that the SQL will have the effect of
1351 case-insensitive "searches". For example, this:
1353 $sql = SQL::Abstract->new(convert => 'upper');
1354 %where = (keywords => 'MaKe iT CAse inSeNSItive');
1356 Will turn out the following SQL:
1358 WHERE upper(keywords) like upper('MaKe iT CAse inSeNSItive')
1360 The conversion can be C<upper()>, C<lower()>, or any other SQL function
1361 that can be applied symmetrically to fields (actually B<SQL::Abstract> does
1362 not validate this option; it will just pass through what you specify verbatim).
1366 This is a kludge because many databases suck. For example, you can't
1367 just bind values using DBI's C<execute()> for Oracle C<CLOB> or C<BLOB> fields.
1368 Instead, you have to use C<bind_param()>:
1370 $sth->bind_param(1, 'reg data');
1371 $sth->bind_param(2, $lots, {ora_type => ORA_CLOB});
1373 The problem is, B<SQL::Abstract> will normally just return a C<@bind> array,
1374 which loses track of which field each slot refers to. Fear not.
1376 If you specify C<bindtype> in new, you can determine how C<@bind> is returned.
1377 Currently, you can specify either C<normal> (default) or C<columns>. If you
1378 specify C<columns>, you will get an array that looks like this:
1380 my $sql = SQL::Abstract->new(bindtype => 'columns');
1381 my($stmt, @bind) = $sql->insert(...);
1384 [ 'column1', 'value1' ],
1385 [ 'column2', 'value2' ],
1386 [ 'column3', 'value3' ],
1389 You can then iterate through this manually, using DBI's C<bind_param()>.
1391 $sth->prepare($stmt);
1394 my($col, $data) = @$_;
1395 if ($col eq 'details' || $col eq 'comments') {
1396 $sth->bind_param($i, $data, {ora_type => ORA_CLOB});
1397 } elsif ($col eq 'image') {
1398 $sth->bind_param($i, $data, {ora_type => ORA_BLOB});
1400 $sth->bind_param($i, $data);
1404 $sth->execute; # execute without @bind now
1406 Now, why would you still use B<SQL::Abstract> if you have to do this crap?
1407 Basically, the advantage is still that you don't have to care which fields
1408 are or are not included. You could wrap that above C<for> loop in a simple
1409 sub called C<bind_fields()> or something and reuse it repeatedly. You still
1410 get a layer of abstraction over manual SQL specification.
1412 Note that if you set L</bindtype> to C<columns>, the C<\[$sql, @bind]>
1413 construct (see L</Literal SQL with placeholders and bind values (subqueries)>)
1414 will expect the bind values in this format.
1418 This is the character that a table or column name will be quoted
1419 with. By default this is an empty string, but you could set it to
1420 the character C<`>, to generate SQL like this:
1422 SELECT `a_field` FROM `a_table` WHERE `some_field` LIKE '%someval%'
1424 Alternatively, you can supply an array ref of two items, the first being the left
1425 hand quote character, and the second the right hand quote character. For
1426 example, you could supply C<['[',']']> for SQL Server 2000 compliant quotes
1427 that generates SQL like this:
1429 SELECT [a_field] FROM [a_table] WHERE [some_field] LIKE '%someval%'
1431 Quoting is useful if you have tables or columns names that are reserved
1432 words in your database's SQL dialect.
1436 This is the character that separates a table and column name. It is
1437 necessary to specify this when the C<quote_char> option is selected,
1438 so that tables and column names can be individually quoted like this:
1440 SELECT `table`.`one_field` FROM `table` WHERE `table`.`other_field` = 1
1442 =item array_datatypes
1444 When this option is true, arrayrefs in INSERT or UPDATE are
1445 interpreted as array datatypes and are passed directly
1447 When this option is false, arrayrefs are interpreted
1448 as literal SQL, just like refs to arrayrefs
1449 (but this behavior is for backwards compatibility; when writing
1450 new queries, use the "reference to arrayref" syntax
1456 Takes a reference to a list of "special operators"
1457 to extend the syntax understood by L<SQL::Abstract>.
1458 See section L</"SPECIAL OPERATORS"> for details.
1464 =head2 insert($table, \@values || \%fieldvals)
1466 This is the simplest function. You simply give it a table name
1467 and either an arrayref of values or hashref of field/value pairs.
1468 It returns an SQL INSERT statement and a list of bind values.
1469 See the sections on L</"Inserting and Updating Arrays"> and
1470 L</"Inserting and Updating SQL"> for information on how to insert
1471 with those data types.
1473 =head2 update($table, \%fieldvals, \%where)
1475 This takes a table, hashref of field/value pairs, and an optional
1476 hashref L<WHERE clause|/WHERE CLAUSES>. It returns an SQL UPDATE function and a list
1478 See the sections on L</"Inserting and Updating Arrays"> and
1479 L</"Inserting and Updating SQL"> for information on how to insert
1480 with those data types.
1482 =head2 select($source, $fields, $where, $order)
1484 This returns a SQL SELECT statement and associated list of bind values, as
1485 specified by the arguments :
1491 Specification of the 'FROM' part of the statement.
1492 The argument can be either a plain scalar (interpreted as a table
1493 name, will be quoted), or an arrayref (interpreted as a list
1494 of table names, joined by commas, quoted), or a scalarref
1495 (literal table name, not quoted), or a ref to an arrayref
1496 (list of literal table names, joined by commas, not quoted).
1500 Specification of the list of fields to retrieve from
1502 The argument can be either an arrayref (interpreted as a list
1503 of field names, will be joined by commas and quoted), or a
1504 plain scalar (literal SQL, not quoted).
1505 Please observe that this API is not as flexible as for
1506 the first argument C<$table>, for backwards compatibility reasons.
1510 Optional argument to specify the WHERE part of the query.
1511 The argument is most often a hashref, but can also be
1512 an arrayref or plain scalar --
1513 see section L<WHERE clause|/"WHERE CLAUSES"> for details.
1517 Optional argument to specify the ORDER BY part of the query.
1518 The argument can be a scalar, a hashref or an arrayref
1519 -- see section L<ORDER BY clause|/"ORDER BY CLAUSES">
1525 =head2 delete($table, \%where)
1527 This takes a table name and optional hashref L<WHERE clause|/WHERE CLAUSES>.
1528 It returns an SQL DELETE statement and list of bind values.
1530 =head2 where(\%where, \@order)
1532 This is used to generate just the WHERE clause. For example,
1533 if you have an arbitrary data structure and know what the
1534 rest of your SQL is going to look like, but want an easy way
1535 to produce a WHERE clause, use this. It returns an SQL WHERE
1536 clause and list of bind values.
1539 =head2 values(\%data)
1541 This just returns the values from the hash C<%data>, in the same
1542 order that would be returned from any of the other above queries.
1543 Using this allows you to markedly speed up your queries if you
1544 are affecting lots of rows. See below under the L</"PERFORMANCE"> section.
1546 =head2 generate($any, 'number', $of, \@data, $struct, \%types)
1548 Warning: This is an experimental method and subject to change.
1550 This returns arbitrarily generated SQL. It's a really basic shortcut.
1551 It will return two different things, depending on return context:
1553 my($stmt, @bind) = $sql->generate('create table', \$table, \@fields);
1554 my $stmt_and_val = $sql->generate('create table', \$table, \@fields);
1556 These would return the following:
1558 # First calling form
1559 $stmt = "CREATE TABLE test (?, ?)";
1560 @bind = (field1, field2);
1562 # Second calling form
1563 $stmt_and_val = "CREATE TABLE test (field1, field2)";
1565 Depending on what you're trying to do, it's up to you to choose the correct
1566 format. In this example, the second form is what you would want.
1570 $sql->generate('alter session', { nls_date_format => 'MM/YY' });
1574 ALTER SESSION SET nls_date_format = 'MM/YY'
1576 You get the idea. Strings get their case twiddled, but everything
1577 else remains verbatim.
1582 =head1 WHERE CLAUSES
1586 This module uses a variation on the idea from L<DBIx::Abstract>. It
1587 is B<NOT>, repeat I<not> 100% compatible. B<The main logic of this
1588 module is that things in arrays are OR'ed, and things in hashes
1591 The easiest way to explain is to show lots of examples. After
1592 each C<%where> hash shown, it is assumed you used:
1594 my($stmt, @bind) = $sql->where(\%where);
1596 However, note that the C<%where> hash can be used directly in any
1597 of the other functions as well, as described above.
1599 =head2 Key-value pairs
1601 So, let's get started. To begin, a simple hash:
1605 status => 'completed'
1608 Is converted to SQL C<key = val> statements:
1610 $stmt = "WHERE user = ? AND status = ?";
1611 @bind = ('nwiger', 'completed');
1613 One common thing I end up doing is having a list of values that
1614 a field can be in. To do this, simply specify a list inside of
1619 status => ['assigned', 'in-progress', 'pending'];
1622 This simple code will create the following:
1624 $stmt = "WHERE user = ? AND ( status = ? OR status = ? OR status = ? )";
1625 @bind = ('nwiger', 'assigned', 'in-progress', 'pending');
1627 A field associated to an empty arrayref will be considered a
1628 logical false and will generate 0=1.
1630 =head2 Key-value pairs
1632 If you want to specify a different type of operator for your comparison,
1633 you can use a hashref for a given column:
1637 status => { '!=', 'completed' }
1640 Which would generate:
1642 $stmt = "WHERE user = ? AND status != ?";
1643 @bind = ('nwiger', 'completed');
1645 To test against multiple values, just enclose the values in an arrayref:
1647 status => { '=', ['assigned', 'in-progress', 'pending'] };
1649 Which would give you:
1651 "WHERE status = ? OR status = ? OR status = ?"
1654 The hashref can also contain multiple pairs, in which case it is expanded
1655 into an C<AND> of its elements:
1659 status => { '!=', 'completed', -not_like => 'pending%' }
1662 # Or more dynamically, like from a form
1663 $where{user} = 'nwiger';
1664 $where{status}{'!='} = 'completed';
1665 $where{status}{'-not_like'} = 'pending%';
1667 # Both generate this
1668 $stmt = "WHERE user = ? AND status != ? AND status NOT LIKE ?";
1669 @bind = ('nwiger', 'completed', 'pending%');
1672 To get an OR instead, you can combine it with the arrayref idea:
1676 priority => [ {'=', 2}, {'!=', 1} ]
1679 Which would generate:
1681 $stmt = "WHERE user = ? AND priority = ? OR priority != ?";
1682 @bind = ('nwiger', '2', '1');
1684 If you want to include literal SQL (with or without bind values), just use a
1685 scalar reference or array reference as the value:
1688 date_entered => { '>' => \["to_date(?, 'MM/DD/YYYY')", "11/26/2008"] },
1689 date_expires => { '<' => \"now()" }
1692 Which would generate:
1694 $stmt = "WHERE date_entered > "to_date(?, 'MM/DD/YYYY') AND date_expires < now()";
1695 @bind = ('11/26/2008');
1698 =head2 Logic and nesting operators
1700 In the example above,
1701 there is a subtle trap if you want to say something like
1702 this (notice the C<AND>):
1704 WHERE priority != ? AND priority != ?
1706 Because, in Perl you I<can't> do this:
1708 priority => { '!=', 2, '!=', 1 }
1710 As the second C<!=> key will obliterate the first. The solution
1711 is to use the special C<-modifier> form inside an arrayref:
1713 priority => [ -and => {'!=', 2},
1717 Normally, these would be joined by C<OR>, but the modifier tells it
1718 to use C<AND> instead. (Hint: You can use this in conjunction with the
1719 C<logic> option to C<new()> in order to change the way your queries
1720 work by default.) B<Important:> Note that the C<-modifier> goes
1721 B<INSIDE> the arrayref, as an extra first element. This will
1722 B<NOT> do what you think it might:
1724 priority => -and => [{'!=', 2}, {'!=', 1}] # WRONG!
1726 Here is a quick list of equivalencies, since there is some overlap:
1729 status => {'!=', 'completed', 'not like', 'pending%' }
1730 status => [ -and => {'!=', 'completed'}, {'not like', 'pending%'}]
1733 status => {'=', ['assigned', 'in-progress']}
1734 status => [ -or => {'=', 'assigned'}, {'=', 'in-progress'}]
1735 status => [ {'=', 'assigned'}, {'=', 'in-progress'} ]
1737 In addition to C<-and> and C<-or>, there is also a special C<-nest>
1738 operator which adds an additional set of parens, to create a subquery.
1739 For example, to get something like this:
1741 $stmt = "WHERE user = ? AND ( workhrs > ? OR geo = ? )";
1742 @bind = ('nwiger', '20', 'ASIA');
1748 -nest => [ workhrs => {'>', 20}, geo => 'ASIA' ],
1751 If you need several nested subexpressions, you can number
1752 the C<-nest> branches :
1762 =head2 Special operators : IN, BETWEEN, etc.
1764 You can also use the hashref format to compare a list of fields using the
1765 C<IN> comparison operator, by specifying the list as an arrayref:
1768 status => 'completed',
1769 reportid => { -in => [567, 2335, 2] }
1772 Which would generate:
1774 $stmt = "WHERE status = ? AND reportid IN (?,?,?)";
1775 @bind = ('completed', '567', '2335', '2');
1777 The reverse operator C<-not_in> generates SQL C<NOT IN> and is used in
1780 Another pair of operators is C<-between> and C<-not_between>,
1781 used with an arrayref of two values:
1785 completion_date => {
1786 -not_between => ['2002-10-01', '2003-02-06']
1792 WHERE user = ? AND completion_date NOT BETWEEN ( ? AND ? )
1794 These are the two builtin "special operators"; but the
1795 list can be expanded : see section L</"SPECIAL OPERATORS"> below.
1797 =head2 Nested conditions
1799 So far, we've seen how multiple conditions are joined with a top-level
1800 C<AND>. We can change this by putting the different conditions we want in
1801 hashes and then putting those hashes in an array. For example:
1806 status => { -like => ['pending%', 'dispatched'] },
1810 status => 'unassigned',
1814 This data structure would create the following:
1816 $stmt = "WHERE ( user = ? AND ( status LIKE ? OR status LIKE ? ) )
1817 OR ( user = ? AND status = ? ) )";
1818 @bind = ('nwiger', 'pending', 'dispatched', 'robot', 'unassigned');
1820 This can be combined with the C<-nest> operator to properly group
1821 SQL statements. Furthermore, hashrefs or arrayrefs can be
1822 prefixed with an C<-and> or C<-or> to change the logic
1829 -and => [workhrs => {'>', 20}, geo => 'ASIA' ],
1830 -and => [workhrs => {'<', 50}, geo => 'EURO' ]
1837 WHERE ( user = ? AND
1838 ( ( workhrs > ? AND geo = ? )
1839 OR ( workhrs < ? AND geo = ? ) ) )
1841 C<Important note>: when connecting several conditions, the C<-and->|C<-or>
1842 operator goes C<outside> of the nested structure; whereas when connecting
1843 several constraints on one column, the C<-and> operator goes
1844 C<inside> the arrayref. Here is an example combining both features :
1847 -and => [a => 1, b => 2],
1848 -or => [c => 3, d => 4],
1849 e => [-and => {-like => 'foo%'}, {-like => '%bar'} ]
1854 WHERE ( ( ( a = ? AND b = ? )
1855 OR ( c = ? OR d = ? )
1856 OR ( e LIKE ? AND e LIKE ? ) ) )
1861 Finally, sometimes only literal SQL will do. If you want to include
1862 literal SQL verbatim, you can specify it as a scalar reference, namely:
1864 my $inn = 'is Not Null';
1866 priority => { '<', 2 },
1872 $stmt = "WHERE priority < ? AND requestor is Not Null";
1875 Note that in this example, you only get one bind parameter back, since
1876 the verbatim SQL is passed as part of the statement.
1878 Of course, just to prove a point, the above can also be accomplished
1882 priority => { '<', 2 },
1883 requestor => { '!=', undef },
1889 Conditions on boolean columns can be expressed in the
1890 same way, passing a reference to an empty string :
1893 priority => { '<', 2 },
1899 $stmt = "WHERE priority < ? AND is_ready";
1903 =head2 Literal SQL with placeholders and bind values (subqueries)
1905 If the literal SQL to be inserted has placeholders and bind values,
1906 use a reference to an arrayref (yes this is a double reference --
1907 not so common, but perfectly legal Perl). For example, to find a date
1908 in Postgres you can use something like this:
1911 date_column => \[q/= date '2008-09-30' - ?::integer/, 10/]
1916 $stmt = "WHERE ( date_column = date '2008-09-30' - ?::integer )"
1919 Note that you must pass the bind values in the same format as they are returned
1920 by L</where>. That means that if you set L</bindtype> to C<columns>, you must
1921 provide the bind values in the C<< [ column_meta => value ] >> format, where
1922 C<column_meta> is an opaque scalar value; most commonly the column name, but
1923 you can use any scalar value (including references and blessed references),
1924 L<SQL::Abstract> will simply pass it through intact. So if C<bindtype> is set
1925 to C<columns> the above example will look like:
1928 date_column => \[q/= date '2008-09-30' - ?::integer/, [ dummy => 10 ]/]
1931 Literal SQL is especially useful for nesting parenthesized clauses in the
1932 main SQL query. Here is a first example :
1934 my ($sub_stmt, @sub_bind) = ("SELECT c1 FROM t1 WHERE c2 < ? AND c3 LIKE ?",
1938 bar => \["IN ($sub_stmt)" => @sub_bind],
1943 $stmt = "WHERE (foo = ? AND bar IN (SELECT c1 FROM t1
1944 WHERE c2 < ? AND c3 LIKE ?))";
1945 @bind = (1234, 100, "foo%");
1947 Other subquery operators, like for example C<"E<gt> ALL"> or C<"NOT IN">,
1948 are expressed in the same way. Of course the C<$sub_stmt> and
1949 its associated bind values can be generated through a former call
1952 my ($sub_stmt, @sub_bind)
1953 = $sql->select("t1", "c1", {c2 => {"<" => 100},
1954 c3 => {-like => "foo%"}});
1957 bar => \["> ALL ($sub_stmt)" => @sub_bind],
1960 In the examples above, the subquery was used as an operator on a column;
1961 but the same principle also applies for a clause within the main C<%where>
1962 hash, like an EXISTS subquery :
1964 my ($sub_stmt, @sub_bind)
1965 = $sql->select("t1", "*", {c1 => 1, c2 => \"> t0.c0"});
1968 -nest => \["EXISTS ($sub_stmt)" => @sub_bind],
1973 $stmt = "WHERE (foo = ? AND EXISTS (SELECT * FROM t1
1974 WHERE c1 = ? AND c2 > t0.c0))";
1978 Observe that the condition on C<c2> in the subquery refers to
1979 column C<t0.c0> of the main query : this is I<not> a bind
1980 value, so we have to express it through a scalar ref.
1981 Writing C<< c2 => {">" => "t0.c0"} >> would have generated
1982 C<< c2 > ? >> with bind value C<"t0.c0"> ... not exactly
1983 what we wanted here.
1985 Another use of the subquery technique is when some SQL clauses need
1986 parentheses, as it often occurs with some proprietary SQL extensions
1987 like for example fulltext expressions, geospatial expressions,
1988 NATIVE clauses, etc. Here is an example of a fulltext query in MySQL :
1991 -nest => \["MATCH (col1, col2) AGAINST (?)" => qw/apples/]
1994 Finally, here is an example where a subquery is used
1995 for expressing unary negation:
1997 my ($sub_stmt, @sub_bind)
1998 = $sql->where({age => [{"<" => 10}, {">" => 20}]});
1999 $sub_stmt =~ s/^ where //i; # don't want "WHERE" in the subclause
2001 lname => {like => '%son%'},
2002 -nest => \["NOT ($sub_stmt)" => @sub_bind],
2007 $stmt = "lname LIKE ? AND NOT ( age < ? OR age > ? )"
2008 @bind = ('%son%', 10, 20)
2014 These pages could go on for a while, since the nesting of the data
2015 structures this module can handle are pretty much unlimited (the
2016 module implements the C<WHERE> expansion as a recursive function
2017 internally). Your best bet is to "play around" with the module a
2018 little to see how the data structures behave, and choose the best
2019 format for your data based on that.
2021 And of course, all the values above will probably be replaced with
2022 variables gotten from forms or the command line. After all, if you
2023 knew everything ahead of time, you wouldn't have to worry about
2024 dynamically-generating SQL and could just hardwire it into your
2030 =head1 ORDER BY CLAUSES
2032 Some functions take an order by clause. This can either be a scalar (just a
2033 column name,) a hash of C<< { -desc => 'col' } >> or C<< { -asc => 'col' } >>,
2034 or an array of either of the two previous forms. Examples:
2036 Given | Will Generate
2037 ----------------------------------------------------------
2038 \'colA DESC' | ORDER BY colA DESC
2039 'colA' | ORDER BY colA
2040 [qw/colA colB/] | ORDER BY colA, colB
2041 {-asc => 'colA'} | ORDER BY colA ASC
2042 {-desc => 'colB'} | ORDER BY colB DESC
2044 {-asc => 'colA'}, | ORDER BY colA ASC, colB DESC
2047 [colA => {-asc => 'colB'}] | ORDER BY colA, colB ASC
2048 ==========================================================
2052 =head1 SPECIAL OPERATORS
2054 my $sqlmaker = SQL::Abstract->new(special_ops => [
2057 my ($self, $field, $op, $arg) = @_;
2063 A "special operator" is a SQL syntactic clause that can be
2064 applied to a field, instead of a usual binary operator.
2067 WHERE field IN (?, ?, ?)
2068 WHERE field BETWEEN ? AND ?
2069 WHERE MATCH(field) AGAINST (?, ?)
2071 Special operators IN and BETWEEN are fairly standard and therefore
2072 are builtin within C<SQL::Abstract>. For other operators,
2073 like the MATCH .. AGAINST example above which is
2074 specific to MySQL, you can write your own operator handlers :
2075 supply a C<special_ops> argument to the C<new> method.
2076 That argument takes an arrayref of operator definitions;
2077 each operator definition is a hashref with two entries
2083 the regular expression to match the operator
2087 coderef that will be called when meeting that operator
2088 in the input tree. The coderef will be called with
2089 arguments C<< ($self, $field, $op, $arg) >>, and
2090 should return a C<< ($sql, @bind) >> structure.
2094 For example, here is an implementation
2095 of the MATCH .. AGAINST syntax for MySQL
2097 my $sqlmaker = SQL::Abstract->new(special_ops => [
2099 # special op for MySql MATCH (field) AGAINST(word1, word2, ...)
2100 {regex => qr/^match$/i,
2102 my ($self, $field, $op, $arg) = @_;
2103 $arg = [$arg] if not ref $arg;
2104 my $label = $self->_quote($field);
2105 my ($placeholder) = $self->_convert('?');
2106 my $placeholders = join ", ", (($placeholder) x @$arg);
2107 my $sql = $self->_sqlcase('match') . " ($label) "
2108 . $self->_sqlcase('against') . " ($placeholders) ";
2109 my @bind = $self->_bindtype($field, @$arg);
2110 return ($sql, @bind);
2119 Thanks to some benchmarking by Mark Stosberg, it turns out that
2120 this module is many orders of magnitude faster than using C<DBIx::Abstract>.
2121 I must admit this wasn't an intentional design issue, but it's a
2122 byproduct of the fact that you get to control your C<DBI> handles
2125 To maximize performance, use a code snippet like the following:
2127 # prepare a statement handle using the first row
2128 # and then reuse it for the rest of the rows
2130 for my $href (@array_of_hashrefs) {
2131 $stmt ||= $sql->insert('table', $href);
2132 $sth ||= $dbh->prepare($stmt);
2133 $sth->execute($sql->values($href));
2136 The reason this works is because the keys in your C<$href> are sorted
2137 internally by B<SQL::Abstract>. Thus, as long as your data retains
2138 the same structure, you only have to generate the SQL the first time
2139 around. On subsequent queries, simply use the C<values> function provided
2140 by this module to return your values in the correct order.
2145 If you use my C<CGI::FormBuilder> module at all, you'll hopefully
2146 really like this part (I do, at least). Building up a complex query
2147 can be as simple as the following:
2151 use CGI::FormBuilder;
2154 my $form = CGI::FormBuilder->new(...);
2155 my $sql = SQL::Abstract->new;
2157 if ($form->submitted) {
2158 my $field = $form->field;
2159 my $id = delete $field->{id};
2160 my($stmt, @bind) = $sql->update('table', $field, {id => $id});
2163 Of course, you would still have to connect using C<DBI> to run the
2164 query, but the point is that if you make your form look like your
2165 table, the actual query script can be extremely simplistic.
2167 If you're B<REALLY> lazy (I am), check out C<HTML::QuickTable> for
2168 a fast interface to returning and formatting data. I frequently
2169 use these three modules together to write complex database query
2170 apps in under 50 lines.
2175 Version 1.50 was a major internal refactoring of C<SQL::Abstract>.
2176 Great care has been taken to preserve the I<published> behavior
2177 documented in previous versions in the 1.* family; however,
2178 some features that were previously undocumented, or behaved
2179 differently from the documentation, had to be changed in order
2180 to clarify the semantics. Hence, client code that was relying
2181 on some dark areas of C<SQL::Abstract> v1.*
2182 B<might behave differently> in v1.50.
2184 The main changes are :
2190 support for literal SQL through the C<< \ [$sql, bind] >> syntax.
2194 support for the { operator => \"..." } construct (to embed literal SQL)
2198 support for the { operator => \["...", @bind] } construct (to embed literal SQL with bind values)
2202 added official support for -nest1, -nest2 or -nest_1, -nest_2, ...
2203 (undocumented in previous versions)
2207 optional support for L<array datatypes|/"Inserting and Updating Arrays">
2211 defensive programming : check arguments
2215 fixed bug with global logic, which was previously implemented
2216 through global variables yielding side-effects. Prior versions would
2217 interpret C<< [ {cond1, cond2}, [cond3, cond4] ] >>
2218 as C<< "(cond1 AND cond2) OR (cond3 AND cond4)" >>.
2219 Now this is interpreted
2220 as C<< "(cond1 AND cond2) OR (cond3 OR cond4)" >>.
2225 fixed semantics of _bindtype on array args
2229 dropped the C<_anoncopy> of the %where tree. No longer necessary,
2230 we just avoid shifting arrays within that tree.
2234 dropped the C<_modlogic> function
2240 =head1 ACKNOWLEDGEMENTS
2242 There are a number of individuals that have really helped out with
2243 this module. Unfortunately, most of them submitted bugs via CPAN
2244 so I have no idea who they are! But the people I do know are:
2246 Ash Berlin (order_by hash term support)
2247 Matt Trout (DBIx::Class support)
2248 Mark Stosberg (benchmarking)
2249 Chas Owens (initial "IN" operator support)
2250 Philip Collins (per-field SQL functions)
2251 Eric Kolve (hashref "AND" support)
2252 Mike Fragassi (enhancements to "BETWEEN" and "LIKE")
2253 Dan Kubb (support for "quote_char" and "name_sep")
2254 Guillermo Roditi (patch to cleanup "IN" and "BETWEEN", fix and tests for _order_by)
2255 Laurent Dami (internal refactoring, multiple -nest, extensible list of special operators, literal SQL)
2256 Norbert Buchmuller (support for literal SQL in hashpair, misc. fixes & tests)
2262 L<DBIx::Class>, L<DBIx::Abstract>, L<CGI::FormBuilder>, L<HTML::QuickTable>.
2266 Copyright (c) 2001-2007 Nathan Wiger <nwiger@cpan.org>. All Rights Reserved.
2268 This module is actively maintained by Matt Trout <mst@shadowcatsystems.co.uk>
2270 For support, your best bet is to try the C<DBIx::Class> users mailing list.
2271 While not an official support venue, C<DBIx::Class> makes heavy use of
2272 C<SQL::Abstract>, and as such list members there are very familiar with
2273 how to create queries.
2275 This module is free software; you may copy this under the terms of
2276 the GNU General Public License, or the Artistic License, copies of
2277 which should have accompanied your Perl kit.