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)
14 #======================================================================
16 #======================================================================
18 our $VERSION = '1.73';
20 # This would confuse some packagers
21 $VERSION = eval $VERSION if $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 \s )? between $/ix, handler => '_where_field_BETWEEN'},
29 {regex => qr/^ (?: not \s )? in $/ix, handler => '_where_field_IN'},
30 {regex => qr/^ ident $/ix, handler => '_where_op_IDENT'},
31 {regex => qr/^ value $/ix, handler => '_where_op_VALUE'},
34 # unaryish operators - key maps to handler
35 my @BUILTIN_UNARY_OPS = (
36 # the digits are backcompat stuff
37 { regex => qr/^ and (?: [_\s]? \d+ )? $/xi, handler => '_where_op_ANDOR' },
38 { regex => qr/^ or (?: [_\s]? \d+ )? $/xi, handler => '_where_op_ANDOR' },
39 { regex => qr/^ nest (?: [_\s]? \d+ )? $/xi, handler => '_where_op_NEST' },
40 { regex => qr/^ (?: not \s )? bool $/xi, handler => '_where_op_BOOL' },
41 { regex => qr/^ ident $/xi, handler => '_where_op_IDENT' },
42 { regex => qr/^ value $/ix, handler => '_where_op_VALUE' },
45 #======================================================================
46 # DEBUGGING AND ERROR REPORTING
47 #======================================================================
50 return unless $_[0]->{debug}; shift; # a little faster
51 my $func = (caller(1))[3];
52 warn "[$func] ", @_, "\n";
56 my($func) = (caller(1))[3];
57 Carp::carp "[$func] Warning: ", @_;
61 my($func) = (caller(1))[3];
62 Carp::croak "[$func] Fatal: ", @_;
66 #======================================================================
68 #======================================================================
72 my $class = ref($self) || $self;
73 my %opt = (ref $_[0] eq 'HASH') ? %{$_[0]} : @_;
75 # choose our case by keeping an option around
76 delete $opt{case} if $opt{case} && $opt{case} ne 'lower';
78 # default logic for interpreting arrayrefs
79 $opt{logic} = $opt{logic} ? uc $opt{logic} : 'OR';
81 # how to return bind vars
82 # LDNOTE: changed nwiger code : why this 'delete' ??
83 # $opt{bindtype} ||= delete($opt{bind_type}) || 'normal';
84 $opt{bindtype} ||= 'normal';
86 # default comparison is "=", but can be overridden
89 # try to recognize which are the 'equality' and 'unequality' ops
90 # (temporary quickfix, should go through a more seasoned API)
91 $opt{equality_op} = qr/^(\Q$opt{cmp}\E|is|(is\s+)?like)$/i;
92 $opt{inequality_op} = qr/^(!=|<>|(is\s+)?not(\s+like)?)$/i;
95 $opt{sqltrue} ||= '1=1';
96 $opt{sqlfalse} ||= '0=1';
99 $opt{special_ops} ||= [];
100 # regexes are applied in order, thus push after user-defines
101 push @{$opt{special_ops}}, @BUILTIN_SPECIAL_OPS;
104 $opt{unary_ops} ||= [];
105 push @{$opt{unary_ops}}, @BUILTIN_UNARY_OPS;
107 # rudimentary saniy-check for user supplied bits treated as functions/operators
108 # If a purported function matches this regular expression, an exception is thrown.
109 # Literal SQL is *NOT* subject to this check, only functions (and column names
110 # when quoting is not in effect)
113 # need to guard against ()'s in column names too, but this will break tons of
114 # hacks... ideas anyone?
115 $opt{injection_guard} ||= qr/
121 return bless \%opt, $class;
125 sub _assert_pass_injection_guard {
126 if ($_[1] =~ $_[0]->{injection_guard}) {
127 my $class = ref $_[0];
128 puke "Possible SQL injection attempt '$_[1]'. If this is indeed a part of the "
129 . "desired SQL use literal SQL ( \'...' or \[ '...' ] ) or supply your own "
130 . "{injection_guard} attribute to ${class}->new()"
135 #======================================================================
137 #======================================================================
141 my $table = $self->_table(shift);
142 my $data = shift || return;
145 my $method = $self->_METHOD_FOR_refkind("_insert", $data);
146 my ($sql, @bind) = $self->$method($data);
147 $sql = join " ", $self->_sqlcase('insert into'), $table, $sql;
149 if ($options->{returning}) {
150 my ($s, @b) = $self->_insert_returning ($options);
155 return wantarray ? ($sql, @bind) : $sql;
158 sub _insert_returning {
159 my ($self, $options) = @_;
161 my $f = $options->{returning};
163 my $fieldlist = $self->_SWITCH_refkind($f, {
164 ARRAYREF => sub {join ', ', map { $self->_quote($_) } @$f;},
165 SCALAR => sub {$self->_quote($f)},
166 SCALARREF => sub {$$f},
168 return $self->_sqlcase(' returning ') . $fieldlist;
171 sub _insert_HASHREF { # explicit list of fields and then values
172 my ($self, $data) = @_;
174 my @fields = sort keys %$data;
176 my ($sql, @bind) = $self->_insert_values($data);
179 $_ = $self->_quote($_) foreach @fields;
180 $sql = "( ".join(", ", @fields).") ".$sql;
182 return ($sql, @bind);
185 sub _insert_ARRAYREF { # just generate values(?,?) part (no list of fields)
186 my ($self, $data) = @_;
188 # no names (arrayref) so can't generate bindtype
189 $self->{bindtype} ne 'columns'
190 or belch "can't do 'columns' bindtype when called with arrayref";
192 # fold the list of values into a hash of column name - value pairs
193 # (where the column names are artificially generated, and their
194 # lexicographical ordering keep the ordering of the original list)
195 my $i = "a"; # incremented values will be in lexicographical order
196 my $data_in_hash = { map { ($i++ => $_) } @$data };
198 return $self->_insert_values($data_in_hash);
201 sub _insert_ARRAYREFREF { # literal SQL with bind
202 my ($self, $data) = @_;
204 my ($sql, @bind) = @${$data};
205 $self->_assert_bindval_matches_bindtype(@bind);
207 return ($sql, @bind);
211 sub _insert_SCALARREF { # literal SQL without bind
212 my ($self, $data) = @_;
218 my ($self, $data) = @_;
220 my (@values, @all_bind);
221 foreach my $column (sort keys %$data) {
222 my $v = $data->{$column};
224 $self->_SWITCH_refkind($v, {
227 if ($self->{array_datatypes}) { # if array datatype are activated
229 push @all_bind, $self->_bindtype($column, $v);
231 else { # else literal SQL with bind
232 my ($sql, @bind) = @$v;
233 $self->_assert_bindval_matches_bindtype(@bind);
235 push @all_bind, @bind;
239 ARRAYREFREF => sub { # literal SQL with bind
240 my ($sql, @bind) = @${$v};
241 $self->_assert_bindval_matches_bindtype(@bind);
243 push @all_bind, @bind;
246 # THINK : anything useful to do with a HASHREF ?
247 HASHREF => sub { # (nothing, but old SQLA passed it through)
248 #TODO in SQLA >= 2.0 it will die instead
249 belch "HASH ref as bind value in insert is not supported";
251 push @all_bind, $self->_bindtype($column, $v);
254 SCALARREF => sub { # literal SQL without bind
258 SCALAR_or_UNDEF => sub {
260 push @all_bind, $self->_bindtype($column, $v);
267 my $sql = $self->_sqlcase('values')." ( ".join(", ", @values)." )";
268 return ($sql, @all_bind);
273 #======================================================================
275 #======================================================================
280 my $table = $self->_table(shift);
281 my $data = shift || return;
284 # first build the 'SET' part of the sql statement
285 my (@set, @all_bind);
286 puke "Unsupported data type specified to \$sql->update"
287 unless ref $data eq 'HASH';
289 for my $k (sort keys %$data) {
292 my $label = $self->_quote($k);
294 $self->_SWITCH_refkind($v, {
296 if ($self->{array_datatypes}) { # array datatype
297 push @set, "$label = ?";
298 push @all_bind, $self->_bindtype($k, $v);
300 else { # literal SQL with bind
301 my ($sql, @bind) = @$v;
302 $self->_assert_bindval_matches_bindtype(@bind);
303 push @set, "$label = $sql";
304 push @all_bind, @bind;
307 ARRAYREFREF => sub { # literal SQL with bind
308 my ($sql, @bind) = @${$v};
309 $self->_assert_bindval_matches_bindtype(@bind);
310 push @set, "$label = $sql";
311 push @all_bind, @bind;
313 SCALARREF => sub { # literal SQL without bind
314 push @set, "$label = $$v";
317 my ($op, $arg, @rest) = %$v;
319 puke 'Operator calls in update must be in the form { -op => $arg }'
320 if (@rest or not $op =~ /^\-(.+)/);
322 local $self->{_nested_func_lhs} = $k;
323 my ($sql, @bind) = $self->_where_unary_op ($1, $arg);
325 push @set, "$label = $sql";
326 push @all_bind, @bind;
328 SCALAR_or_UNDEF => sub {
329 push @set, "$label = ?";
330 push @all_bind, $self->_bindtype($k, $v);
336 my $sql = $self->_sqlcase('update') . " $table " . $self->_sqlcase('set ')
340 my($where_sql, @where_bind) = $self->where($where);
342 push @all_bind, @where_bind;
345 return wantarray ? ($sql, @all_bind) : $sql;
351 #======================================================================
353 #======================================================================
358 my $table = $self->_table(shift);
359 my $fields = shift || '*';
363 my($where_sql, @bind) = $self->where($where, $order);
365 my $f = (ref $fields eq 'ARRAY') ? join ', ', map { $self->_quote($_) } @$fields
367 my $sql = join(' ', $self->_sqlcase('select'), $f,
368 $self->_sqlcase('from'), $table)
371 return wantarray ? ($sql, @bind) : $sql;
374 #======================================================================
376 #======================================================================
381 my $table = $self->_table(shift);
385 my($where_sql, @bind) = $self->where($where);
386 my $sql = $self->_sqlcase('delete from') . " $table" . $where_sql;
388 return wantarray ? ($sql, @bind) : $sql;
392 #======================================================================
394 #======================================================================
398 # Finally, a separate routine just to handle WHERE clauses
400 my ($self, $where, $order) = @_;
403 my ($sql, @bind) = $self->_recurse_where($where);
404 $sql = $sql ? $self->_sqlcase(' where ') . "( $sql )" : '';
408 $sql .= $self->_order_by($order);
411 return wantarray ? ($sql, @bind) : $sql;
416 my ($self, $where, $logic) = @_;
418 # dispatch on appropriate method according to refkind of $where
419 my $method = $self->_METHOD_FOR_refkind("_where", $where);
421 my ($sql, @bind) = $self->$method($where, $logic);
423 # DBIx::Class directly calls _recurse_where in scalar context, so
424 # we must implement it, even if not in the official API
425 return wantarray ? ($sql, @bind) : $sql;
430 #======================================================================
431 # WHERE: top-level ARRAYREF
432 #======================================================================
435 sub _where_ARRAYREF {
436 my ($self, $where, $logic) = @_;
438 $logic = uc($logic || $self->{logic});
439 $logic eq 'AND' or $logic eq 'OR' or puke "unknown logic: $logic";
441 my @clauses = @$where;
443 my (@sql_clauses, @all_bind);
444 # need to use while() so can shift() for pairs
445 while (my $el = shift @clauses) {
447 # switch according to kind of $el and get corresponding ($sql, @bind)
448 my ($sql, @bind) = $self->_SWITCH_refkind($el, {
450 # skip empty elements, otherwise get invalid trailing AND stuff
451 ARRAYREF => sub {$self->_recurse_where($el) if @$el},
455 $self->_assert_bindval_matches_bindtype(@b);
459 HASHREF => sub {$self->_recurse_where($el, 'and') if %$el},
460 # LDNOTE : previous SQLA code for hashrefs was creating a dirty
461 # side-effect: the first hashref within an array would change
462 # the global logic to 'AND'. So [ {cond1, cond2}, [cond3, cond4] ]
463 # was interpreted as "(cond1 AND cond2) OR (cond3 AND cond4)",
464 # whereas it should be "(cond1 AND cond2) OR (cond3 OR cond4)".
466 SCALARREF => sub { ($$el); },
468 SCALAR => sub {# top-level arrayref with scalars, recurse in pairs
469 $self->_recurse_where({$el => shift(@clauses)})},
471 UNDEF => sub {puke "not supported : UNDEF in arrayref" },
475 push @sql_clauses, $sql;
476 push @all_bind, @bind;
480 return $self->_join_sql_clauses($logic, \@sql_clauses, \@all_bind);
483 #======================================================================
484 # WHERE: top-level ARRAYREFREF
485 #======================================================================
487 sub _where_ARRAYREFREF {
488 my ($self, $where) = @_;
489 my ($sql, @bind) = @$$where;
490 $self->_assert_bindval_matches_bindtype(@bind);
491 return ($sql, @bind);
494 #======================================================================
495 # WHERE: top-level HASHREF
496 #======================================================================
499 my ($self, $where) = @_;
500 my (@sql_clauses, @all_bind);
502 for my $k (sort keys %$where) {
503 my $v = $where->{$k};
505 # ($k => $v) is either a special unary op or a regular hashpair
506 my ($sql, @bind) = do {
508 # put the operator in canonical form
510 $op = substr $op, 1; # remove initial dash
511 $op =~ s/^\s+|\s+$//g;# remove leading/trailing space
512 $op =~ s/\s+/ /g; # compress whitespace
514 # so that -not_foo works correctly
515 $op =~ s/^not_/NOT /i;
517 $self->_debug("Unary OP(-$op) within hashref, recursing...");
518 my ($s, @b) = $self->_where_unary_op ($op, $v);
520 # top level vs nested
521 # we assume that handled unary ops will take care of their ()s
523 List::Util::first {$op =~ $_->{regex}} @{$self->{unary_ops}}
525 defined($self->{_nested_func_lhs}) && ($self->{_nested_func_lhs} eq $k)
530 my $method = $self->_METHOD_FOR_refkind("_where_hashpair", $v);
531 $self->$method($k, $v);
535 push @sql_clauses, $sql;
536 push @all_bind, @bind;
539 return $self->_join_sql_clauses('and', \@sql_clauses, \@all_bind);
542 sub _where_unary_op {
543 my ($self, $op, $rhs) = @_;
545 if (my $op_entry = List::Util::first {$op =~ $_->{regex}} @{$self->{unary_ops}}) {
546 my $handler = $op_entry->{handler};
548 if (not ref $handler) {
549 if ($op =~ s/ [_\s]? \d+ $//x ) {
550 belch 'Use of [and|or|nest]_N modifiers is deprecated and will be removed in SQLA v2.0. '
551 . "You probably wanted ...-and => [ -$op => COND1, -$op => COND2 ... ]";
553 return $self->$handler ($op, $rhs);
555 elsif (ref $handler eq 'CODE') {
556 return $handler->($self, $op, $rhs);
559 puke "Illegal handler for operator $op - expecting a method name or a coderef";
563 $self->_debug("Generic unary OP: $op - recursing as function");
565 $self->_assert_pass_injection_guard($op);
567 my ($sql, @bind) = $self->_SWITCH_refkind ($rhs, {
569 puke "Illegal use of top-level '$op'"
570 unless $self->{_nested_func_lhs};
573 $self->_convert('?'),
574 $self->_bindtype($self->{_nested_func_lhs}, $rhs)
578 $self->_recurse_where ($rhs)
582 $sql = sprintf ('%s %s',
583 $self->_sqlcase($op),
587 return ($sql, @bind);
590 sub _where_op_ANDOR {
591 my ($self, $op, $v) = @_;
593 $self->_SWITCH_refkind($v, {
595 return $self->_where_ARRAYREF($v, $op);
599 return ( $op =~ /^or/i )
600 ? $self->_where_ARRAYREF( [ map { $_ => $v->{$_} } ( sort keys %$v ) ], $op )
601 : $self->_where_HASHREF($v);
605 puke "-$op => \\\$scalar makes little sense, use " .
607 ? '[ \$scalar, \%rest_of_conditions ] instead'
608 : '-and => [ \$scalar, \%rest_of_conditions ] instead'
613 puke "-$op => \\[...] makes little sense, use " .
615 ? '[ \[...], \%rest_of_conditions ] instead'
616 : '-and => [ \[...], \%rest_of_conditions ] instead'
620 SCALAR => sub { # permissively interpreted as SQL
621 puke "-$op => \$value makes little sense, use -bool => \$value instead";
625 puke "-$op => undef not supported";
631 my ($self, $op, $v) = @_;
633 $self->_SWITCH_refkind($v, {
635 SCALAR => sub { # permissively interpreted as SQL
636 belch "literal SQL should be -nest => \\'scalar' "
637 . "instead of -nest => 'scalar' ";
642 puke "-$op => undef not supported";
646 $self->_recurse_where ($v);
654 my ($self, $op, $v) = @_;
656 my ($s, @b) = $self->_SWITCH_refkind($v, {
657 SCALAR => sub { # interpreted as SQL column
658 $self->_convert($self->_quote($v));
662 puke "-$op => undef not supported";
666 $self->_recurse_where ($v);
670 $s = "(NOT $s)" if $op =~ /^not/i;
675 sub _where_op_IDENT {
677 my ($op, $rhs) = splice @_, -2;
679 puke "-$op takes a single scalar argument (a quotable identifier)";
682 # in case we are called as a top level special op (no '=')
685 $_ = $self->_convert($self->_quote($_)) for ($lhs, $rhs);
693 sub _where_op_VALUE {
695 my ($op, $rhs) = splice @_, -2;
697 # in case we are called as a top level special op (no '=')
702 ($lhs || $self->{_nested_func_lhs}),
709 $self->_convert($self->_quote($lhs)) . ' = ' . $self->_convert('?'),
713 $self->_convert('?'),
719 sub _where_hashpair_ARRAYREF {
720 my ($self, $k, $v) = @_;
723 my @v = @$v; # need copy because of shift below
724 $self->_debug("ARRAY($k) means distribute over elements");
726 # put apart first element if it is an operator (-and, -or)
728 (defined $v[0] && $v[0] =~ /^ - (?: AND|OR ) $/ix)
732 my @distributed = map { {$k => $_} } @v;
735 $self->_debug("OP($op) reinjected into the distributed array");
736 unshift @distributed, $op;
739 my $logic = $op ? substr($op, 1) : '';
741 return $self->_recurse_where(\@distributed, $logic);
744 # LDNOTE : not sure of this one. What does "distribute over nothing" mean?
745 $self->_debug("empty ARRAY($k) means 0=1");
746 return ($self->{sqlfalse});
750 sub _where_hashpair_HASHREF {
751 my ($self, $k, $v, $logic) = @_;
754 local $self->{_nested_func_lhs} = $self->{_nested_func_lhs};
756 my ($all_sql, @all_bind);
758 for my $orig_op (sort keys %$v) {
759 my $val = $v->{$orig_op};
761 # put the operator in canonical form
764 # FIXME - we need to phase out dash-less ops
765 $op =~ s/^-//; # remove possible initial dash
766 $op =~ s/^\s+|\s+$//g;# remove leading/trailing space
767 $op =~ s/\s+/ /g; # compress whitespace
769 $self->_assert_pass_injection_guard($op);
771 # so that -not_foo works correctly
772 $op =~ s/^not_/NOT /i;
776 # CASE: col-value logic modifiers
777 if ( $orig_op =~ /^ \- (and|or) $/xi ) {
778 ($sql, @bind) = $self->_where_hashpair_HASHREF($k, $val, $1);
780 # CASE: special operators like -in or -between
781 elsif ( my $special_op = List::Util::first {$op =~ $_->{regex}} @{$self->{special_ops}} ) {
782 my $handler = $special_op->{handler};
784 puke "No handler supplied for special operator $orig_op";
786 elsif (not ref $handler) {
787 ($sql, @bind) = $self->$handler ($k, $op, $val);
789 elsif (ref $handler eq 'CODE') {
790 ($sql, @bind) = $handler->($self, $k, $op, $val);
793 puke "Illegal handler for special operator $orig_op - expecting a method name or a coderef";
797 $self->_SWITCH_refkind($val, {
799 ARRAYREF => sub { # CASE: col => {op => \@vals}
800 ($sql, @bind) = $self->_where_field_op_ARRAYREF($k, $op, $val);
803 ARRAYREFREF => sub { # CASE: col => {op => \[$sql, @bind]} (literal SQL with bind)
804 my ($sub_sql, @sub_bind) = @$$val;
805 $self->_assert_bindval_matches_bindtype(@sub_bind);
806 $sql = join ' ', $self->_convert($self->_quote($k)),
807 $self->_sqlcase($op),
812 UNDEF => sub { # CASE: col => {op => undef} : sql "IS (NOT)? NULL"
813 my $is = ($op =~ $self->{equality_op}) ? 'is' :
814 ($op =~ $self->{inequality_op}) ? 'is not' :
815 puke "unexpected operator '$orig_op' with undef operand";
816 $sql = $self->_quote($k) . $self->_sqlcase(" $is null");
819 FALLBACK => sub { # CASE: col => {op/func => $stuff}
821 # retain for proper column type bind
822 $self->{_nested_func_lhs} ||= $k;
824 ($sql, @bind) = $self->_where_unary_op ($op, $val);
827 $self->_convert($self->_quote($k)),
828 $self->{_nested_func_lhs} eq $k ? $sql : "($sql)", # top level vs nested
834 ($all_sql) = (defined $all_sql and $all_sql) ? $self->_join_sql_clauses($logic, [$all_sql, $sql], []) : $sql;
835 push @all_bind, @bind;
837 return ($all_sql, @all_bind);
842 sub _where_field_op_ARRAYREF {
843 my ($self, $k, $op, $vals) = @_;
845 my @vals = @$vals; #always work on a copy
848 $self->_debug(sprintf '%s means multiple elements: [ %s ]',
850 join (', ', map { defined $_ ? "'$_'" : 'NULL' } @vals ),
853 # see if the first element is an -and/-or op
855 if (defined $vals[0] && $vals[0] =~ /^ - ( AND|OR ) $/ix) {
860 # distribute $op over each remaining member of @vals, append logic if exists
861 return $self->_recurse_where([map { {$k => {$op, $_}} } @vals], $logic);
863 # LDNOTE : had planned to change the distribution logic when
864 # $op =~ $self->{inequality_op}, because of Morgan laws :
865 # with {field => {'!=' => [22, 33]}}, it would be ridiculous to generate
866 # WHERE field != 22 OR field != 33 : the user probably means
867 # WHERE field != 22 AND field != 33.
868 # To do this, replace the above to roughly :
869 # my $logic = ($op =~ $self->{inequality_op}) ? 'AND' : 'OR';
870 # return $self->_recurse_where([map { {$k => {$op, $_}} } @vals], $logic);
874 # try to DWIM on equality operators
875 # LDNOTE : not 100% sure this is the correct thing to do ...
876 return ($self->{sqlfalse}) if $op =~ $self->{equality_op};
877 return ($self->{sqltrue}) if $op =~ $self->{inequality_op};
880 puke "operator '$op' applied on an empty array (field '$k')";
885 sub _where_hashpair_SCALARREF {
886 my ($self, $k, $v) = @_;
887 $self->_debug("SCALAR($k) means literal SQL: $$v");
888 my $sql = $self->_quote($k) . " " . $$v;
892 # literal SQL with bind
893 sub _where_hashpair_ARRAYREFREF {
894 my ($self, $k, $v) = @_;
895 $self->_debug("REF($k) means literal SQL: @${$v}");
896 my ($sql, @bind) = @$$v;
897 $self->_assert_bindval_matches_bindtype(@bind);
898 $sql = $self->_quote($k) . " " . $sql;
899 return ($sql, @bind );
902 # literal SQL without bind
903 sub _where_hashpair_SCALAR {
904 my ($self, $k, $v) = @_;
905 $self->_debug("NOREF($k) means simple key=val: $k $self->{cmp} $v");
906 my $sql = join ' ', $self->_convert($self->_quote($k)),
907 $self->_sqlcase($self->{cmp}),
908 $self->_convert('?');
909 my @bind = $self->_bindtype($k, $v);
910 return ( $sql, @bind);
914 sub _where_hashpair_UNDEF {
915 my ($self, $k, $v) = @_;
916 $self->_debug("UNDEF($k) means IS NULL");
917 my $sql = $self->_quote($k) . $self->_sqlcase(' is null');
921 #======================================================================
922 # WHERE: TOP-LEVEL OTHERS (SCALARREF, SCALAR, UNDEF)
923 #======================================================================
926 sub _where_SCALARREF {
927 my ($self, $where) = @_;
930 $self->_debug("SCALAR(*top) means literal SQL: $$where");
936 my ($self, $where) = @_;
939 $self->_debug("NOREF(*top) means literal SQL: $where");
950 #======================================================================
951 # WHERE: BUILTIN SPECIAL OPERATORS (-in, -between)
952 #======================================================================
955 sub _where_field_BETWEEN {
956 my ($self, $k, $op, $vals) = @_;
958 my ($label, $and, $placeholder);
959 $label = $self->_convert($self->_quote($k));
960 $and = ' ' . $self->_sqlcase('and') . ' ';
961 $placeholder = $self->_convert('?');
962 $op = $self->_sqlcase($op);
964 my ($clause, @bind) = $self->_SWITCH_refkind($vals, {
966 my ($s, @b) = @$$vals;
967 $self->_assert_bindval_matches_bindtype(@b);
974 puke "special op 'between' accepts an arrayref with exactly two values"
977 my (@all_sql, @all_bind);
978 foreach my $val (@$vals) {
979 my ($sql, @bind) = $self->_SWITCH_refkind($val, {
981 return ($placeholder, $self->_bindtype($k, $val) );
987 my ($sql, @bind) = @$$val;
988 $self->_assert_bindval_matches_bindtype(@bind);
989 return ($sql, @bind);
992 my ($func, $arg, @rest) = %$val;
993 puke ("Only simple { -func => arg } functions accepted as sub-arguments to BETWEEN")
994 if (@rest or $func !~ /^ \- (.+)/x);
995 local $self->{_nested_func_lhs} = $k;
996 $self->_where_unary_op ($1 => $arg);
1000 push @all_bind, @bind;
1004 (join $and, @all_sql),
1009 puke "special op 'between' accepts an arrayref with two values, or a single literal scalarref/arrayref-ref";
1013 my $sql = "( $label $op $clause )";
1014 return ($sql, @bind)
1018 sub _where_field_IN {
1019 my ($self, $k, $op, $vals) = @_;
1021 # backwards compatibility : if scalar, force into an arrayref
1022 $vals = [$vals] if defined $vals && ! ref $vals;
1024 my ($label) = $self->_convert($self->_quote($k));
1025 my ($placeholder) = $self->_convert('?');
1026 $op = $self->_sqlcase($op);
1028 my ($sql, @bind) = $self->_SWITCH_refkind($vals, {
1029 ARRAYREF => sub { # list of choices
1030 if (@$vals) { # nonempty list
1031 my (@all_sql, @all_bind);
1033 for my $val (@$vals) {
1034 my ($sql, @bind) = $self->_SWITCH_refkind($val, {
1036 return ($placeholder, $val);
1041 ARRAYREFREF => sub {
1042 my ($sql, @bind) = @$$val;
1043 $self->_assert_bindval_matches_bindtype(@bind);
1044 return ($sql, @bind);
1047 my ($func, $arg, @rest) = %$val;
1048 puke ("Only simple { -func => arg } functions accepted as sub-arguments to IN")
1049 if (@rest or $func !~ /^ \- (.+)/x);
1050 local $self->{_nested_func_lhs} = $k;
1051 $self->_where_unary_op ($1 => $arg);
1054 return $self->_sqlcase('null');
1057 push @all_sql, $sql;
1058 push @all_bind, @bind;
1062 sprintf ('%s %s ( %s )',
1065 join (', ', @all_sql)
1067 $self->_bindtype($k, @all_bind),
1070 else { # empty list : some databases won't understand "IN ()", so DWIM
1071 my $sql = ($op =~ /\bnot\b/i) ? $self->{sqltrue} : $self->{sqlfalse};
1076 SCALARREF => sub { # literal SQL
1077 my $sql = $self->_open_outer_paren ($$vals);
1078 return ("$label $op ( $sql )");
1080 ARRAYREFREF => sub { # literal SQL with bind
1081 my ($sql, @bind) = @$$vals;
1082 $self->_assert_bindval_matches_bindtype(@bind);
1083 $sql = $self->_open_outer_paren ($sql);
1084 return ("$label $op ( $sql )", @bind);
1088 puke "special op 'in' requires an arrayref (or scalarref/arrayref-ref)";
1092 return ($sql, @bind);
1095 # Some databases (SQLite) treat col IN (1, 2) different from
1096 # col IN ( (1, 2) ). Use this to strip all outer parens while
1097 # adding them back in the corresponding method
1098 sub _open_outer_paren {
1099 my ($self, $sql) = @_;
1100 $sql = $1 while $sql =~ /^ \s* \( (.*) \) \s* $/xs;
1105 #======================================================================
1107 #======================================================================
1110 my ($self, $arg) = @_;
1113 for my $c ($self->_order_by_chunks ($arg) ) {
1114 $self->_SWITCH_refkind ($c, {
1115 SCALAR => sub { push @sql, $c },
1116 ARRAYREF => sub { push @sql, shift @$c; push @bind, @$c },
1122 $self->_sqlcase(' order by'),
1128 return wantarray ? ($sql, @bind) : $sql;
1131 sub _order_by_chunks {
1132 my ($self, $arg) = @_;
1134 return $self->_SWITCH_refkind($arg, {
1137 map { $self->_order_by_chunks ($_ ) } @$arg;
1140 ARRAYREFREF => sub {
1141 my ($s, @b) = @$$arg;
1142 $self->_assert_bindval_matches_bindtype(@b);
1146 SCALAR => sub {$self->_quote($arg)},
1148 UNDEF => sub {return () },
1150 SCALARREF => sub {$$arg}, # literal SQL, no quoting
1153 return () unless %$arg;
1155 my ($direction, $nulls, $val);
1156 foreach my $key (keys %$arg) {
1157 if ( $key =~ /^-(desc|asc)/i ) {
1158 puke "hash passed to _order_by must have exactly one of -desc or -asc"
1159 if defined $direction;
1161 $val = $arg->{$key};
1162 } elsif ($key =~ /^-nulls$/i) {
1163 $nulls = $arg->{$key};
1164 puke "invalid value for -nulls" unless $nulls =~ /^(?:first|last)$/;
1166 puke "invalid key in hash passed to _order_by";
1169 puke "hash passed to _order_by must have exactly one of -desc or -asc"
1170 unless defined $direction;
1173 for my $c ($self->_order_by_chunks ($val)) {
1176 $self->_SWITCH_refkind ($c, {
1181 ($sql, @bind) = @$c;
1185 $sql .= ' ' . $self->_sqlcase($direction);
1186 $sql .= ' ' . $self->_sqlcase("nulls $nulls")
1189 push @ret, [ $sql, @bind];
1198 #======================================================================
1199 # DATASOURCE (FOR NOW, JUST PLAIN TABLE OR LIST OF TABLES)
1200 #======================================================================
1205 $self->_SWITCH_refkind($from, {
1206 ARRAYREF => sub {join ', ', map { $self->_quote($_) } @$from;},
1207 SCALAR => sub {$self->_quote($from)},
1208 SCALARREF => sub {$$from},
1213 #======================================================================
1215 #======================================================================
1217 # highly optimized, as it's called way too often
1219 # my ($self, $label) = @_;
1221 return '' unless defined $_[1];
1222 return ${$_[1]} if ref($_[1]) eq 'SCALAR';
1224 unless ($_[0]->{quote_char}) {
1225 $_[0]->_assert_pass_injection_guard($_[1]);
1229 my $qref = ref $_[0]->{quote_char};
1232 ($l, $r) = ( $_[0]->{quote_char}, $_[0]->{quote_char} );
1234 elsif ($qref eq 'ARRAY') {
1235 ($l, $r) = @{$_[0]->{quote_char}};
1238 puke "Unsupported quote_char format: $_[0]->{quote_char}";
1241 # parts containing * are naturally unquoted
1242 return join( $_[0]->{name_sep}||'', map
1243 { $_ eq '*' ? $_ : $l . $_ . $r }
1244 ( $_[0]->{name_sep} ? split (/\Q$_[0]->{name_sep}\E/, $_[1] ) : $_[1] )
1249 # Conversion, if applicable
1251 #my ($self, $arg) = @_;
1253 # LDNOTE : modified the previous implementation below because
1254 # it was not consistent : the first "return" is always an array,
1255 # the second "return" is context-dependent. Anyway, _convert
1256 # seems always used with just a single argument, so make it a
1258 # return @_ unless $self->{convert};
1259 # my $conv = $self->_sqlcase($self->{convert});
1260 # my @ret = map { $conv.'('.$_.')' } @_;
1261 # return wantarray ? @ret : $ret[0];
1262 if ($_[0]->{convert}) {
1263 return $_[0]->_sqlcase($_[0]->{convert}) .'(' . $_[1] . ')';
1270 #my ($self, $col, @vals) = @_;
1272 #LDNOTE : changed original implementation below because it did not make
1273 # sense when bindtype eq 'columns' and @vals > 1.
1274 # return $self->{bindtype} eq 'columns' ? [ $col, @vals ] : @vals;
1276 # called often - tighten code
1277 return $_[0]->{bindtype} eq 'columns'
1278 ? map {[$_[1], $_]} @_[2 .. $#_]
1283 # Dies if any element of @bind is not in [colname => value] format
1284 # if bindtype is 'columns'.
1285 sub _assert_bindval_matches_bindtype {
1286 # my ($self, @bind) = @_;
1288 if ($self->{bindtype} eq 'columns') {
1290 if (!defined $_ || ref($_) ne 'ARRAY' || @$_ != 2) {
1291 puke "bindtype 'columns' selected, you need to pass: [column_name => bind_value]"
1297 sub _join_sql_clauses {
1298 my ($self, $logic, $clauses_aref, $bind_aref) = @_;
1300 if (@$clauses_aref > 1) {
1301 my $join = " " . $self->_sqlcase($logic) . " ";
1302 my $sql = '( ' . join($join, @$clauses_aref) . ' )';
1303 return ($sql, @$bind_aref);
1305 elsif (@$clauses_aref) {
1306 return ($clauses_aref->[0], @$bind_aref); # no parentheses
1309 return (); # if no SQL, ignore @$bind_aref
1314 # Fix SQL case, if so requested
1316 # LDNOTE: if $self->{case} is true, then it contains 'lower', so we
1317 # don't touch the argument ... crooked logic, but let's not change it!
1318 return $_[0]->{case} ? $_[1] : uc($_[1]);
1322 #======================================================================
1323 # DISPATCHING FROM REFKIND
1324 #======================================================================
1327 my ($self, $data) = @_;
1329 return 'UNDEF' unless defined $data;
1331 # blessed objects are treated like scalars
1332 my $ref = (Scalar::Util::blessed $data) ? '' : ref $data;
1334 return 'SCALAR' unless $ref;
1337 while ($ref eq 'REF') {
1339 $ref = (Scalar::Util::blessed $data) ? '' : ref $data;
1343 return ($ref||'SCALAR') . ('REF' x $n_steps);
1347 my ($self, $data) = @_;
1348 my @try = ($self->_refkind($data));
1349 push @try, 'SCALAR_or_UNDEF' if $try[0] eq 'SCALAR' || $try[0] eq 'UNDEF';
1350 push @try, 'FALLBACK';
1354 sub _METHOD_FOR_refkind {
1355 my ($self, $meth_prefix, $data) = @_;
1358 for (@{$self->_try_refkind($data)}) {
1359 $method = $self->can($meth_prefix."_".$_)
1363 return $method || puke "cannot dispatch on '$meth_prefix' for ".$self->_refkind($data);
1367 sub _SWITCH_refkind {
1368 my ($self, $data, $dispatch_table) = @_;
1371 for (@{$self->_try_refkind($data)}) {
1372 $coderef = $dispatch_table->{$_}
1376 puke "no dispatch entry for ".$self->_refkind($data)
1385 #======================================================================
1386 # VALUES, GENERATE, AUTOLOAD
1387 #======================================================================
1389 # LDNOTE: original code from nwiger, didn't touch code in that section
1390 # I feel the AUTOLOAD stuff should not be the default, it should
1391 # only be activated on explicit demand by user.
1395 my $data = shift || return;
1396 puke "Argument to ", __PACKAGE__, "->values must be a \\%hash"
1397 unless ref $data eq 'HASH';
1400 foreach my $k ( sort keys %$data ) {
1401 my $v = $data->{$k};
1402 $self->_SWITCH_refkind($v, {
1404 if ($self->{array_datatypes}) { # array datatype
1405 push @all_bind, $self->_bindtype($k, $v);
1407 else { # literal SQL with bind
1408 my ($sql, @bind) = @$v;
1409 $self->_assert_bindval_matches_bindtype(@bind);
1410 push @all_bind, @bind;
1413 ARRAYREFREF => sub { # literal SQL with bind
1414 my ($sql, @bind) = @${$v};
1415 $self->_assert_bindval_matches_bindtype(@bind);
1416 push @all_bind, @bind;
1418 SCALARREF => sub { # literal SQL without bind
1420 SCALAR_or_UNDEF => sub {
1421 push @all_bind, $self->_bindtype($k, $v);
1432 my(@sql, @sqlq, @sqlv);
1436 if ($ref eq 'HASH') {
1437 for my $k (sort keys %$_) {
1440 my $label = $self->_quote($k);
1441 if ($r eq 'ARRAY') {
1442 # literal SQL with bind
1443 my ($sql, @bind) = @$v;
1444 $self->_assert_bindval_matches_bindtype(@bind);
1445 push @sqlq, "$label = $sql";
1447 } elsif ($r eq 'SCALAR') {
1448 # literal SQL without bind
1449 push @sqlq, "$label = $$v";
1451 push @sqlq, "$label = ?";
1452 push @sqlv, $self->_bindtype($k, $v);
1455 push @sql, $self->_sqlcase('set'), join ', ', @sqlq;
1456 } elsif ($ref eq 'ARRAY') {
1457 # unlike insert(), assume these are ONLY the column names, i.e. for SQL
1460 if ($r eq 'ARRAY') { # literal SQL with bind
1461 my ($sql, @bind) = @$v;
1462 $self->_assert_bindval_matches_bindtype(@bind);
1465 } elsif ($r eq 'SCALAR') { # literal SQL without bind
1466 # embedded literal SQL
1473 push @sql, '(' . join(', ', @sqlq) . ')';
1474 } elsif ($ref eq 'SCALAR') {
1478 # strings get case twiddled
1479 push @sql, $self->_sqlcase($_);
1483 my $sql = join ' ', @sql;
1485 # this is pretty tricky
1486 # if ask for an array, return ($stmt, @bind)
1487 # otherwise, s/?/shift @sqlv/ to put it inline
1489 return ($sql, @sqlv);
1491 1 while $sql =~ s/\?/my $d = shift(@sqlv);
1492 ref $d ? $d->[1] : $d/e;
1501 # This allows us to check for a local, then _form, attr
1503 my($name) = $AUTOLOAD =~ /.*::(.+)/;
1504 return $self->generate($name, @_);
1515 SQL::Abstract - Generate SQL from Perl data structures
1521 my $sql = SQL::Abstract->new;
1523 my($stmt, @bind) = $sql->select($table, \@fields, \%where, \@order);
1525 my($stmt, @bind) = $sql->insert($table, \%fieldvals || \@values);
1527 my($stmt, @bind) = $sql->update($table, \%fieldvals, \%where);
1529 my($stmt, @bind) = $sql->delete($table, \%where);
1531 # Then, use these in your DBI statements
1532 my $sth = $dbh->prepare($stmt);
1533 $sth->execute(@bind);
1535 # Just generate the WHERE clause
1536 my($stmt, @bind) = $sql->where(\%where, \@order);
1538 # Return values in the same order, for hashed queries
1539 # See PERFORMANCE section for more details
1540 my @bind = $sql->values(\%fieldvals);
1544 This module was inspired by the excellent L<DBIx::Abstract>.
1545 However, in using that module I found that what I really wanted
1546 to do was generate SQL, but still retain complete control over my
1547 statement handles and use the DBI interface. So, I set out to
1548 create an abstract SQL generation module.
1550 While based on the concepts used by L<DBIx::Abstract>, there are
1551 several important differences, especially when it comes to WHERE
1552 clauses. I have modified the concepts used to make the SQL easier
1553 to generate from Perl data structures and, IMO, more intuitive.
1554 The underlying idea is for this module to do what you mean, based
1555 on the data structures you provide it. The big advantage is that
1556 you don't have to modify your code every time your data changes,
1557 as this module figures it out.
1559 To begin with, an SQL INSERT is as easy as just specifying a hash
1560 of C<key=value> pairs:
1563 name => 'Jimbo Bobson',
1564 phone => '123-456-7890',
1565 address => '42 Sister Lane',
1566 city => 'St. Louis',
1567 state => 'Louisiana',
1570 The SQL can then be generated with this:
1572 my($stmt, @bind) = $sql->insert('people', \%data);
1574 Which would give you something like this:
1576 $stmt = "INSERT INTO people
1577 (address, city, name, phone, state)
1578 VALUES (?, ?, ?, ?, ?)";
1579 @bind = ('42 Sister Lane', 'St. Louis', 'Jimbo Bobson',
1580 '123-456-7890', 'Louisiana');
1582 These are then used directly in your DBI code:
1584 my $sth = $dbh->prepare($stmt);
1585 $sth->execute(@bind);
1587 =head2 Inserting and Updating Arrays
1589 If your database has array types (like for example Postgres),
1590 activate the special option C<< array_datatypes => 1 >>
1591 when creating the C<SQL::Abstract> object.
1592 Then you may use an arrayref to insert and update database array types:
1594 my $sql = SQL::Abstract->new(array_datatypes => 1);
1596 planets => [qw/Mercury Venus Earth Mars/]
1599 my($stmt, @bind) = $sql->insert('solar_system', \%data);
1603 $stmt = "INSERT INTO solar_system (planets) VALUES (?)"
1605 @bind = (['Mercury', 'Venus', 'Earth', 'Mars']);
1608 =head2 Inserting and Updating SQL
1610 In order to apply SQL functions to elements of your C<%data> you may
1611 specify a reference to an arrayref for the given hash value. For example,
1612 if you need to execute the Oracle C<to_date> function on a value, you can
1613 say something like this:
1617 date_entered => \["to_date(?,'MM/DD/YYYY')", "03/02/2003"],
1620 The first value in the array is the actual SQL. Any other values are
1621 optional and would be included in the bind values array. This gives
1624 my($stmt, @bind) = $sql->insert('people', \%data);
1626 $stmt = "INSERT INTO people (name, date_entered)
1627 VALUES (?, to_date(?,'MM/DD/YYYY'))";
1628 @bind = ('Bill', '03/02/2003');
1630 An UPDATE is just as easy, all you change is the name of the function:
1632 my($stmt, @bind) = $sql->update('people', \%data);
1634 Notice that your C<%data> isn't touched; the module will generate
1635 the appropriately quirky SQL for you automatically. Usually you'll
1636 want to specify a WHERE clause for your UPDATE, though, which is
1637 where handling C<%where> hashes comes in handy...
1639 =head2 Complex where statements
1641 This module can generate pretty complicated WHERE statements
1642 easily. For example, simple C<key=value> pairs are taken to mean
1643 equality, and if you want to see if a field is within a set
1644 of values, you can use an arrayref. Let's say we wanted to
1645 SELECT some data based on this criteria:
1648 requestor => 'inna',
1649 worker => ['nwiger', 'rcwe', 'sfz'],
1650 status => { '!=', 'completed' }
1653 my($stmt, @bind) = $sql->select('tickets', '*', \%where);
1655 The above would give you something like this:
1657 $stmt = "SELECT * FROM tickets WHERE
1658 ( requestor = ? ) AND ( status != ? )
1659 AND ( worker = ? OR worker = ? OR worker = ? )";
1660 @bind = ('inna', 'completed', 'nwiger', 'rcwe', 'sfz');
1662 Which you could then use in DBI code like so:
1664 my $sth = $dbh->prepare($stmt);
1665 $sth->execute(@bind);
1671 The functions are simple. There's one for each major SQL operation,
1672 and a constructor you use first. The arguments are specified in a
1673 similar order to each function (table, then fields, then a where
1674 clause) to try and simplify things.
1679 =head2 new(option => 'value')
1681 The C<new()> function takes a list of options and values, and returns
1682 a new B<SQL::Abstract> object which can then be used to generate SQL
1683 through the methods below. The options accepted are:
1689 If set to 'lower', then SQL will be generated in all lowercase. By
1690 default SQL is generated in "textbook" case meaning something like:
1692 SELECT a_field FROM a_table WHERE some_field LIKE '%someval%'
1694 Any setting other than 'lower' is ignored.
1698 This determines what the default comparison operator is. By default
1699 it is C<=>, meaning that a hash like this:
1701 %where = (name => 'nwiger', email => 'nate@wiger.org');
1703 Will generate SQL like this:
1705 WHERE name = 'nwiger' AND email = 'nate@wiger.org'
1707 However, you may want loose comparisons by default, so if you set
1708 C<cmp> to C<like> you would get SQL such as:
1710 WHERE name like 'nwiger' AND email like 'nate@wiger.org'
1712 You can also override the comparsion on an individual basis - see
1713 the huge section on L</"WHERE CLAUSES"> at the bottom.
1715 =item sqltrue, sqlfalse
1717 Expressions for inserting boolean values within SQL statements.
1718 By default these are C<1=1> and C<1=0>. They are used
1719 by the special operators C<-in> and C<-not_in> for generating
1720 correct SQL even when the argument is an empty array (see below).
1724 This determines the default logical operator for multiple WHERE
1725 statements in arrays or hashes. If absent, the default logic is "or"
1726 for arrays, and "and" for hashes. This means that a WHERE
1730 event_date => {'>=', '2/13/99'},
1731 event_date => {'<=', '4/24/03'},
1734 will generate SQL like this:
1736 WHERE event_date >= '2/13/99' OR event_date <= '4/24/03'
1738 This is probably not what you want given this query, though (look
1739 at the dates). To change the "OR" to an "AND", simply specify:
1741 my $sql = SQL::Abstract->new(logic => 'and');
1743 Which will change the above C<WHERE> to:
1745 WHERE event_date >= '2/13/99' AND event_date <= '4/24/03'
1747 The logic can also be changed locally by inserting
1748 a modifier in front of an arrayref :
1750 @where = (-and => [event_date => {'>=', '2/13/99'},
1751 event_date => {'<=', '4/24/03'} ]);
1753 See the L</"WHERE CLAUSES"> section for explanations.
1757 This will automatically convert comparisons using the specified SQL
1758 function for both column and value. This is mostly used with an argument
1759 of C<upper> or C<lower>, so that the SQL will have the effect of
1760 case-insensitive "searches". For example, this:
1762 $sql = SQL::Abstract->new(convert => 'upper');
1763 %where = (keywords => 'MaKe iT CAse inSeNSItive');
1765 Will turn out the following SQL:
1767 WHERE upper(keywords) like upper('MaKe iT CAse inSeNSItive')
1769 The conversion can be C<upper()>, C<lower()>, or any other SQL function
1770 that can be applied symmetrically to fields (actually B<SQL::Abstract> does
1771 not validate this option; it will just pass through what you specify verbatim).
1775 This is a kludge because many databases suck. For example, you can't
1776 just bind values using DBI's C<execute()> for Oracle C<CLOB> or C<BLOB> fields.
1777 Instead, you have to use C<bind_param()>:
1779 $sth->bind_param(1, 'reg data');
1780 $sth->bind_param(2, $lots, {ora_type => ORA_CLOB});
1782 The problem is, B<SQL::Abstract> will normally just return a C<@bind> array,
1783 which loses track of which field each slot refers to. Fear not.
1785 If you specify C<bindtype> in new, you can determine how C<@bind> is returned.
1786 Currently, you can specify either C<normal> (default) or C<columns>. If you
1787 specify C<columns>, you will get an array that looks like this:
1789 my $sql = SQL::Abstract->new(bindtype => 'columns');
1790 my($stmt, @bind) = $sql->insert(...);
1793 [ 'column1', 'value1' ],
1794 [ 'column2', 'value2' ],
1795 [ 'column3', 'value3' ],
1798 You can then iterate through this manually, using DBI's C<bind_param()>.
1800 $sth->prepare($stmt);
1803 my($col, $data) = @$_;
1804 if ($col eq 'details' || $col eq 'comments') {
1805 $sth->bind_param($i, $data, {ora_type => ORA_CLOB});
1806 } elsif ($col eq 'image') {
1807 $sth->bind_param($i, $data, {ora_type => ORA_BLOB});
1809 $sth->bind_param($i, $data);
1813 $sth->execute; # execute without @bind now
1815 Now, why would you still use B<SQL::Abstract> if you have to do this crap?
1816 Basically, the advantage is still that you don't have to care which fields
1817 are or are not included. You could wrap that above C<for> loop in a simple
1818 sub called C<bind_fields()> or something and reuse it repeatedly. You still
1819 get a layer of abstraction over manual SQL specification.
1821 Note that if you set L</bindtype> to C<columns>, the C<\[$sql, @bind]>
1822 construct (see L</Literal SQL with placeholders and bind values (subqueries)>)
1823 will expect the bind values in this format.
1827 This is the character that a table or column name will be quoted
1828 with. By default this is an empty string, but you could set it to
1829 the character C<`>, to generate SQL like this:
1831 SELECT `a_field` FROM `a_table` WHERE `some_field` LIKE '%someval%'
1833 Alternatively, you can supply an array ref of two items, the first being the left
1834 hand quote character, and the second the right hand quote character. For
1835 example, you could supply C<['[',']']> for SQL Server 2000 compliant quotes
1836 that generates SQL like this:
1838 SELECT [a_field] FROM [a_table] WHERE [some_field] LIKE '%someval%'
1840 Quoting is useful if you have tables or columns names that are reserved
1841 words in your database's SQL dialect.
1845 This is the character that separates a table and column name. It is
1846 necessary to specify this when the C<quote_char> option is selected,
1847 so that tables and column names can be individually quoted like this:
1849 SELECT `table`.`one_field` FROM `table` WHERE `table`.`other_field` = 1
1851 =item injection_guard
1853 A regular expression C<qr/.../> that is applied to any C<-function> and unquoted
1854 column name specified in a query structure. This is a safety mechanism to avoid
1855 injection attacks when mishandling user input e.g.:
1857 my %condition_as_column_value_pairs = get_values_from_user();
1858 $sqla->select( ... , \%condition_as_column_value_pairs );
1860 If the expression matches an exception is thrown. Note that literal SQL
1861 supplied via C<\'...'> or C<\['...']> is B<not> checked in any way.
1863 Defaults to checking for C<;> and the C<GO> keyword (TransactSQL)
1865 =item array_datatypes
1867 When this option is true, arrayrefs in INSERT or UPDATE are
1868 interpreted as array datatypes and are passed directly
1870 When this option is false, arrayrefs are interpreted
1871 as literal SQL, just like refs to arrayrefs
1872 (but this behavior is for backwards compatibility; when writing
1873 new queries, use the "reference to arrayref" syntax
1879 Takes a reference to a list of "special operators"
1880 to extend the syntax understood by L<SQL::Abstract>.
1881 See section L</"SPECIAL OPERATORS"> for details.
1885 Takes a reference to a list of "unary operators"
1886 to extend the syntax understood by L<SQL::Abstract>.
1887 See section L</"UNARY OPERATORS"> for details.
1893 =head2 insert($table, \@values || \%fieldvals, \%options)
1895 This is the simplest function. You simply give it a table name
1896 and either an arrayref of values or hashref of field/value pairs.
1897 It returns an SQL INSERT statement and a list of bind values.
1898 See the sections on L</"Inserting and Updating Arrays"> and
1899 L</"Inserting and Updating SQL"> for information on how to insert
1900 with those data types.
1902 The optional C<\%options> hash reference may contain additional
1903 options to generate the insert SQL. Currently supported options
1910 Takes either a scalar of raw SQL fields, or an array reference of
1911 field names, and adds on an SQL C<RETURNING> statement at the end.
1912 This allows you to return data generated by the insert statement
1913 (such as row IDs) without performing another C<SELECT> statement.
1914 Note, however, this is not part of the SQL standard and may not
1915 be supported by all database engines.
1919 =head2 update($table, \%fieldvals, \%where)
1921 This takes a table, hashref of field/value pairs, and an optional
1922 hashref L<WHERE clause|/WHERE CLAUSES>. It returns an SQL UPDATE function and a list
1924 See the sections on L</"Inserting and Updating Arrays"> and
1925 L</"Inserting and Updating SQL"> for information on how to insert
1926 with those data types.
1928 =head2 select($source, $fields, $where, $order)
1930 This returns a SQL SELECT statement and associated list of bind values, as
1931 specified by the arguments :
1937 Specification of the 'FROM' part of the statement.
1938 The argument can be either a plain scalar (interpreted as a table
1939 name, will be quoted), or an arrayref (interpreted as a list
1940 of table names, joined by commas, quoted), or a scalarref
1941 (literal table name, not quoted), or a ref to an arrayref
1942 (list of literal table names, joined by commas, not quoted).
1946 Specification of the list of fields to retrieve from
1948 The argument can be either an arrayref (interpreted as a list
1949 of field names, will be joined by commas and quoted), or a
1950 plain scalar (literal SQL, not quoted).
1951 Please observe that this API is not as flexible as for
1952 the first argument C<$table>, for backwards compatibility reasons.
1956 Optional argument to specify the WHERE part of the query.
1957 The argument is most often a hashref, but can also be
1958 an arrayref or plain scalar --
1959 see section L<WHERE clause|/"WHERE CLAUSES"> for details.
1963 Optional argument to specify the ORDER BY part of the query.
1964 The argument can be a scalar, a hashref or an arrayref
1965 -- see section L<ORDER BY clause|/"ORDER BY CLAUSES">
1971 =head2 delete($table, \%where)
1973 This takes a table name and optional hashref L<WHERE clause|/WHERE CLAUSES>.
1974 It returns an SQL DELETE statement and list of bind values.
1976 =head2 where(\%where, \@order)
1978 This is used to generate just the WHERE clause. For example,
1979 if you have an arbitrary data structure and know what the
1980 rest of your SQL is going to look like, but want an easy way
1981 to produce a WHERE clause, use this. It returns an SQL WHERE
1982 clause and list of bind values.
1985 =head2 values(\%data)
1987 This just returns the values from the hash C<%data>, in the same
1988 order that would be returned from any of the other above queries.
1989 Using this allows you to markedly speed up your queries if you
1990 are affecting lots of rows. See below under the L</"PERFORMANCE"> section.
1992 =head2 generate($any, 'number', $of, \@data, $struct, \%types)
1994 Warning: This is an experimental method and subject to change.
1996 This returns arbitrarily generated SQL. It's a really basic shortcut.
1997 It will return two different things, depending on return context:
1999 my($stmt, @bind) = $sql->generate('create table', \$table, \@fields);
2000 my $stmt_and_val = $sql->generate('create table', \$table, \@fields);
2002 These would return the following:
2004 # First calling form
2005 $stmt = "CREATE TABLE test (?, ?)";
2006 @bind = (field1, field2);
2008 # Second calling form
2009 $stmt_and_val = "CREATE TABLE test (field1, field2)";
2011 Depending on what you're trying to do, it's up to you to choose the correct
2012 format. In this example, the second form is what you would want.
2016 $sql->generate('alter session', { nls_date_format => 'MM/YY' });
2020 ALTER SESSION SET nls_date_format = 'MM/YY'
2022 You get the idea. Strings get their case twiddled, but everything
2023 else remains verbatim.
2025 =head1 WHERE CLAUSES
2029 This module uses a variation on the idea from L<DBIx::Abstract>. It
2030 is B<NOT>, repeat I<not> 100% compatible. B<The main logic of this
2031 module is that things in arrays are OR'ed, and things in hashes
2034 The easiest way to explain is to show lots of examples. After
2035 each C<%where> hash shown, it is assumed you used:
2037 my($stmt, @bind) = $sql->where(\%where);
2039 However, note that the C<%where> hash can be used directly in any
2040 of the other functions as well, as described above.
2042 =head2 Key-value pairs
2044 So, let's get started. To begin, a simple hash:
2048 status => 'completed'
2051 Is converted to SQL C<key = val> statements:
2053 $stmt = "WHERE user = ? AND status = ?";
2054 @bind = ('nwiger', 'completed');
2056 One common thing I end up doing is having a list of values that
2057 a field can be in. To do this, simply specify a list inside of
2062 status => ['assigned', 'in-progress', 'pending'];
2065 This simple code will create the following:
2067 $stmt = "WHERE user = ? AND ( status = ? OR status = ? OR status = ? )";
2068 @bind = ('nwiger', 'assigned', 'in-progress', 'pending');
2070 A field associated to an empty arrayref will be considered a
2071 logical false and will generate 0=1.
2073 =head2 Tests for NULL values
2075 If the value part is C<undef> then this is converted to SQL <IS NULL>
2084 $stmt = "WHERE user = ? AND status IS NULL";
2087 To test if a column IS NOT NULL:
2091 status => { '!=', undef },
2094 =head2 Specific comparison operators
2096 If you want to specify a different type of operator for your comparison,
2097 you can use a hashref for a given column:
2101 status => { '!=', 'completed' }
2104 Which would generate:
2106 $stmt = "WHERE user = ? AND status != ?";
2107 @bind = ('nwiger', 'completed');
2109 To test against multiple values, just enclose the values in an arrayref:
2111 status => { '=', ['assigned', 'in-progress', 'pending'] };
2113 Which would give you:
2115 "WHERE status = ? OR status = ? OR status = ?"
2118 The hashref can also contain multiple pairs, in which case it is expanded
2119 into an C<AND> of its elements:
2123 status => { '!=', 'completed', -not_like => 'pending%' }
2126 # Or more dynamically, like from a form
2127 $where{user} = 'nwiger';
2128 $where{status}{'!='} = 'completed';
2129 $where{status}{'-not_like'} = 'pending%';
2131 # Both generate this
2132 $stmt = "WHERE user = ? AND status != ? AND status NOT LIKE ?";
2133 @bind = ('nwiger', 'completed', 'pending%');
2136 To get an OR instead, you can combine it with the arrayref idea:
2140 priority => [ { '=', 2 }, { '>', 5 } ]
2143 Which would generate:
2145 $stmt = "WHERE ( priority = ? OR priority > ? ) AND user = ?";
2146 @bind = ('2', '5', 'nwiger');
2148 If you want to include literal SQL (with or without bind values), just use a
2149 scalar reference or array reference as the value:
2152 date_entered => { '>' => \["to_date(?, 'MM/DD/YYYY')", "11/26/2008"] },
2153 date_expires => { '<' => \"now()" }
2156 Which would generate:
2158 $stmt = "WHERE date_entered > "to_date(?, 'MM/DD/YYYY') AND date_expires < now()";
2159 @bind = ('11/26/2008');
2162 =head2 Logic and nesting operators
2164 In the example above,
2165 there is a subtle trap if you want to say something like
2166 this (notice the C<AND>):
2168 WHERE priority != ? AND priority != ?
2170 Because, in Perl you I<can't> do this:
2172 priority => { '!=', 2, '!=', 1 }
2174 As the second C<!=> key will obliterate the first. The solution
2175 is to use the special C<-modifier> form inside an arrayref:
2177 priority => [ -and => {'!=', 2},
2181 Normally, these would be joined by C<OR>, but the modifier tells it
2182 to use C<AND> instead. (Hint: You can use this in conjunction with the
2183 C<logic> option to C<new()> in order to change the way your queries
2184 work by default.) B<Important:> Note that the C<-modifier> goes
2185 B<INSIDE> the arrayref, as an extra first element. This will
2186 B<NOT> do what you think it might:
2188 priority => -and => [{'!=', 2}, {'!=', 1}] # WRONG!
2190 Here is a quick list of equivalencies, since there is some overlap:
2193 status => {'!=', 'completed', 'not like', 'pending%' }
2194 status => [ -and => {'!=', 'completed'}, {'not like', 'pending%'}]
2197 status => {'=', ['assigned', 'in-progress']}
2198 status => [ -or => {'=', 'assigned'}, {'=', 'in-progress'}]
2199 status => [ {'=', 'assigned'}, {'=', 'in-progress'} ]
2203 =head2 Special operators : IN, BETWEEN, etc.
2205 You can also use the hashref format to compare a list of fields using the
2206 C<IN> comparison operator, by specifying the list as an arrayref:
2209 status => 'completed',
2210 reportid => { -in => [567, 2335, 2] }
2213 Which would generate:
2215 $stmt = "WHERE status = ? AND reportid IN (?,?,?)";
2216 @bind = ('completed', '567', '2335', '2');
2218 The reverse operator C<-not_in> generates SQL C<NOT IN> and is used in
2221 If the argument to C<-in> is an empty array, 'sqlfalse' is generated
2222 (by default : C<1=0>). Similarly, C<< -not_in => [] >> generates
2223 'sqltrue' (by default : C<1=1>).
2225 In addition to the array you can supply a chunk of literal sql or
2226 literal sql with bind:
2229 customer => { -in => \[
2230 'SELECT cust_id FROM cust WHERE balance > ?',
2233 status => { -in => \'SELECT status_codes FROM states' },
2239 customer IN ( SELECT cust_id FROM cust WHERE balance > ? )
2240 AND status IN ( SELECT status_codes FROM states )
2246 Another pair of operators is C<-between> and C<-not_between>,
2247 used with an arrayref of two values:
2251 completion_date => {
2252 -not_between => ['2002-10-01', '2003-02-06']
2258 WHERE user = ? AND completion_date NOT BETWEEN ( ? AND ? )
2260 Just like with C<-in> all plausible combinations of literal SQL
2264 start0 => { -between => [ 1, 2 ] },
2265 start1 => { -between => \["? AND ?", 1, 2] },
2266 start2 => { -between => \"lower(x) AND upper(y)" },
2267 start3 => { -between => [
2269 \["upper(?)", 'stuff' ],
2276 ( start0 BETWEEN ? AND ? )
2277 AND ( start1 BETWEEN ? AND ? )
2278 AND ( start2 BETWEEN lower(x) AND upper(y) )
2279 AND ( start3 BETWEEN lower(x) AND upper(?) )
2281 @bind = (1, 2, 1, 2, 'stuff');
2284 These are the two builtin "special operators"; but the
2285 list can be expanded : see section L</"SPECIAL OPERATORS"> below.
2287 =head2 Unary operators: bool
2289 If you wish to test against boolean columns or functions within your
2290 database you can use the C<-bool> and C<-not_bool> operators. For
2291 example to test the column C<is_user> being true and the column
2292 C<is_enabled> being false you would use:-
2296 -not_bool => 'is_enabled',
2301 WHERE is_user AND NOT is_enabled
2303 If a more complex combination is required, testing more conditions,
2304 then you should use the and/or operators:-
2311 -not_bool => 'four',
2317 WHERE one AND two AND three AND NOT four
2320 =head2 Nested conditions, -and/-or prefixes
2322 So far, we've seen how multiple conditions are joined with a top-level
2323 C<AND>. We can change this by putting the different conditions we want in
2324 hashes and then putting those hashes in an array. For example:
2329 status => { -like => ['pending%', 'dispatched'] },
2333 status => 'unassigned',
2337 This data structure would create the following:
2339 $stmt = "WHERE ( user = ? AND ( status LIKE ? OR status LIKE ? ) )
2340 OR ( user = ? AND status = ? ) )";
2341 @bind = ('nwiger', 'pending', 'dispatched', 'robot', 'unassigned');
2344 Clauses in hashrefs or arrayrefs can be prefixed with an C<-and> or C<-or>
2345 to change the logic inside :
2351 -and => [ workhrs => {'>', 20}, geo => 'ASIA' ],
2352 -or => { workhrs => {'<', 50}, geo => 'EURO' },
2359 WHERE ( user = ? AND (
2360 ( workhrs > ? AND geo = ? )
2361 OR ( workhrs < ? OR geo = ? )
2364 =head3 Algebraic inconsistency, for historical reasons
2366 C<Important note>: when connecting several conditions, the C<-and->|C<-or>
2367 operator goes C<outside> of the nested structure; whereas when connecting
2368 several constraints on one column, the C<-and> operator goes
2369 C<inside> the arrayref. Here is an example combining both features :
2372 -and => [a => 1, b => 2],
2373 -or => [c => 3, d => 4],
2374 e => [-and => {-like => 'foo%'}, {-like => '%bar'} ]
2379 WHERE ( ( ( a = ? AND b = ? )
2380 OR ( c = ? OR d = ? )
2381 OR ( e LIKE ? AND e LIKE ? ) ) )
2383 This difference in syntax is unfortunate but must be preserved for
2384 historical reasons. So be careful : the two examples below would
2385 seem algebraically equivalent, but they are not
2387 {col => [-and => {-like => 'foo%'}, {-like => '%bar'}]}
2388 # yields : WHERE ( ( col LIKE ? AND col LIKE ? ) )
2390 [-and => {col => {-like => 'foo%'}, {col => {-like => '%bar'}}]]
2391 # yields : WHERE ( ( col LIKE ? OR col LIKE ? ) )
2394 =head2 Literal SQL and value type operators
2396 The basic premise of SQL::Abstract is that in WHERE specifications the "left
2397 side" is a column name and the "right side" is a value (normally rendered as
2398 a placeholder). This holds true for both hashrefs and arrayref pairs as you
2399 see in the L</WHERE CLAUSES> examples above. Sometimes it is necessary to
2400 alter this behavior. There are several ways of doing so.
2404 This is a virtual operator that signals the string to its right side is an
2405 identifier (a column name) and not a value. For example to compare two
2406 columns you would write:
2409 priority => { '<', 2 },
2410 requestor => { -ident => 'submitter' },
2415 $stmt = "WHERE priority < ? AND requestor = submitter";
2418 If you are maintaining legacy code you may see a different construct as
2419 described in L</Deprecated usage of Literal SQL>, please use C<-ident> in new
2424 This is a virtual operator that signals that the construct to its right side
2425 is a value to be passed to DBI. This is for example necessary when you want
2426 to write a where clause against an array (for RDBMS that support such
2427 datatypes). For example:
2430 array => { -value => [1, 2, 3] }
2435 $stmt = 'WHERE array = ?';
2436 @bind = ([1, 2, 3]);
2438 Note that if you were to simply say:
2444 the result would porbably be not what you wanted:
2446 $stmt = 'WHERE array = ? OR array = ? OR array = ?';
2451 Finally, sometimes only literal SQL will do. To include a random snippet
2452 of SQL verbatim, you specify it as a scalar reference. Consider this only
2453 as a last resort. Usually there is a better way. For example:
2456 priority => { '<', 2 },
2457 requestor => { -in => \'(SELECT name FROM hitmen)' },
2462 $stmt = "WHERE priority < ? AND requestor IN (SELECT name FROM hitmen)"
2465 Note that in this example, you only get one bind parameter back, since
2466 the verbatim SQL is passed as part of the statement.
2470 Never use untrusted input as a literal SQL argument - this is a massive
2471 security risk (there is no way to check literal snippets for SQL
2472 injections and other nastyness). If you need to deal with untrusted input
2473 use literal SQL with placeholders as described next.
2475 =head3 Literal SQL with placeholders and bind values (subqueries)
2477 If the literal SQL to be inserted has placeholders and bind values,
2478 use a reference to an arrayref (yes this is a double reference --
2479 not so common, but perfectly legal Perl). For example, to find a date
2480 in Postgres you can use something like this:
2483 date_column => \[q/= date '2008-09-30' - ?::integer/, 10/]
2488 $stmt = "WHERE ( date_column = date '2008-09-30' - ?::integer )"
2491 Note that you must pass the bind values in the same format as they are returned
2492 by L</where>. That means that if you set L</bindtype> to C<columns>, you must
2493 provide the bind values in the C<< [ column_meta => value ] >> format, where
2494 C<column_meta> is an opaque scalar value; most commonly the column name, but
2495 you can use any scalar value (including references and blessed references),
2496 L<SQL::Abstract> will simply pass it through intact. So if C<bindtype> is set
2497 to C<columns> the above example will look like:
2500 date_column => \[q/= date '2008-09-30' - ?::integer/, [ dummy => 10 ]/]
2503 Literal SQL is especially useful for nesting parenthesized clauses in the
2504 main SQL query. Here is a first example :
2506 my ($sub_stmt, @sub_bind) = ("SELECT c1 FROM t1 WHERE c2 < ? AND c3 LIKE ?",
2510 bar => \["IN ($sub_stmt)" => @sub_bind],
2515 $stmt = "WHERE (foo = ? AND bar IN (SELECT c1 FROM t1
2516 WHERE c2 < ? AND c3 LIKE ?))";
2517 @bind = (1234, 100, "foo%");
2519 Other subquery operators, like for example C<"E<gt> ALL"> or C<"NOT IN">,
2520 are expressed in the same way. Of course the C<$sub_stmt> and
2521 its associated bind values can be generated through a former call
2524 my ($sub_stmt, @sub_bind)
2525 = $sql->select("t1", "c1", {c2 => {"<" => 100},
2526 c3 => {-like => "foo%"}});
2529 bar => \["> ALL ($sub_stmt)" => @sub_bind],
2532 In the examples above, the subquery was used as an operator on a column;
2533 but the same principle also applies for a clause within the main C<%where>
2534 hash, like an EXISTS subquery :
2536 my ($sub_stmt, @sub_bind)
2537 = $sql->select("t1", "*", {c1 => 1, c2 => \"> t0.c0"});
2538 my %where = ( -and => [
2540 \["EXISTS ($sub_stmt)" => @sub_bind],
2545 $stmt = "WHERE (foo = ? AND EXISTS (SELECT * FROM t1
2546 WHERE c1 = ? AND c2 > t0.c0))";
2550 Observe that the condition on C<c2> in the subquery refers to
2551 column C<t0.c0> of the main query : this is I<not> a bind
2552 value, so we have to express it through a scalar ref.
2553 Writing C<< c2 => {">" => "t0.c0"} >> would have generated
2554 C<< c2 > ? >> with bind value C<"t0.c0"> ... not exactly
2555 what we wanted here.
2557 Finally, here is an example where a subquery is used
2558 for expressing unary negation:
2560 my ($sub_stmt, @sub_bind)
2561 = $sql->where({age => [{"<" => 10}, {">" => 20}]});
2562 $sub_stmt =~ s/^ where //i; # don't want "WHERE" in the subclause
2564 lname => {like => '%son%'},
2565 \["NOT ($sub_stmt)" => @sub_bind],
2570 $stmt = "lname LIKE ? AND NOT ( age < ? OR age > ? )"
2571 @bind = ('%son%', 10, 20)
2573 =head3 Deprecated usage of Literal SQL
2575 Below are some examples of archaic use of literal SQL. It is shown only as
2576 reference for those who deal with legacy code. Each example has a much
2577 better, cleaner and safer alternative that users should opt for in new code.
2583 my %where = ( requestor => \'IS NOT NULL' )
2585 $stmt = "WHERE requestor IS NOT NULL"
2587 This used to be the way of generating NULL comparisons, before the handling
2588 of C<undef> got formalized. For new code please use the superior syntax as
2589 described in L</Tests for NULL values>.
2593 my %where = ( requestor => \'= submitter' )
2595 $stmt = "WHERE requestor = submitter"
2597 This used to be the only way to compare columns. Use the superior L</-ident>
2598 method for all new code. For example an identifier declared in such a way
2599 will be properly quoted if L</quote_char> is properly set, while the legacy
2600 form will remain as supplied.
2604 my %where = ( is_ready => \"", completed => { '>', '2012-12-21' } )
2606 $stmt = "WHERE completed > ? AND is_ready"
2607 @bind = ('2012-12-21')
2609 Using an empty string literal used to be the only way to express a boolean.
2610 For all new code please use the much more readable
2611 L<-bool|/Unary operators: bool> operator.
2617 These pages could go on for a while, since the nesting of the data
2618 structures this module can handle are pretty much unlimited (the
2619 module implements the C<WHERE> expansion as a recursive function
2620 internally). Your best bet is to "play around" with the module a
2621 little to see how the data structures behave, and choose the best
2622 format for your data based on that.
2624 And of course, all the values above will probably be replaced with
2625 variables gotten from forms or the command line. After all, if you
2626 knew everything ahead of time, you wouldn't have to worry about
2627 dynamically-generating SQL and could just hardwire it into your
2630 =head1 ORDER BY CLAUSES
2632 Some functions take an order by clause. This can either be a scalar (just a
2633 column name,) a hash of C<< { -desc => 'col' } >> or C<< { -asc => 'col' } >>,
2634 optionally with C<< -nulls => 'first' >> or C<< -nulls => 'last' >>,
2635 or an array of either of the two previous forms. Examples:
2637 Given | Will Generate
2638 ----------------------------------------------------------
2640 \'colA DESC' | ORDER BY colA DESC
2642 'colA' | ORDER BY colA
2644 [qw/colA colB/] | ORDER BY colA, colB
2646 {-asc => 'colA'} | ORDER BY colA ASC
2648 {-desc => 'colB'} | ORDER BY colB DESC
2651 -asc => 'colA', | ORDER BY colA ASC NULLS LAST
2655 ['colA', {-asc => 'colB'}] | ORDER BY colA, colB ASC
2657 { -asc => [qw/colA colB/] } | ORDER BY colA ASC, colB ASC
2660 -asc => [qw/colA colB/] | ORDER BY colA ASC NULLS FIRST,
2661 -nulls => 'first' | colB ASC NULLS FIRST
2665 { -asc => 'colA' }, | ORDER BY colA ASC, colB DESC,
2666 { -desc => [qw/colB/], | colC ASC, colD ASC
2667 { -asc => [qw/colC colD/],|
2669 ===========================================================
2673 =head1 SPECIAL OPERATORS
2675 my $sqlmaker = SQL::Abstract->new(special_ops => [
2679 my ($self, $field, $op, $arg) = @_;
2685 handler => 'method_name',
2689 A "special operator" is a SQL syntactic clause that can be
2690 applied to a field, instead of a usual binary operator.
2693 WHERE field IN (?, ?, ?)
2694 WHERE field BETWEEN ? AND ?
2695 WHERE MATCH(field) AGAINST (?, ?)
2697 Special operators IN and BETWEEN are fairly standard and therefore
2698 are builtin within C<SQL::Abstract> (as the overridable methods
2699 C<_where_field_IN> and C<_where_field_BETWEEN>). For other operators,
2700 like the MATCH .. AGAINST example above which is specific to MySQL,
2701 you can write your own operator handlers - supply a C<special_ops>
2702 argument to the C<new> method. That argument takes an arrayref of
2703 operator definitions; each operator definition is a hashref with two
2710 the regular expression to match the operator
2714 Either a coderef or a plain scalar method name. In both cases
2715 the expected return is C<< ($sql, @bind) >>.
2717 When supplied with a method name, it is simply called on the
2718 L<SQL::Abstract/> object as:
2720 $self->$method_name ($field, $op, $arg)
2724 $op is the part that matched the handler regex
2725 $field is the LHS of the operator
2728 When supplied with a coderef, it is called as:
2730 $coderef->($self, $field, $op, $arg)
2735 For example, here is an implementation
2736 of the MATCH .. AGAINST syntax for MySQL
2738 my $sqlmaker = SQL::Abstract->new(special_ops => [
2740 # special op for MySql MATCH (field) AGAINST(word1, word2, ...)
2741 {regex => qr/^match$/i,
2743 my ($self, $field, $op, $arg) = @_;
2744 $arg = [$arg] if not ref $arg;
2745 my $label = $self->_quote($field);
2746 my ($placeholder) = $self->_convert('?');
2747 my $placeholders = join ", ", (($placeholder) x @$arg);
2748 my $sql = $self->_sqlcase('match') . " ($label) "
2749 . $self->_sqlcase('against') . " ($placeholders) ";
2750 my @bind = $self->_bindtype($field, @$arg);
2751 return ($sql, @bind);
2758 =head1 UNARY OPERATORS
2760 my $sqlmaker = SQL::Abstract->new(unary_ops => [
2764 my ($self, $op, $arg) = @_;
2770 handler => 'method_name',
2774 A "unary operator" is a SQL syntactic clause that can be
2775 applied to a field - the operator goes before the field
2777 You can write your own operator handlers - supply a C<unary_ops>
2778 argument to the C<new> method. That argument takes an arrayref of
2779 operator definitions; each operator definition is a hashref with two
2786 the regular expression to match the operator
2790 Either a coderef or a plain scalar method name. In both cases
2791 the expected return is C<< $sql >>.
2793 When supplied with a method name, it is simply called on the
2794 L<SQL::Abstract/> object as:
2796 $self->$method_name ($op, $arg)
2800 $op is the part that matched the handler regex
2801 $arg is the RHS or argument of the operator
2803 When supplied with a coderef, it is called as:
2805 $coderef->($self, $op, $arg)
2813 Thanks to some benchmarking by Mark Stosberg, it turns out that
2814 this module is many orders of magnitude faster than using C<DBIx::Abstract>.
2815 I must admit this wasn't an intentional design issue, but it's a
2816 byproduct of the fact that you get to control your C<DBI> handles
2819 To maximize performance, use a code snippet like the following:
2821 # prepare a statement handle using the first row
2822 # and then reuse it for the rest of the rows
2824 for my $href (@array_of_hashrefs) {
2825 $stmt ||= $sql->insert('table', $href);
2826 $sth ||= $dbh->prepare($stmt);
2827 $sth->execute($sql->values($href));
2830 The reason this works is because the keys in your C<$href> are sorted
2831 internally by B<SQL::Abstract>. Thus, as long as your data retains
2832 the same structure, you only have to generate the SQL the first time
2833 around. On subsequent queries, simply use the C<values> function provided
2834 by this module to return your values in the correct order.
2836 However this depends on the values having the same type - if, for
2837 example, the values of a where clause may either have values
2838 (resulting in sql of the form C<column = ?> with a single bind
2839 value), or alternatively the values might be C<undef> (resulting in
2840 sql of the form C<column IS NULL> with no bind value) then the
2841 caching technique suggested will not work.
2845 If you use my C<CGI::FormBuilder> module at all, you'll hopefully
2846 really like this part (I do, at least). Building up a complex query
2847 can be as simple as the following:
2851 use CGI::FormBuilder;
2854 my $form = CGI::FormBuilder->new(...);
2855 my $sql = SQL::Abstract->new;
2857 if ($form->submitted) {
2858 my $field = $form->field;
2859 my $id = delete $field->{id};
2860 my($stmt, @bind) = $sql->update('table', $field, {id => $id});
2863 Of course, you would still have to connect using C<DBI> to run the
2864 query, but the point is that if you make your form look like your
2865 table, the actual query script can be extremely simplistic.
2867 If you're B<REALLY> lazy (I am), check out C<HTML::QuickTable> for
2868 a fast interface to returning and formatting data. I frequently
2869 use these three modules together to write complex database query
2870 apps in under 50 lines.
2876 =item * gitweb: L<http://git.shadowcat.co.uk/gitweb/gitweb.cgi?p=dbsrgits/SQL-Abstract.git>
2878 =item * git: L<git://git.shadowcat.co.uk/dbsrgits/SQL-Abstract.git>
2884 Version 1.50 was a major internal refactoring of C<SQL::Abstract>.
2885 Great care has been taken to preserve the I<published> behavior
2886 documented in previous versions in the 1.* family; however,
2887 some features that were previously undocumented, or behaved
2888 differently from the documentation, had to be changed in order
2889 to clarify the semantics. Hence, client code that was relying
2890 on some dark areas of C<SQL::Abstract> v1.*
2891 B<might behave differently> in v1.50.
2893 The main changes are :
2899 support for literal SQL through the C<< \ [$sql, bind] >> syntax.
2903 support for the { operator => \"..." } construct (to embed literal SQL)
2907 support for the { operator => \["...", @bind] } construct (to embed literal SQL with bind values)
2911 optional support for L<array datatypes|/"Inserting and Updating Arrays">
2915 defensive programming : check arguments
2919 fixed bug with global logic, which was previously implemented
2920 through global variables yielding side-effects. Prior versions would
2921 interpret C<< [ {cond1, cond2}, [cond3, cond4] ] >>
2922 as C<< "(cond1 AND cond2) OR (cond3 AND cond4)" >>.
2923 Now this is interpreted
2924 as C<< "(cond1 AND cond2) OR (cond3 OR cond4)" >>.
2929 fixed semantics of _bindtype on array args
2933 dropped the C<_anoncopy> of the %where tree. No longer necessary,
2934 we just avoid shifting arrays within that tree.
2938 dropped the C<_modlogic> function
2942 =head1 ACKNOWLEDGEMENTS
2944 There are a number of individuals that have really helped out with
2945 this module. Unfortunately, most of them submitted bugs via CPAN
2946 so I have no idea who they are! But the people I do know are:
2948 Ash Berlin (order_by hash term support)
2949 Matt Trout (DBIx::Class support)
2950 Mark Stosberg (benchmarking)
2951 Chas Owens (initial "IN" operator support)
2952 Philip Collins (per-field SQL functions)
2953 Eric Kolve (hashref "AND" support)
2954 Mike Fragassi (enhancements to "BETWEEN" and "LIKE")
2955 Dan Kubb (support for "quote_char" and "name_sep")
2956 Guillermo Roditi (patch to cleanup "IN" and "BETWEEN", fix and tests for _order_by)
2957 Laurent Dami (internal refactoring, extensible list of special operators, literal SQL)
2958 Norbert Buchmuller (support for literal SQL in hashpair, misc. fixes & tests)
2959 Peter Rabbitson (rewrite of SQLA::Test, misc. fixes & tests)
2960 Oliver Charles (support for "RETURNING" after "INSERT")
2966 L<DBIx::Class>, L<DBIx::Abstract>, L<CGI::FormBuilder>, L<HTML::QuickTable>.
2970 Copyright (c) 2001-2007 Nathan Wiger <nwiger@cpan.org>. All Rights Reserved.
2972 This module is actively maintained by Matt Trout <mst@shadowcatsystems.co.uk>
2974 For support, your best bet is to try the C<DBIx::Class> users mailing list.
2975 While not an official support venue, C<DBIx::Class> makes heavy use of
2976 C<SQL::Abstract>, and as such list members there are very familiar with
2977 how to create queries.
2981 This module is free software; you may copy this under the same
2982 terms as perl itself (either the GNU General Public License or
2983 the Artistic License)