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)
13 use Data::Query::Constants qw(
14 DQ_IDENTIFIER DQ_OPERATOR DQ_VALUE DQ_LITERAL
17 #======================================================================
19 #======================================================================
21 our $VERSION = '1.72';
23 # This would confuse some packagers
24 $VERSION = eval $VERSION if $VERSION =~ /_/; # numify for warning-free dev releases
28 # special operators (-in, -between). May be extended/overridden by user.
29 # See section WHERE: BUILTIN SPECIAL OPERATORS below for implementation
30 my @BUILTIN_SPECIAL_OPS = (
31 {regex => qr/^ (?: not \s )? between $/ix, handler => '_where_field_BETWEEN'},
32 {regex => qr/^ (?: not \s )? in $/ix, handler => '_where_field_IN'},
33 {regex => qr/^ ident $/ix, handler => '_where_op_IDENT'},
34 {regex => qr/^ value $/ix, handler => '_where_op_VALUE'},
37 # unaryish operators - key maps to handler
38 my @BUILTIN_UNARY_OPS = (
39 # the digits are backcompat stuff
40 { regex => qr/^ and (?: [_\s]? \d+ )? $/xi, handler => '_where_op_ANDOR' },
41 { regex => qr/^ or (?: [_\s]? \d+ )? $/xi, handler => '_where_op_ANDOR' },
42 { regex => qr/^ nest (?: [_\s]? \d+ )? $/xi, handler => '_where_op_NEST' },
43 { regex => qr/^ (?: not \s )? bool $/xi, handler => '_where_op_BOOL' },
44 { regex => qr/^ ident $/xi, handler => '_where_op_IDENT' },
45 { regex => qr/^ value $/ix, handler => '_where_op_VALUE' },
48 #======================================================================
49 # DEBUGGING AND ERROR REPORTING
50 #======================================================================
53 return unless $_[0]->{debug}; shift; # a little faster
54 my $func = (caller(1))[3];
55 warn "[$func] ", @_, "\n";
59 my($func) = (caller(1))[3];
60 Carp::carp "[$func] Warning: ", @_;
64 my($func) = (caller(1))[3];
65 Carp::croak "[$func] Fatal: ", @_;
69 #======================================================================
71 #======================================================================
75 my $class = ref($self) || $self;
76 my %opt = (ref $_[0] eq 'HASH') ? %{$_[0]} : @_;
78 # choose our case by keeping an option around
79 delete $opt{case} if $opt{case} && $opt{case} ne 'lower';
81 # default logic for interpreting arrayrefs
82 $opt{logic} = $opt{logic} ? uc $opt{logic} : 'OR';
84 # how to return bind vars
85 # LDNOTE: changed nwiger code : why this 'delete' ??
86 # $opt{bindtype} ||= delete($opt{bind_type}) || 'normal';
87 $opt{bindtype} ||= 'normal';
89 # default comparison is "=", but can be overridden
92 # try to recognize which are the 'equality' and 'unequality' ops
93 # (temporary quickfix, should go through a more seasoned API)
94 $opt{equality_op} = qr/^(\Q$opt{cmp}\E|is|(is\s+)?like)$/i;
95 $opt{inequality_op} = qr/^(!=|<>|(is\s+)?not(\s+like)?)$/i;
98 $opt{sqltrue} ||= '1=1';
99 $opt{sqlfalse} ||= '0=1';
102 $opt{special_ops} ||= [];
103 # regexes are applied in order, thus push after user-defines
104 push @{$opt{special_ops}}, @BUILTIN_SPECIAL_OPS;
107 $opt{unary_ops} ||= [];
108 push @{$opt{unary_ops}}, @BUILTIN_UNARY_OPS;
110 # rudimentary saniy-check for user supplied bits treated as functions/operators
111 # If a purported function matches this regular expression, an exception is thrown.
112 # Literal SQL is *NOT* subject to this check, only functions (and column names
113 # when quoting is not in effect)
116 # need to guard against ()'s in column names too, but this will break tons of
117 # hacks... ideas anyone?
118 $opt{injection_guard} ||= qr/
124 $opt{name_sep} ||= '.';
126 $opt{renderer} ||= do {
127 require Data::Query::Renderer::SQL::Naive;
128 my ($always, $chars);
129 for ($opt{quote_char}) {
130 $chars = defined() ? (ref() ? $_ : [$_]) : ['',''];
133 Data::Query::Renderer::SQL::Naive->new({
134 quote_chars => $chars, always_quote => $always,
138 return bless \%opt, $class;
142 my ($self, $dq) = @_;
143 my ($sql, @bind) = @{$self->{renderer}->render($dq)};
144 wantarray ? ($sql, map $_->{value}, @bind) : $sql;
147 sub _assert_pass_injection_guard {
148 if ($_[1] =~ $_[0]->{injection_guard}) {
149 my $class = ref $_[0];
150 puke "Possible SQL injection attempt '$_[1]'. If this is indeed a part of the "
151 . "desired SQL use literal SQL ( \'...' or \[ '...' ] ) or supply your own "
152 . "{injection_guard} attribute to ${class}->new()"
157 #======================================================================
159 #======================================================================
163 my $table = $self->_table(shift);
164 my $data = shift || return;
167 my $method = $self->_METHOD_FOR_refkind("_insert", $data);
168 my ($sql, @bind) = $self->$method($data);
169 $sql = join " ", $self->_sqlcase('insert into'), $table, $sql;
171 if ($options->{returning}) {
172 my ($s, @b) = $self->_insert_returning ($options);
177 return wantarray ? ($sql, @bind) : $sql;
180 sub _insert_returning {
181 my ($self, $options) = @_;
183 my $f = $options->{returning};
185 my $fieldlist = $self->_SWITCH_refkind($f, {
186 ARRAYREF => sub {join ', ', map { $self->_quote($_) } @$f;},
187 SCALAR => sub {$self->_quote($f)},
188 SCALARREF => sub {$$f},
190 return $self->_sqlcase(' returning ') . $fieldlist;
193 sub _insert_HASHREF { # explicit list of fields and then values
194 my ($self, $data) = @_;
196 my @fields = sort keys %$data;
198 my ($sql, @bind) = $self->_insert_values($data);
201 $_ = $self->_quote($_) foreach @fields;
202 $sql = "( ".join(", ", @fields).") ".$sql;
204 return ($sql, @bind);
207 sub _insert_ARRAYREF { # just generate values(?,?) part (no list of fields)
208 my ($self, $data) = @_;
210 # no names (arrayref) so can't generate bindtype
211 $self->{bindtype} ne 'columns'
212 or belch "can't do 'columns' bindtype when called with arrayref";
214 # fold the list of values into a hash of column name - value pairs
215 # (where the column names are artificially generated, and their
216 # lexicographical ordering keep the ordering of the original list)
217 my $i = "a"; # incremented values will be in lexicographical order
218 my $data_in_hash = { map { ($i++ => $_) } @$data };
220 return $self->_insert_values($data_in_hash);
223 sub _insert_ARRAYREFREF { # literal SQL with bind
224 my ($self, $data) = @_;
226 my ($sql, @bind) = @${$data};
227 $self->_assert_bindval_matches_bindtype(@bind);
229 return ($sql, @bind);
233 sub _insert_SCALARREF { # literal SQL without bind
234 my ($self, $data) = @_;
240 my ($self, $data) = @_;
242 my (@values, @all_bind);
243 foreach my $column (sort keys %$data) {
244 my $v = $data->{$column};
246 $self->_SWITCH_refkind($v, {
249 if ($self->{array_datatypes}) { # if array datatype are activated
251 push @all_bind, $self->_bindtype($column, $v);
253 else { # else literal SQL with bind
254 my ($sql, @bind) = @$v;
255 $self->_assert_bindval_matches_bindtype(@bind);
257 push @all_bind, @bind;
261 ARRAYREFREF => sub { # literal SQL with bind
262 my ($sql, @bind) = @${$v};
263 $self->_assert_bindval_matches_bindtype(@bind);
265 push @all_bind, @bind;
268 # THINK : anything useful to do with a HASHREF ?
269 HASHREF => sub { # (nothing, but old SQLA passed it through)
270 #TODO in SQLA >= 2.0 it will die instead
271 belch "HASH ref as bind value in insert is not supported";
273 push @all_bind, $self->_bindtype($column, $v);
276 SCALARREF => sub { # literal SQL without bind
280 SCALAR_or_UNDEF => sub {
282 push @all_bind, $self->_bindtype($column, $v);
289 my $sql = $self->_sqlcase('values')." ( ".join(", ", @values)." )";
290 return ($sql, @all_bind);
295 #======================================================================
297 #======================================================================
302 my $table = $self->_table(shift);
303 my $data = shift || return;
306 # first build the 'SET' part of the sql statement
307 my (@set, @all_bind);
308 puke "Unsupported data type specified to \$sql->update"
309 unless ref $data eq 'HASH';
311 for my $k (sort keys %$data) {
314 my $label = $self->_quote($k);
316 $self->_SWITCH_refkind($v, {
318 if ($self->{array_datatypes}) { # array datatype
319 push @set, "$label = ?";
320 push @all_bind, $self->_bindtype($k, $v);
322 else { # literal SQL with bind
323 my ($sql, @bind) = @$v;
324 $self->_assert_bindval_matches_bindtype(@bind);
325 push @set, "$label = $sql";
326 push @all_bind, @bind;
329 ARRAYREFREF => sub { # literal SQL with bind
330 my ($sql, @bind) = @${$v};
331 $self->_assert_bindval_matches_bindtype(@bind);
332 push @set, "$label = $sql";
333 push @all_bind, @bind;
335 SCALARREF => sub { # literal SQL without bind
336 push @set, "$label = $$v";
339 my ($op, $arg, @rest) = %$v;
341 puke 'Operator calls in update must be in the form { -op => $arg }'
342 if (@rest or not $op =~ /^\-(.+)/);
344 local $self->{_nested_func_lhs} = $k;
345 my ($sql, @bind) = $self->_where_unary_op ($1, $arg);
347 push @set, "$label = $sql";
348 push @all_bind, @bind;
350 SCALAR_or_UNDEF => sub {
351 push @set, "$label = ?";
352 push @all_bind, $self->_bindtype($k, $v);
358 my $sql = $self->_sqlcase('update') . " $table " . $self->_sqlcase('set ')
362 my($where_sql, @where_bind) = $self->where($where);
364 push @all_bind, @where_bind;
367 return wantarray ? ($sql, @all_bind) : $sql;
373 #======================================================================
375 #======================================================================
380 my $table = $self->_table(shift);
381 my $fields = shift || '*';
385 my($where_sql, @bind) = $self->where($where, $order);
387 my $f = (ref $fields eq 'ARRAY') ? join ', ', map { $self->_quote($_) } @$fields
389 my $sql = join(' ', $self->_sqlcase('select'), $f,
390 $self->_sqlcase('from'), $table)
393 return wantarray ? ($sql, @bind) : $sql;
396 #======================================================================
398 #======================================================================
403 my $table = $self->_table(shift);
407 my($where_sql, @bind) = $self->where($where);
408 my $sql = $self->_sqlcase('delete from') . " $table" . $where_sql;
410 return wantarray ? ($sql, @bind) : $sql;
414 #======================================================================
416 #======================================================================
420 # Finally, a separate routine just to handle WHERE clauses
422 my ($self, $where, $order) = @_;
425 my ($sql, @bind) = $self->_recurse_where($where);
426 $sql = $sql ? $self->_sqlcase(' where ') . "( $sql )" : '';
430 $sql .= $self->_order_by($order);
433 return wantarray ? ($sql, @bind) : $sql;
438 my ($self, $where, $logic) = @_;
440 # dispatch on appropriate method according to refkind of $where
441 my $method = $self->_METHOD_FOR_refkind("_where", $where);
443 my ($sql, @bind) = $self->$method($where, $logic);
445 # DBIx::Class directly calls _recurse_where in scalar context, so
446 # we must implement it, even if not in the official API
447 return wantarray ? ($sql, @bind) : $sql;
452 #======================================================================
453 # WHERE: top-level ARRAYREF
454 #======================================================================
457 sub _where_ARRAYREF {
458 my ($self, $where, $logic) = @_;
460 $logic = uc($logic || $self->{logic});
461 $logic eq 'AND' or $logic eq 'OR' or puke "unknown logic: $logic";
463 my @clauses = @$where;
465 my (@sql_clauses, @all_bind);
466 # need to use while() so can shift() for pairs
467 while (my $el = shift @clauses) {
469 # switch according to kind of $el and get corresponding ($sql, @bind)
470 my ($sql, @bind) = $self->_SWITCH_refkind($el, {
472 # skip empty elements, otherwise get invalid trailing AND stuff
473 ARRAYREF => sub {$self->_recurse_where($el) if @$el},
477 $self->_assert_bindval_matches_bindtype(@b);
481 HASHREF => sub {$self->_recurse_where($el, 'and') if %$el},
482 # LDNOTE : previous SQLA code for hashrefs was creating a dirty
483 # side-effect: the first hashref within an array would change
484 # the global logic to 'AND'. So [ {cond1, cond2}, [cond3, cond4] ]
485 # was interpreted as "(cond1 AND cond2) OR (cond3 AND cond4)",
486 # whereas it should be "(cond1 AND cond2) OR (cond3 OR cond4)".
488 SCALARREF => sub { ($$el); },
490 SCALAR => sub {# top-level arrayref with scalars, recurse in pairs
491 $self->_recurse_where({$el => shift(@clauses)})},
493 UNDEF => sub {puke "not supported : UNDEF in arrayref" },
497 push @sql_clauses, $sql;
498 push @all_bind, @bind;
502 return $self->_join_sql_clauses($logic, \@sql_clauses, \@all_bind);
505 #======================================================================
506 # WHERE: top-level ARRAYREFREF
507 #======================================================================
509 sub _where_ARRAYREFREF {
510 my ($self, $where) = @_;
511 my ($sql, @bind) = @$$where;
512 $self->_assert_bindval_matches_bindtype(@bind);
513 return ($sql, @bind);
516 #======================================================================
517 # WHERE: top-level HASHREF
518 #======================================================================
521 my ($self, $where) = @_;
522 my (@sql_clauses, @all_bind);
524 for my $k (sort keys %$where) {
525 my $v = $where->{$k};
527 # ($k => $v) is either a special unary op or a regular hashpair
528 my ($sql, @bind) = do {
530 # put the operator in canonical form
532 $op = substr $op, 1; # remove initial dash
533 $op =~ s/^\s+|\s+$//g;# remove leading/trailing space
534 $op =~ s/\s+/ /g; # compress whitespace
536 # so that -not_foo works correctly
537 $op =~ s/^not_/NOT /i;
539 $self->_debug("Unary OP(-$op) within hashref, recursing...");
540 my ($s, @b) = $self->_where_unary_op ($op, $v);
542 # top level vs nested
543 # we assume that handled unary ops will take care of their ()s
545 List::Util::first {$op =~ $_->{regex}} @{$self->{unary_ops}}
547 defined($self->{_nested_func_lhs}) && ($self->{_nested_func_lhs} eq $k)
552 my $method = $self->_METHOD_FOR_refkind("_where_hashpair", $v);
553 $self->$method($k, $v);
557 push @sql_clauses, $sql;
558 push @all_bind, @bind;
561 return $self->_join_sql_clauses('and', \@sql_clauses, \@all_bind);
564 sub _where_unary_op {
565 my ($self, $op, $rhs) = @_;
567 if (my $op_entry = List::Util::first {$op =~ $_->{regex}} @{$self->{unary_ops}}) {
568 my $handler = $op_entry->{handler};
570 if (not ref $handler) {
571 if ($op =~ s/ [_\s]? \d+ $//x ) {
572 belch 'Use of [and|or|nest]_N modifiers is deprecated and will be removed in SQLA v2.0. '
573 . "You probably wanted ...-and => [ -$op => COND1, -$op => COND2 ... ]";
575 return $self->$handler ($op, $rhs);
577 elsif (ref $handler eq 'CODE') {
578 return $handler->($self, $op, $rhs);
581 puke "Illegal handler for operator $op - expecting a method name or a coderef";
585 $self->_debug("Generic unary OP: $op - recursing as function");
587 $self->_assert_pass_injection_guard($op);
589 my ($sql, @bind) = $self->_SWITCH_refkind ($rhs, {
591 puke "Illegal use of top-level '$op'"
592 unless $self->{_nested_func_lhs};
595 $self->_convert('?'),
596 $self->_bindtype($self->{_nested_func_lhs}, $rhs)
600 $self->_recurse_where ($rhs)
604 $sql = sprintf ('%s %s',
605 $self->_sqlcase($op),
609 return ($sql, @bind);
612 sub _where_op_ANDOR {
613 my ($self, $op, $v) = @_;
615 $self->_SWITCH_refkind($v, {
617 return $self->_where_ARRAYREF($v, $op);
621 return ( $op =~ /^or/i )
622 ? $self->_where_ARRAYREF( [ map { $_ => $v->{$_} } ( sort keys %$v ) ], $op )
623 : $self->_where_HASHREF($v);
627 puke "-$op => \\\$scalar makes little sense, use " .
629 ? '[ \$scalar, \%rest_of_conditions ] instead'
630 : '-and => [ \$scalar, \%rest_of_conditions ] instead'
635 puke "-$op => \\[...] makes little sense, use " .
637 ? '[ \[...], \%rest_of_conditions ] instead'
638 : '-and => [ \[...], \%rest_of_conditions ] instead'
642 SCALAR => sub { # permissively interpreted as SQL
643 puke "-$op => \$value makes little sense, use -bool => \$value instead";
647 puke "-$op => undef not supported";
653 my ($self, $op, $v) = @_;
655 $self->_SWITCH_refkind($v, {
657 SCALAR => sub { # permissively interpreted as SQL
658 belch "literal SQL should be -nest => \\'scalar' "
659 . "instead of -nest => 'scalar' ";
664 puke "-$op => undef not supported";
668 $self->_recurse_where ($v);
676 my ($self, $op, $v) = @_;
678 my ($s, @b) = $self->_SWITCH_refkind($v, {
679 SCALAR => sub { # interpreted as SQL column
680 $self->_convert($self->_quote($v));
684 puke "-$op => undef not supported";
688 $self->_recurse_where ($v);
692 $s = "(NOT $s)" if $op =~ /^not/i;
697 sub _where_op_IDENT {
699 my ($op, $rhs) = splice @_, -2;
701 puke "-$op takes a single scalar argument (a quotable identifier)";
704 # in case we are called as a top level special op (no '=')
707 $_ = $self->_convert($self->_quote($_)) for ($lhs, $rhs);
715 sub _where_op_VALUE {
717 my ($op, $rhs) = splice @_, -2;
719 # in case we are called as a top level special op (no '=')
724 ($lhs || $self->{_nested_func_lhs}),
731 $self->_convert($self->_quote($lhs)) . ' = ' . $self->_convert('?'),
735 $self->_convert('?'),
741 sub _where_hashpair_ARRAYREF {
742 my ($self, $k, $v) = @_;
745 my @v = @$v; # need copy because of shift below
746 $self->_debug("ARRAY($k) means distribute over elements");
748 # put apart first element if it is an operator (-and, -or)
750 (defined $v[0] && $v[0] =~ /^ - (?: AND|OR ) $/ix)
754 my @distributed = map { {$k => $_} } @v;
757 $self->_debug("OP($op) reinjected into the distributed array");
758 unshift @distributed, $op;
761 my $logic = $op ? substr($op, 1) : '';
763 return $self->_recurse_where(\@distributed, $logic);
766 # LDNOTE : not sure of this one. What does "distribute over nothing" mean?
767 $self->_debug("empty ARRAY($k) means 0=1");
768 return ($self->{sqlfalse});
772 sub _where_hashpair_HASHREF {
773 my ($self, $k, $v, $logic) = @_;
776 local $self->{_nested_func_lhs} = $self->{_nested_func_lhs};
778 my ($all_sql, @all_bind);
780 for my $orig_op (sort keys %$v) {
781 my $val = $v->{$orig_op};
783 # put the operator in canonical form
786 # FIXME - we need to phase out dash-less ops
787 $op =~ s/^-//; # remove possible initial dash
788 $op =~ s/^\s+|\s+$//g;# remove leading/trailing space
789 $op =~ s/\s+/ /g; # compress whitespace
791 $self->_assert_pass_injection_guard($op);
793 # so that -not_foo works correctly
794 $op =~ s/^not_/NOT /i;
798 # CASE: col-value logic modifiers
799 if ( $orig_op =~ /^ \- (and|or) $/xi ) {
800 ($sql, @bind) = $self->_where_hashpair_HASHREF($k, $val, $1);
802 # CASE: special operators like -in or -between
803 elsif ( my $special_op = List::Util::first {$op =~ $_->{regex}} @{$self->{special_ops}} ) {
804 my $handler = $special_op->{handler};
806 puke "No handler supplied for special operator $orig_op";
808 elsif (not ref $handler) {
809 ($sql, @bind) = $self->$handler ($k, $op, $val);
811 elsif (ref $handler eq 'CODE') {
812 ($sql, @bind) = $handler->($self, $k, $op, $val);
815 puke "Illegal handler for special operator $orig_op - expecting a method name or a coderef";
819 $self->_SWITCH_refkind($val, {
821 ARRAYREF => sub { # CASE: col => {op => \@vals}
822 ($sql, @bind) = $self->_where_field_op_ARRAYREF($k, $op, $val);
825 ARRAYREFREF => sub { # CASE: col => {op => \[$sql, @bind]} (literal SQL with bind)
826 my ($sub_sql, @sub_bind) = @$$val;
827 $self->_assert_bindval_matches_bindtype(@sub_bind);
828 $sql = join ' ', $self->_convert($self->_quote($k)),
829 $self->_sqlcase($op),
834 UNDEF => sub { # CASE: col => {op => undef} : sql "IS (NOT)? NULL"
835 my $is = ($op =~ $self->{equality_op}) ? 'is' :
836 ($op =~ $self->{inequality_op}) ? 'is not' :
837 puke "unexpected operator '$orig_op' with undef operand";
838 $sql = $self->_quote($k) . $self->_sqlcase(" $is null");
841 FALLBACK => sub { # CASE: col => {op/func => $stuff}
843 # retain for proper column type bind
844 $self->{_nested_func_lhs} ||= $k;
846 ($sql, @bind) = $self->_where_unary_op ($op, $val);
849 $self->_convert($self->_quote($k)),
850 $self->{_nested_func_lhs} eq $k ? $sql : "($sql)", # top level vs nested
856 ($all_sql) = (defined $all_sql and $all_sql) ? $self->_join_sql_clauses($logic, [$all_sql, $sql], []) : $sql;
857 push @all_bind, @bind;
859 return ($all_sql, @all_bind);
864 sub _where_field_op_ARRAYREF {
865 my ($self, $k, $op, $vals) = @_;
867 my @vals = @$vals; #always work on a copy
870 $self->_debug(sprintf '%s means multiple elements: [ %s ]',
872 join (', ', map { defined $_ ? "'$_'" : 'NULL' } @vals ),
875 # see if the first element is an -and/-or op
877 if (defined $vals[0] && $vals[0] =~ /^ - ( AND|OR ) $/ix) {
882 # distribute $op over each remaining member of @vals, append logic if exists
883 return $self->_recurse_where([map { {$k => {$op, $_}} } @vals], $logic);
885 # LDNOTE : had planned to change the distribution logic when
886 # $op =~ $self->{inequality_op}, because of Morgan laws :
887 # with {field => {'!=' => [22, 33]}}, it would be ridiculous to generate
888 # WHERE field != 22 OR field != 33 : the user probably means
889 # WHERE field != 22 AND field != 33.
890 # To do this, replace the above to roughly :
891 # my $logic = ($op =~ $self->{inequality_op}) ? 'AND' : 'OR';
892 # return $self->_recurse_where([map { {$k => {$op, $_}} } @vals], $logic);
896 # try to DWIM on equality operators
897 # LDNOTE : not 100% sure this is the correct thing to do ...
898 return ($self->{sqlfalse}) if $op =~ $self->{equality_op};
899 return ($self->{sqltrue}) if $op =~ $self->{inequality_op};
902 puke "operator '$op' applied on an empty array (field '$k')";
907 sub _where_hashpair_SCALARREF {
908 my ($self, $k, $v) = @_;
909 $self->_debug("SCALAR($k) means literal SQL: $$v");
910 my $sql = $self->_quote($k) . " " . $$v;
914 # literal SQL with bind
915 sub _where_hashpair_ARRAYREFREF {
916 my ($self, $k, $v) = @_;
917 $self->_debug("REF($k) means literal SQL: @${$v}");
918 my ($sql, @bind) = @$$v;
919 $self->_assert_bindval_matches_bindtype(@bind);
920 $sql = $self->_quote($k) . " " . $sql;
921 return ($sql, @bind );
924 # literal SQL without bind
925 sub _where_hashpair_SCALAR {
926 my ($self, $k, $v) = @_;
927 $self->_debug("NOREF($k) means simple key=val: $k $self->{cmp} $v");
928 my $sql = join ' ', $self->_convert($self->_quote($k)),
929 $self->_sqlcase($self->{cmp}),
930 $self->_convert('?');
931 my @bind = $self->_bindtype($k, $v);
932 return ( $sql, @bind);
936 sub _where_hashpair_UNDEF {
937 my ($self, $k, $v) = @_;
938 $self->_debug("UNDEF($k) means IS NULL");
939 my $sql = $self->_quote($k) . $self->_sqlcase(' is null');
943 #======================================================================
944 # WHERE: TOP-LEVEL OTHERS (SCALARREF, SCALAR, UNDEF)
945 #======================================================================
948 sub _where_SCALARREF {
949 my ($self, $where) = @_;
952 $self->_debug("SCALAR(*top) means literal SQL: $$where");
958 my ($self, $where) = @_;
961 $self->_debug("NOREF(*top) means literal SQL: $where");
972 #======================================================================
973 # WHERE: BUILTIN SPECIAL OPERATORS (-in, -between)
974 #======================================================================
977 sub _where_field_BETWEEN {
978 my ($self, $k, $op, $vals) = @_;
980 my ($label, $and, $placeholder);
981 $label = $self->_convert($self->_quote($k));
982 $and = ' ' . $self->_sqlcase('and') . ' ';
983 $placeholder = $self->_convert('?');
984 $op = $self->_sqlcase($op);
986 my ($clause, @bind) = $self->_SWITCH_refkind($vals, {
988 my ($s, @b) = @$$vals;
989 $self->_assert_bindval_matches_bindtype(@b);
996 puke "special op 'between' accepts an arrayref with exactly two values"
999 my (@all_sql, @all_bind);
1000 foreach my $val (@$vals) {
1001 my ($sql, @bind) = $self->_SWITCH_refkind($val, {
1003 return ($placeholder, $self->_bindtype($k, $val) );
1008 ARRAYREFREF => sub {
1009 my ($sql, @bind) = @$$val;
1010 $self->_assert_bindval_matches_bindtype(@bind);
1011 return ($sql, @bind);
1014 my ($func, $arg, @rest) = %$val;
1015 puke ("Only simple { -func => arg } functions accepted as sub-arguments to BETWEEN")
1016 if (@rest or $func !~ /^ \- (.+)/x);
1017 local $self->{_nested_func_lhs} = $k;
1018 $self->_where_unary_op ($1 => $arg);
1021 push @all_sql, $sql;
1022 push @all_bind, @bind;
1026 (join $and, @all_sql),
1031 puke "special op 'between' accepts an arrayref with two values, or a single literal scalarref/arrayref-ref";
1035 my $sql = "( $label $op $clause )";
1036 return ($sql, @bind)
1040 sub _where_field_IN {
1041 my ($self, $k, $op, $vals) = @_;
1043 # backwards compatibility : if scalar, force into an arrayref
1044 $vals = [$vals] if defined $vals && ! ref $vals;
1046 my ($label) = $self->_convert($self->_quote($k));
1047 my ($placeholder) = $self->_convert('?');
1048 $op = $self->_sqlcase($op);
1050 my ($sql, @bind) = $self->_SWITCH_refkind($vals, {
1051 ARRAYREF => sub { # list of choices
1052 if (@$vals) { # nonempty list
1053 my (@all_sql, @all_bind);
1055 for my $val (@$vals) {
1056 my ($sql, @bind) = $self->_SWITCH_refkind($val, {
1058 return ($placeholder, $val);
1063 ARRAYREFREF => sub {
1064 my ($sql, @bind) = @$$val;
1065 $self->_assert_bindval_matches_bindtype(@bind);
1066 return ($sql, @bind);
1069 my ($func, $arg, @rest) = %$val;
1070 puke ("Only simple { -func => arg } functions accepted as sub-arguments to IN")
1071 if (@rest or $func !~ /^ \- (.+)/x);
1072 local $self->{_nested_func_lhs} = $k;
1073 $self->_where_unary_op ($1 => $arg);
1076 return $self->_sqlcase('null');
1079 push @all_sql, $sql;
1080 push @all_bind, @bind;
1084 sprintf ('%s %s ( %s )',
1087 join (', ', @all_sql)
1089 $self->_bindtype($k, @all_bind),
1092 else { # empty list : some databases won't understand "IN ()", so DWIM
1093 my $sql = ($op =~ /\bnot\b/i) ? $self->{sqltrue} : $self->{sqlfalse};
1098 SCALARREF => sub { # literal SQL
1099 my $sql = $self->_open_outer_paren ($$vals);
1100 return ("$label $op ( $sql )");
1102 ARRAYREFREF => sub { # literal SQL with bind
1103 my ($sql, @bind) = @$$vals;
1104 $self->_assert_bindval_matches_bindtype(@bind);
1105 $sql = $self->_open_outer_paren ($sql);
1106 return ("$label $op ( $sql )", @bind);
1110 puke "special op 'in' requires an arrayref (or scalarref/arrayref-ref)";
1114 return ($sql, @bind);
1117 # Some databases (SQLite) treat col IN (1, 2) different from
1118 # col IN ( (1, 2) ). Use this to strip all outer parens while
1119 # adding them back in the corresponding method
1120 sub _open_outer_paren {
1121 my ($self, $sql) = @_;
1122 $sql = $1 while $sql =~ /^ \s* \( (.*) \) \s* $/xs;
1127 #======================================================================
1129 #======================================================================
1132 my ($self, $arg) = @_;
1135 for my $c ($self->_order_by_chunks ($arg) ) {
1136 $self->_SWITCH_refkind ($c, {
1137 SCALAR => sub { push @sql, $c },
1138 ARRAYREF => sub { push @sql, shift @$c; push @bind, @$c },
1144 $self->_sqlcase(' order by'),
1150 return wantarray ? ($sql, @bind) : $sql;
1153 sub _order_by_chunks {
1154 my ($self, $arg) = @_;
1156 return $self->_SWITCH_refkind($arg, {
1159 map { $self->_order_by_chunks ($_ ) } @$arg;
1162 ARRAYREFREF => sub {
1163 my ($s, @b) = @$$arg;
1164 $self->_assert_bindval_matches_bindtype(@b);
1168 SCALAR => sub {$self->_quote($arg)},
1170 UNDEF => sub {return () },
1172 SCALARREF => sub {$$arg}, # literal SQL, no quoting
1175 # get first pair in hash
1176 my ($key, $val, @rest) = %$arg;
1178 return () unless $key;
1180 if ( @rest or not $key =~ /^-(desc|asc)/i ) {
1181 puke "hash passed to _order_by must have exactly one key (-desc or -asc)";
1187 for my $c ($self->_order_by_chunks ($val)) {
1190 $self->_SWITCH_refkind ($c, {
1195 ($sql, @bind) = @$c;
1199 $sql = $sql . ' ' . $self->_sqlcase($direction);
1201 push @ret, [ $sql, @bind];
1210 #======================================================================
1211 # DATASOURCE (FOR NOW, JUST PLAIN TABLE OR LIST OF TABLES)
1212 #======================================================================
1217 $self->_SWITCH_refkind($from, {
1218 ARRAYREF => sub {join ', ', map { $self->_quote($_) } @$from;},
1221 type => DQ_IDENTIFIER,
1222 elements => [ split /\Q$self->{name_sep}/, $from ],
1236 #======================================================================
1238 #======================================================================
1240 # highly optimized, as it's called way too often
1242 # my ($self, $label) = @_;
1244 return '' unless defined $_[1];
1245 return ${$_[1]} if ref($_[1]) eq 'SCALAR';
1247 unless ($_[0]->{quote_char}) {
1248 $_[0]->_assert_pass_injection_guard($_[1]);
1252 my $qref = ref $_[0]->{quote_char};
1255 ($l, $r) = ( $_[0]->{quote_char}, $_[0]->{quote_char} );
1257 elsif ($qref eq 'ARRAY') {
1258 ($l, $r) = @{$_[0]->{quote_char}};
1261 puke "Unsupported quote_char format: $_[0]->{quote_char}";
1264 # parts containing * are naturally unquoted
1265 return join( $_[0]->{name_sep}||'', map
1266 { $_ eq '*' ? $_ : $l . $_ . $r }
1267 ( $_[0]->{name_sep} ? split (/\Q$_[0]->{name_sep}\E/, $_[1] ) : $_[1] )
1272 # Conversion, if applicable
1274 #my ($self, $arg) = @_;
1276 # LDNOTE : modified the previous implementation below because
1277 # it was not consistent : the first "return" is always an array,
1278 # the second "return" is context-dependent. Anyway, _convert
1279 # seems always used with just a single argument, so make it a
1281 # return @_ unless $self->{convert};
1282 # my $conv = $self->_sqlcase($self->{convert});
1283 # my @ret = map { $conv.'('.$_.')' } @_;
1284 # return wantarray ? @ret : $ret[0];
1285 if ($_[0]->{convert}) {
1286 return $_[0]->_sqlcase($_[0]->{convert}) .'(' . $_[1] . ')';
1293 #my ($self, $col, @vals) = @_;
1295 #LDNOTE : changed original implementation below because it did not make
1296 # sense when bindtype eq 'columns' and @vals > 1.
1297 # return $self->{bindtype} eq 'columns' ? [ $col, @vals ] : @vals;
1299 # called often - tighten code
1300 return $_[0]->{bindtype} eq 'columns'
1301 ? map {[$_[1], $_]} @_[2 .. $#_]
1306 # Dies if any element of @bind is not in [colname => value] format
1307 # if bindtype is 'columns'.
1308 sub _assert_bindval_matches_bindtype {
1309 # my ($self, @bind) = @_;
1311 if ($self->{bindtype} eq 'columns') {
1313 if (!defined $_ || ref($_) ne 'ARRAY' || @$_ != 2) {
1314 puke "bindtype 'columns' selected, you need to pass: [column_name => bind_value]"
1320 sub _join_sql_clauses {
1321 my ($self, $logic, $clauses_aref, $bind_aref) = @_;
1323 if (@$clauses_aref > 1) {
1324 my $join = " " . $self->_sqlcase($logic) . " ";
1325 my $sql = '( ' . join($join, @$clauses_aref) . ' )';
1326 return ($sql, @$bind_aref);
1328 elsif (@$clauses_aref) {
1329 return ($clauses_aref->[0], @$bind_aref); # no parentheses
1332 return (); # if no SQL, ignore @$bind_aref
1337 # Fix SQL case, if so requested
1339 # LDNOTE: if $self->{case} is true, then it contains 'lower', so we
1340 # don't touch the argument ... crooked logic, but let's not change it!
1341 return $_[0]->{case} ? $_[1] : uc($_[1]);
1345 #======================================================================
1346 # DISPATCHING FROM REFKIND
1347 #======================================================================
1350 my ($self, $data) = @_;
1352 return 'UNDEF' unless defined $data;
1354 # blessed objects are treated like scalars
1355 my $ref = (Scalar::Util::blessed $data) ? '' : ref $data;
1357 return 'SCALAR' unless $ref;
1360 while ($ref eq 'REF') {
1362 $ref = (Scalar::Util::blessed $data) ? '' : ref $data;
1366 return ($ref||'SCALAR') . ('REF' x $n_steps);
1370 my ($self, $data) = @_;
1371 my @try = ($self->_refkind($data));
1372 push @try, 'SCALAR_or_UNDEF' if $try[0] eq 'SCALAR' || $try[0] eq 'UNDEF';
1373 push @try, 'FALLBACK';
1377 sub _METHOD_FOR_refkind {
1378 my ($self, $meth_prefix, $data) = @_;
1381 for (@{$self->_try_refkind($data)}) {
1382 $method = $self->can($meth_prefix."_".$_)
1386 return $method || puke "cannot dispatch on '$meth_prefix' for ".$self->_refkind($data);
1390 sub _SWITCH_refkind {
1391 my ($self, $data, $dispatch_table) = @_;
1394 for (@{$self->_try_refkind($data)}) {
1395 $coderef = $dispatch_table->{$_}
1399 puke "no dispatch entry for ".$self->_refkind($data)
1408 #======================================================================
1409 # VALUES, GENERATE, AUTOLOAD
1410 #======================================================================
1412 # LDNOTE: original code from nwiger, didn't touch code in that section
1413 # I feel the AUTOLOAD stuff should not be the default, it should
1414 # only be activated on explicit demand by user.
1418 my $data = shift || return;
1419 puke "Argument to ", __PACKAGE__, "->values must be a \\%hash"
1420 unless ref $data eq 'HASH';
1423 foreach my $k ( sort keys %$data ) {
1424 my $v = $data->{$k};
1425 $self->_SWITCH_refkind($v, {
1427 if ($self->{array_datatypes}) { # array datatype
1428 push @all_bind, $self->_bindtype($k, $v);
1430 else { # literal SQL with bind
1431 my ($sql, @bind) = @$v;
1432 $self->_assert_bindval_matches_bindtype(@bind);
1433 push @all_bind, @bind;
1436 ARRAYREFREF => sub { # literal SQL with bind
1437 my ($sql, @bind) = @${$v};
1438 $self->_assert_bindval_matches_bindtype(@bind);
1439 push @all_bind, @bind;
1441 SCALARREF => sub { # literal SQL without bind
1443 SCALAR_or_UNDEF => sub {
1444 push @all_bind, $self->_bindtype($k, $v);
1455 my(@sql, @sqlq, @sqlv);
1459 if ($ref eq 'HASH') {
1460 for my $k (sort keys %$_) {
1463 my $label = $self->_quote($k);
1464 if ($r eq 'ARRAY') {
1465 # literal SQL with bind
1466 my ($sql, @bind) = @$v;
1467 $self->_assert_bindval_matches_bindtype(@bind);
1468 push @sqlq, "$label = $sql";
1470 } elsif ($r eq 'SCALAR') {
1471 # literal SQL without bind
1472 push @sqlq, "$label = $$v";
1474 push @sqlq, "$label = ?";
1475 push @sqlv, $self->_bindtype($k, $v);
1478 push @sql, $self->_sqlcase('set'), join ', ', @sqlq;
1479 } elsif ($ref eq 'ARRAY') {
1480 # unlike insert(), assume these are ONLY the column names, i.e. for SQL
1483 if ($r eq 'ARRAY') { # literal SQL with bind
1484 my ($sql, @bind) = @$v;
1485 $self->_assert_bindval_matches_bindtype(@bind);
1488 } elsif ($r eq 'SCALAR') { # literal SQL without bind
1489 # embedded literal SQL
1496 push @sql, '(' . join(', ', @sqlq) . ')';
1497 } elsif ($ref eq 'SCALAR') {
1501 # strings get case twiddled
1502 push @sql, $self->_sqlcase($_);
1506 my $sql = join ' ', @sql;
1508 # this is pretty tricky
1509 # if ask for an array, return ($stmt, @bind)
1510 # otherwise, s/?/shift @sqlv/ to put it inline
1512 return ($sql, @sqlv);
1514 1 while $sql =~ s/\?/my $d = shift(@sqlv);
1515 ref $d ? $d->[1] : $d/e;
1524 # This allows us to check for a local, then _form, attr
1526 my($name) = $AUTOLOAD =~ /.*::(.+)/;
1527 return $self->generate($name, @_);
1538 SQL::Abstract - Generate SQL from Perl data structures
1544 my $sql = SQL::Abstract->new;
1546 my($stmt, @bind) = $sql->select($table, \@fields, \%where, \@order);
1548 my($stmt, @bind) = $sql->insert($table, \%fieldvals || \@values);
1550 my($stmt, @bind) = $sql->update($table, \%fieldvals, \%where);
1552 my($stmt, @bind) = $sql->delete($table, \%where);
1554 # Then, use these in your DBI statements
1555 my $sth = $dbh->prepare($stmt);
1556 $sth->execute(@bind);
1558 # Just generate the WHERE clause
1559 my($stmt, @bind) = $sql->where(\%where, \@order);
1561 # Return values in the same order, for hashed queries
1562 # See PERFORMANCE section for more details
1563 my @bind = $sql->values(\%fieldvals);
1567 This module was inspired by the excellent L<DBIx::Abstract>.
1568 However, in using that module I found that what I really wanted
1569 to do was generate SQL, but still retain complete control over my
1570 statement handles and use the DBI interface. So, I set out to
1571 create an abstract SQL generation module.
1573 While based on the concepts used by L<DBIx::Abstract>, there are
1574 several important differences, especially when it comes to WHERE
1575 clauses. I have modified the concepts used to make the SQL easier
1576 to generate from Perl data structures and, IMO, more intuitive.
1577 The underlying idea is for this module to do what you mean, based
1578 on the data structures you provide it. The big advantage is that
1579 you don't have to modify your code every time your data changes,
1580 as this module figures it out.
1582 To begin with, an SQL INSERT is as easy as just specifying a hash
1583 of C<key=value> pairs:
1586 name => 'Jimbo Bobson',
1587 phone => '123-456-7890',
1588 address => '42 Sister Lane',
1589 city => 'St. Louis',
1590 state => 'Louisiana',
1593 The SQL can then be generated with this:
1595 my($stmt, @bind) = $sql->insert('people', \%data);
1597 Which would give you something like this:
1599 $stmt = "INSERT INTO people
1600 (address, city, name, phone, state)
1601 VALUES (?, ?, ?, ?, ?)";
1602 @bind = ('42 Sister Lane', 'St. Louis', 'Jimbo Bobson',
1603 '123-456-7890', 'Louisiana');
1605 These are then used directly in your DBI code:
1607 my $sth = $dbh->prepare($stmt);
1608 $sth->execute(@bind);
1610 =head2 Inserting and Updating Arrays
1612 If your database has array types (like for example Postgres),
1613 activate the special option C<< array_datatypes => 1 >>
1614 when creating the C<SQL::Abstract> object.
1615 Then you may use an arrayref to insert and update database array types:
1617 my $sql = SQL::Abstract->new(array_datatypes => 1);
1619 planets => [qw/Mercury Venus Earth Mars/]
1622 my($stmt, @bind) = $sql->insert('solar_system', \%data);
1626 $stmt = "INSERT INTO solar_system (planets) VALUES (?)"
1628 @bind = (['Mercury', 'Venus', 'Earth', 'Mars']);
1631 =head2 Inserting and Updating SQL
1633 In order to apply SQL functions to elements of your C<%data> you may
1634 specify a reference to an arrayref for the given hash value. For example,
1635 if you need to execute the Oracle C<to_date> function on a value, you can
1636 say something like this:
1640 date_entered => \["to_date(?,'MM/DD/YYYY')", "03/02/2003"],
1643 The first value in the array is the actual SQL. Any other values are
1644 optional and would be included in the bind values array. This gives
1647 my($stmt, @bind) = $sql->insert('people', \%data);
1649 $stmt = "INSERT INTO people (name, date_entered)
1650 VALUES (?, to_date(?,'MM/DD/YYYY'))";
1651 @bind = ('Bill', '03/02/2003');
1653 An UPDATE is just as easy, all you change is the name of the function:
1655 my($stmt, @bind) = $sql->update('people', \%data);
1657 Notice that your C<%data> isn't touched; the module will generate
1658 the appropriately quirky SQL for you automatically. Usually you'll
1659 want to specify a WHERE clause for your UPDATE, though, which is
1660 where handling C<%where> hashes comes in handy...
1662 =head2 Complex where statements
1664 This module can generate pretty complicated WHERE statements
1665 easily. For example, simple C<key=value> pairs are taken to mean
1666 equality, and if you want to see if a field is within a set
1667 of values, you can use an arrayref. Let's say we wanted to
1668 SELECT some data based on this criteria:
1671 requestor => 'inna',
1672 worker => ['nwiger', 'rcwe', 'sfz'],
1673 status => { '!=', 'completed' }
1676 my($stmt, @bind) = $sql->select('tickets', '*', \%where);
1678 The above would give you something like this:
1680 $stmt = "SELECT * FROM tickets WHERE
1681 ( requestor = ? ) AND ( status != ? )
1682 AND ( worker = ? OR worker = ? OR worker = ? )";
1683 @bind = ('inna', 'completed', 'nwiger', 'rcwe', 'sfz');
1685 Which you could then use in DBI code like so:
1687 my $sth = $dbh->prepare($stmt);
1688 $sth->execute(@bind);
1694 The functions are simple. There's one for each major SQL operation,
1695 and a constructor you use first. The arguments are specified in a
1696 similar order to each function (table, then fields, then a where
1697 clause) to try and simplify things.
1702 =head2 new(option => 'value')
1704 The C<new()> function takes a list of options and values, and returns
1705 a new B<SQL::Abstract> object which can then be used to generate SQL
1706 through the methods below. The options accepted are:
1712 If set to 'lower', then SQL will be generated in all lowercase. By
1713 default SQL is generated in "textbook" case meaning something like:
1715 SELECT a_field FROM a_table WHERE some_field LIKE '%someval%'
1717 Any setting other than 'lower' is ignored.
1721 This determines what the default comparison operator is. By default
1722 it is C<=>, meaning that a hash like this:
1724 %where = (name => 'nwiger', email => 'nate@wiger.org');
1726 Will generate SQL like this:
1728 WHERE name = 'nwiger' AND email = 'nate@wiger.org'
1730 However, you may want loose comparisons by default, so if you set
1731 C<cmp> to C<like> you would get SQL such as:
1733 WHERE name like 'nwiger' AND email like 'nate@wiger.org'
1735 You can also override the comparsion on an individual basis - see
1736 the huge section on L</"WHERE CLAUSES"> at the bottom.
1738 =item sqltrue, sqlfalse
1740 Expressions for inserting boolean values within SQL statements.
1741 By default these are C<1=1> and C<1=0>. They are used
1742 by the special operators C<-in> and C<-not_in> for generating
1743 correct SQL even when the argument is an empty array (see below).
1747 This determines the default logical operator for multiple WHERE
1748 statements in arrays or hashes. If absent, the default logic is "or"
1749 for arrays, and "and" for hashes. This means that a WHERE
1753 event_date => {'>=', '2/13/99'},
1754 event_date => {'<=', '4/24/03'},
1757 will generate SQL like this:
1759 WHERE event_date >= '2/13/99' OR event_date <= '4/24/03'
1761 This is probably not what you want given this query, though (look
1762 at the dates). To change the "OR" to an "AND", simply specify:
1764 my $sql = SQL::Abstract->new(logic => 'and');
1766 Which will change the above C<WHERE> to:
1768 WHERE event_date >= '2/13/99' AND event_date <= '4/24/03'
1770 The logic can also be changed locally by inserting
1771 a modifier in front of an arrayref :
1773 @where = (-and => [event_date => {'>=', '2/13/99'},
1774 event_date => {'<=', '4/24/03'} ]);
1776 See the L</"WHERE CLAUSES"> section for explanations.
1780 This will automatically convert comparisons using the specified SQL
1781 function for both column and value. This is mostly used with an argument
1782 of C<upper> or C<lower>, so that the SQL will have the effect of
1783 case-insensitive "searches". For example, this:
1785 $sql = SQL::Abstract->new(convert => 'upper');
1786 %where = (keywords => 'MaKe iT CAse inSeNSItive');
1788 Will turn out the following SQL:
1790 WHERE upper(keywords) like upper('MaKe iT CAse inSeNSItive')
1792 The conversion can be C<upper()>, C<lower()>, or any other SQL function
1793 that can be applied symmetrically to fields (actually B<SQL::Abstract> does
1794 not validate this option; it will just pass through what you specify verbatim).
1798 This is a kludge because many databases suck. For example, you can't
1799 just bind values using DBI's C<execute()> for Oracle C<CLOB> or C<BLOB> fields.
1800 Instead, you have to use C<bind_param()>:
1802 $sth->bind_param(1, 'reg data');
1803 $sth->bind_param(2, $lots, {ora_type => ORA_CLOB});
1805 The problem is, B<SQL::Abstract> will normally just return a C<@bind> array,
1806 which loses track of which field each slot refers to. Fear not.
1808 If you specify C<bindtype> in new, you can determine how C<@bind> is returned.
1809 Currently, you can specify either C<normal> (default) or C<columns>. If you
1810 specify C<columns>, you will get an array that looks like this:
1812 my $sql = SQL::Abstract->new(bindtype => 'columns');
1813 my($stmt, @bind) = $sql->insert(...);
1816 [ 'column1', 'value1' ],
1817 [ 'column2', 'value2' ],
1818 [ 'column3', 'value3' ],
1821 You can then iterate through this manually, using DBI's C<bind_param()>.
1823 $sth->prepare($stmt);
1826 my($col, $data) = @$_;
1827 if ($col eq 'details' || $col eq 'comments') {
1828 $sth->bind_param($i, $data, {ora_type => ORA_CLOB});
1829 } elsif ($col eq 'image') {
1830 $sth->bind_param($i, $data, {ora_type => ORA_BLOB});
1832 $sth->bind_param($i, $data);
1836 $sth->execute; # execute without @bind now
1838 Now, why would you still use B<SQL::Abstract> if you have to do this crap?
1839 Basically, the advantage is still that you don't have to care which fields
1840 are or are not included. You could wrap that above C<for> loop in a simple
1841 sub called C<bind_fields()> or something and reuse it repeatedly. You still
1842 get a layer of abstraction over manual SQL specification.
1844 Note that if you set L</bindtype> to C<columns>, the C<\[$sql, @bind]>
1845 construct (see L</Literal SQL with placeholders and bind values (subqueries)>)
1846 will expect the bind values in this format.
1850 This is the character that a table or column name will be quoted
1851 with. By default this is an empty string, but you could set it to
1852 the character C<`>, to generate SQL like this:
1854 SELECT `a_field` FROM `a_table` WHERE `some_field` LIKE '%someval%'
1856 Alternatively, you can supply an array ref of two items, the first being the left
1857 hand quote character, and the second the right hand quote character. For
1858 example, you could supply C<['[',']']> for SQL Server 2000 compliant quotes
1859 that generates SQL like this:
1861 SELECT [a_field] FROM [a_table] WHERE [some_field] LIKE '%someval%'
1863 Quoting is useful if you have tables or columns names that are reserved
1864 words in your database's SQL dialect.
1868 This is the character that separates a table and column name. It is
1869 necessary to specify this when the C<quote_char> option is selected,
1870 so that tables and column names can be individually quoted like this:
1872 SELECT `table`.`one_field` FROM `table` WHERE `table`.`other_field` = 1
1874 =item injection_guard
1876 A regular expression C<qr/.../> that is applied to any C<-function> and unquoted
1877 column name specified in a query structure. This is a safety mechanism to avoid
1878 injection attacks when mishandling user input e.g.:
1880 my %condition_as_column_value_pairs = get_values_from_user();
1881 $sqla->select( ... , \%condition_as_column_value_pairs );
1883 If the expression matches an exception is thrown. Note that literal SQL
1884 supplied via C<\'...'> or C<\['...']> is B<not> checked in any way.
1886 Defaults to checking for C<;> and the C<GO> keyword (TransactSQL)
1888 =item array_datatypes
1890 When this option is true, arrayrefs in INSERT or UPDATE are
1891 interpreted as array datatypes and are passed directly
1893 When this option is false, arrayrefs are interpreted
1894 as literal SQL, just like refs to arrayrefs
1895 (but this behavior is for backwards compatibility; when writing
1896 new queries, use the "reference to arrayref" syntax
1902 Takes a reference to a list of "special operators"
1903 to extend the syntax understood by L<SQL::Abstract>.
1904 See section L</"SPECIAL OPERATORS"> for details.
1908 Takes a reference to a list of "unary operators"
1909 to extend the syntax understood by L<SQL::Abstract>.
1910 See section L</"UNARY OPERATORS"> for details.
1916 =head2 insert($table, \@values || \%fieldvals, \%options)
1918 This is the simplest function. You simply give it a table name
1919 and either an arrayref of values or hashref of field/value pairs.
1920 It returns an SQL INSERT statement and a list of bind values.
1921 See the sections on L</"Inserting and Updating Arrays"> and
1922 L</"Inserting and Updating SQL"> for information on how to insert
1923 with those data types.
1925 The optional C<\%options> hash reference may contain additional
1926 options to generate the insert SQL. Currently supported options
1933 Takes either a scalar of raw SQL fields, or an array reference of
1934 field names, and adds on an SQL C<RETURNING> statement at the end.
1935 This allows you to return data generated by the insert statement
1936 (such as row IDs) without performing another C<SELECT> statement.
1937 Note, however, this is not part of the SQL standard and may not
1938 be supported by all database engines.
1942 =head2 update($table, \%fieldvals, \%where)
1944 This takes a table, hashref of field/value pairs, and an optional
1945 hashref L<WHERE clause|/WHERE CLAUSES>. It returns an SQL UPDATE function and a list
1947 See the sections on L</"Inserting and Updating Arrays"> and
1948 L</"Inserting and Updating SQL"> for information on how to insert
1949 with those data types.
1951 =head2 select($source, $fields, $where, $order)
1953 This returns a SQL SELECT statement and associated list of bind values, as
1954 specified by the arguments :
1960 Specification of the 'FROM' part of the statement.
1961 The argument can be either a plain scalar (interpreted as a table
1962 name, will be quoted), or an arrayref (interpreted as a list
1963 of table names, joined by commas, quoted), or a scalarref
1964 (literal table name, not quoted), or a ref to an arrayref
1965 (list of literal table names, joined by commas, not quoted).
1969 Specification of the list of fields to retrieve from
1971 The argument can be either an arrayref (interpreted as a list
1972 of field names, will be joined by commas and quoted), or a
1973 plain scalar (literal SQL, not quoted).
1974 Please observe that this API is not as flexible as for
1975 the first argument C<$table>, for backwards compatibility reasons.
1979 Optional argument to specify the WHERE part of the query.
1980 The argument is most often a hashref, but can also be
1981 an arrayref or plain scalar --
1982 see section L<WHERE clause|/"WHERE CLAUSES"> for details.
1986 Optional argument to specify the ORDER BY part of the query.
1987 The argument can be a scalar, a hashref or an arrayref
1988 -- see section L<ORDER BY clause|/"ORDER BY CLAUSES">
1994 =head2 delete($table, \%where)
1996 This takes a table name and optional hashref L<WHERE clause|/WHERE CLAUSES>.
1997 It returns an SQL DELETE statement and list of bind values.
1999 =head2 where(\%where, \@order)
2001 This is used to generate just the WHERE clause. For example,
2002 if you have an arbitrary data structure and know what the
2003 rest of your SQL is going to look like, but want an easy way
2004 to produce a WHERE clause, use this. It returns an SQL WHERE
2005 clause and list of bind values.
2008 =head2 values(\%data)
2010 This just returns the values from the hash C<%data>, in the same
2011 order that would be returned from any of the other above queries.
2012 Using this allows you to markedly speed up your queries if you
2013 are affecting lots of rows. See below under the L</"PERFORMANCE"> section.
2015 =head2 generate($any, 'number', $of, \@data, $struct, \%types)
2017 Warning: This is an experimental method and subject to change.
2019 This returns arbitrarily generated SQL. It's a really basic shortcut.
2020 It will return two different things, depending on return context:
2022 my($stmt, @bind) = $sql->generate('create table', \$table, \@fields);
2023 my $stmt_and_val = $sql->generate('create table', \$table, \@fields);
2025 These would return the following:
2027 # First calling form
2028 $stmt = "CREATE TABLE test (?, ?)";
2029 @bind = (field1, field2);
2031 # Second calling form
2032 $stmt_and_val = "CREATE TABLE test (field1, field2)";
2034 Depending on what you're trying to do, it's up to you to choose the correct
2035 format. In this example, the second form is what you would want.
2039 $sql->generate('alter session', { nls_date_format => 'MM/YY' });
2043 ALTER SESSION SET nls_date_format = 'MM/YY'
2045 You get the idea. Strings get their case twiddled, but everything
2046 else remains verbatim.
2048 =head1 WHERE CLAUSES
2052 This module uses a variation on the idea from L<DBIx::Abstract>. It
2053 is B<NOT>, repeat I<not> 100% compatible. B<The main logic of this
2054 module is that things in arrays are OR'ed, and things in hashes
2057 The easiest way to explain is to show lots of examples. After
2058 each C<%where> hash shown, it is assumed you used:
2060 my($stmt, @bind) = $sql->where(\%where);
2062 However, note that the C<%where> hash can be used directly in any
2063 of the other functions as well, as described above.
2065 =head2 Key-value pairs
2067 So, let's get started. To begin, a simple hash:
2071 status => 'completed'
2074 Is converted to SQL C<key = val> statements:
2076 $stmt = "WHERE user = ? AND status = ?";
2077 @bind = ('nwiger', 'completed');
2079 One common thing I end up doing is having a list of values that
2080 a field can be in. To do this, simply specify a list inside of
2085 status => ['assigned', 'in-progress', 'pending'];
2088 This simple code will create the following:
2090 $stmt = "WHERE user = ? AND ( status = ? OR status = ? OR status = ? )";
2091 @bind = ('nwiger', 'assigned', 'in-progress', 'pending');
2093 A field associated to an empty arrayref will be considered a
2094 logical false and will generate 0=1.
2096 =head2 Tests for NULL values
2098 If the value part is C<undef> then this is converted to SQL <IS NULL>
2107 $stmt = "WHERE user = ? AND status IS NULL";
2110 To test if a column IS NOT NULL:
2114 status => { '!=', undef },
2117 =head2 Specific comparison operators
2119 If you want to specify a different type of operator for your comparison,
2120 you can use a hashref for a given column:
2124 status => { '!=', 'completed' }
2127 Which would generate:
2129 $stmt = "WHERE user = ? AND status != ?";
2130 @bind = ('nwiger', 'completed');
2132 To test against multiple values, just enclose the values in an arrayref:
2134 status => { '=', ['assigned', 'in-progress', 'pending'] };
2136 Which would give you:
2138 "WHERE status = ? OR status = ? OR status = ?"
2141 The hashref can also contain multiple pairs, in which case it is expanded
2142 into an C<AND> of its elements:
2146 status => { '!=', 'completed', -not_like => 'pending%' }
2149 # Or more dynamically, like from a form
2150 $where{user} = 'nwiger';
2151 $where{status}{'!='} = 'completed';
2152 $where{status}{'-not_like'} = 'pending%';
2154 # Both generate this
2155 $stmt = "WHERE user = ? AND status != ? AND status NOT LIKE ?";
2156 @bind = ('nwiger', 'completed', 'pending%');
2159 To get an OR instead, you can combine it with the arrayref idea:
2163 priority => [ { '=', 2 }, { '>', 5 } ]
2166 Which would generate:
2168 $stmt = "WHERE ( priority = ? OR priority > ? ) AND user = ?";
2169 @bind = ('2', '5', 'nwiger');
2171 If you want to include literal SQL (with or without bind values), just use a
2172 scalar reference or array reference as the value:
2175 date_entered => { '>' => \["to_date(?, 'MM/DD/YYYY')", "11/26/2008"] },
2176 date_expires => { '<' => \"now()" }
2179 Which would generate:
2181 $stmt = "WHERE date_entered > "to_date(?, 'MM/DD/YYYY') AND date_expires < now()";
2182 @bind = ('11/26/2008');
2185 =head2 Logic and nesting operators
2187 In the example above,
2188 there is a subtle trap if you want to say something like
2189 this (notice the C<AND>):
2191 WHERE priority != ? AND priority != ?
2193 Because, in Perl you I<can't> do this:
2195 priority => { '!=', 2, '!=', 1 }
2197 As the second C<!=> key will obliterate the first. The solution
2198 is to use the special C<-modifier> form inside an arrayref:
2200 priority => [ -and => {'!=', 2},
2204 Normally, these would be joined by C<OR>, but the modifier tells it
2205 to use C<AND> instead. (Hint: You can use this in conjunction with the
2206 C<logic> option to C<new()> in order to change the way your queries
2207 work by default.) B<Important:> Note that the C<-modifier> goes
2208 B<INSIDE> the arrayref, as an extra first element. This will
2209 B<NOT> do what you think it might:
2211 priority => -and => [{'!=', 2}, {'!=', 1}] # WRONG!
2213 Here is a quick list of equivalencies, since there is some overlap:
2216 status => {'!=', 'completed', 'not like', 'pending%' }
2217 status => [ -and => {'!=', 'completed'}, {'not like', 'pending%'}]
2220 status => {'=', ['assigned', 'in-progress']}
2221 status => [ -or => {'=', 'assigned'}, {'=', 'in-progress'}]
2222 status => [ {'=', 'assigned'}, {'=', 'in-progress'} ]
2226 =head2 Special operators : IN, BETWEEN, etc.
2228 You can also use the hashref format to compare a list of fields using the
2229 C<IN> comparison operator, by specifying the list as an arrayref:
2232 status => 'completed',
2233 reportid => { -in => [567, 2335, 2] }
2236 Which would generate:
2238 $stmt = "WHERE status = ? AND reportid IN (?,?,?)";
2239 @bind = ('completed', '567', '2335', '2');
2241 The reverse operator C<-not_in> generates SQL C<NOT IN> and is used in
2244 If the argument to C<-in> is an empty array, 'sqlfalse' is generated
2245 (by default : C<1=0>). Similarly, C<< -not_in => [] >> generates
2246 'sqltrue' (by default : C<1=1>).
2248 In addition to the array you can supply a chunk of literal sql or
2249 literal sql with bind:
2252 customer => { -in => \[
2253 'SELECT cust_id FROM cust WHERE balance > ?',
2256 status => { -in => \'SELECT status_codes FROM states' },
2262 customer IN ( SELECT cust_id FROM cust WHERE balance > ? )
2263 AND status IN ( SELECT status_codes FROM states )
2269 Another pair of operators is C<-between> and C<-not_between>,
2270 used with an arrayref of two values:
2274 completion_date => {
2275 -not_between => ['2002-10-01', '2003-02-06']
2281 WHERE user = ? AND completion_date NOT BETWEEN ( ? AND ? )
2283 Just like with C<-in> all plausible combinations of literal SQL
2287 start0 => { -between => [ 1, 2 ] },
2288 start1 => { -between => \["? AND ?", 1, 2] },
2289 start2 => { -between => \"lower(x) AND upper(y)" },
2290 start3 => { -between => [
2292 \["upper(?)", 'stuff' ],
2299 ( start0 BETWEEN ? AND ? )
2300 AND ( start1 BETWEEN ? AND ? )
2301 AND ( start2 BETWEEN lower(x) AND upper(y) )
2302 AND ( start3 BETWEEN lower(x) AND upper(?) )
2304 @bind = (1, 2, 1, 2, 'stuff');
2307 These are the two builtin "special operators"; but the
2308 list can be expanded : see section L</"SPECIAL OPERATORS"> below.
2310 =head2 Unary operators: bool
2312 If you wish to test against boolean columns or functions within your
2313 database you can use the C<-bool> and C<-not_bool> operators. For
2314 example to test the column C<is_user> being true and the column
2315 C<is_enabled> being false you would use:-
2319 -not_bool => 'is_enabled',
2324 WHERE is_user AND NOT is_enabled
2326 If a more complex combination is required, testing more conditions,
2327 then you should use the and/or operators:-
2334 -not_bool => 'four',
2340 WHERE one AND two AND three AND NOT four
2343 =head2 Nested conditions, -and/-or prefixes
2345 So far, we've seen how multiple conditions are joined with a top-level
2346 C<AND>. We can change this by putting the different conditions we want in
2347 hashes and then putting those hashes in an array. For example:
2352 status => { -like => ['pending%', 'dispatched'] },
2356 status => 'unassigned',
2360 This data structure would create the following:
2362 $stmt = "WHERE ( user = ? AND ( status LIKE ? OR status LIKE ? ) )
2363 OR ( user = ? AND status = ? ) )";
2364 @bind = ('nwiger', 'pending', 'dispatched', 'robot', 'unassigned');
2367 Clauses in hashrefs or arrayrefs can be prefixed with an C<-and> or C<-or>
2368 to change the logic inside :
2374 -and => [ workhrs => {'>', 20}, geo => 'ASIA' ],
2375 -or => { workhrs => {'<', 50}, geo => 'EURO' },
2382 WHERE ( user = ? AND (
2383 ( workhrs > ? AND geo = ? )
2384 OR ( workhrs < ? OR geo = ? )
2387 =head3 Algebraic inconsistency, for historical reasons
2389 C<Important note>: when connecting several conditions, the C<-and->|C<-or>
2390 operator goes C<outside> of the nested structure; whereas when connecting
2391 several constraints on one column, the C<-and> operator goes
2392 C<inside> the arrayref. Here is an example combining both features :
2395 -and => [a => 1, b => 2],
2396 -or => [c => 3, d => 4],
2397 e => [-and => {-like => 'foo%'}, {-like => '%bar'} ]
2402 WHERE ( ( ( a = ? AND b = ? )
2403 OR ( c = ? OR d = ? )
2404 OR ( e LIKE ? AND e LIKE ? ) ) )
2406 This difference in syntax is unfortunate but must be preserved for
2407 historical reasons. So be careful : the two examples below would
2408 seem algebraically equivalent, but they are not
2410 {col => [-and => {-like => 'foo%'}, {-like => '%bar'}]}
2411 # yields : WHERE ( ( col LIKE ? AND col LIKE ? ) )
2413 [-and => {col => {-like => 'foo%'}, {col => {-like => '%bar'}}]]
2414 # yields : WHERE ( ( col LIKE ? OR col LIKE ? ) )
2417 =head2 Literal SQL and value type operators
2419 The basic premise of SQL::Abstract is that in WHERE specifications the "left
2420 side" is a column name and the "right side" is a value (normally rendered as
2421 a placeholder). This holds true for both hashrefs and arrayref pairs as you
2422 see in the L</WHERE CLAUSES> examples above. Sometimes it is necessary to
2423 alter this behavior. There are several ways of doing so.
2427 This is a virtual operator that signals the string to its right side is an
2428 identifier (a column name) and not a value. For example to compare two
2429 columns you would write:
2432 priority => { '<', 2 },
2433 requestor => { -ident => 'submitter' },
2438 $stmt = "WHERE priority < ? AND requestor = submitter";
2441 If you are maintaining legacy code you may see a different construct as
2442 described in L</Deprecated usage of Literal SQL>, please use C<-ident> in new
2447 This is a virtual operator that signals that the construct to its right side
2448 is a value to be passed to DBI. This is for example necessary when you want
2449 to write a where clause against an array (for RDBMS that support such
2450 datatypes). For example:
2453 array => { -value => [1, 2, 3] }
2458 $stmt = 'WHERE array = ?';
2459 @bind = ([1, 2, 3]);
2461 Note that if you were to simply say:
2467 the result would porbably be not what you wanted:
2469 $stmt = 'WHERE array = ? OR array = ? OR array = ?';
2474 Finally, sometimes only literal SQL will do. To include a random snippet
2475 of SQL verbatim, you specify it as a scalar reference. Consider this only
2476 as a last resort. Usually there is a better way. For example:
2479 priority => { '<', 2 },
2480 requestor => { -in => \'(SELECT name FROM hitmen)' },
2485 $stmt = "WHERE priority < ? AND requestor IN (SELECT name FROM hitmen)"
2488 Note that in this example, you only get one bind parameter back, since
2489 the verbatim SQL is passed as part of the statement.
2493 Never use untrusted input as a literal SQL argument - this is a massive
2494 security risk (there is no way to check literal snippets for SQL
2495 injections and other nastyness). If you need to deal with untrusted input
2496 use literal SQL with placeholders as described next.
2498 =head3 Literal SQL with placeholders and bind values (subqueries)
2500 If the literal SQL to be inserted has placeholders and bind values,
2501 use a reference to an arrayref (yes this is a double reference --
2502 not so common, but perfectly legal Perl). For example, to find a date
2503 in Postgres you can use something like this:
2506 date_column => \[q/= date '2008-09-30' - ?::integer/, 10/]
2511 $stmt = "WHERE ( date_column = date '2008-09-30' - ?::integer )"
2514 Note that you must pass the bind values in the same format as they are returned
2515 by L</where>. That means that if you set L</bindtype> to C<columns>, you must
2516 provide the bind values in the C<< [ column_meta => value ] >> format, where
2517 C<column_meta> is an opaque scalar value; most commonly the column name, but
2518 you can use any scalar value (including references and blessed references),
2519 L<SQL::Abstract> will simply pass it through intact. So if C<bindtype> is set
2520 to C<columns> the above example will look like:
2523 date_column => \[q/= date '2008-09-30' - ?::integer/, [ dummy => 10 ]/]
2526 Literal SQL is especially useful for nesting parenthesized clauses in the
2527 main SQL query. Here is a first example :
2529 my ($sub_stmt, @sub_bind) = ("SELECT c1 FROM t1 WHERE c2 < ? AND c3 LIKE ?",
2533 bar => \["IN ($sub_stmt)" => @sub_bind],
2538 $stmt = "WHERE (foo = ? AND bar IN (SELECT c1 FROM t1
2539 WHERE c2 < ? AND c3 LIKE ?))";
2540 @bind = (1234, 100, "foo%");
2542 Other subquery operators, like for example C<"E<gt> ALL"> or C<"NOT IN">,
2543 are expressed in the same way. Of course the C<$sub_stmt> and
2544 its associated bind values can be generated through a former call
2547 my ($sub_stmt, @sub_bind)
2548 = $sql->select("t1", "c1", {c2 => {"<" => 100},
2549 c3 => {-like => "foo%"}});
2552 bar => \["> ALL ($sub_stmt)" => @sub_bind],
2555 In the examples above, the subquery was used as an operator on a column;
2556 but the same principle also applies for a clause within the main C<%where>
2557 hash, like an EXISTS subquery :
2559 my ($sub_stmt, @sub_bind)
2560 = $sql->select("t1", "*", {c1 => 1, c2 => \"> t0.c0"});
2561 my %where = ( -and => [
2563 \["EXISTS ($sub_stmt)" => @sub_bind],
2568 $stmt = "WHERE (foo = ? AND EXISTS (SELECT * FROM t1
2569 WHERE c1 = ? AND c2 > t0.c0))";
2573 Observe that the condition on C<c2> in the subquery refers to
2574 column C<t0.c0> of the main query : this is I<not> a bind
2575 value, so we have to express it through a scalar ref.
2576 Writing C<< c2 => {">" => "t0.c0"} >> would have generated
2577 C<< c2 > ? >> with bind value C<"t0.c0"> ... not exactly
2578 what we wanted here.
2580 Finally, here is an example where a subquery is used
2581 for expressing unary negation:
2583 my ($sub_stmt, @sub_bind)
2584 = $sql->where({age => [{"<" => 10}, {">" => 20}]});
2585 $sub_stmt =~ s/^ where //i; # don't want "WHERE" in the subclause
2587 lname => {like => '%son%'},
2588 \["NOT ($sub_stmt)" => @sub_bind],
2593 $stmt = "lname LIKE ? AND NOT ( age < ? OR age > ? )"
2594 @bind = ('%son%', 10, 20)
2596 =head3 Deprecated usage of Literal SQL
2598 Below are some examples of archaic use of literal SQL. It is shown only as
2599 reference for those who deal with legacy code. Each example has a much
2600 better, cleaner and safer alternative that users should opt for in new code.
2606 my %where = ( requestor => \'IS NOT NULL' )
2608 $stmt = "WHERE requestor IS NOT NULL"
2610 This used to be the way of generating NULL comparisons, before the handling
2611 of C<undef> got formalized. For new code please use the superior syntax as
2612 described in L</Tests for NULL values>.
2616 my %where = ( requestor => \'= submitter' )
2618 $stmt = "WHERE requestor = submitter"
2620 This used to be the only way to compare columns. Use the superior L</-ident>
2621 method for all new code. For example an identifier declared in such a way
2622 will be properly quoted if L</quote_char> is properly set, while the legacy
2623 form will remain as supplied.
2627 my %where = ( is_ready => \"", completed => { '>', '2012-12-21' } )
2629 $stmt = "WHERE completed > ? AND is_ready"
2630 @bind = ('2012-12-21')
2632 Using an empty string literal used to be the only way to express a boolean.
2633 For all new code please use the much more readable
2634 L<-bool|/Unary operators: bool> operator.
2640 These pages could go on for a while, since the nesting of the data
2641 structures this module can handle are pretty much unlimited (the
2642 module implements the C<WHERE> expansion as a recursive function
2643 internally). Your best bet is to "play around" with the module a
2644 little to see how the data structures behave, and choose the best
2645 format for your data based on that.
2647 And of course, all the values above will probably be replaced with
2648 variables gotten from forms or the command line. After all, if you
2649 knew everything ahead of time, you wouldn't have to worry about
2650 dynamically-generating SQL and could just hardwire it into your
2653 =head1 ORDER BY CLAUSES
2655 Some functions take an order by clause. This can either be a scalar (just a
2656 column name,) a hash of C<< { -desc => 'col' } >> or C<< { -asc => 'col' } >>,
2657 or an array of either of the two previous forms. Examples:
2659 Given | Will Generate
2660 ----------------------------------------------------------
2662 \'colA DESC' | ORDER BY colA DESC
2664 'colA' | ORDER BY colA
2666 [qw/colA colB/] | ORDER BY colA, colB
2668 {-asc => 'colA'} | ORDER BY colA ASC
2670 {-desc => 'colB'} | ORDER BY colB DESC
2672 ['colA', {-asc => 'colB'}] | ORDER BY colA, colB ASC
2674 { -asc => [qw/colA colB/] } | ORDER BY colA ASC, colB ASC
2677 { -asc => 'colA' }, | ORDER BY colA ASC, colB DESC,
2678 { -desc => [qw/colB/], | colC ASC, colD ASC
2679 { -asc => [qw/colC colD/],|
2681 ===========================================================
2685 =head1 SPECIAL OPERATORS
2687 my $sqlmaker = SQL::Abstract->new(special_ops => [
2691 my ($self, $field, $op, $arg) = @_;
2697 handler => 'method_name',
2701 A "special operator" is a SQL syntactic clause that can be
2702 applied to a field, instead of a usual binary operator.
2705 WHERE field IN (?, ?, ?)
2706 WHERE field BETWEEN ? AND ?
2707 WHERE MATCH(field) AGAINST (?, ?)
2709 Special operators IN and BETWEEN are fairly standard and therefore
2710 are builtin within C<SQL::Abstract> (as the overridable methods
2711 C<_where_field_IN> and C<_where_field_BETWEEN>). For other operators,
2712 like the MATCH .. AGAINST example above which is specific to MySQL,
2713 you can write your own operator handlers - supply a C<special_ops>
2714 argument to the C<new> method. That argument takes an arrayref of
2715 operator definitions; each operator definition is a hashref with two
2722 the regular expression to match the operator
2726 Either a coderef or a plain scalar method name. In both cases
2727 the expected return is C<< ($sql, @bind) >>.
2729 When supplied with a method name, it is simply called on the
2730 L<SQL::Abstract/> object as:
2732 $self->$method_name ($field, $op, $arg)
2736 $op is the part that matched the handler regex
2737 $field is the LHS of the operator
2740 When supplied with a coderef, it is called as:
2742 $coderef->($self, $field, $op, $arg)
2747 For example, here is an implementation
2748 of the MATCH .. AGAINST syntax for MySQL
2750 my $sqlmaker = SQL::Abstract->new(special_ops => [
2752 # special op for MySql MATCH (field) AGAINST(word1, word2, ...)
2753 {regex => qr/^match$/i,
2755 my ($self, $field, $op, $arg) = @_;
2756 $arg = [$arg] if not ref $arg;
2757 my $label = $self->_quote($field);
2758 my ($placeholder) = $self->_convert('?');
2759 my $placeholders = join ", ", (($placeholder) x @$arg);
2760 my $sql = $self->_sqlcase('match') . " ($label) "
2761 . $self->_sqlcase('against') . " ($placeholders) ";
2762 my @bind = $self->_bindtype($field, @$arg);
2763 return ($sql, @bind);
2770 =head1 UNARY OPERATORS
2772 my $sqlmaker = SQL::Abstract->new(unary_ops => [
2776 my ($self, $op, $arg) = @_;
2782 handler => 'method_name',
2786 A "unary operator" is a SQL syntactic clause that can be
2787 applied to a field - the operator goes before the field
2789 You can write your own operator handlers - supply a C<unary_ops>
2790 argument to the C<new> method. That argument takes an arrayref of
2791 operator definitions; each operator definition is a hashref with two
2798 the regular expression to match the operator
2802 Either a coderef or a plain scalar method name. In both cases
2803 the expected return is C<< $sql >>.
2805 When supplied with a method name, it is simply called on the
2806 L<SQL::Abstract/> object as:
2808 $self->$method_name ($op, $arg)
2812 $op is the part that matched the handler regex
2813 $arg is the RHS or argument of the operator
2815 When supplied with a coderef, it is called as:
2817 $coderef->($self, $op, $arg)
2825 Thanks to some benchmarking by Mark Stosberg, it turns out that
2826 this module is many orders of magnitude faster than using C<DBIx::Abstract>.
2827 I must admit this wasn't an intentional design issue, but it's a
2828 byproduct of the fact that you get to control your C<DBI> handles
2831 To maximize performance, use a code snippet like the following:
2833 # prepare a statement handle using the first row
2834 # and then reuse it for the rest of the rows
2836 for my $href (@array_of_hashrefs) {
2837 $stmt ||= $sql->insert('table', $href);
2838 $sth ||= $dbh->prepare($stmt);
2839 $sth->execute($sql->values($href));
2842 The reason this works is because the keys in your C<$href> are sorted
2843 internally by B<SQL::Abstract>. Thus, as long as your data retains
2844 the same structure, you only have to generate the SQL the first time
2845 around. On subsequent queries, simply use the C<values> function provided
2846 by this module to return your values in the correct order.
2848 However this depends on the values having the same type - if, for
2849 example, the values of a where clause may either have values
2850 (resulting in sql of the form C<column = ?> with a single bind
2851 value), or alternatively the values might be C<undef> (resulting in
2852 sql of the form C<column IS NULL> with no bind value) then the
2853 caching technique suggested will not work.
2857 If you use my C<CGI::FormBuilder> module at all, you'll hopefully
2858 really like this part (I do, at least). Building up a complex query
2859 can be as simple as the following:
2863 use CGI::FormBuilder;
2866 my $form = CGI::FormBuilder->new(...);
2867 my $sql = SQL::Abstract->new;
2869 if ($form->submitted) {
2870 my $field = $form->field;
2871 my $id = delete $field->{id};
2872 my($stmt, @bind) = $sql->update('table', $field, {id => $id});
2875 Of course, you would still have to connect using C<DBI> to run the
2876 query, but the point is that if you make your form look like your
2877 table, the actual query script can be extremely simplistic.
2879 If you're B<REALLY> lazy (I am), check out C<HTML::QuickTable> for
2880 a fast interface to returning and formatting data. I frequently
2881 use these three modules together to write complex database query
2882 apps in under 50 lines.
2888 =item * gitweb: L<http://git.shadowcat.co.uk/gitweb/gitweb.cgi?p=dbsrgits/SQL-Abstract.git>
2890 =item * git: L<git://git.shadowcat.co.uk/dbsrgits/SQL-Abstract.git>
2896 Version 1.50 was a major internal refactoring of C<SQL::Abstract>.
2897 Great care has been taken to preserve the I<published> behavior
2898 documented in previous versions in the 1.* family; however,
2899 some features that were previously undocumented, or behaved
2900 differently from the documentation, had to be changed in order
2901 to clarify the semantics. Hence, client code that was relying
2902 on some dark areas of C<SQL::Abstract> v1.*
2903 B<might behave differently> in v1.50.
2905 The main changes are :
2911 support for literal SQL through the C<< \ [$sql, bind] >> syntax.
2915 support for the { operator => \"..." } construct (to embed literal SQL)
2919 support for the { operator => \["...", @bind] } construct (to embed literal SQL with bind values)
2923 optional support for L<array datatypes|/"Inserting and Updating Arrays">
2927 defensive programming : check arguments
2931 fixed bug with global logic, which was previously implemented
2932 through global variables yielding side-effects. Prior versions would
2933 interpret C<< [ {cond1, cond2}, [cond3, cond4] ] >>
2934 as C<< "(cond1 AND cond2) OR (cond3 AND cond4)" >>.
2935 Now this is interpreted
2936 as C<< "(cond1 AND cond2) OR (cond3 OR cond4)" >>.
2941 fixed semantics of _bindtype on array args
2945 dropped the C<_anoncopy> of the %where tree. No longer necessary,
2946 we just avoid shifting arrays within that tree.
2950 dropped the C<_modlogic> function
2954 =head1 ACKNOWLEDGEMENTS
2956 There are a number of individuals that have really helped out with
2957 this module. Unfortunately, most of them submitted bugs via CPAN
2958 so I have no idea who they are! But the people I do know are:
2960 Ash Berlin (order_by hash term support)
2961 Matt Trout (DBIx::Class support)
2962 Mark Stosberg (benchmarking)
2963 Chas Owens (initial "IN" operator support)
2964 Philip Collins (per-field SQL functions)
2965 Eric Kolve (hashref "AND" support)
2966 Mike Fragassi (enhancements to "BETWEEN" and "LIKE")
2967 Dan Kubb (support for "quote_char" and "name_sep")
2968 Guillermo Roditi (patch to cleanup "IN" and "BETWEEN", fix and tests for _order_by)
2969 Laurent Dami (internal refactoring, extensible list of special operators, literal SQL)
2970 Norbert Buchmuller (support for literal SQL in hashpair, misc. fixes & tests)
2971 Peter Rabbitson (rewrite of SQLA::Test, misc. fixes & tests)
2972 Oliver Charles (support for "RETURNING" after "INSERT")
2978 L<DBIx::Class>, L<DBIx::Abstract>, L<CGI::FormBuilder>, L<HTML::QuickTable>.
2982 Copyright (c) 2001-2007 Nathan Wiger <nwiger@cpan.org>. All Rights Reserved.
2984 This module is actively maintained by Matt Trout <mst@shadowcatsystems.co.uk>
2986 For support, your best bet is to try the C<DBIx::Class> users mailing list.
2987 While not an official support venue, C<DBIx::Class> makes heavy use of
2988 C<SQL::Abstract>, and as such list members there are very familiar with
2989 how to create queries.
2993 This module is free software; you may copy this under the same
2994 terms as perl itself (either the GNU General Public License or
2995 the Artistic License)