1 package DBIx::Class::SQLMaker;
8 DBIx::Class::SQLMaker - An SQL::Abstract-based SQL maker class
12 This module is a subclass of L<SQL::Abstract> and includes a number of
13 DBIC-specific workarounds, not yet suitable for inclusion into the
14 L<SQL::Abstract> core. It also provides all (and more than) the functionality
15 of L<SQL::Abstract::Limit>, see L<DBIx::Class::SQLMaker::LimitDialects> for
18 Currently the enhancements to L<SQL::Abstract> are:
22 =item * Support for C<JOIN> statements (via extended C<table/from> support)
24 =item * Support of functions in C<SELECT> lists
26 =item * C<GROUP BY>/C<HAVING> support (via extensions to the order_by parameter)
28 =item * Support of C<...FOR UPDATE> type of select statement modifiers
35 DBIx::Class::SQLMaker::LimitDialects
41 use Sub::Name 'subname';
42 use DBIx::Class::Carp;
45 __PACKAGE__->mk_group_accessors (simple => qw/quote_char name_sep limit_dialect/);
47 # for when I need a normalized l/r pair
50 { defined $_ ? $_ : '' }
51 ( ref $_[0]->{quote_char} ? (@{$_[0]->{quote_char}}) : ( ($_[0]->{quote_char}) x 2 ) )
55 # FIXME when we bring in the storage weaklink, check its schema
56 # weaklink and channel through $schema->throw_exception
57 sub throw_exception { DBIx::Class::Exception->throw($_[1]) }
60 # reinstall the belch()/puke() functions of SQL::Abstract with custom versions
61 # that use DBIx::Class::Carp/DBIx::Class::Exception instead of plain Carp
62 no warnings qw/redefine/;
64 *SQL::Abstract::belch = subname 'SQL::Abstract::belch' => sub (@) {
65 my($func) = (caller(1))[3];
66 carp "[$func] Warning: ", @_;
69 *SQL::Abstract::puke = subname 'SQL::Abstract::puke' => sub (@) {
70 my($func) = (caller(1))[3];
71 __PACKAGE__->throw_exception("[$func] Fatal: " . join ('', @_));
75 # the "oh noes offset/top without limit" constant
76 # limited to 31 bits for sanity (and consistency,
77 # since it may be handed to the like of sprintf %u)
79 # Also *some* builds of SQLite fail the test
80 # some_column BETWEEN ? AND ?: 1, 4294967295
81 # with the proper integer bind attrs
83 # Implemented as a method, since ::Storage::DBI also
84 # refers to it (i.e. for the case of software_limit or
85 # as the value to abuse with MSSQL ordered subqueries)
86 sub __max_int () { 0x7FFFFFFF };
88 # poor man's de-qualifier
90 $_[0]->next::method( ( $_[0]{_dequalify_idents} and ! ref $_[1] )
91 ? $_[1] =~ / ([^\.]+) $ /x
97 carp_unique ("-nest in search conditions is deprecated, you most probably wanted:\n"
98 .q|{..., -and => [ \%cond0, \@cond1, \'cond2', \[ 'cond3', [ col => bind ] ], etc. ], ... }|
101 shift->next::method(@_);
104 # Handle limit-dialect selection
106 my ($self, $table, $fields, $where, $rs_attrs, $limit, $offset) = @_;
109 $fields = $self->_recurse_fields($fields);
111 if (defined $offset) {
112 $self->throw_exception('A supplied offset must be a non-negative integer')
113 if ( $offset =~ /\D/ or $offset < 0 );
117 if (defined $limit) {
118 $self->throw_exception('A supplied limit must be a positive integer')
119 if ( $limit =~ /\D/ or $limit <= 0 );
122 $limit = $self->__max_int;
128 # this is legacy code-flow from SQLA::Limit, it is not set in stone
130 ($sql, @bind) = $self->next::method ($table, $fields, $where);
134 if( $limiter = $self->can ('emulate_limit') ) {
136 'Support for the legacy emulate_limit() mechanism inherited from '
137 . 'SQL::Abstract::Limit has been deprecated, and will be removed when '
138 . 'DBIC transitions to Data::Query. If your code uses this type of '
139 . 'limit specification please file an RT and provide the source of '
140 . 'your emulate_limit() implementation, so an acceptable upgrade-path '
145 my $dialect = $self->limit_dialect
146 or $self->throw_exception( "Unable to generate SQL-limit - no limit dialect specified on $self" );
148 $limiter = $self->can ("_$dialect")
149 or $self->throw_exception(__PACKAGE__ . " does not implement the requested dialect '$dialect'");
152 $sql = $self->$limiter (
154 { %{$rs_attrs||{}}, _selector_sql => $fields },
160 ($sql, @bind) = $self->next::method ($table, $fields, $where, $rs_attrs);
163 push @{$self->{where_bind}}, @bind;
165 # this *must* be called, otherwise extra binds will remain in the sql-maker
166 my @all_bind = $self->_assemble_binds;
168 $sql .= $self->_lock_select ($rs_attrs->{for})
171 return wantarray ? ($sql, @all_bind) : $sql;
174 sub _assemble_binds {
176 return map { @{ (delete $self->{"${_}_bind"}) || [] } } (qw/pre_select select from where group having order limit/);
180 update => 'FOR UPDATE',
181 shared => 'FOR SHARE',
184 my ($self, $type) = @_;
187 if (ref($type) eq 'SCALAR') {
191 $sql = $for_syntax->{$type} || $self->throw_exception( "Unknown SELECT .. FOR type '$type' requested" );
197 # Handle default inserts
199 # optimized due to hotttnesss
200 # my ($self, $table, $data, $options) = @_;
202 # SQLA will emit INSERT INTO $table ( ) VALUES ( )
203 # which is sadly understood only by MySQL. Change default behavior here,
204 # until SQLA2 comes with proper dialect support
205 if (! $_[2] or (ref $_[2] eq 'HASH' and !keys %{$_[2]} ) ) {
208 'INSERT INTO %s DEFAULT VALUES', $_[0]->_quote($_[1])
211 if ( ($_[3]||{})->{returning} ) {
213 ($s, @bind) = $_[0]->_insert_returning ($_[3]);
217 return ($sql, @bind);
223 sub _recurse_fields {
224 my ($self, $fields) = @_;
225 my $ref = ref $fields;
226 return $self->_quote($fields) unless $ref;
227 return $$fields if $ref eq 'SCALAR';
229 if ($ref eq 'ARRAY') {
230 return join(', ', map { $self->_recurse_fields($_) } @$fields);
232 elsif ($ref eq 'HASH') {
233 my %hash = %$fields; # shallow copy
235 my $as = delete $hash{-as}; # if supplied
237 my ($func, $args, @toomany) = %hash;
239 # there should be only one pair
241 $self->throw_exception( "Malformed select argument - too many keys in hash: " . join (',', keys %$fields ) );
244 if (lc ($func) eq 'distinct' && ref $args eq 'ARRAY' && @$args > 1) {
245 $self->throw_exception (
246 'The select => { distinct => ... } syntax is not supported for multiple columns.'
247 .' Instead please use { group_by => [ qw/' . (join ' ', @$args) . '/ ] }'
248 .' or { select => [ qw/' . (join ' ', @$args) . '/ ], distinct => 1 }'
252 my $select = sprintf ('%s( %s )%s',
253 $self->_sqlcase($func),
254 $self->_recurse_fields($args),
256 ? sprintf (' %s %s', $self->_sqlcase('as'), $self->_quote ($as) )
262 # Is the second check absolutely necessary?
263 elsif ( $ref eq 'REF' and ref($$fields) eq 'ARRAY' ) {
264 push @{$self->{select_bind}}, @{$$fields}[1..$#$$fields];
265 return $$fields->[0];
268 $self->throw_exception( $ref . qq{ unexpected in _recurse_fields()} );
273 # this used to be a part of _order_by but is broken out for clarity.
274 # What we have been doing forever is hijacking the $order arg of
275 # SQLA::select to pass in arbitrary pieces of data (first the group_by,
276 # then pretty much the entire resultset attr-hash, as more and more
277 # things in the SQLA space need to have mopre info about the $rs they
278 # create SQL for. The alternative would be to keep expanding the
279 # signature of _select with more and more positional parameters, which
280 # is just gross. All hail SQLA2!
281 sub _parse_rs_attrs {
282 my ($self, $arg) = @_;
286 if ($arg->{group_by}) {
287 # horible horrible, waiting for refactor
288 local $self->{select_bind};
289 if (my $g = $self->_recurse_fields($arg->{group_by}) ) {
290 $sql .= $self->_sqlcase(' group by ') . $g;
291 push @{$self->{group_bind} ||= []}, @{$self->{select_bind}||[]};
295 if (defined $arg->{having}) {
296 my ($frag, @bind) = $self->_recurse_where($arg->{having});
297 push(@{$self->{having_bind}}, @bind);
298 $sql .= $self->_sqlcase(' having ') . $frag;
301 if (defined $arg->{order_by}) {
302 $sql .= $self->_order_by ($arg->{order_by});
309 my ($self, $arg) = @_;
311 # check that we are not called in legacy mode (order_by as 4th argument)
312 if (ref $arg eq 'HASH' and not grep { $_ =~ /^-(?:desc|asc)/i } keys %$arg ) {
313 return $self->_parse_rs_attrs ($arg);
316 my ($sql, @bind) = $self->next::method($arg);
317 push @{$self->{order_bind}}, @bind;
323 # optimized due to hotttnesss
324 # my ($self, $from) = @_;
325 if (my $ref = ref $_[1] ) {
326 if ($ref eq 'ARRAY') {
327 return $_[0]->_recurse_from(@{$_[1]});
329 elsif ($ref eq 'HASH') {
330 return $_[0]->_recurse_from($_[1]);
332 elsif ($ref eq 'REF' && ref ${$_[1]} eq 'ARRAY') {
333 my ($sql, @bind) = @{ ${$_[1]} };
334 push @{$_[0]->{from_bind}}, @bind;
338 return $_[0]->next::method ($_[1]);
341 sub _generate_join_clause {
342 my ($self, $join_type) = @_;
344 $join_type = $self->{_default_jointype}
345 if ! defined $join_type;
347 return sprintf ('%s JOIN ',
348 $join_type ? $self->_sqlcase($join_type) : ''
354 return join (' ', $self->_gen_from_blocks(@_) );
357 sub _gen_from_blocks {
358 my ($self, $from, @joins) = @_;
360 my @fchunks = $self->_from_chunk_to_sql($from);
365 # check whether a join type exists
366 my $to_jt = ref($to) eq 'ARRAY' ? $to->[0] : $to;
368 if (ref($to_jt) eq 'HASH' and defined($to_jt->{-join_type})) {
369 $join_type = $to_jt->{-join_type};
370 $join_type =~ s/^\s+ | \s+$//xg;
373 my @j = $self->_generate_join_clause( $join_type );
375 if (ref $to eq 'ARRAY') {
376 push(@j, '(', $self->_recurse_from(@$to), ')');
379 push(@j, $self->_from_chunk_to_sql($to));
382 my ($sql, @bind) = $self->_join_condition($on);
383 push(@j, ' ON ', $sql);
384 push @{$self->{from_bind}}, @bind;
386 push @fchunks, join '', @j;
392 sub _from_chunk_to_sql {
393 my ($self, $fromspec) = @_;
395 return join (' ', do {
396 if (! ref $fromspec) {
397 $self->_quote($fromspec);
399 elsif (ref $fromspec eq 'SCALAR') {
402 elsif (ref $fromspec eq 'REF' and ref $$fromspec eq 'ARRAY') {
403 push @{$self->{from_bind}}, @{$$fromspec}[1..$#$$fromspec];
406 elsif (ref $fromspec eq 'HASH') {
407 my ($as, $table, $toomuch) = ( map
408 { $_ => $fromspec->{$_} }
409 ( grep { $_ !~ /^\-/ } keys %$fromspec )
412 $self->throw_exception( "Only one table/as pair expected in from-spec but an exra '$toomuch' key present" )
415 ($self->_from_chunk_to_sql($table), $self->_quote($as) );
418 $self->throw_exception('Unsupported from refkind: ' . ref $fromspec );
423 sub _join_condition {
424 my ($self, $cond) = @_;
426 # Backcompat for the old days when a plain hashref
427 # { 't1.col1' => 't2.col2' } meant ON t1.col1 = t2.col2
428 # Once things settle we should start warning here so that
429 # folks unroll their hacks
435 (keys %$cond)[0] =~ /\./
437 ! ref ( (values %$cond)[0] )
439 $cond = { keys %$cond => { -ident => values %$cond } }
441 elsif ( ref $cond eq 'ARRAY' ) {
442 # do our own ORing so that the hashref-shim above is invoked
445 foreach my $c (@$cond) {
446 my ($sql, @bind) = $self->_join_condition($c);
450 return join(' OR ', @parts), @binds;
453 return $self->_recurse_where($cond);
456 # This is hideously ugly, but SQLA does not understand multicol IN expressions
457 # FIXME TEMPORARY - DQ should have native syntax for this
458 # moved here to raise API questions
460 # !!! EXPERIMENTAL API !!! WILL CHANGE !!!
461 sub _where_op_multicolumn_in {
462 my ($self, $lhs, $rhs) = @_;
464 if (! ref $lhs or ref $lhs eq 'ARRAY') {
466 for (ref $lhs ? @$lhs : $lhs) {
468 push @sql, $self->_quote($_);
470 elsif (ref $_ eq 'SCALAR') {
473 elsif (ref $_ eq 'REF' and ref $$_ eq 'ARRAY') {
479 $self->throw_exception("ARRAY of @{[ ref $_ ]}es unsupported for multicolumn IN lhs...");
482 $lhs = \[ join(', ', @sql), @bind];
484 elsif (ref $lhs eq 'SCALAR') {
487 elsif (ref $lhs eq 'REF' and ref $$lhs eq 'ARRAY' ) {
491 $self->throw_exception( ref($lhs) . "es unsupported for multicolumn IN lhs...");
495 $rhs = \[ $self->_recurse_where($rhs) ];
498 $$_->[0] = "( $$_->[0] )"
499 unless $$_->[0] =~ /^ \s* \( .* \) \s* ^/xs;
502 \[ join( ' IN ', shift @$$lhs, shift @$$rhs ), @$$lhs, @$$rhs ];
509 See L<DBIx::Class/CONTRIBUTORS>.
513 You may distribute this code under the same terms as Perl itself.