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
30 =item * The -ident operator
32 =item * The -value operator
39 DBIx::Class::SQLMaker::LimitDialects
45 use Sub::Name 'subname';
46 use DBIx::Class::Carp;
47 use DBIx::Class::Exception;
50 __PACKAGE__->mk_group_accessors (simple => qw/quote_char name_sep limit_dialect/);
52 # for when I need a normalized l/r pair
55 { defined $_ ? $_ : '' }
56 ( ref $_[0]->{quote_char} ? (@{$_[0]->{quote_char}}) : ( ($_[0]->{quote_char}) x 2 ) )
60 # FIXME when we bring in the storage weaklink, check its schema
61 # weaklink and channel through $schema->throw_exception
62 sub throw_exception { DBIx::Class::Exception->throw($_[1]) }
65 # reinstall the belch()/puke() functions of SQL::Abstract with custom versions
66 # that use DBIx::Class::Carp/DBIx::Class::Exception instead of plain Carp
67 no warnings qw/redefine/;
69 *SQL::Abstract::belch = subname 'SQL::Abstract::belch' => sub (@) {
70 my($func) = (caller(1))[3];
71 carp "[$func] Warning: ", @_;
74 *SQL::Abstract::puke = subname 'SQL::Abstract::puke' => sub (@) {
75 my($func) = (caller(1))[3];
76 __PACKAGE__->throw_exception("[$func] Fatal: " . join ('', @_));
79 # Current SQLA pollutes its namespace - clean for the time being
80 namespace::clean->clean_subroutines(qw/SQL::Abstract carp croak confess/);
83 # the "oh noes offset/top without limit" constant
84 # limited to 32 bits for sanity (and consistency,
85 # since it is ultimately handed to sprintf %u)
86 # Implemented as a method, since ::Storage::DBI also
87 # refers to it (i.e. for the case of software_limit or
88 # as the value to abuse with MSSQL ordered subqueries)
89 sub __max_int { 0xFFFFFFFF };
92 my $self = shift->next::method(@_);
94 # use the same coderefs, they are prepared to handle both cases
95 my @extra_dbic_syntax = (
96 { regex => qr/^ ident $/xi, handler => '_where_op_IDENT' },
97 { regex => qr/^ value $/xi, handler => '_where_op_VALUE' },
100 push @{$self->{special_ops}}, @extra_dbic_syntax;
101 push @{$self->{unary_ops}}, @extra_dbic_syntax;
106 sub _where_op_IDENT {
108 my ($op, $rhs) = splice @_, -2;
110 $self->throw_exception("-$op takes a single scalar argument (a quotable identifier)");
113 # in case we are called as a top level special op (no '=')
116 $_ = $self->_convert($self->_quote($_)) for ($lhs, $rhs);
124 sub _where_op_VALUE {
126 my ($op, $rhs) = splice @_, -2;
128 # in case we are called as a top level special op (no '=')
132 ($lhs || $self->{_nested_func_lhs} || $self->throw_exception("Unable to find bindtype for -value $rhs") ),
138 $self->_convert($self->_quote($lhs)) . ' = ' . $self->_convert('?'),
142 $self->_convert('?'),
149 carp_unique ("-nest in search conditions is deprecated, you most probably wanted:\n"
150 .q|{..., -and => [ \%cond0, \@cond1, \'cond2', \[ 'cond3', [ col => bind ] ], etc. ], ... }|
153 shift->next::method(@_);
156 # Handle limit-dialect selection
158 my ($self, $table, $fields, $where, $rs_attrs, $limit, $offset) = @_;
161 $fields = $self->_recurse_fields($fields);
163 if (defined $offset) {
164 $self->throw_exception('A supplied offset must be a non-negative integer')
165 if ( $offset =~ /\D/ or $offset < 0 );
169 if (defined $limit) {
170 $self->throw_exception('A supplied limit must be a positive integer')
171 if ( $limit =~ /\D/ or $limit <= 0 );
174 $limit = $self->__max_int;
180 # this is legacy code-flow from SQLA::Limit, it is not set in stone
182 ($sql, @bind) = $self->next::method ($table, $fields, $where);
185 $self->can ('emulate_limit') # also backcompat hook from SQLA::Limit
188 my $dialect = $self->limit_dialect
189 or $self->throw_exception( "Unable to generate SQL-limit - no limit dialect specified on $self, and no emulate_limit method found" );
190 $self->can ("_$dialect")
191 or $self->throw_exception(__PACKAGE__ . " does not implement the requested dialect '$dialect'");
195 $sql = $self->$limiter ($sql, $rs_attrs, $limit, $offset);
198 ($sql, @bind) = $self->next::method ($table, $fields, $where, $rs_attrs);
201 push @{$self->{where_bind}}, @bind;
203 # this *must* be called, otherwise extra binds will remain in the sql-maker
204 my @all_bind = $self->_assemble_binds;
206 $sql .= $self->_lock_select ($rs_attrs->{for})
209 return wantarray ? ($sql, @all_bind) : $sql;
212 sub _assemble_binds {
214 return map { @{ (delete $self->{"${_}_bind"}) || [] } } (qw/select from where group having order/);
218 update => 'FOR UPDATE',
219 shared => 'FOR SHARE',
222 my ($self, $type) = @_;
223 my $sql = $for_syntax->{$type} || $self->throw_exception( "Unknown SELECT .. FOR type '$type' requested" );
227 # Handle default inserts
229 # optimized due to hotttnesss
230 # my ($self, $table, $data, $options) = @_;
232 # SQLA will emit INSERT INTO $table ( ) VALUES ( )
233 # which is sadly understood only by MySQL. Change default behavior here,
234 # until SQLA2 comes with proper dialect support
235 if (! $_[2] or (ref $_[2] eq 'HASH' and !keys %{$_[2]} ) ) {
238 'INSERT INTO %s DEFAULT VALUES', $_[0]->_quote($_[1])
241 if ( ($_[3]||{})->{returning} ) {
243 ($s, @bind) = $_[0]->_insert_returning ($_[3]);
247 return ($sql, @bind);
253 sub _recurse_fields {
254 my ($self, $fields) = @_;
255 my $ref = ref $fields;
256 return $self->_quote($fields) unless $ref;
257 return $$fields if $ref eq 'SCALAR';
259 if ($ref eq 'ARRAY') {
260 return join(', ', map { $self->_recurse_fields($_) } @$fields);
262 elsif ($ref eq 'HASH') {
263 my %hash = %$fields; # shallow copy
265 my $as = delete $hash{-as}; # if supplied
267 my ($func, $args, @toomany) = %hash;
269 # there should be only one pair
271 $self->throw_exception( "Malformed select argument - too many keys in hash: " . join (',', keys %$fields ) );
274 if (lc ($func) eq 'distinct' && ref $args eq 'ARRAY' && @$args > 1) {
275 $self->throw_exception (
276 'The select => { distinct => ... } syntax is not supported for multiple columns.'
277 .' Instead please use { group_by => [ qw/' . (join ' ', @$args) . '/ ] }'
278 .' or { select => [ qw/' . (join ' ', @$args) . '/ ], distinct => 1 }'
282 my $select = sprintf ('%s( %s )%s',
283 $self->_sqlcase($func),
284 $self->_recurse_fields($args),
286 ? sprintf (' %s %s', $self->_sqlcase('as'), $self->_quote ($as) )
292 # Is the second check absolutely necessary?
293 elsif ( $ref eq 'REF' and ref($$fields) eq 'ARRAY' ) {
294 push @{$self->{select_bind}}, @{$$fields}[1..$#$$fields];
295 return $$fields->[0];
298 $self->throw_exception( $ref . qq{ unexpected in _recurse_fields()} );
303 # this used to be a part of _order_by but is broken out for clarity.
304 # What we have been doing forever is hijacking the $order arg of
305 # SQLA::select to pass in arbitrary pieces of data (first the group_by,
306 # then pretty much the entire resultset attr-hash, as more and more
307 # things in the SQLA space need to have mopre info about the $rs they
308 # create SQL for. The alternative would be to keep expanding the
309 # signature of _select with more and more positional parameters, which
310 # is just gross. All hail SQLA2!
311 sub _parse_rs_attrs {
312 my ($self, $arg) = @_;
316 if ($arg->{group_by}) {
317 # horible horrible, waiting for refactor
318 local $self->{select_bind};
319 if (my $g = $self->_recurse_fields($arg->{group_by}) ) {
320 $sql .= $self->_sqlcase(' group by ') . $g;
321 push @{$self->{group_bind} ||= []}, @{$self->{select_bind}||[]};
325 if (defined $arg->{having}) {
326 my ($frag, @bind) = $self->_recurse_where($arg->{having});
327 push(@{$self->{having_bind}}, @bind);
328 $sql .= $self->_sqlcase(' having ') . $frag;
331 if (defined $arg->{order_by}) {
332 $sql .= $self->_order_by ($arg->{order_by});
339 my ($self, $arg) = @_;
341 # check that we are not called in legacy mode (order_by as 4th argument)
342 if (ref $arg eq 'HASH' and not grep { $_ =~ /^-(?:desc|asc)/i } keys %$arg ) {
343 return $self->_parse_rs_attrs ($arg);
346 my ($sql, @bind) = $self->next::method($arg);
347 push @{$self->{order_bind}}, @bind;
353 # optimized due to hotttnesss
354 # my ($self, $from) = @_;
355 if (my $ref = ref $_[1] ) {
356 if ($ref eq 'ARRAY') {
357 return $_[0]->_recurse_from(@{$_[1]});
359 elsif ($ref eq 'HASH') {
360 return $_[0]->_recurse_from($_[1]);
362 elsif ($ref eq 'REF' && ref ${$_[1]} eq 'ARRAY') {
363 my ($sql, @bind) = @{ ${$_[1]} };
364 push @{$_[0]->{from_bind}}, @bind;
368 return $_[0]->next::method ($_[1]);
371 sub _generate_join_clause {
372 my ($self, $join_type) = @_;
374 $join_type = $self->{_default_jointype}
375 if ! defined $join_type;
377 return sprintf ('%s JOIN ',
378 $join_type ? $self->_sqlcase($join_type) : ''
385 return join (' ', $self->_gen_from_blocks(@_) );
388 sub _gen_from_blocks {
389 my ($self, $from, @joins) = @_;
391 my @fchunks = $self->_from_chunk_to_sql($from);
396 # check whether a join type exists
397 my $to_jt = ref($to) eq 'ARRAY' ? $to->[0] : $to;
399 if (ref($to_jt) eq 'HASH' and defined($to_jt->{-join_type})) {
400 $join_type = $to_jt->{-join_type};
401 $join_type =~ s/^\s+ | \s+$//xg;
404 my @j = $self->_generate_join_clause( $join_type );
406 if (ref $to eq 'ARRAY') {
407 push(@j, '(', $self->_recurse_from(@$to), ')');
410 push(@j, $self->_from_chunk_to_sql($to));
413 my ($sql, @bind) = $self->_join_condition($on);
414 push(@j, ' ON ', $sql);
415 push @{$self->{from_bind}}, @bind;
417 push @fchunks, join '', @j;
423 sub _from_chunk_to_sql {
424 my ($self, $fromspec) = @_;
426 return join (' ', $self->_SWITCH_refkind($fromspec, {
431 push @{$self->{from_bind}}, @{$$fromspec}[1..$#$$fromspec];
435 my ($as, $table, $toomuch) = ( map
436 { $_ => $fromspec->{$_} }
437 ( grep { $_ !~ /^\-/ } keys %$fromspec )
440 $self->throw_exception( "Only one table/as pair expected in from-spec but an exra '$toomuch' key present" )
443 ($self->_from_chunk_to_sql($table), $self->_quote($as) );
446 $self->_quote($fromspec);
451 sub _join_condition {
452 my ($self, $cond) = @_;
454 # Backcompat for the old days when a plain hashref
455 # { 't1.col1' => 't2.col2' } meant ON t1.col1 = t2.col2
456 # Once things settle we should start warning here so that
457 # folks unroll their hacks
463 (keys %$cond)[0] =~ /\./
465 ! ref ( (values %$cond)[0] )
467 $cond = { keys %$cond => { -ident => values %$cond } }
469 elsif ( ref $cond eq 'ARRAY' ) {
470 # do our own ORing so that the hashref-shim above is invoked
473 foreach my $c (@$cond) {
474 my ($sql, @bind) = $self->_join_condition($c);
478 return join(' OR ', @parts), @binds;
481 return $self->_recurse_where($cond);
488 See L<DBIx::Class/CONTRIBUTORS>.
492 You may distribute this code under the same terms as Perl itself.