1 package DBIx::Class::SQLMaker;
5 DBIx::Class::SQLMaker - An SQL::Abstract-based SQL maker class
9 This module is a subclass of L<SQL::Abstract> and includes a number of
10 DBIC-specific workarounds, not yet suitable for inclusion into the
11 L<SQL::Abstract> core. It also provides all (and more than) the functionality
12 of L<SQL::Abstract::Limit>, see L<DBIx::Class::SQLMaker::LimitDialects> for
15 Currently the enhancements to L<SQL::Abstract> are:
19 =item * Support for C<JOIN> statements (via extended C<table/from> support)
21 =item * Support of functions in C<SELECT> lists
23 =item * C<GROUP BY>/C<HAVING> support (via extensions to the order_by parameter)
25 =item * Support of C<...FOR UPDATE> type of select statement modifiers
32 DBIx::Class::SQLMaker::LimitDialects
34 Class::Accessor::Grouped
39 use Sub::Name 'subname';
40 use Carp::Clan qw/^DBIx::Class|^SQL::Abstract|^Try::Tiny/;
43 __PACKAGE__->mk_group_accessors (simple => qw/quote_char name_sep limit_dialect/);
46 # reinstall the carp()/croak() functions imported into SQL::Abstract
47 # as Carp and Carp::Clan do not like each other much
48 no warnings qw/redefine/;
50 for my $f (qw/carp croak/) {
52 my $orig = \&{"SQL::Abstract::$f"};
53 my $clan_import = \&{$f};
54 *{"SQL::Abstract::$f"} = subname "SQL::Abstract::$f" =>
56 if (Carp::longmess() =~ /DBIx::Class::SQLMaker::[\w]+ .+? called \s at/x) {
66 # the "oh noes offset/top without limit" constant
67 # limited to 32 bits for sanity (and consistency,
68 # since it is ultimately handed to sprintf %u)
69 # Implemented as a method, since ::Storage::DBI also
70 # refers to it (i.e. for the case of software_limit or
71 # as the value to abuse with MSSQL ordered subqueries)
72 sub __max_int { 0xFFFFFFFF };
74 # Handle limit-dialect selection
76 my ($self, $table, $fields, $where, $rs_attrs, $limit, $offset) = @_;
79 $fields = $self->_recurse_fields($fields);
81 if (defined $offset) {
82 croak ('A supplied offset must be a non-negative integer')
83 if ( $offset =~ /\D/ or $offset < 0 );
88 croak ('A supplied limit must be a positive integer')
89 if ( $limit =~ /\D/ or $limit <= 0 );
92 $limit = $self->__max_int;
98 # this is legacy code-flow from SQLA::Limit, it is not set in stone
100 ($sql, @bind) = $self->next::method ($table, $fields, $where);
103 $self->can ('emulate_limit') # also backcompat hook from SQLA::Limit
106 my $dialect = $self->limit_dialect
107 or croak "Unable to generate SQL-limit - no limit dialect specified on $self, and no emulate_limit method found";
108 $self->can ("_$dialect")
109 or croak (__PACKAGE__ . " does not implement the requested dialect '$dialect'");
113 $sql = $self->$limiter ($sql, $rs_attrs, $limit, $offset);
116 ($sql, @bind) = $self->next::method ($table, $fields, $where, $rs_attrs);
119 push @{$self->{where_bind}}, @bind;
121 # this *must* be called, otherwise extra binds will remain in the sql-maker
122 my @all_bind = $self->_assemble_binds;
124 $sql .= $self->_lock_select ($rs_attrs->{for})
127 return wantarray ? ($sql, @all_bind) : $sql;
130 sub _assemble_binds {
132 return map { @{ (delete $self->{"${_}_bind"}) || [] } } (qw/from where having order/);
136 update => 'FOR UPDATE',
137 shared => 'FOR SHARE',
140 my ($self, $type) = @_;
141 my $sql = $for_syntax->{$type} || croak "Unknown SELECT .. FOR type '$type' requested";
145 # Handle default inserts
147 # optimized due to hotttnesss
148 # my ($self, $table, $data, $options) = @_;
150 # SQLA will emit INSERT INTO $table ( ) VALUES ( )
151 # which is sadly understood only by MySQL. Change default behavior here,
152 # until SQLA2 comes with proper dialect support
153 if (! $_[2] or (ref $_[2] eq 'HASH' and !keys %{$_[2]} ) ) {
154 my $sql = "INSERT INTO $_[1] DEFAULT VALUES";
156 if (my $ret = ($_[3]||{})->{returning} ) {
157 $sql .= $_[0]->_insert_returning ($ret);
166 sub _recurse_fields {
167 my ($self, $fields) = @_;
168 my $ref = ref $fields;
169 return $self->_quote($fields) unless $ref;
170 return $$fields if $ref eq 'SCALAR';
172 if ($ref eq 'ARRAY') {
173 return join(', ', map { $self->_recurse_fields($_) } @$fields);
175 elsif ($ref eq 'HASH') {
176 my %hash = %$fields; # shallow copy
178 my $as = delete $hash{-as}; # if supplied
180 my ($func, $args, @toomany) = %hash;
182 # there should be only one pair
184 croak "Malformed select argument - too many keys in hash: " . join (',', keys %$fields );
187 if (lc ($func) eq 'distinct' && ref $args eq 'ARRAY' && @$args > 1) {
189 'The select => { distinct => ... } syntax is not supported for multiple columns.'
190 .' Instead please use { group_by => [ qw/' . (join ' ', @$args) . '/ ] }'
191 .' or { select => [ qw/' . (join ' ', @$args) . '/ ], distinct => 1 }'
195 my $select = sprintf ('%s( %s )%s',
196 $self->_sqlcase($func),
197 $self->_recurse_fields($args),
199 ? sprintf (' %s %s', $self->_sqlcase('as'), $self->_quote ($as) )
205 # Is the second check absolutely necessary?
206 elsif ( $ref eq 'REF' and ref($$fields) eq 'ARRAY' ) {
207 return $self->_fold_sqlbind( $fields );
210 croak($ref . qq{ unexpected in _recurse_fields()})
215 # this used to be a part of _order_by but is broken out for clarity.
216 # What we have been doing forever is hijacking the $order arg of
217 # SQLA::select to pass in arbitrary pieces of data (first the group_by,
218 # then pretty much the entire resultset attr-hash, as more and more
219 # things in the SQLA space need to have mopre info about the $rs they
220 # create SQL for. The alternative would be to keep expanding the
221 # signature of _select with more and more positional parameters, which
222 # is just gross. All hail SQLA2!
223 sub _parse_rs_attrs {
224 my ($self, $arg) = @_;
228 if (my $g = $self->_recurse_fields($arg->{group_by}) ) {
229 $sql .= $self->_sqlcase(' group by ') . $g;
232 if (defined $arg->{having}) {
233 my ($frag, @bind) = $self->_recurse_where($arg->{having});
234 push(@{$self->{having_bind}}, @bind);
235 $sql .= $self->_sqlcase(' having ') . $frag;
238 if (defined $arg->{order_by}) {
239 $sql .= $self->_order_by ($arg->{order_by});
246 my ($self, $arg) = @_;
248 # check that we are not called in legacy mode (order_by as 4th argument)
249 if (ref $arg eq 'HASH' and not grep { $_ =~ /^-(?:desc|asc)/i } keys %$arg ) {
250 return $self->_parse_rs_attrs ($arg);
253 my ($sql, @bind) = $self->next::method($arg);
254 push @{$self->{order_bind}}, @bind;
260 # optimized due to hotttnesss
261 # my ($self, $from) = @_;
262 if (my $ref = ref $_[1] ) {
263 if ($ref eq 'ARRAY') {
264 return $_[0]->_recurse_from(@{$_[1]});
266 elsif ($ref eq 'HASH') {
267 return $_[0]->_make_as($_[1]);
271 return $_[0]->next::method ($_[1]);
274 sub _generate_join_clause {
275 my ($self, $join_type) = @_;
277 return sprintf ('%s JOIN ',
278 $join_type ? ' ' . uc($join_type) : ''
283 my ($self, $from, @join) = @_;
285 push(@sqlf, $self->_make_as($from));
286 foreach my $j (@join) {
290 # check whether a join type exists
291 my $to_jt = ref($to) eq 'ARRAY' ? $to->[0] : $to;
293 if (ref($to_jt) eq 'HASH' and defined($to_jt->{-join_type})) {
294 $join_type = $to_jt->{-join_type};
295 $join_type =~ s/^\s+ | \s+$//xg;
298 $join_type = $self->{_default_jointype} if not defined $join_type;
300 push @sqlf, $self->_generate_join_clause( $join_type );
302 if (ref $to eq 'ARRAY') {
303 push(@sqlf, '(', $self->_recurse_from(@$to), ')');
305 push(@sqlf, $self->_make_as($to));
307 push(@sqlf, ' ON ', $self->_join_condition($on));
309 return join('', @sqlf);
313 my ($self, $sqlbind) = @_;
315 my @sqlbind = @$$sqlbind; # copy
316 my $sql = shift @sqlbind;
317 push @{$self->{from_bind}}, @sqlbind;
323 my ($self, $from) = @_;
324 return join(' ', map { (ref $_ eq 'SCALAR' ? $$_
325 : ref $_ eq 'REF' ? $self->_fold_sqlbind($_)
327 } reverse each %{$self->_skip_options($from)});
331 my ($self, $hash) = @_;
333 $clean_hash->{$_} = $hash->{$_}
334 for grep {!/^-/} keys %$hash;
338 sub _join_condition {
339 my ($self, $cond) = @_;
340 if (ref $cond eq 'HASH') {
345 croak (ref($v) . qq{ reference arguments are not supported in JOINS - try using \"..." instead'})
346 if ref($v) ne 'SCALAR';
350 my $x = '= '.$self->_quote($v); $j{$_} = \$x;
353 return scalar($self->_recurse_where(\%j));
354 } elsif (ref $cond eq 'ARRAY') {
355 return join(' OR ', map { $self->_join_condition($_) } @$cond);
357 croak "Can't handle this yet!";
365 See L<DBIx::Class/CONTRIBUTORS>.
369 You may distribute this code under the same terms as Perl itself.