1 package # Hide from PAUSE
2 DBIx::Class::SQLAHacks;
4 # This module is a subclass of SQL::Abstract::Limit and includes a number
5 # of DBIC-specific workarounds, not yet suitable for inclusion into the
8 use base qw/SQL::Abstract::Limit/;
11 use Carp::Clan qw/^DBIx::Class|^SQL::Abstract/;
15 # reinstall the carp()/croak() functions imported into SQL::Abstract
16 # as Carp and Carp::Clan do not like each other much
17 no warnings qw/redefine/;
19 for my $f (qw/carp croak/) {
21 my $orig = \&{"SQL::Abstract::$f"};
22 *{"SQL::Abstract::$f"} = Sub::Name::subname "SQL::Abstract::$f" =>
24 if (Carp::longmess() =~ /DBIx::Class::SQLAHacks::[\w]+ .+? called \s at/x) {
25 __PACKAGE__->can($f)->(@_);
35 # Tries to determine limit dialect.
38 my $self = shift->SUPER::new(@_);
40 # This prevents the caching of $dbh in S::A::L, I believe
41 # If limit_dialect is a ref (like a $dbh), go ahead and replace
42 # it with what it resolves to:
43 $self->{limit_dialect} = $self->_find_syntax($self->{limit_dialect})
44 if ref $self->{limit_dialect};
49 # !!! THIS IS ALSO HORRIFIC !!! /me ashamed
51 # generate inner/outer select lists for various limit dialects
52 # which result in one or more subqueries (e.g. RNO, Top, RowNum)
53 # Any non-root-table columns need to have their table qualifier
54 # turned into a column alias (otherwise names in subqueries clash
55 # and/or lose their source table)
57 # returns inner/outer strings of SQL QUOTED selectors with aliases
58 # (to be used in whatever select statement), and an alias index hashref
59 # of QUOTED SEL => QUOTED ALIAS pairs (to maybe be used for string-subst
62 # If the $scan_order option is supplied, it signals that the limit dialect
63 # needs to order the outer side of the query, which in turn means that the
64 # inner select needs to bring out columns used in implicit (non-selected)
65 # orders, and the order condition itself needs to be realiased to the proper
66 # names in the outer query.
68 # In this case ($scan_order os true) we also return a hashref (order doesn't
69 # matter) of QUOTED EXTRA-SEL => QUOTED ALIAS pairs, which is a list of extra
70 # selectors that do *not* exist in the original select list
72 sub _subqueried_limit_attrs {
73 my ($self, $rs_attrs, $scan_order) = @_;
75 croak 'Limit dialect implementation usable only in the context of DBIC (missing $rs_attrs)'
76 unless ref ($rs_attrs) eq 'HASH';
78 my ($re_sep, $re_alias) = map { quotemeta $_ } (
79 $self->name_sep || '.',
83 # correlate select and as, build selection index
84 my (@sel, $in_sel_index);
85 for my $i (0 .. $#{$rs_attrs->{select}}) {
87 my $s = $rs_attrs->{select}[$i];
88 my $sql_sel = $self->_recurse_fields ($s);
89 my $sql_alias = (ref $s) eq 'HASH' ? $s->{-as} : undef;
94 unquoted_sql => do { local $self->{quote_char}; $self->_recurse_fields ($s) },
100 croak "Select argument $i ($s) without corresponding 'as'"
104 $in_sel_index->{$sql_sel}++;
105 $in_sel_index->{$self->_quote ($sql_alias)}++ if $sql_alias;
107 # this *may* turn out to be necessary, not sure yet
108 # my ($sql_unqualified_sel) = $sql_sel =~ / $re_sep (.+) $/x
110 # $in_sel_index->{$sql_unqualified_sel}++;
114 # re-alias and remove any name separators from aliases,
115 # unless we are dealing with the current source alias
116 # (which will transcend the subqueries as it is necessary
117 # for possible further chaining)
118 my (@in_sel, @out_sel, %renamed);
119 for my $node (@sel) {
120 if (List::Util::first { $_ =~ / (?<! $re_alias ) $re_sep /x } ($node->{as}, $node->{unquoted_sql}) ) {
121 $node->{as} =~ s/ $re_sep /__/xg;
122 my $quoted_as = $self->_quote($node->{as});
123 push @in_sel, sprintf '%s AS %s', $node->{sql}, $quoted_as;
124 push @out_sel, $quoted_as;
125 $renamed{$node->{sql}} = $quoted_as;
128 push @in_sel, $node->{sql};
129 push @out_sel, $self->_quote ($node->{as});
135 for my $chunk ($self->_order_by_chunks ($rs_attrs->{order_by})) {
137 $chunk = $chunk->[0] if (ref $chunk) eq 'ARRAY';
138 $chunk =~ s/\s+ (?: ASC|DESC ) \s* $//ix;
140 next if $in_sel_index->{$chunk};
142 $extra_order_sel{$chunk} ||= $self->_quote (
143 'ORDER__BY__' . scalar keys %extra_order_sel
148 (map { join (', ', @$_ ) } (
153 keys %extra_order_sel ? \%extra_order_sel : (),
157 # ANSI standard Limit/Offset implementation. DB2 and MSSQL >= 2005 use this
159 my ($self, $sql, $rs_attrs, $rows, $offset ) = @_;
161 # mangle the input sql as we will be replacing the selector
162 $sql =~ s/^ \s* SELECT \s+ .+? \s+ (?= \b FROM \b )//ix
163 or croak "Unrecognizable SELECT: $sql";
165 # get selectors, and scan the order_by (if any)
166 my ($in_sel, $out_sel, $alias_map, $extra_order_sel) = $self->_subqueried_limit_attrs (
167 $rs_attrs, 'scan_order_by',
170 # make up an order if none exists
171 my $requested_order = (delete $rs_attrs->{order_by}) || $self->_rno_default_order;
172 my $rno_ord = $self->_order_by ($requested_order);
174 # this is the order supplement magic
175 my $mid_sel = $out_sel;
176 if ($extra_order_sel) {
177 for my $extra_col (sort
178 { $extra_order_sel->{$a} cmp $extra_order_sel->{$b} }
179 keys %$extra_order_sel
181 $in_sel .= sprintf (', %s AS %s',
183 $extra_order_sel->{$extra_col},
186 $mid_sel .= ', ' . $extra_order_sel->{$extra_col};
190 # and this is order re-alias magic
191 for ($extra_order_sel, $alias_map) {
192 for my $col (keys %$_) {
193 my $re_col = quotemeta ($col);
194 $rno_ord =~ s/$re_col/$_->{$col}/;
198 # whatever is left of the order_by (only where is processed at this point)
199 my $group_having = $self->_parse_rs_attrs($rs_attrs);
201 my $qalias = $self->_quote ($rs_attrs->{alias});
202 my $idx_name = $self->_quote ('rno__row__index');
204 $sql = sprintf (<<EOS, $offset + 1, $offset + $rows, );
206 SELECT $out_sel FROM (
207 SELECT $mid_sel, ROW_NUMBER() OVER( $rno_ord ) AS $idx_name FROM (
208 SELECT $in_sel ${sql}${group_having}
210 ) $qalias WHERE $idx_name BETWEEN %d AND %d
214 $sql =~ s/\s*\n\s*/ /g; # easier to read in the debugger
218 # some databases are happy with OVER (), some need OVER (ORDER BY (SELECT (1)) )
219 sub _rno_default_order {
223 # Informix specific limit, almost like LIMIT/OFFSET
225 my ($self, $sql, $rs_attrs, $rows, $offset) = @_;
227 $sql =~ s/^ \s* SELECT \s+ //ix
228 or croak "Unrecognizable SELECT: $sql";
230 return sprintf ('SELECT %s%s%s%s',
232 ? sprintf ('SKIP %d ', $offset)
235 sprintf ('FIRST %d ', $rows),
237 $self->_parse_rs_attrs ($rs_attrs),
241 # Firebird specific limit, reverse of _SkipFirst for Informix
243 my ($self, $sql, $rs_attrs, $rows, $offset) = @_;
245 $sql =~ s/^ \s* SELECT \s+ //ix
246 or croak "Unrecognizable SELECT: $sql";
248 return sprintf ('SELECT %s%s%s%s',
249 sprintf ('FIRST %d ', $rows),
251 ? sprintf ('SKIP %d ', $offset)
255 $self->_parse_rs_attrs ($rs_attrs),
261 my ( $self, $sql, $rs_attrs, $rows, $offset ) = @_;
263 # mangle the input sql as we will be replacing the selector
264 $sql =~ s/^ \s* SELECT \s+ .+? \s+ (?= \b FROM \b )//ix
265 or croak "Unrecognizable SELECT: $sql";
267 my ($insel, $outsel) = $self->_subqueried_limit_attrs ($rs_attrs);
269 my $qalias = $self->_quote ($rs_attrs->{alias});
270 my $idx_name = $self->_quote ('rownum__index');
271 my $order_group_having = $self->_parse_rs_attrs($rs_attrs);
273 $sql = sprintf (<<EOS, $offset + 1, $offset + $rows, );
275 SELECT $outsel FROM (
276 SELECT $outsel, ROWNUM $idx_name FROM (
277 SELECT $insel ${sql}${order_group_having}
279 ) $qalias WHERE $idx_name BETWEEN %d AND %d
283 $sql =~ s/\s*\n\s*/ /g; # easier to read in the debugger
287 # Crappy Top based Limit/Offset support. Legacy for MSSQL < 2005
289 my ( $self, $sql, $rs_attrs, $rows, $offset ) = @_;
291 # mangle the input sql as we will be replacing the selector
292 $sql =~ s/^ \s* SELECT \s+ .+? \s+ (?= \b FROM \b )//ix
293 or croak "Unrecognizable SELECT: $sql";
296 my ($in_sel, $out_sel, $alias_map, $extra_order_sel)
297 = $self->_subqueried_limit_attrs ($rs_attrs, 'outer_order_by');
299 my $requested_order = delete $rs_attrs->{order_by};
301 my $order_by_requested = $self->_order_by ($requested_order);
303 # make up an order unless supplied
304 my $inner_order = ($order_by_requested
307 { join ('', $rs_attrs->{alias}, $self->{name_sep}||'.', $_ ) }
308 ( $rs_attrs->{_rsroot_source_handle}->resolve->_pri_cols )
312 my ($order_by_inner, $order_by_reversed);
314 # localise as we already have all the bind values we need
316 local $self->{order_bind};
317 $order_by_inner = $self->_order_by ($inner_order);
320 for my $ch ($self->_order_by_chunks ($inner_order)) {
321 $ch = $ch->[0] if ref $ch eq 'ARRAY';
323 $ch =~ s/\s+ ( ASC|DESC ) \s* $//ix;
324 my $dir = uc ($1||'ASC');
326 push @out_chunks, \join (' ', $ch, $dir eq 'ASC' ? 'DESC' : 'ASC' );
329 $order_by_reversed = $self->_order_by (\@out_chunks);
332 # this is the order supplement magic
333 my $mid_sel = $out_sel;
334 if ($extra_order_sel) {
335 for my $extra_col (sort
336 { $extra_order_sel->{$a} cmp $extra_order_sel->{$b} }
337 keys %$extra_order_sel
339 $in_sel .= sprintf (', %s AS %s',
341 $extra_order_sel->{$extra_col},
344 $mid_sel .= ', ' . $extra_order_sel->{$extra_col};
348 # and this is order re-alias magic
349 for my $map ($extra_order_sel, $alias_map) {
350 for my $col (keys %$map) {
351 my $re_col = quotemeta ($col);
352 $_ =~ s/$re_col/$map->{$col}/
353 for ($order_by_reversed, $order_by_requested);
357 # generate the rest of the sql
358 my $grpby_having = $self->_parse_rs_attrs ($rs_attrs);
360 my $quoted_rs_alias = $self->_quote ($rs_attrs->{alias});
362 $sql = sprintf ('SELECT TOP %d %s %s %s %s',
363 $rows + ($offset||0),
370 $sql = sprintf ('SELECT TOP %d %s FROM ( %s ) %s %s',
378 $sql = sprintf ('SELECT TOP %d %s FROM ( %s ) %s %s',
384 ) if ( ($offset && $order_by_requested) || ($mid_sel ne $out_sel) );
390 # While we're at it, this should make LIMIT queries more efficient,
391 # without digging into things too deeply
393 my ($self, $syntax) = @_;
394 return $self->{_cached_syntax} ||= $self->SUPER::_find_syntax($syntax);
397 # Quotes table names, handles "limit" dialects (e.g. where rownum between x and
400 my ($self, $table, $fields, $where, $rs_attrs, @rest) = @_;
402 $self->{"${_}_bind"} = [] for (qw/having from order/);
404 if (not ref($table) or ref($table) eq 'SCALAR') {
405 $table = $self->_quote($table);
408 @rest = (-1) unless defined $rest[0];
409 croak "LIMIT 0 Does Not Compute" if $rest[0] == 0;
410 # and anyway, SQL::Abstract::Limit will cause a barf if we don't first
412 my ($sql, @where_bind) = $self->SUPER::select(
413 $table, $self->_recurse_fields($fields), $where, $rs_attrs, @rest
415 return wantarray ? ($sql, @{$self->{from_bind}}, @where_bind, @{$self->{having_bind}}, @{$self->{order_bind}} ) : $sql;
418 # Quotes table names, and handles default inserts
422 $table = $self->_quote($table);
424 # SQLA will emit INSERT INTO $table ( ) VALUES ( )
425 # which is sadly understood only by MySQL. Change default behavior here,
426 # until SQLA2 comes with proper dialect support
427 if (! $_[0] or (ref $_[0] eq 'HASH' and !keys %{$_[0]} ) ) {
428 my $sql = "INSERT INTO ${table} DEFAULT VALUES";
430 if (my $ret = ($_[1]||{})->{returning} ) {
431 $sql .= $self->_insert_returning ($ret);
437 $self->SUPER::insert($table, @_);
440 # Just quotes table names.
444 $table = $self->_quote($table);
445 $self->SUPER::update($table, @_);
448 # Just quotes table names.
452 $table = $self->_quote($table);
453 $self->SUPER::delete($table, @_);
458 # my ( $syntax, $sql, $order, $rows, $offset ) = @_;
461 return $_[1] . $self->_parse_rs_attrs($_[2]);
463 return $self->SUPER::_emulate_limit(@_);
467 sub _recurse_fields {
468 my ($self, $fields) = @_;
469 my $ref = ref $fields;
470 return $self->_quote($fields) unless $ref;
471 return $$fields if $ref eq 'SCALAR';
473 if ($ref eq 'ARRAY') {
474 return join(', ', map { $self->_recurse_fields($_) } @$fields);
476 elsif ($ref eq 'HASH') {
477 my %hash = %$fields; # shallow copy
479 my $as = delete $hash{-as}; # if supplied
481 my ($func, $args, @toomany) = %hash;
483 # there should be only one pair
485 croak "Malformed select argument - too many keys in hash: " . join (',', keys %$fields );
488 if (lc ($func) eq 'distinct' && ref $args eq 'ARRAY' && @$args > 1) {
490 'The select => { distinct => ... } syntax is not supported for multiple columns.'
491 .' Instead please use { group_by => [ qw/' . (join ' ', @$args) . '/ ] }'
492 .' or { select => [ qw/' . (join ' ', @$args) . '/ ], distinct => 1 }'
496 my $select = sprintf ('%s( %s )%s',
497 $self->_sqlcase($func),
498 $self->_recurse_fields($args),
500 ? sprintf (' %s %s', $self->_sqlcase('as'), $self->_quote ($as) )
506 # Is the second check absolutely necessary?
507 elsif ( $ref eq 'REF' and ref($$fields) eq 'ARRAY' ) {
508 return $self->_fold_sqlbind( $fields );
511 croak($ref . qq{ unexpected in _recurse_fields()})
516 update => 'FOR UPDATE',
517 shared => 'FOR SHARE',
520 # this used to be a part of _order_by but is broken out for clarity.
521 # What we have been doing forever is hijacking the $order arg of
522 # SQLA::select to pass in arbitrary pieces of data (first the group_by,
523 # then pretty much the entire resultset attr-hash, as more and more
524 # things in the SQLA space need to have mopre info about the $rs they
525 # create SQL for. The alternative would be to keep expanding the
526 # signature of _select with more and more positional parameters, which
527 # is just gross. All hail SQLA2!
528 sub _parse_rs_attrs {
529 my ($self, $arg) = @_;
533 if (my $g = $self->_recurse_fields($arg->{group_by}) ) {
534 $sql .= $self->_sqlcase(' group by ') . $g;
537 if (defined $arg->{having}) {
538 my ($frag, @bind) = $self->_recurse_where($arg->{having});
539 push(@{$self->{having_bind}}, @bind);
540 $sql .= $self->_sqlcase(' having ') . $frag;
543 if (defined $arg->{order_by}) {
544 $sql .= $self->_order_by ($arg->{order_by});
547 if (my $for = $arg->{for}) {
548 $sql .= " $for_syntax->{$for}" if $for_syntax->{$for};
555 my ($self, $arg) = @_;
557 # check that we are not called in legacy mode (order_by as 4th argument)
558 if (ref $arg eq 'HASH' and not grep { $_ =~ /^-(?:desc|asc)/i } keys %$arg ) {
559 return $self->_parse_rs_attrs ($arg);
562 my ($sql, @bind) = $self->SUPER::_order_by ($arg);
563 push @{$self->{order_bind}}, @bind;
568 sub _order_directions {
569 my ($self, $order) = @_;
571 # strip bind values - none of the current _order_directions users support them
572 return $self->SUPER::_order_directions( [ map
573 { ref $_ ? $_->[0] : $_ }
574 $self->_order_by_chunks ($order)
579 my ($self, $from) = @_;
580 if (ref $from eq 'ARRAY') {
581 return $self->_recurse_from(@$from);
582 } elsif (ref $from eq 'HASH') {
583 return $self->_make_as($from);
585 return $from; # would love to quote here but _table ends up getting called
586 # twice during an ->select without a limit clause due to
587 # the way S::A::Limit->select works. should maybe consider
588 # bypassing this and doing S::A::select($self, ...) in
589 # our select method above. meantime, quoting shims have
590 # been added to select/insert/update/delete here
594 sub _generate_join_clause {
595 my ($self, $join_type) = @_;
597 return sprintf ('%s JOIN ',
598 $join_type ? ' ' . uc($join_type) : ''
603 my ($self, $from, @join) = @_;
605 push(@sqlf, $self->_make_as($from));
606 foreach my $j (@join) {
610 # check whether a join type exists
611 my $to_jt = ref($to) eq 'ARRAY' ? $to->[0] : $to;
613 if (ref($to_jt) eq 'HASH' and defined($to_jt->{-join_type})) {
614 $join_type = $to_jt->{-join_type};
615 $join_type =~ s/^\s+ | \s+$//xg;
618 $join_type = $self->{_default_jointype} if not defined $join_type;
620 push @sqlf, $self->_generate_join_clause( $join_type );
622 if (ref $to eq 'ARRAY') {
623 push(@sqlf, '(', $self->_recurse_from(@$to), ')');
625 push(@sqlf, $self->_make_as($to));
627 push(@sqlf, ' ON ', $self->_join_condition($on));
629 return join('', @sqlf);
633 my ($self, $sqlbind) = @_;
635 my @sqlbind = @$$sqlbind; # copy
636 my $sql = shift @sqlbind;
637 push @{$self->{from_bind}}, @sqlbind;
643 my ($self, $from) = @_;
644 return join(' ', map { (ref $_ eq 'SCALAR' ? $$_
645 : ref $_ eq 'REF' ? $self->_fold_sqlbind($_)
647 } reverse each %{$self->_skip_options($from)});
651 my ($self, $hash) = @_;
653 $clean_hash->{$_} = $hash->{$_}
654 for grep {!/^-/} keys %$hash;
658 sub _join_condition {
659 my ($self, $cond) = @_;
660 if (ref $cond eq 'HASH') {
665 croak (ref($v) . qq{ reference arguments are not supported in JOINS - try using \"..." instead'})
666 if ref($v) ne 'SCALAR';
670 my $x = '= '.$self->_quote($v); $j{$_} = \$x;
673 return scalar($self->_recurse_where(\%j));
674 } elsif (ref $cond eq 'ARRAY') {
675 return join(' OR ', map { $self->_join_condition($_) } @$cond);
677 die "Can't handle this yet!";
684 $self->{limit_dialect} = shift;
685 undef $self->{_cached_syntax};
687 return $self->{limit_dialect};
690 # Set to an array-ref to specify separate left and right quotes for table names.
691 # A single scalar is equivalen to [ $char, $char ]
694 $self->{quote_char} = shift if @_;
695 return $self->{quote_char};
698 # Character separating quoted table names.
701 $self->{name_sep} = shift if @_;
702 return $self->{name_sep};