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 $self->{limit_dialect};
49 # !!! THIS IS ALSO HORRIFIC !!! /me ashamed
51 # Generates inner/outer select lists for various limit dialects
52 # which result in one or more subqueries (e.g. RNO, Top, RowNum)
53 # Any non-root-table columns need to have their table qualifier
54 # turned into a column alias (otherwise names in subqueries clash
55 # and/or lose their source table)
57 # Returns inner/outer strings of SQL QUOTED selectors with aliases
58 # (to be used in whatever select statement), and an alias index hashref
59 # of QUOTED SEL => QUOTED ALIAS pairs (to maybe be used for string-subst
61 # If an order_by is supplied, the inner select needs to bring out columns
62 # used in implicit (non-selected) orders, and the order condition itself
63 # needs to be realiased to the proper names in the outer query. Thus we
64 # also return a hashref (order doesn't matter) of QUOTED EXTRA-SEL =>
65 # QUOTED ALIAS pairs, which is a list of extra selectors that do *not*
66 # exist in the original select list
68 sub _subqueried_limit_attrs {
69 my ($self, $rs_attrs) = @_;
71 croak 'Limit dialect implementation usable only in the context of DBIC (missing $rs_attrs)'
72 unless ref ($rs_attrs) eq 'HASH';
74 my ($re_sep, $re_alias) = map { quotemeta $_ } (
75 $self->name_sep || '.',
79 # correlate select and as, build selection index
80 my (@sel, $in_sel_index);
81 for my $i (0 .. $#{$rs_attrs->{select}}) {
83 my $s = $rs_attrs->{select}[$i];
84 my $sql_sel = $self->_recurse_fields ($s);
85 my $sql_alias = (ref $s) eq 'HASH' ? $s->{-as} : undef;
90 unquoted_sql => do { local $self->{quote_char}; $self->_recurse_fields ($s) },
96 croak "Select argument $i ($s) without corresponding 'as'"
100 $in_sel_index->{$sql_sel}++;
101 $in_sel_index->{$self->_quote ($sql_alias)}++ if $sql_alias;
103 # record unqualified versions too, so we do not have
104 # to reselect the same column twice (in qualified and
106 if (! ref $s && $sql_sel =~ / $re_sep (.+) $/x) {
107 $in_sel_index->{$1}++;
112 # re-alias and remove any name separators from aliases,
113 # unless we are dealing with the current source alias
114 # (which will transcend the subqueries as it is necessary
115 # for possible further chaining)
116 my (@in_sel, @out_sel, %renamed);
117 for my $node (@sel) {
118 if (List::Util::first { $_ =~ / (?<! $re_alias ) $re_sep /x } ($node->{as}, $node->{unquoted_sql}) ) {
119 $node->{as} =~ s/ $re_sep /__/xg;
120 my $quoted_as = $self->_quote($node->{as});
121 push @in_sel, sprintf '%s AS %s', $node->{sql}, $quoted_as;
122 push @out_sel, $quoted_as;
123 $renamed{$node->{sql}} = $quoted_as;
126 push @in_sel, $node->{sql};
127 push @out_sel, $self->_quote ($node->{as});
131 # see if the order gives us anything
133 for my $chunk ($self->_order_by_chunks ($rs_attrs->{order_by})) {
135 $chunk = $chunk->[0] if (ref $chunk) eq 'ARRAY';
136 $chunk =~ s/\s+ (?: ASC|DESC ) \s* $//ix;
138 next if $in_sel_index->{$chunk};
140 $extra_order_sel{$chunk} ||= $self->_quote (
141 'ORDER__BY__' . scalar keys %extra_order_sel
146 (map { join (', ', @$_ ) } (
151 keys %extra_order_sel ? \%extra_order_sel : (),
155 # ANSI standard Limit/Offset implementation. DB2 and MSSQL >= 2005 use this
157 my ($self, $sql, $rs_attrs, $rows, $offset ) = @_;
159 # mangle the input sql as we will be replacing the selector
160 $sql =~ s/^ \s* SELECT \s+ .+? \s+ (?= \b FROM \b )//ix
161 or croak "Unrecognizable SELECT: $sql";
163 # get selectors, and scan the order_by (if any)
164 my ($in_sel, $out_sel, $alias_map, $extra_order_sel)
165 = $self->_subqueried_limit_attrs ( $rs_attrs );
167 # make up an order if none exists
168 my $requested_order = (delete $rs_attrs->{order_by}) || $self->_rno_default_order;
169 my $rno_ord = $self->_order_by ($requested_order);
171 # this is the order supplement magic
172 my $mid_sel = $out_sel;
173 if ($extra_order_sel) {
174 for my $extra_col (sort
175 { $extra_order_sel->{$a} cmp $extra_order_sel->{$b} }
176 keys %$extra_order_sel
178 $in_sel .= sprintf (', %s AS %s',
180 $extra_order_sel->{$extra_col},
183 $mid_sel .= ', ' . $extra_order_sel->{$extra_col};
187 # and this is order re-alias magic
188 for ($extra_order_sel, $alias_map) {
189 for my $col (keys %$_) {
190 my $re_col = quotemeta ($col);
191 $rno_ord =~ s/$re_col/$_->{$col}/;
195 # whatever is left of the order_by (only where is processed at this point)
196 my $group_having = $self->_parse_rs_attrs($rs_attrs);
198 my $qalias = $self->_quote ($rs_attrs->{alias});
199 my $idx_name = $self->_quote ('rno__row__index');
201 $sql = sprintf (<<EOS, $offset + 1, $offset + $rows, );
203 SELECT $out_sel FROM (
204 SELECT $mid_sel, ROW_NUMBER() OVER( $rno_ord ) AS $idx_name FROM (
205 SELECT $in_sel ${sql}${group_having}
207 ) $qalias WHERE $idx_name BETWEEN %u AND %u
211 $sql =~ s/\s*\n\s*/ /g; # easier to read in the debugger
215 # some databases are happy with OVER (), some need OVER (ORDER BY (SELECT (1)) )
216 sub _rno_default_order {
220 # Informix specific limit, almost like LIMIT/OFFSET
222 my ($self, $sql, $rs_attrs, $rows, $offset) = @_;
224 $sql =~ s/^ \s* SELECT \s+ //ix
225 or croak "Unrecognizable SELECT: $sql";
227 return sprintf ('SELECT %s%s%s%s',
229 ? sprintf ('SKIP %u ', $offset)
232 sprintf ('FIRST %u ', $rows),
234 $self->_parse_rs_attrs ($rs_attrs),
238 # Firebird specific limit, reverse of _SkipFirst for Informix
240 my ($self, $sql, $rs_attrs, $rows, $offset) = @_;
242 $sql =~ s/^ \s* SELECT \s+ //ix
243 or croak "Unrecognizable SELECT: $sql";
245 return sprintf ('SELECT %s%s%s%s',
246 sprintf ('FIRST %u ', $rows),
248 ? sprintf ('SKIP %u ', $offset)
252 $self->_parse_rs_attrs ($rs_attrs),
258 my ( $self, $sql, $rs_attrs, $rows, $offset ) = @_;
260 # mangle the input sql as we will be replacing the selector
261 $sql =~ s/^ \s* SELECT \s+ .+? \s+ (?= \b FROM \b )//ix
262 or croak "Unrecognizable SELECT: $sql";
264 my ($insel, $outsel) = $self->_subqueried_limit_attrs ($rs_attrs);
266 my $qalias = $self->_quote ($rs_attrs->{alias});
267 my $idx_name = $self->_quote ('rownum__index');
268 my $order_group_having = $self->_parse_rs_attrs($rs_attrs);
270 $sql = sprintf (<<EOS, $offset + 1, $offset + $rows, );
272 SELECT $outsel FROM (
273 SELECT $outsel, ROWNUM $idx_name FROM (
274 SELECT $insel ${sql}${order_group_having}
276 ) $qalias WHERE $idx_name BETWEEN %u AND %u
280 $sql =~ s/\s*\n\s*/ /g; # easier to read in the debugger
284 # Crappy Top based Limit/Offset support. Legacy for MSSQL < 2005
286 my ( $self, $sql, $rs_attrs, $rows, $offset ) = @_;
288 # mangle the input sql as we will be replacing the selector
289 $sql =~ s/^ \s* SELECT \s+ .+? \s+ (?= \b FROM \b )//ix
290 or croak "Unrecognizable SELECT: $sql";
293 my ($in_sel, $out_sel, $alias_map, $extra_order_sel)
294 = $self->_subqueried_limit_attrs ($rs_attrs);
296 my $requested_order = delete $rs_attrs->{order_by};
298 my $order_by_requested = $self->_order_by ($requested_order);
300 # make up an order unless supplied
301 my $inner_order = ($order_by_requested
304 { join ('', $rs_attrs->{alias}, $self->{name_sep}||'.', $_ ) }
305 ( $rs_attrs->{_rsroot_source_handle}->resolve->_pri_cols )
309 my ($order_by_inner, $order_by_reversed);
311 # localise as we already have all the bind values we need
313 local $self->{order_bind};
314 $order_by_inner = $self->_order_by ($inner_order);
317 for my $ch ($self->_order_by_chunks ($inner_order)) {
318 $ch = $ch->[0] if ref $ch eq 'ARRAY';
320 $ch =~ s/\s+ ( ASC|DESC ) \s* $//ix;
321 my $dir = uc ($1||'ASC');
323 push @out_chunks, \join (' ', $ch, $dir eq 'ASC' ? 'DESC' : 'ASC' );
326 $order_by_reversed = $self->_order_by (\@out_chunks);
329 # this is the order supplement magic
330 my $mid_sel = $out_sel;
331 if ($extra_order_sel) {
332 for my $extra_col (sort
333 { $extra_order_sel->{$a} cmp $extra_order_sel->{$b} }
334 keys %$extra_order_sel
336 $in_sel .= sprintf (', %s AS %s',
338 $extra_order_sel->{$extra_col},
341 $mid_sel .= ', ' . $extra_order_sel->{$extra_col};
344 # since whatever order bindvals there are, they will be realiased
345 # and need to show up in front of the entire initial inner subquery
346 # Unshift *from_bind* to make this happen (horrible, horrible, but
347 # we don't have another mechanism yet)
348 unshift @{$self->{from_bind}}, @{$self->{order_bind}};
351 # and this is order re-alias magic
352 for my $map ($extra_order_sel, $alias_map) {
353 for my $col (keys %$map) {
354 my $re_col = quotemeta ($col);
355 $_ =~ s/$re_col/$map->{$col}/
356 for ($order_by_reversed, $order_by_requested);
360 # generate the rest of the sql
361 my $grpby_having = $self->_parse_rs_attrs ($rs_attrs);
363 my $quoted_rs_alias = $self->_quote ($rs_attrs->{alias});
365 $sql = sprintf ('SELECT TOP %u %s %s %s %s',
366 $rows + ($offset||0),
373 $sql = sprintf ('SELECT TOP %u %s FROM ( %s ) %s %s',
381 $sql = sprintf ('SELECT TOP %u %s FROM ( %s ) %s %s',
387 ) if ( ($offset && $order_by_requested) || ($mid_sel ne $out_sel) );
389 $sql =~ s/\s*\n\s*/ /g; # easier to read in the debugger
393 # This is the most evil limit "dialect" (more of a hack) for *really*
394 # stupid databases. It works by ordering the set by some unique column,
395 # and calculating amount of rows that have a less-er value (thus
396 # emulating a RowNum-like index). Of course this implies the set can
397 # only be ordered by a single unique columns.
399 my ($self, $sql, $rs_attrs, $rows, $offset) = @_;
401 my $root_rsrc = $rs_attrs->{_rsroot_source_handle}->resolve;
402 my $root_tbl_name = $root_rsrc->name;
404 # mangle the input sql as we will be replacing the selector
405 $sql =~ s/^ \s* SELECT \s+ .+? \s+ (?= \b FROM \b )//ix
406 or croak "Unrecognizable SELECT: $sql";
408 my ($order_by, @rest) = do {
409 local $self->{quote_char};
410 $self->_order_by_chunks ($rs_attrs->{order_by})
420 ( ref $order_by eq 'ARRAY' and @$order_by == 1 )
424 'Generic Subquery Limit does not work on resultsets without an order, or resultsets '
425 . 'with complex order criteria (multicolumn and/or functions). Provide a single, '
426 . 'unique-column order criteria.'
430 ($order_by) = @$order_by if ref $order_by;
432 $order_by =~ s/\s+ ( ASC|DESC ) \s* $//ix;
433 my $direction = lc ($1 || 'asc');
435 my ($unq_sort_col) = $order_by =~ /(?:^|\.)([^\.]+)$/;
437 my $inf = $root_rsrc->storage->_resolve_column_info (
438 $rs_attrs->{from}, [$order_by, $unq_sort_col]
441 my $ord_colinfo = $inf->{$order_by} || croak "Unable to determine source of order-criteria '$order_by'";
443 if ($ord_colinfo->{-result_source}->name ne $root_tbl_name) {
444 croak "Generic Subquery Limit order criteria can be only based on the root-source '"
445 . $root_rsrc->source_name . "' (aliased as '$rs_attrs->{alias}')";
448 # make sure order column is qualified
449 $order_by = "$rs_attrs->{alias}.$order_by"
450 unless $order_by =~ /^$rs_attrs->{alias}\./;
453 my $ucs = { $root_rsrc->unique_constraints };
454 for (values %$ucs ) {
455 if (@$_ == 1 && "$rs_attrs->{alias}.$_->[0]" eq $order_by) {
460 croak "Generic Subquery Limit order criteria column '$order_by' must be unique (no unique constraint found)"
463 my ($in_sel, $out_sel, $alias_map, $extra_order_sel)
464 = $self->_subqueried_limit_attrs ($rs_attrs);
466 my $cmp_op = $direction eq 'desc' ? '>' : '<';
467 my $count_tbl_alias = 'rownum__emulation';
469 my $order_group_having = $self->_parse_rs_attrs($rs_attrs);
471 # add the order supplement (if any) as this is what will be used for the outer WHERE
472 $in_sel .= ", $_" for keys %{$extra_order_sel||{}};
474 $sql = sprintf (<<EOS,
477 SELECT $in_sel ${sql}${order_group_having}
479 WHERE ( SELECT COUNT(*) FROM %s %s WHERE %s $cmp_op %s ) %s
481 ( map { $self->_quote ($_) } (
485 "$count_tbl_alias.$unq_sort_col",
489 ? sprintf ('BETWEEN %u AND %u', $offset, $offset + $rows - 1)
490 : sprintf ('< %u', $rows )
494 $sql =~ s/\s*\n\s*/ /g; # easier to read in the debugger
499 # While we're at it, this should make LIMIT queries more efficient,
500 # without digging into things too deeply
502 my ($self, $syntax) = @_;
503 return $self->{_cached_syntax} ||= $self->SUPER::_find_syntax($syntax);
506 # Quotes table names, handles "limit" dialects (e.g. where rownum between x and
509 my ($self, $table, $fields, $where, $rs_attrs, @rest) = @_;
511 $self->{"${_}_bind"} = [] for (qw/having from order where/);
513 if (not ref($table) or ref($table) eq 'SCALAR') {
514 $table = $self->_quote($table);
517 @rest = (-1) unless defined $rest[0];
518 croak "LIMIT 0 Does Not Compute" if $rest[0] == 0;
519 # and anyway, SQL::Abstract::Limit will cause a barf if we don't first
522 ($sql, @{$self->{where_bind}}) = $self->SUPER::select(
523 $table, $self->_recurse_fields($fields), $where, $rs_attrs, @rest
525 return wantarray ? ($sql, @{$self->{from_bind}}, @{$self->{where_bind}}, @{$self->{having_bind}}, @{$self->{order_bind}} ) : $sql;
528 # Quotes table names, and handles default inserts
532 $table = $self->_quote($table);
534 # SQLA will emit INSERT INTO $table ( ) VALUES ( )
535 # which is sadly understood only by MySQL. Change default behavior here,
536 # until SQLA2 comes with proper dialect support
537 if (! $_[0] or (ref $_[0] eq 'HASH' and !keys %{$_[0]} ) ) {
538 my $sql = "INSERT INTO ${table} DEFAULT VALUES";
540 if (my $ret = ($_[1]||{})->{returning} ) {
541 $sql .= $self->_insert_returning ($ret);
547 $self->SUPER::insert($table, @_);
550 # Just quotes table names.
554 $table = $self->_quote($table);
555 $self->SUPER::update($table, @_);
558 # Just quotes table names.
562 $table = $self->_quote($table);
563 $self->SUPER::delete($table, @_);
568 # my ( $syntax, $sql, $order, $rows, $offset ) = @_;
571 return $_[1] . $self->_parse_rs_attrs($_[2]);
573 return $self->SUPER::_emulate_limit(@_);
577 sub _recurse_fields {
578 my ($self, $fields) = @_;
579 my $ref = ref $fields;
580 return $self->_quote($fields) unless $ref;
581 return $$fields if $ref eq 'SCALAR';
583 if ($ref eq 'ARRAY') {
584 return join(', ', map { $self->_recurse_fields($_) } @$fields);
586 elsif ($ref eq 'HASH') {
587 my %hash = %$fields; # shallow copy
589 my $as = delete $hash{-as}; # if supplied
591 my ($func, $args, @toomany) = %hash;
593 # there should be only one pair
595 croak "Malformed select argument - too many keys in hash: " . join (',', keys %$fields );
598 if (lc ($func) eq 'distinct' && ref $args eq 'ARRAY' && @$args > 1) {
600 'The select => { distinct => ... } syntax is not supported for multiple columns.'
601 .' Instead please use { group_by => [ qw/' . (join ' ', @$args) . '/ ] }'
602 .' or { select => [ qw/' . (join ' ', @$args) . '/ ], distinct => 1 }'
606 my $select = sprintf ('%s( %s )%s',
607 $self->_sqlcase($func),
608 $self->_recurse_fields($args),
610 ? sprintf (' %s %s', $self->_sqlcase('as'), $self->_quote ($as) )
616 # Is the second check absolutely necessary?
617 elsif ( $ref eq 'REF' and ref($$fields) eq 'ARRAY' ) {
618 return $self->_fold_sqlbind( $fields );
621 croak($ref . qq{ unexpected in _recurse_fields()})
626 update => 'FOR UPDATE',
627 shared => 'FOR SHARE',
630 # this used to be a part of _order_by but is broken out for clarity.
631 # What we have been doing forever is hijacking the $order arg of
632 # SQLA::select to pass in arbitrary pieces of data (first the group_by,
633 # then pretty much the entire resultset attr-hash, as more and more
634 # things in the SQLA space need to have mopre info about the $rs they
635 # create SQL for. The alternative would be to keep expanding the
636 # signature of _select with more and more positional parameters, which
637 # is just gross. All hail SQLA2!
638 sub _parse_rs_attrs {
639 my ($self, $arg) = @_;
643 if (my $g = $self->_recurse_fields($arg->{group_by}) ) {
644 $sql .= $self->_sqlcase(' group by ') . $g;
647 if (defined $arg->{having}) {
648 my ($frag, @bind) = $self->_recurse_where($arg->{having});
649 push(@{$self->{having_bind}}, @bind);
650 $sql .= $self->_sqlcase(' having ') . $frag;
653 if (defined $arg->{order_by}) {
654 $sql .= $self->_order_by ($arg->{order_by});
657 if (my $for = $arg->{for}) {
658 $sql .= " $for_syntax->{$for}" if $for_syntax->{$for};
665 my ($self, $arg) = @_;
667 # check that we are not called in legacy mode (order_by as 4th argument)
668 if (ref $arg eq 'HASH' and not grep { $_ =~ /^-(?:desc|asc)/i } keys %$arg ) {
669 return $self->_parse_rs_attrs ($arg);
672 my ($sql, @bind) = $self->SUPER::_order_by ($arg);
673 push @{$self->{order_bind}}, @bind;
678 sub _order_directions {
679 my ($self, $order) = @_;
681 # strip bind values - none of the current _order_directions users support them
682 return $self->SUPER::_order_directions( [ map
683 { ref $_ ? $_->[0] : $_ }
684 $self->_order_by_chunks ($order)
689 my ($self, $from) = @_;
690 if (ref $from eq 'ARRAY') {
691 return $self->_recurse_from(@$from);
692 } elsif (ref $from eq 'HASH') {
693 return $self->_make_as($from);
695 return $from; # would love to quote here but _table ends up getting called
696 # twice during an ->select without a limit clause due to
697 # the way S::A::Limit->select works. should maybe consider
698 # bypassing this and doing S::A::select($self, ...) in
699 # our select method above. meantime, quoting shims have
700 # been added to select/insert/update/delete here
704 sub _generate_join_clause {
705 my ($self, $join_type) = @_;
707 return sprintf ('%s JOIN ',
708 $join_type ? ' ' . uc($join_type) : ''
713 my ($self, $from, @join) = @_;
715 push(@sqlf, $self->_make_as($from));
716 foreach my $j (@join) {
720 # check whether a join type exists
721 my $to_jt = ref($to) eq 'ARRAY' ? $to->[0] : $to;
723 if (ref($to_jt) eq 'HASH' and defined($to_jt->{-join_type})) {
724 $join_type = $to_jt->{-join_type};
725 $join_type =~ s/^\s+ | \s+$//xg;
728 $join_type = $self->{_default_jointype} if not defined $join_type;
730 push @sqlf, $self->_generate_join_clause( $join_type );
732 if (ref $to eq 'ARRAY') {
733 push(@sqlf, '(', $self->_recurse_from(@$to), ')');
735 push(@sqlf, $self->_make_as($to));
737 push(@sqlf, ' ON ', $self->_join_condition($on));
739 return join('', @sqlf);
743 my ($self, $sqlbind) = @_;
745 my @sqlbind = @$$sqlbind; # copy
746 my $sql = shift @sqlbind;
747 push @{$self->{from_bind}}, @sqlbind;
753 my ($self, $from) = @_;
754 return join(' ', map { (ref $_ eq 'SCALAR' ? $$_
755 : ref $_ eq 'REF' ? $self->_fold_sqlbind($_)
757 } reverse each %{$self->_skip_options($from)});
761 my ($self, $hash) = @_;
763 $clean_hash->{$_} = $hash->{$_}
764 for grep {!/^-/} keys %$hash;
768 sub _join_condition {
769 my ($self, $cond) = @_;
770 if (ref $cond eq 'HASH') {
775 croak (ref($v) . qq{ reference arguments are not supported in JOINS - try using \"..." instead'})
776 if ref($v) ne 'SCALAR';
780 my $x = '= '.$self->_quote($v); $j{$_} = \$x;
783 return scalar($self->_recurse_where(\%j));
784 } elsif (ref $cond eq 'ARRAY') {
785 return join(' OR ', map { $self->_join_condition($_) } @$cond);
787 die "Can't handle this yet!";
794 $self->{limit_dialect} = shift;
795 undef $self->{_cached_syntax};
797 return $self->{limit_dialect};
800 # Set to an array-ref to specify separate left and right quotes for table names.
801 # A single scalar is equivalen to [ $char, $char ]
804 $self->{quote_char} = shift if @_;
805 return $self->{quote_char};
808 # Character separating quoted table names.
811 $self->{name_sep} = shift if @_;
812 return $self->{name_sep};