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 List::Util 'first';
12 use Sub::Name 'subname';
14 use Carp::Clan qw/^DBIx::Class|^SQL::Abstract|^Try::Tiny/;
17 # reinstall the carp()/croak() functions imported into SQL::Abstract
18 # as Carp and Carp::Clan do not like each other much
19 no warnings qw/redefine/;
21 for my $f (qw/carp croak/) {
23 my $orig = \&{"SQL::Abstract::$f"};
24 *{"SQL::Abstract::$f"} = subname "SQL::Abstract::$f" =>
26 if (Carp::longmess() =~ /DBIx::Class::SQLAHacks::[\w]+ .+? called \s at/x) {
27 __PACKAGE__->can($f)->(@_);
36 # the "oh noes offset/top without limit" constant
37 # limited to 32 bits for sanity (and since it is fed
39 sub __max_int { 0xFFFFFFFF };
42 # Tries to determine limit dialect.
45 my $self = shift->SUPER::new(@_);
47 # This prevents the caching of $dbh in S::A::L, I believe
48 # If limit_dialect is a ref (like a $dbh), go ahead and replace
49 # it with what it resolves to:
50 $self->{limit_dialect} = $self->_find_syntax($self->{limit_dialect})
51 if ref $self->{limit_dialect};
56 # !!! THIS IS ALSO HORRIFIC !!! /me ashamed
58 # Generates inner/outer select lists for various limit dialects
59 # which result in one or more subqueries (e.g. RNO, Top, RowNum)
60 # Any non-root-table columns need to have their table qualifier
61 # turned into a column alias (otherwise names in subqueries clash
62 # and/or lose their source table)
64 # Returns inner/outer strings of SQL QUOTED selectors with aliases
65 # (to be used in whatever select statement), and an alias index hashref
66 # of QUOTED SEL => QUOTED ALIAS pairs (to maybe be used for string-subst
68 # If an order_by is supplied, the inner select needs to bring out columns
69 # used in implicit (non-selected) orders, and the order condition itself
70 # needs to be realiased to the proper names in the outer query. Thus we
71 # also return a hashref (order doesn't matter) of QUOTED EXTRA-SEL =>
72 # QUOTED ALIAS pairs, which is a list of extra selectors that do *not*
73 # exist in the original select list
75 sub _subqueried_limit_attrs {
76 my ($self, $rs_attrs) = @_;
78 croak 'Limit dialect implementation usable only in the context of DBIC (missing $rs_attrs)'
79 unless ref ($rs_attrs) eq 'HASH';
81 my ($re_sep, $re_alias) = map { quotemeta $_ } (
82 $self->name_sep || '.',
86 # correlate select and as, build selection index
87 my (@sel, $in_sel_index);
88 for my $i (0 .. $#{$rs_attrs->{select}}) {
90 my $s = $rs_attrs->{select}[$i];
91 my $sql_sel = $self->_recurse_fields ($s);
92 my $sql_alias = (ref $s) eq 'HASH' ? $s->{-as} : undef;
97 unquoted_sql => do { local $self->{quote_char}; $self->_recurse_fields ($s) },
103 croak "Select argument $i ($s) without corresponding 'as'"
107 $in_sel_index->{$sql_sel}++;
108 $in_sel_index->{$self->_quote ($sql_alias)}++ if $sql_alias;
110 # record unqualified versions too, so we do not have
111 # to reselect the same column twice (in qualified and
113 if (! ref $s && $sql_sel =~ / $re_sep (.+) $/x) {
114 $in_sel_index->{$1}++;
119 # re-alias and remove any name separators from aliases,
120 # unless we are dealing with the current source alias
121 # (which will transcend the subqueries as it is necessary
122 # for possible further chaining)
123 my (@in_sel, @out_sel, %renamed);
124 for my $node (@sel) {
125 if (first { $_ =~ / (?<! $re_alias ) $re_sep /x } ($node->{as}, $node->{unquoted_sql}) ) {
126 $node->{as} =~ s/ $re_sep /__/xg;
127 my $quoted_as = $self->_quote($node->{as});
128 push @in_sel, sprintf '%s AS %s', $node->{sql}, $quoted_as;
129 push @out_sel, $quoted_as;
130 $renamed{$node->{sql}} = $quoted_as;
133 push @in_sel, $node->{sql};
134 push @out_sel, $self->_quote ($node->{as});
138 # see if the order gives us anything
140 for my $chunk ($self->_order_by_chunks ($rs_attrs->{order_by})) {
142 $chunk = $chunk->[0] if (ref $chunk) eq 'ARRAY';
143 $chunk =~ s/\s+ (?: ASC|DESC ) \s* $//ix;
145 next if $in_sel_index->{$chunk};
147 $extra_order_sel{$chunk} ||= $self->_quote (
148 'ORDER__BY__' . scalar keys %extra_order_sel
153 (map { join (', ', @$_ ) } (
158 keys %extra_order_sel ? \%extra_order_sel : (),
162 # ANSI standard Limit/Offset implementation. DB2 and MSSQL >= 2005 use this
164 my ($self, $sql, $rs_attrs, $rows, $offset ) = @_;
166 # mangle the input sql as we will be replacing the selector
167 $sql =~ s/^ \s* SELECT \s+ .+? \s+ (?= \b FROM \b )//ix
168 or croak "Unrecognizable SELECT: $sql";
170 # get selectors, and scan the order_by (if any)
171 my ($in_sel, $out_sel, $alias_map, $extra_order_sel)
172 = $self->_subqueried_limit_attrs ( $rs_attrs );
174 # make up an order if none exists
175 my $requested_order = (delete $rs_attrs->{order_by}) || $self->_rno_default_order;
176 my $rno_ord = $self->_order_by ($requested_order);
178 # this is the order supplement magic
179 my $mid_sel = $out_sel;
180 if ($extra_order_sel) {
181 for my $extra_col (sort
182 { $extra_order_sel->{$a} cmp $extra_order_sel->{$b} }
183 keys %$extra_order_sel
185 $in_sel .= sprintf (', %s AS %s',
187 $extra_order_sel->{$extra_col},
190 $mid_sel .= ', ' . $extra_order_sel->{$extra_col};
194 # and this is order re-alias magic
195 for ($extra_order_sel, $alias_map) {
196 for my $col (keys %$_) {
197 my $re_col = quotemeta ($col);
198 $rno_ord =~ s/$re_col/$_->{$col}/;
202 # whatever is left of the order_by (only where is processed at this point)
203 my $group_having = $self->_parse_rs_attrs($rs_attrs);
205 my $qalias = $self->_quote ($rs_attrs->{alias});
206 my $idx_name = $self->_quote ('rno__row__index');
208 $sql = sprintf (<<EOS, $offset + 1, $offset + $rows, );
210 SELECT $out_sel FROM (
211 SELECT $mid_sel, ROW_NUMBER() OVER( $rno_ord ) AS $idx_name FROM (
212 SELECT $in_sel ${sql}${group_having}
214 ) $qalias WHERE $idx_name BETWEEN %u AND %u
218 $sql =~ s/\s*\n\s*/ /g; # easier to read in the debugger
222 # some databases are happy with OVER (), some need OVER (ORDER BY (SELECT (1)) )
223 sub _rno_default_order {
227 # Informix specific limit, almost like LIMIT/OFFSET
229 my ($self, $sql, $rs_attrs, $rows, $offset) = @_;
231 $sql =~ s/^ \s* SELECT \s+ //ix
232 or croak "Unrecognizable SELECT: $sql";
234 return sprintf ('SELECT %s%s%s%s',
236 ? sprintf ('SKIP %u ', $offset)
239 sprintf ('FIRST %u ', $rows),
241 $self->_parse_rs_attrs ($rs_attrs),
245 # Firebird specific limit, reverse of _SkipFirst for Informix
247 my ($self, $sql, $rs_attrs, $rows, $offset) = @_;
249 $sql =~ s/^ \s* SELECT \s+ //ix
250 or croak "Unrecognizable SELECT: $sql";
252 return sprintf ('SELECT %s%s%s%s',
253 sprintf ('FIRST %u ', $rows),
255 ? sprintf ('SKIP %u ', $offset)
259 $self->_parse_rs_attrs ($rs_attrs),
265 my ( $self, $sql, $rs_attrs, $rows, $offset ) = @_;
267 # mangle the input sql as we will be replacing the selector
268 $sql =~ s/^ \s* SELECT \s+ .+? \s+ (?= \b FROM \b )//ix
269 or croak "Unrecognizable SELECT: $sql";
271 my ($insel, $outsel) = $self->_subqueried_limit_attrs ($rs_attrs);
273 my $qalias = $self->_quote ($rs_attrs->{alias});
274 my $idx_name = $self->_quote ('rownum__index');
275 my $order_group_having = $self->_parse_rs_attrs($rs_attrs);
277 $sql = sprintf (<<EOS, $offset + 1, $offset + $rows, );
279 SELECT $outsel FROM (
280 SELECT $outsel, ROWNUM $idx_name FROM (
281 SELECT $insel ${sql}${order_group_having}
283 ) $qalias WHERE $idx_name BETWEEN %u AND %u
287 $sql =~ s/\s*\n\s*/ /g; # easier to read in the debugger
291 # Crappy Top based Limit/Offset support. Legacy for MSSQL < 2005
293 my ( $self, $sql, $rs_attrs, $rows, $offset ) = @_;
295 # mangle the input sql as we will be replacing the selector
296 $sql =~ s/^ \s* SELECT \s+ .+? \s+ (?= \b FROM \b )//ix
297 or croak "Unrecognizable SELECT: $sql";
300 my ($in_sel, $out_sel, $alias_map, $extra_order_sel)
301 = $self->_subqueried_limit_attrs ($rs_attrs);
303 my $requested_order = delete $rs_attrs->{order_by};
305 my $order_by_requested = $self->_order_by ($requested_order);
307 # make up an order unless supplied
308 my $inner_order = ($order_by_requested
311 { join ('', $rs_attrs->{alias}, $self->{name_sep}||'.', $_ ) }
312 ( $rs_attrs->{_rsroot_source_handle}->resolve->_pri_cols )
316 my ($order_by_inner, $order_by_reversed);
318 # localise as we already have all the bind values we need
320 local $self->{order_bind};
321 $order_by_inner = $self->_order_by ($inner_order);
324 for my $ch ($self->_order_by_chunks ($inner_order)) {
325 $ch = $ch->[0] if ref $ch eq 'ARRAY';
327 $ch =~ s/\s+ ( ASC|DESC ) \s* $//ix;
328 my $dir = uc ($1||'ASC');
330 push @out_chunks, \join (' ', $ch, $dir eq 'ASC' ? 'DESC' : 'ASC' );
333 $order_by_reversed = $self->_order_by (\@out_chunks);
336 # this is the order supplement magic
337 my $mid_sel = $out_sel;
338 if ($extra_order_sel) {
339 for my $extra_col (sort
340 { $extra_order_sel->{$a} cmp $extra_order_sel->{$b} }
341 keys %$extra_order_sel
343 $in_sel .= sprintf (', %s AS %s',
345 $extra_order_sel->{$extra_col},
348 $mid_sel .= ', ' . $extra_order_sel->{$extra_col};
351 # since whatever order bindvals there are, they will be realiased
352 # and need to show up in front of the entire initial inner subquery
353 # Unshift *from_bind* to make this happen (horrible, horrible, but
354 # we don't have another mechanism yet)
355 unshift @{$self->{from_bind}}, @{$self->{order_bind}};
358 # and this is order re-alias magic
359 for my $map ($extra_order_sel, $alias_map) {
360 for my $col (keys %$map) {
361 my $re_col = quotemeta ($col);
362 $_ =~ s/$re_col/$map->{$col}/
363 for ($order_by_reversed, $order_by_requested);
367 # generate the rest of the sql
368 my $grpby_having = $self->_parse_rs_attrs ($rs_attrs);
370 my $quoted_rs_alias = $self->_quote ($rs_attrs->{alias});
372 $sql = sprintf ('SELECT TOP %u %s %s %s %s',
373 $rows + ($offset||0),
380 $sql = sprintf ('SELECT TOP %u %s FROM ( %s ) %s %s',
388 $sql = sprintf ('SELECT TOP %u %s FROM ( %s ) %s %s',
394 ) if ( ($offset && $order_by_requested) || ($mid_sel ne $out_sel) );
396 $sql =~ s/\s*\n\s*/ /g; # easier to read in the debugger
400 # This for Sybase ASE, to use SET ROWCOUNT when there is no offset, and
401 # GenericSubQ otherwise.
402 sub _RowCountOrGenericSubQ {
404 my ($sql, $rs_attrs, $rows, $offset) = @_;
406 return $self->_GenericSubQ(@_) if $offset;
408 return sprintf <<"EOF", $rows, $sql;
415 # This is the most evil limit "dialect" (more of a hack) for *really*
416 # stupid databases. It works by ordering the set by some unique column,
417 # and calculating amount of rows that have a less-er value (thus
418 # emulating a RowNum-like index). Of course this implies the set can
419 # only be ordered by a single unique columns.
421 my ($self, $sql, $rs_attrs, $rows, $offset) = @_;
423 my $root_rsrc = $rs_attrs->{_rsroot_source_handle}->resolve;
424 my $root_tbl_name = $root_rsrc->name;
426 # mangle the input sql as we will be replacing the selector
427 $sql =~ s/^ \s* SELECT \s+ .+? \s+ (?= \b FROM \b )//ix
428 or croak "Unrecognizable SELECT: $sql";
430 my ($order_by, @rest) = do {
431 local $self->{quote_char};
432 $self->_order_by_chunks ($rs_attrs->{order_by})
442 ( ref $order_by eq 'ARRAY' and @$order_by == 1 )
446 'Generic Subquery Limit does not work on resultsets without an order, or resultsets '
447 . 'with complex order criteria (multicolumn and/or functions). Provide a single, '
448 . 'unique-column order criteria.'
452 ($order_by) = @$order_by if ref $order_by;
454 $order_by =~ s/\s+ ( ASC|DESC ) \s* $//ix;
455 my $direction = lc ($1 || 'asc');
457 my ($unq_sort_col) = $order_by =~ /(?:^|\.)([^\.]+)$/;
459 my $inf = $root_rsrc->storage->_resolve_column_info (
460 $rs_attrs->{from}, [$order_by, $unq_sort_col]
463 my $ord_colinfo = $inf->{$order_by} || croak "Unable to determine source of order-criteria '$order_by'";
465 if ($ord_colinfo->{-result_source}->name ne $root_tbl_name) {
466 croak "Generic Subquery Limit order criteria can be only based on the root-source '"
467 . $root_rsrc->source_name . "' (aliased as '$rs_attrs->{alias}')";
470 # make sure order column is qualified
471 $order_by = "$rs_attrs->{alias}.$order_by"
472 unless $order_by =~ /^$rs_attrs->{alias}\./;
475 my $ucs = { $root_rsrc->unique_constraints };
476 for (values %$ucs ) {
477 if (@$_ == 1 && "$rs_attrs->{alias}.$_->[0]" eq $order_by) {
482 croak "Generic Subquery Limit order criteria column '$order_by' must be unique (no unique constraint found)"
485 my ($in_sel, $out_sel, $alias_map, $extra_order_sel)
486 = $self->_subqueried_limit_attrs ($rs_attrs);
488 my $cmp_op = $direction eq 'desc' ? '>' : '<';
489 my $count_tbl_alias = 'rownum__emulation';
491 my $order_sql = $self->_order_by (delete $rs_attrs->{order_by});
492 my $group_having_sql = $self->_parse_rs_attrs($rs_attrs);
494 # add the order supplement (if any) as this is what will be used for the outer WHERE
495 $in_sel .= ", $_" for keys %{$extra_order_sel||{}};
497 $sql = sprintf (<<EOS,
500 SELECT $in_sel ${sql}${group_having_sql}
502 WHERE ( SELECT COUNT(*) FROM %s %s WHERE %s $cmp_op %s ) %s
505 ( map { $self->_quote ($_) } (
509 "$count_tbl_alias.$unq_sort_col",
513 ? sprintf ('BETWEEN %u AND %u', $offset, $offset + $rows - 1)
514 : sprintf ('< %u', $rows )
518 $sql =~ s/\s*\n\s*/ /g; # easier to read in the debugger
523 # While we're at it, this should make LIMIT queries more efficient,
524 # without digging into things too deeply
526 my ($self, $syntax) = @_;
527 return $self->{_cached_syntax} ||= $self->SUPER::_find_syntax($syntax);
530 # Quotes table names, handles "limit" dialects (e.g. where rownum between x and
533 my ($self, $table, $fields, $where, $rs_attrs, @rest) = @_;
535 if (not ref($table) or ref($table) eq 'SCALAR') {
536 $table = $self->_quote($table);
539 @rest = (-1) unless defined $rest[0];
540 croak "LIMIT 0 Does Not Compute" if $rest[0] == 0;
541 # and anyway, SQL::Abstract::Limit will cause a barf if we don't first
543 my ($sql, @bind) = $self->SUPER::select(
544 $table, $self->_recurse_fields($fields), $where, $rs_attrs, @rest
546 push @{$self->{where_bind}}, @bind;
548 # this *must* be called, otherwise extra binds will remain in the sql-maker
549 my @all_bind = $self->_assemble_binds;
551 return wantarray ? ($sql, @all_bind) : $sql;
554 sub _assemble_binds {
556 return map { @{ (delete $self->{"${_}_bind"}) || [] } } (qw/from where having order/);
559 # Quotes table names, and handles default inserts
563 $table = $self->_quote($table);
565 # SQLA will emit INSERT INTO $table ( ) VALUES ( )
566 # which is sadly understood only by MySQL. Change default behavior here,
567 # until SQLA2 comes with proper dialect support
568 if (! $_[0] or (ref $_[0] eq 'HASH' and !keys %{$_[0]} ) ) {
569 my $sql = "INSERT INTO ${table} DEFAULT VALUES";
571 if (my $ret = ($_[1]||{})->{returning} ) {
572 $sql .= $self->_insert_returning ($ret);
578 $self->SUPER::insert($table, @_);
581 # Just quotes table names.
585 $table = $self->_quote($table);
586 $self->SUPER::update($table, @_);
589 # Just quotes table names.
593 $table = $self->_quote($table);
594 $self->SUPER::delete($table, @_);
599 # my ( $syntax, $sql, $order, $rows, $offset ) = @_;
602 return $_[1] . $self->_parse_rs_attrs($_[2]);
604 return $self->SUPER::_emulate_limit(@_);
608 sub _recurse_fields {
609 my ($self, $fields) = @_;
610 my $ref = ref $fields;
611 return $self->_quote($fields) unless $ref;
612 return $$fields if $ref eq 'SCALAR';
614 if ($ref eq 'ARRAY') {
615 return join(', ', map { $self->_recurse_fields($_) } @$fields);
617 elsif ($ref eq 'HASH') {
618 my %hash = %$fields; # shallow copy
620 my $as = delete $hash{-as}; # if supplied
622 my ($func, $args, @toomany) = %hash;
624 # there should be only one pair
626 croak "Malformed select argument - too many keys in hash: " . join (',', keys %$fields );
629 if (lc ($func) eq 'distinct' && ref $args eq 'ARRAY' && @$args > 1) {
631 'The select => { distinct => ... } syntax is not supported for multiple columns.'
632 .' Instead please use { group_by => [ qw/' . (join ' ', @$args) . '/ ] }'
633 .' or { select => [ qw/' . (join ' ', @$args) . '/ ], distinct => 1 }'
637 my $select = sprintf ('%s( %s )%s',
638 $self->_sqlcase($func),
639 $self->_recurse_fields($args),
641 ? sprintf (' %s %s', $self->_sqlcase('as'), $self->_quote ($as) )
647 # Is the second check absolutely necessary?
648 elsif ( $ref eq 'REF' and ref($$fields) eq 'ARRAY' ) {
649 return $self->_fold_sqlbind( $fields );
652 croak($ref . qq{ unexpected in _recurse_fields()})
657 update => 'FOR UPDATE',
658 shared => 'FOR SHARE',
661 # this used to be a part of _order_by but is broken out for clarity.
662 # What we have been doing forever is hijacking the $order arg of
663 # SQLA::select to pass in arbitrary pieces of data (first the group_by,
664 # then pretty much the entire resultset attr-hash, as more and more
665 # things in the SQLA space need to have mopre info about the $rs they
666 # create SQL for. The alternative would be to keep expanding the
667 # signature of _select with more and more positional parameters, which
668 # is just gross. All hail SQLA2!
669 sub _parse_rs_attrs {
670 my ($self, $arg) = @_;
674 if (my $g = $self->_recurse_fields($arg->{group_by}) ) {
675 $sql .= $self->_sqlcase(' group by ') . $g;
678 if (defined $arg->{having}) {
679 my ($frag, @bind) = $self->_recurse_where($arg->{having});
680 push(@{$self->{having_bind}}, @bind);
681 $sql .= $self->_sqlcase(' having ') . $frag;
684 if (defined $arg->{order_by}) {
685 $sql .= $self->_order_by ($arg->{order_by});
688 if (my $for = $arg->{for}) {
689 $sql .= " $for_syntax->{$for}" if $for_syntax->{$for};
696 my ($self, $arg) = @_;
698 # check that we are not called in legacy mode (order_by as 4th argument)
699 if (ref $arg eq 'HASH' and not grep { $_ =~ /^-(?:desc|asc)/i } keys %$arg ) {
700 return $self->_parse_rs_attrs ($arg);
703 my ($sql, @bind) = $self->SUPER::_order_by ($arg);
704 push @{$self->{order_bind}}, @bind;
709 sub _order_directions {
710 my ($self, $order) = @_;
712 # strip bind values - none of the current _order_directions users support them
713 return $self->SUPER::_order_directions( [ map
714 { ref $_ ? $_->[0] : $_ }
715 $self->_order_by_chunks ($order)
720 my ($self, $from) = @_;
721 if (ref $from eq 'ARRAY') {
722 return $self->_recurse_from(@$from);
723 } elsif (ref $from eq 'HASH') {
724 return $self->_make_as($from);
726 return $from; # would love to quote here but _table ends up getting called
727 # twice during an ->select without a limit clause due to
728 # the way S::A::Limit->select works. should maybe consider
729 # bypassing this and doing S::A::select($self, ...) in
730 # our select method above. meantime, quoting shims have
731 # been added to select/insert/update/delete here
735 sub _generate_join_clause {
736 my ($self, $join_type) = @_;
738 return sprintf ('%s JOIN ',
739 $join_type ? ' ' . uc($join_type) : ''
744 my ($self, $from, @join) = @_;
746 push(@sqlf, $self->_make_as($from));
747 foreach my $j (@join) {
751 # check whether a join type exists
752 my $to_jt = ref($to) eq 'ARRAY' ? $to->[0] : $to;
754 if (ref($to_jt) eq 'HASH' and defined($to_jt->{-join_type})) {
755 $join_type = $to_jt->{-join_type};
756 $join_type =~ s/^\s+ | \s+$//xg;
759 $join_type = $self->{_default_jointype} if not defined $join_type;
761 push @sqlf, $self->_generate_join_clause( $join_type );
763 if (ref $to eq 'ARRAY') {
764 push(@sqlf, '(', $self->_recurse_from(@$to), ')');
766 push(@sqlf, $self->_make_as($to));
768 push(@sqlf, ' ON ', $self->_join_condition($on));
770 return join('', @sqlf);
774 my ($self, $sqlbind) = @_;
776 my @sqlbind = @$$sqlbind; # copy
777 my $sql = shift @sqlbind;
778 push @{$self->{from_bind}}, @sqlbind;
784 my ($self, $from) = @_;
785 return join(' ', map { (ref $_ eq 'SCALAR' ? $$_
786 : ref $_ eq 'REF' ? $self->_fold_sqlbind($_)
788 } reverse each %{$self->_skip_options($from)});
792 my ($self, $hash) = @_;
794 $clean_hash->{$_} = $hash->{$_}
795 for grep {!/^-/} keys %$hash;
799 sub _join_condition {
800 my ($self, $cond) = @_;
801 if (ref $cond eq 'HASH') {
806 croak (ref($v) . qq{ reference arguments are not supported in JOINS - try using \"..." instead'})
807 if ref($v) ne 'SCALAR';
811 my $x = '= '.$self->_quote($v); $j{$_} = \$x;
814 return scalar($self->_recurse_where(\%j));
815 } elsif (ref $cond eq 'ARRAY') {
816 return join(' OR ', map { $self->_join_condition($_) } @$cond);
818 die "Can't handle this yet!";
825 $self->{limit_dialect} = shift;
826 undef $self->{_cached_syntax};
828 return $self->{limit_dialect};
831 # Set to an array-ref to specify separate left and right quotes for table names.
832 # A single scalar is equivalen to [ $char, $char ]
835 $self->{quote_char} = shift if @_;
836 return $self->{quote_char};
839 # Character separating quoted table names.
842 $self->{name_sep} = shift if @_;
843 return $self->{name_sep};