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 $self->{limit_dialect};
50 # ANSI standard Limit/Offset implementation. DB2 and MSSQL use this
52 my ($self, $sql, $order, $rows, $offset ) = @_;
54 # get the order_by only (or make up an order if none exists)
55 my $order_by = $self->_order_by(
56 (delete $order->{order_by}) || $self->_rno_default_order
60 my $group_having = $self->_order_by($order);
62 my $qalias = $self->_quote ($self->{_dbic_rs_attrs}{alias});
64 $sql = sprintf (<<'EOS', $qalias, $order_by, $sql, $group_having, $qalias, $offset + 1, $offset + $rows, );
67 SELECT %s.*, ROW_NUMBER() OVER(%s ) AS rno__row__index FROM (%s%s) %s
68 ) rno_subq WHERE rno__row__index BETWEEN %d AND %d
72 $sql =~ s/\s*\n\s*/ /g; # easier to read in the debugger
76 # some databases are happy with OVER (), some need OVER (ORDER BY (SELECT (1)) )
77 sub _rno_default_order {
81 # Crappy Top based Limit/Offset support. Legacy from MSSQL.
83 my ( $self, $sql, $order, $rows, $offset ) = @_;
85 # mangle the input sql so it can be properly aliased in the outer queries
86 $sql =~ s/^ \s* SELECT \s+ (.+?) \s+ (?=FROM)//ix
87 or croak "Unrecognizable SELECT: $sql";
89 my @sql_select = split (/\s*,\s*/, $sql_select);
91 # we can't support subqueries (in fact MSSQL can't) - croak
92 if (@sql_select != @{$self->{_dbic_rs_attrs}{select}}) {
94 'SQL SELECT did not parse cleanly - retrieved %d comma separated elements, while '
95 . 'the resultset select attribure contains %d elements: %s',
97 scalar @{$self->{_dbic_rs_attrs}{select}},
102 my $name_sep = $self->name_sep || '.';
103 my $esc_name_sep = "\Q$name_sep\E";
104 my $col_re = qr/ ^ (?: (.+) $esc_name_sep )? ([^$esc_name_sep]+) $ /x;
106 my $rs_alias = $self->{_dbic_rs_attrs}{alias};
107 my $quoted_rs_alias = $self->_quote ($rs_alias);
109 # construct the new select lists, rename(alias) some columns if necessary
110 my (@outer_select, @inner_select, %seen_names, %col_aliases, %outer_col_aliases);
112 for (@{$self->{_dbic_rs_attrs}{select}}) {
114 my ($table, $orig_colname) = ( $_ =~ $col_re );
116 $seen_names{$orig_colname}++;
119 for my $i (0 .. $#sql_select) {
121 my $colsel_arg = $self->{_dbic_rs_attrs}{select}[$i];
122 my $colsel_sql = $sql_select[$i];
124 # this may or may not work (in case of a scalarref or something)
125 my ($table, $orig_colname) = ( $colsel_arg =~ $col_re );
128 # do not attempt to understand non-scalar selects - alias numerically
129 if (ref $colsel_arg) {
130 $quoted_alias = $self->_quote ('column_' . (@inner_select + 1) );
132 # column name seen more than once - alias it
133 elsif ($orig_colname &&
134 ($seen_names{$orig_colname} && $seen_names{$orig_colname} > 1) ) {
135 $quoted_alias = $self->_quote ("${table}__${orig_colname}");
138 # we did rename - make a record and adjust
141 push @inner_select, "$colsel_sql AS $quoted_alias";
143 # push alias to outer
144 push @outer_select, $quoted_alias;
146 # Any aliasing accumulated here will be considered
147 # both for inner and outer adjustments of ORDER BY
148 $self->__record_alias (
152 $table ? $orig_colname : undef,
156 # otherwise just leave things intact inside, and use the abbreviated one outside
157 # (as we do not have table names anymore)
159 push @inner_select, $colsel_sql;
161 my $outer_quoted = $self->_quote ($orig_colname); # it was not a duplicate so should just work
162 push @outer_select, $outer_quoted;
163 $self->__record_alias (
167 $table ? $orig_colname : undef,
172 my $outer_select = join (', ', @outer_select );
173 my $inner_select = join (', ', @inner_select );
175 %outer_col_aliases = (%outer_col_aliases, %col_aliases);
178 croak '$order supplied to SQLAHacks limit emulators must be a hash'
179 if (ref $order ne 'HASH');
181 $order = { %$order }; #copy
183 my $req_order = $order->{order_by};
185 # examine normalized version, collapses nesting
187 if (scalar $self->_order_by_chunks ($req_order)) {
188 $limit_order = $req_order;
192 { join ('', $rs_alias, $name_sep, $_ ) }
193 ( $self->{_dbic_rs_attrs}{_source_handle}->resolve->primary_columns )
197 my ( $order_by_inner, $order_by_outer ) = $self->_order_directions($limit_order);
198 my $order_by_requested = $self->_order_by ($req_order);
201 delete $order->{order_by};
202 my $grpby_having = $self->_order_by ($order);
204 # short circuit for counts - the ordering complexity is needless
205 if ($self->{_dbic_rs_attrs}{-for_count_only}) {
206 return "SELECT TOP $rows $inner_select $sql $grpby_having $order_by_outer";
209 # we can't really adjust the order_by columns, as introspection is lacking
210 # resort to simple substitution
211 for my $col (keys %outer_col_aliases) {
212 for ($order_by_requested, $order_by_outer) {
213 $_ =~ s/\s+$col\s+/ $outer_col_aliases{$col} /g;
216 for my $col (keys %col_aliases) {
217 $order_by_inner =~ s/\s+$col\s+/ $col_aliases{$col} /g;
221 my $inner_lim = $rows + $offset;
223 $sql = "SELECT TOP $inner_lim $inner_select $sql $grpby_having $order_by_inner";
228 SELECT TOP $rows $outer_select FROM
237 if ($order_by_requested) {
240 SELECT $outer_select FROM
241 ( $sql ) $quoted_rs_alias
247 $sql =~ s/\s*\n\s*/ /g; # parsing out multiline statements is harder than a single line
251 # action at a distance to shorten Top code above
253 my ($self, $register, $alias, $fqcol, $col) = @_;
255 # record qualified name
256 $register->{$fqcol} = $alias;
257 $register->{$self->_quote($fqcol)} = $alias;
261 # record unqualified name, undef (no adjustment) if a duplicate is found
262 if (exists $register->{$col}) {
263 $register->{$col} = undef;
266 $register->{$col} = $alias;
269 $register->{$self->_quote($col)} = $register->{$col};
274 # While we're at it, this should make LIMIT queries more efficient,
275 # without digging into things too deeply
277 my ($self, $syntax) = @_;
278 return $self->{_cached_syntax} ||= $self->SUPER::_find_syntax($syntax);
282 update => 'FOR UPDATE',
283 shared => 'FOR SHARE',
285 # Quotes table names, handles "limit" dialects (e.g. where rownum between x and
286 # y), supports SELECT ... FOR UPDATE and SELECT ... FOR SHARE.
288 my ($self, $table, $fields, $where, $order, @rest) = @_;
290 $self->{"${_}_bind"} = [] for (qw/having from order/);
292 if (not ref($table) or ref($table) eq 'SCALAR') {
293 $table = $self->_quote($table);
296 local $self->{rownum_hack_count} = 1
297 if (defined $rest[0] && $self->{limit_dialect} eq 'RowNum');
298 @rest = (-1) unless defined $rest[0];
299 croak "LIMIT 0 Does Not Compute" if $rest[0] == 0;
300 # and anyway, SQL::Abstract::Limit will cause a barf if we don't first
301 my ($sql, @where_bind) = $self->SUPER::select(
302 $table, $self->_recurse_fields($fields), $where, $order, @rest
304 if (my $for = delete $self->{_dbic_rs_attrs}{for}) {
305 $sql .= " $for_syntax->{$for}" if $for_syntax->{$for};
308 return wantarray ? ($sql, @{$self->{from_bind}}, @where_bind, @{$self->{having_bind}}, @{$self->{order_bind}} ) : $sql;
311 # Quotes table names, and handles default inserts
315 $table = $self->_quote($table);
317 # SQLA will emit INSERT INTO $table ( ) VALUES ( )
318 # which is sadly understood only by MySQL. Change default behavior here,
319 # until SQLA2 comes with proper dialect support
320 if (! $_[0] or (ref $_[0] eq 'HASH' and !keys %{$_[0]} ) ) {
321 return "INSERT INTO ${table} DEFAULT VALUES"
324 $self->SUPER::insert($table, @_);
327 # Just quotes table names.
331 $table = $self->_quote($table);
332 $self->SUPER::update($table, @_);
335 # Just quotes table names.
339 $table = $self->_quote($table);
340 $self->SUPER::delete($table, @_);
346 return $_[1].$self->_order_by($_[2]);
348 return $self->SUPER::_emulate_limit(@_);
352 sub _recurse_fields {
353 my ($self, $fields, $params) = @_;
354 my $ref = ref $fields;
355 return $self->_quote($fields) unless $ref;
356 return $$fields if $ref eq 'SCALAR';
358 if ($ref eq 'ARRAY') {
359 return join(', ', map {
360 $self->_recurse_fields($_)
361 .(exists $self->{rownum_hack_count} && !($params && $params->{no_rownum_hack})
362 ? ' AS col'.$self->{rownum_hack_count}++
366 elsif ($ref eq 'HASH') {
369 my $as = delete $hash{-as}; # if supplied
371 my ($func, $args) = each %hash;
374 if (lc ($func) eq 'distinct' && ref $args eq 'ARRAY' && @$args > 1) {
376 'The select => { distinct => ... } syntax is not supported for multiple columns.'
377 .' Instead please use { group_by => [ qw/' . (join ' ', @$args) . '/ ] }'
378 .' or { select => [ qw/' . (join ' ', @$args) . '/ ], distinct => 1 }'
382 my $select = sprintf ('%s( %s )%s',
383 $self->_sqlcase($func),
384 $self->_recurse_fields($args),
386 ? sprintf (' %s %s', $self->_sqlcase('as'), $as)
390 # there should be nothing left
392 croak "Malformed select argument - too many keys in hash: " . join (',', keys %$fields );
397 # Is the second check absolutely necessary?
398 elsif ( $ref eq 'REF' and ref($$fields) eq 'ARRAY' ) {
399 return $self->_fold_sqlbind( $fields );
402 croak($ref . qq{ unexpected in _recurse_fields()})
407 my ($self, $arg) = @_;
409 if (ref $arg eq 'HASH' and keys %$arg and not grep { $_ =~ /^-(?:desc|asc)/i } keys %$arg ) {
413 if (my $g = $self->_recurse_fields($arg->{group_by}, { no_rownum_hack => 1 }) ) {
414 $ret = $self->_sqlcase(' group by ') . $g;
417 if (defined $arg->{having}) {
418 my ($frag, @bind) = $self->_recurse_where($arg->{having});
419 push(@{$self->{having_bind}}, @bind);
420 $ret .= $self->_sqlcase(' having ').$frag;
423 if (defined $arg->{order_by}) {
424 my ($frag, @bind) = $self->SUPER::_order_by($arg->{order_by});
425 push(@{$self->{order_bind}}, @bind);
432 my ($sql, @bind) = $self->SUPER::_order_by ($arg);
433 push(@{$self->{order_bind}}, @bind);
438 sub _order_directions {
439 my ($self, $order) = @_;
441 # strip bind values - none of the current _order_directions users support them
442 return $self->SUPER::_order_directions( [ map
443 { ref $_ ? $_->[0] : $_ }
444 $self->_order_by_chunks ($order)
449 my ($self, $from) = @_;
450 if (ref $from eq 'ARRAY') {
451 return $self->_recurse_from(@$from);
452 } elsif (ref $from eq 'HASH') {
453 return $self->_make_as($from);
455 return $from; # would love to quote here but _table ends up getting called
456 # twice during an ->select without a limit clause due to
457 # the way S::A::Limit->select works. should maybe consider
458 # bypassing this and doing S::A::select($self, ...) in
459 # our select method above. meantime, quoting shims have
460 # been added to select/insert/update/delete here
465 my ($self, $from, @join) = @_;
467 push(@sqlf, $self->_make_as($from));
468 foreach my $j (@join) {
472 # check whether a join type exists
473 my $to_jt = ref($to) eq 'ARRAY' ? $to->[0] : $to;
475 if (ref($to_jt) eq 'HASH' and defined($to_jt->{-join_type})) {
476 $join_type = $to_jt->{-join_type};
477 $join_type =~ s/^\s+ | \s+$//xg;
480 $join_type = $self->{_default_jointype} if not defined $join_type;
482 my $join_clause = sprintf ('%s JOIN ',
483 $join_type ? ' ' . uc($join_type) : ''
485 push @sqlf, $join_clause;
487 if (ref $to eq 'ARRAY') {
488 push(@sqlf, '(', $self->_recurse_from(@$to), ')');
490 push(@sqlf, $self->_make_as($to));
492 push(@sqlf, ' ON ', $self->_join_condition($on));
494 return join('', @sqlf);
498 my ($self, $sqlbind) = @_;
500 my @sqlbind = @$$sqlbind; # copy
501 my $sql = shift @sqlbind;
502 push @{$self->{from_bind}}, @sqlbind;
508 my ($self, $from) = @_;
509 return join(' ', map { (ref $_ eq 'SCALAR' ? $$_
510 : ref $_ eq 'REF' ? $self->_fold_sqlbind($_)
512 } reverse each %{$self->_skip_options($from)});
516 my ($self, $hash) = @_;
518 $clean_hash->{$_} = $hash->{$_}
519 for grep {!/^-/} keys %$hash;
523 sub _join_condition {
524 my ($self, $cond) = @_;
525 if (ref $cond eq 'HASH') {
530 croak (ref($v) . qq{ reference arguments are not supported in JOINS - try using \"..." instead'})
531 if ref($v) ne 'SCALAR';
535 my $x = '= '.$self->_quote($v); $j{$_} = \$x;
538 return scalar($self->_recurse_where(\%j));
539 } elsif (ref $cond eq 'ARRAY') {
540 return join(' OR ', map { $self->_join_condition($_) } @$cond);
542 die "Can't handle this yet!";
547 my ($self, $label) = @_;
548 return '' unless defined $label;
549 return $$label if ref($label) eq 'SCALAR';
550 return "*" if $label eq '*';
551 return $label unless $self->{quote_char};
552 if(ref $self->{quote_char} eq "ARRAY"){
553 return $self->{quote_char}->[0] . $label . $self->{quote_char}->[1]
554 if !defined $self->{name_sep};
555 my $sep = $self->{name_sep};
556 return join($self->{name_sep},
557 map { $self->{quote_char}->[0] . $_ . $self->{quote_char}->[1] }
558 split(/\Q$sep\E/,$label));
560 return $self->SUPER::_quote($label);
565 $self->{limit_dialect} = shift if @_;
566 return $self->{limit_dialect};
569 # Set to an array-ref to specify separate left and right quotes for table names.
570 # A single scalar is equivalen to [ $char, $char ]
573 $self->{quote_char} = shift if @_;
574 return $self->{quote_char};
577 # Character separating quoted table names.
580 $self->{name_sep} = shift if @_;
581 return $self->{name_sep};