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, $rs_attrs, $rows, $offset ) = @_;
54 # get the select to make the final amount of columns equal the original one
55 my ($select) = $sql =~ /^ \s* SELECT \s+ (.+?) \s+ FROM/ix
56 or croak "Unrecognizable SELECT: $sql";
58 # make up an order if none exists
59 my $order_by = $self->_order_by(
60 (delete $rs_attrs->{order_by}) || $self->_rno_default_order
63 # whatever is left of the order_by
64 my $group_having = $self->_parse_rs_attrs($rs_attrs);
66 my $qalias = $self->_quote ($rs_attrs->{alias});
68 $sql = sprintf (<<EOS, $offset + 1, $offset + $rows, );
71 SELECT $qalias.*, ROW_NUMBER() OVER($order_by ) AS rno__row__index FROM (
74 ) $qalias WHERE rno__row__index BETWEEN %d AND %d
78 $sql =~ s/\s*\n\s*/ /g; # easier to read in the debugger
82 # some databases are happy with OVER (), some need OVER (ORDER BY (SELECT (1)) )
83 sub _rno_default_order {
87 # Informix specific limit, almost like LIMIT/OFFSET
89 my ($self, $sql, $rs_attrs, $rows, $offset) = @_;
91 $sql =~ s/^ \s* SELECT \s+ //ix
92 or croak "Unrecognizable SELECT: $sql";
94 return sprintf ('SELECT %s%s%s%s',
96 ? sprintf ('SKIP %d ', $offset)
99 sprintf ('FIRST %d ', $rows),
101 $self->_parse_rs_attrs ($rs_attrs),
105 # Firebird specific limit, reverse of _SkipFirst for Informix
107 my ($self, $sql, $rs_attrs, $rows, $offset) = @_;
109 $sql =~ s/^ \s* SELECT \s+ //ix
110 or croak "Unrecognizable SELECT: $sql";
112 return sprintf ('SELECT %s%s%s%s',
113 sprintf ('FIRST %d ', $rows),
115 ? sprintf ('SKIP %d ', $offset)
119 $self->_parse_rs_attrs ($rs_attrs),
123 # Crappy Top based Limit/Offset support. Legacy from MSSQL.
125 my ( $self, $sql, $rs_attrs, $rows, $offset ) = @_;
127 # mangle the input sql so it can be properly aliased in the outer queries
128 $sql =~ s/^ \s* SELECT \s+ (.+?) \s+ (?=FROM)//ix
129 or croak "Unrecognizable SELECT: $sql";
131 my @sql_select = split (/\s*,\s*/, $sql_select);
133 # we can't support subqueries (in fact MSSQL can't) - croak
134 if (@sql_select != @{$rs_attrs->{select}}) {
136 'SQL SELECT did not parse cleanly - retrieved %d comma separated elements, while '
137 . 'the resultset select attribure contains %d elements: %s',
139 scalar @{$rs_attrs->{select}},
144 my $name_sep = $self->name_sep || '.';
145 my $esc_name_sep = "\Q$name_sep\E";
146 my $col_re = qr/ ^ (?: (.+) $esc_name_sep )? ([^$esc_name_sep]+) $ /x;
148 my $rs_alias = $rs_attrs->{alias};
149 my $quoted_rs_alias = $self->_quote ($rs_alias);
151 # construct the new select lists, rename(alias) some columns if necessary
152 my (@outer_select, @inner_select, %seen_names, %col_aliases, %outer_col_aliases);
154 for (@{$rs_attrs->{select}}) {
156 my ($table, $orig_colname) = ( $_ =~ $col_re );
158 $seen_names{$orig_colname}++;
161 for my $i (0 .. $#sql_select) {
163 my $colsel_arg = $rs_attrs->{select}[$i];
164 my $colsel_sql = $sql_select[$i];
166 # this may or may not work (in case of a scalarref or something)
167 my ($table, $orig_colname) = ( $colsel_arg =~ $col_re );
170 # do not attempt to understand non-scalar selects - alias numerically
171 if (ref $colsel_arg) {
172 $quoted_alias = $self->_quote ('column_' . (@inner_select + 1) );
174 # column name seen more than once - alias it
175 elsif ($orig_colname &&
176 ($seen_names{$orig_colname} && $seen_names{$orig_colname} > 1) ) {
177 $quoted_alias = $self->_quote ("${table}__${orig_colname}");
180 # we did rename - make a record and adjust
183 push @inner_select, "$colsel_sql AS $quoted_alias";
185 # push alias to outer
186 push @outer_select, $quoted_alias;
188 # Any aliasing accumulated here will be considered
189 # both for inner and outer adjustments of ORDER BY
190 $self->__record_alias (
194 $table ? $orig_colname : undef,
198 # otherwise just leave things intact inside, and use the abbreviated one outside
199 # (as we do not have table names anymore)
201 push @inner_select, $colsel_sql;
203 my $outer_quoted = $self->_quote ($orig_colname); # it was not a duplicate so should just work
204 push @outer_select, $outer_quoted;
205 $self->__record_alias (
209 $table ? $orig_colname : undef,
214 my $outer_select = join (', ', @outer_select );
215 my $inner_select = join (', ', @inner_select );
217 %outer_col_aliases = (%outer_col_aliases, %col_aliases);
220 croak '$order/attr container supplied to SQLAHacks limit emulators must be a hash'
221 if (ref $rs_attrs ne 'HASH');
223 my $req_order = $rs_attrs->{order_by};
225 # examine normalized version, collapses nesting
226 my $limit_order = scalar $self->_order_by_chunks ($req_order)
229 { join ('', $rs_alias, $name_sep, $_ ) }
230 ( $rs_attrs->{_rsroot_source_handle}->resolve->primary_columns )
234 my ( $order_by_inner, $order_by_outer ) = $self->_order_directions($limit_order);
235 my $order_by_requested = $self->_order_by ($req_order);
238 delete $rs_attrs->{order_by};
239 my $grpby_having = $self->_parse_rs_attrs ($rs_attrs);
241 # short circuit for counts - the ordering complexity is needless
242 if ($rs_attrs->{-for_count_only}) {
243 return "SELECT TOP $rows $inner_select $sql $grpby_having $order_by_outer";
246 # we can't really adjust the order_by columns, as introspection is lacking
247 # resort to simple substitution
248 for my $col (keys %outer_col_aliases) {
249 for ($order_by_requested, $order_by_outer) {
250 $_ =~ s/\s+$col\s+/ $outer_col_aliases{$col} /g;
253 for my $col (keys %col_aliases) {
254 $order_by_inner =~ s/\s+$col\s+/ $col_aliases{$col} /g;
258 my $inner_lim = $rows + $offset;
260 $sql = "SELECT TOP $inner_lim $inner_select $sql $grpby_having $order_by_inner";
265 SELECT TOP $rows $outer_select FROM
274 if ($order_by_requested) {
277 SELECT $outer_select FROM
278 ( $sql ) $quoted_rs_alias
284 $sql =~ s/\s*\n\s*/ /g; # parsing out multiline statements is harder than a single line
288 # action at a distance to shorten Top code above
290 my ($self, $register, $alias, $fqcol, $col) = @_;
292 # record qualified name
293 $register->{$fqcol} = $alias;
294 $register->{$self->_quote($fqcol)} = $alias;
298 # record unqualified name, undef (no adjustment) if a duplicate is found
299 if (exists $register->{$col}) {
300 $register->{$col} = undef;
303 $register->{$col} = $alias;
306 $register->{$self->_quote($col)} = $register->{$col};
311 # While we're at it, this should make LIMIT queries more efficient,
312 # without digging into things too deeply
314 my ($self, $syntax) = @_;
315 return $self->{_cached_syntax} ||= $self->SUPER::_find_syntax($syntax);
318 # Quotes table names, handles "limit" dialects (e.g. where rownum between x and
321 my ($self, $table, $fields, $where, $rs_attrs, @rest) = @_;
323 $self->{"${_}_bind"} = [] for (qw/having from order/);
325 if (not ref($table) or ref($table) eq 'SCALAR') {
326 $table = $self->_quote($table);
329 local $self->{rownum_hack_count} = 1
330 if (defined $rest[0] && $self->{limit_dialect} eq 'RowNum');
331 @rest = (-1) unless defined $rest[0];
332 croak "LIMIT 0 Does Not Compute" if $rest[0] == 0;
333 # and anyway, SQL::Abstract::Limit will cause a barf if we don't first
335 my ($sql, @where_bind) = $self->SUPER::select(
336 $table, $self->_recurse_fields($fields), $where, $rs_attrs, @rest
338 return wantarray ? ($sql, @{$self->{from_bind}}, @where_bind, @{$self->{having_bind}}, @{$self->{order_bind}} ) : $sql;
341 # Quotes table names, and handles default inserts
345 $table = $self->_quote($table);
347 # SQLA will emit INSERT INTO $table ( ) VALUES ( )
348 # which is sadly understood only by MySQL. Change default behavior here,
349 # until SQLA2 comes with proper dialect support
350 if (! $_[0] or (ref $_[0] eq 'HASH' and !keys %{$_[0]} ) ) {
351 my $sql = "INSERT INTO ${table} DEFAULT VALUES";
353 if (my $ret = ($_[1]||{})->{returning} ) {
354 $sql .= $self->_insert_returning ($ret);
360 $self->SUPER::insert($table, @_);
363 # Just quotes table names.
367 $table = $self->_quote($table);
368 $self->SUPER::update($table, @_);
371 # Just quotes table names.
375 $table = $self->_quote($table);
376 $self->SUPER::delete($table, @_);
381 # my ( $syntax, $sql, $order, $rows, $offset ) = @_;
384 return $_[1] . $self->_parse_rs_attrs($_[2]);
386 return $self->SUPER::_emulate_limit(@_);
390 sub _recurse_fields {
391 my ($self, $fields, $params) = @_;
392 my $ref = ref $fields;
393 return $self->_quote($fields) unless $ref;
394 return $$fields if $ref eq 'SCALAR';
396 if ($ref eq 'ARRAY') {
397 return join(', ', map {
398 $self->_recurse_fields($_)
399 .(exists $self->{rownum_hack_count} && !($params && $params->{no_rownum_hack})
400 ? ' AS col'.$self->{rownum_hack_count}++
404 elsif ($ref eq 'HASH') {
407 my $as = delete $hash{-as}; # if supplied
409 my ($func, $args) = each %hash;
412 if (lc ($func) eq 'distinct' && ref $args eq 'ARRAY' && @$args > 1) {
414 'The select => { distinct => ... } syntax is not supported for multiple columns.'
415 .' Instead please use { group_by => [ qw/' . (join ' ', @$args) . '/ ] }'
416 .' or { select => [ qw/' . (join ' ', @$args) . '/ ], distinct => 1 }'
420 my $select = sprintf ('%s( %s )%s',
421 $self->_sqlcase($func),
422 $self->_recurse_fields($args),
424 ? sprintf (' %s %s', $self->_sqlcase('as'), $self->_quote ($as) )
428 # there should be nothing left
430 croak "Malformed select argument - too many keys in hash: " . join (',', keys %$fields );
435 # Is the second check absolutely necessary?
436 elsif ( $ref eq 'REF' and ref($$fields) eq 'ARRAY' ) {
437 return $self->_fold_sqlbind( $fields );
440 croak($ref . qq{ unexpected in _recurse_fields()})
445 update => 'FOR UPDATE',
446 shared => 'FOR SHARE',
449 # this used to be a part of _order_by but is broken out for clarity.
450 # What we have been doing forever is hijacking the $order arg of
451 # SQLA::select to pass in arbitrary pieces of data (first the group_by,
452 # then pretty much the entire resultset attr-hash, as more and more
453 # things in the SQLA space need to have mopre info about the $rs they
454 # create SQL for. The alternative would be to keep expanding the
455 # signature of _select with more and more positional parameters, which
456 # is just gross. All hail SQLA2!
457 sub _parse_rs_attrs {
458 my ($self, $arg) = @_;
462 if (my $g = $self->_recurse_fields($arg->{group_by}, { no_rownum_hack => 1 }) ) {
463 $sql .= $self->_sqlcase(' group by ') . $g;
466 if (defined $arg->{having}) {
467 my ($frag, @bind) = $self->_recurse_where($arg->{having});
468 push(@{$self->{having_bind}}, @bind);
469 $sql .= $self->_sqlcase(' having ') . $frag;
472 if (defined $arg->{order_by}) {
473 $sql .= $self->_order_by ($arg->{order_by});
476 if (my $for = $arg->{for}) {
477 $sql .= " $for_syntax->{$for}" if $for_syntax->{$for};
484 my ($self, $arg) = @_;
486 # check that we are not called in legacy mode (order_by as 4th argument)
487 if (ref $arg eq 'HASH' and not grep { $_ =~ /^-(?:desc|asc)/i } keys %$arg ) {
488 return $self->_parse_rs_attrs ($arg);
491 my ($sql, @bind) = $self->SUPER::_order_by ($arg);
492 push @{$self->{order_bind}}, @bind;
497 sub _order_directions {
498 my ($self, $order) = @_;
500 # strip bind values - none of the current _order_directions users support them
501 return $self->SUPER::_order_directions( [ map
502 { ref $_ ? $_->[0] : $_ }
503 $self->_order_by_chunks ($order)
508 my ($self, $from) = @_;
509 if (ref $from eq 'ARRAY') {
510 return $self->_recurse_from(@$from);
511 } elsif (ref $from eq 'HASH') {
512 return $self->_make_as($from);
514 return $from; # would love to quote here but _table ends up getting called
515 # twice during an ->select without a limit clause due to
516 # the way S::A::Limit->select works. should maybe consider
517 # bypassing this and doing S::A::select($self, ...) in
518 # our select method above. meantime, quoting shims have
519 # been added to select/insert/update/delete here
523 sub _generate_join_clause {
524 my ($self, $join_type) = @_;
526 return sprintf ('%s JOIN ',
527 $join_type ? ' ' . uc($join_type) : ''
532 my ($self, $from, @join) = @_;
534 push(@sqlf, $self->_make_as($from));
535 foreach my $j (@join) {
539 # check whether a join type exists
540 my $to_jt = ref($to) eq 'ARRAY' ? $to->[0] : $to;
542 if (ref($to_jt) eq 'HASH' and defined($to_jt->{-join_type})) {
543 $join_type = $to_jt->{-join_type};
544 $join_type =~ s/^\s+ | \s+$//xg;
547 $join_type = $self->{_default_jointype} if not defined $join_type;
549 push @sqlf, $self->_generate_join_clause( $join_type );
551 if (ref $to eq 'ARRAY') {
552 push(@sqlf, '(', $self->_recurse_from(@$to), ')');
554 push(@sqlf, $self->_make_as($to));
556 push(@sqlf, ' ON ', $self->_join_condition($on));
558 return join('', @sqlf);
562 my ($self, $sqlbind) = @_;
564 my @sqlbind = @$$sqlbind; # copy
565 my $sql = shift @sqlbind;
566 push @{$self->{from_bind}}, @sqlbind;
572 my ($self, $from) = @_;
573 return join(' ', map { (ref $_ eq 'SCALAR' ? $$_
574 : ref $_ eq 'REF' ? $self->_fold_sqlbind($_)
576 } reverse each %{$self->_skip_options($from)});
580 my ($self, $hash) = @_;
582 $clean_hash->{$_} = $hash->{$_}
583 for grep {!/^-/} keys %$hash;
587 sub _join_condition {
588 my ($self, $cond) = @_;
589 if (ref $cond eq 'HASH') {
594 croak (ref($v) . qq{ reference arguments are not supported in JOINS - try using \"..." instead'})
595 if ref($v) ne 'SCALAR';
599 my $x = '= '.$self->_quote($v); $j{$_} = \$x;
602 return scalar($self->_recurse_where(\%j));
603 } elsif (ref $cond eq 'ARRAY') {
604 return join(' OR ', map { $self->_join_condition($_) } @$cond);
606 die "Can't handle this yet!";
612 $self->{limit_dialect} = shift if @_;
613 return $self->{limit_dialect};
616 # Set to an array-ref to specify separate left and right quotes for table names.
617 # A single scalar is equivalen to [ $char, $char ]
620 $self->{quote_char} = shift if @_;
621 return $self->{quote_char};
624 # Character separating quoted table names.
627 $self->{name_sep} = shift if @_;
628 return $self->{name_sep};