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 $sql = sprintf (<<'EOS', $order_by, $sql, $group_having, $offset + 1, $offset + $rows, );
65 SELECT orig_query.*, ROW_NUMBER() OVER(%s ) AS rno__row__index FROM (%s%s) orig_query
66 ) rno_subq WHERE rno__row__index BETWEEN %d AND %d
70 $sql =~ s/\s*\n\s*/ /g; # easier to read in the debugger
74 # some databases are happy with OVER (), some need OVER (ORDER BY (SELECT (1)) )
75 sub _rno_default_order {
79 # Crappy Top based Limit/Offset support. Legacy from MSSQL.
81 my ( $self, $sql, $order, $rows, $offset ) = @_;
83 # mangle the input sql so it can be properly aliased in the outer queries
84 $sql =~ s/^ \s* SELECT \s+ (.+?) \s+ (?=FROM)//ix
85 or croak "Unrecognizable SELECT: $sql";
87 my @sql_select = split (/\s*,\s*/, $sql_select);
89 # we can't support subqueries (in fact MSSQL can't) - croak
90 if (@sql_select != @{$self->{_dbic_rs_attrs}{select}}) {
92 'SQL SELECT did not parse cleanly - retrieved %d comma separated elements, while '
93 . 'the resultset select attribure contains %d elements: %s',
95 scalar @{$self->{_dbic_rs_attrs}{select}},
100 my $name_sep = $self->name_sep || '.';
101 my $esc_name_sep = "\Q$name_sep\E";
102 my $col_re = qr/ ^ (?: (.+) $esc_name_sep )? ([^$esc_name_sep]+) $ /x;
104 my $rs_alias = $self->{_dbic_rs_attrs}{alias};
105 my $quoted_rs_alias = $self->_quote ($rs_alias);
107 # construct the new select lists, rename(alias) some columns if necessary
108 my (@outer_select, @inner_select, %seen_names, %col_aliases, %outer_col_aliases);
110 for (@{$self->{_dbic_rs_attrs}{select}}) {
112 my ($table, $orig_colname) = ( $_ =~ $col_re );
114 $seen_names{$orig_colname}++;
117 for my $i (0 .. $#sql_select) {
119 my $colsel_arg = $self->{_dbic_rs_attrs}{select}[$i];
120 my $colsel_sql = $sql_select[$i];
122 # this may or may not work (in case of a scalarref or something)
123 my ($table, $orig_colname) = ( $colsel_arg =~ $col_re );
126 # do not attempt to understand non-scalar selects - alias numerically
127 if (ref $colsel_arg) {
128 $quoted_alias = $self->_quote ('column_' . (@inner_select + 1) );
130 # column name seen more than once - alias it
131 elsif ($orig_colname &&
132 ($seen_names{$orig_colname} && $seen_names{$orig_colname} > 1) ) {
133 $quoted_alias = $self->_quote ("${table}__${orig_colname}");
136 # we did rename - make a record and adjust
139 push @inner_select, "$colsel_sql AS $quoted_alias";
141 # push alias to outer
142 push @outer_select, $quoted_alias;
144 # Any aliasing accumulated here will be considered
145 # both for inner and outer adjustments of ORDER BY
146 $self->__record_alias (
150 $table ? $orig_colname : undef,
154 # otherwise just leave things intact inside, and use the abbreviated one outside
155 # (as we do not have table names anymore)
157 push @inner_select, $colsel_sql;
159 my $outer_quoted = $self->_quote ($orig_colname); # it was not a duplicate so should just work
160 push @outer_select, $outer_quoted;
161 $self->__record_alias (
165 $table ? $orig_colname : undef,
170 my $outer_select = join (', ', @outer_select );
171 my $inner_select = join (', ', @inner_select );
173 %outer_col_aliases = (%outer_col_aliases, %col_aliases);
176 croak '$order supplied to SQLAHacks limit emulators must be a hash'
177 if (ref $order ne 'HASH');
179 $order = { %$order }; #copy
181 my $req_order = $order->{order_by};
183 # examine normalized version, collapses nesting
185 if (scalar $self->_order_by_chunks ($req_order)) {
186 $limit_order = $req_order;
190 { join ('', $rs_alias, $name_sep, $_ ) }
191 ( $self->{_dbic_rs_attrs}{_source_handle}->resolve->primary_columns )
195 my ( $order_by_inner, $order_by_outer ) = $self->_order_directions($limit_order);
196 my $order_by_requested = $self->_order_by ($req_order);
199 delete $order->{order_by};
200 my $grpby_having = $self->_order_by ($order);
202 # short circuit for counts - the ordering complexity is needless
203 if ($self->{_dbic_rs_attrs}{-for_count_only}) {
204 return "SELECT TOP $rows $inner_select $sql $grpby_having $order_by_outer";
207 # we can't really adjust the order_by columns, as introspection is lacking
208 # resort to simple substitution
209 for my $col (keys %outer_col_aliases) {
210 for ($order_by_requested, $order_by_outer) {
211 $_ =~ s/\s+$col\s+/ $outer_col_aliases{$col} /g;
214 for my $col (keys %col_aliases) {
215 $order_by_inner =~ s/\s+$col\s+/ $col_aliases{$col} /g;
219 my $inner_lim = $rows + $offset;
221 $sql = "SELECT TOP $inner_lim $inner_select $sql $grpby_having $order_by_inner";
226 SELECT TOP $rows $outer_select FROM
235 if ($order_by_requested) {
238 SELECT $outer_select FROM
239 ( $sql ) $quoted_rs_alias
245 $sql =~ s/\s*\n\s*/ /g; # parsing out multiline statements is harder than a single line
249 # action at a distance to shorten Top code above
251 my ($self, $register, $alias, $fqcol, $col) = @_;
253 # record qualified name
254 $register->{$fqcol} = $alias;
255 $register->{$self->_quote($fqcol)} = $alias;
259 # record unqualified name, undef (no adjustment) if a duplicate is found
260 if (exists $register->{$col}) {
261 $register->{$col} = undef;
264 $register->{$col} = $alias;
267 $register->{$self->_quote($col)} = $register->{$col};
272 # While we're at it, this should make LIMIT queries more efficient,
273 # without digging into things too deeply
275 my ($self, $syntax) = @_;
276 return $self->{_cached_syntax} ||= $self->SUPER::_find_syntax($syntax);
280 update => 'FOR UPDATE',
281 shared => 'FOR SHARE',
283 # Quotes table names, handles "limit" dialects (e.g. where rownum between x and
284 # y), supports SELECT ... FOR UPDATE and SELECT ... FOR SHARE.
286 my ($self, $table, $fields, $where, $order, @rest) = @_;
288 $self->{"${_}_bind"} = [] for (qw/having from order/);
290 if (not ref($table) or ref($table) eq 'SCALAR') {
291 $table = $self->_quote($table);
294 local $self->{rownum_hack_count} = 1
295 if (defined $rest[0] && $self->{limit_dialect} eq 'RowNum');
296 @rest = (-1) unless defined $rest[0];
297 croak "LIMIT 0 Does Not Compute" if $rest[0] == 0;
298 # and anyway, SQL::Abstract::Limit will cause a barf if we don't first
299 my ($sql, @where_bind) = $self->SUPER::select(
300 $table, $self->_recurse_fields($fields), $where, $order, @rest
302 if (my $for = delete $self->{_dbic_rs_attrs}{for}) {
303 $sql .= " $for_syntax->{$for}" if $for_syntax->{$for};
306 return wantarray ? ($sql, @{$self->{from_bind}}, @where_bind, @{$self->{having_bind}}, @{$self->{order_bind}} ) : $sql;
309 # Quotes table names, and handles default inserts
313 $table = $self->_quote($table);
315 # SQLA will emit INSERT INTO $table ( ) VALUES ( )
316 # which is sadly understood only by MySQL. Change default behavior here,
317 # until SQLA2 comes with proper dialect support
318 if (! $_[0] or (ref $_[0] eq 'HASH' and !keys %{$_[0]} ) ) {
319 return "INSERT INTO ${table} DEFAULT VALUES"
322 $self->SUPER::insert($table, @_);
325 # Just quotes table names.
329 $table = $self->_quote($table);
330 $self->SUPER::update($table, @_);
333 # Just quotes table names.
337 $table = $self->_quote($table);
338 $self->SUPER::delete($table, @_);
344 return $_[1].$self->_order_by($_[2]);
346 return $self->SUPER::_emulate_limit(@_);
350 sub _recurse_fields {
351 my ($self, $fields, $params) = @_;
352 my $ref = ref $fields;
353 return $self->_quote($fields) unless $ref;
354 return $$fields if $ref eq 'SCALAR';
356 if ($ref eq 'ARRAY') {
357 return join(', ', map {
358 $self->_recurse_fields($_)
359 .(exists $self->{rownum_hack_count} && !($params && $params->{no_rownum_hack})
360 ? ' AS col'.$self->{rownum_hack_count}++
364 elsif ($ref eq 'HASH') {
367 my $as = delete $hash{-as}; # if supplied
369 my ($func, $args) = each %hash;
372 if (lc ($func) eq 'distinct' && ref $args eq 'ARRAY' && @$args > 1) {
374 'The select => { distinct => ... } syntax is not supported for multiple columns.'
375 .' Instead please use { group_by => [ qw/' . (join ' ', @$args) . '/ ] }'
376 .' or { select => [ qw/' . (join ' ', @$args) . '/ ], distinct => 1 }'
380 my $select = sprintf ('%s( %s )%s',
381 $self->_sqlcase($func),
382 $self->_recurse_fields($args),
384 ? sprintf (' %s %s', $self->_sqlcase('as'), $as)
388 # there should be nothing left
390 croak "Malformed select argument - too many keys in hash: " . join (',', keys %$fields );
395 # Is the second check absolutely necessary?
396 elsif ( $ref eq 'REF' and ref($$fields) eq 'ARRAY' ) {
397 return $self->_fold_sqlbind( $fields );
400 croak($ref . qq{ unexpected in _recurse_fields()})
405 my ($self, $arg) = @_;
407 if (ref $arg eq 'HASH' and keys %$arg and not grep { $_ =~ /^-(?:desc|asc)/i } keys %$arg ) {
411 if (my $g = $self->_recurse_fields($arg->{group_by}, { no_rownum_hack => 1 }) ) {
412 $ret = $self->_sqlcase(' group by ') . $g;
415 if (defined $arg->{having}) {
416 my ($frag, @bind) = $self->_recurse_where($arg->{having});
417 push(@{$self->{having_bind}}, @bind);
418 $ret .= $self->_sqlcase(' having ').$frag;
421 if (defined $arg->{order_by}) {
422 my ($frag, @bind) = $self->SUPER::_order_by($arg->{order_by});
423 push(@{$self->{order_bind}}, @bind);
430 my ($sql, @bind) = $self->SUPER::_order_by ($arg);
431 push(@{$self->{order_bind}}, @bind);
436 sub _order_directions {
437 my ($self, $order) = @_;
439 # strip bind values - none of the current _order_directions users support them
440 return $self->SUPER::_order_directions( [ map
441 { ref $_ ? $_->[0] : $_ }
442 $self->_order_by_chunks ($order)
447 my ($self, $from) = @_;
448 if (ref $from eq 'ARRAY') {
449 return $self->_recurse_from(@$from);
450 } elsif (ref $from eq 'HASH') {
451 return $self->_make_as($from);
453 return $from; # would love to quote here but _table ends up getting called
454 # twice during an ->select without a limit clause due to
455 # the way S::A::Limit->select works. should maybe consider
456 # bypassing this and doing S::A::select($self, ...) in
457 # our select method above. meantime, quoting shims have
458 # been added to select/insert/update/delete here
463 my ($self, $from, @join) = @_;
465 push(@sqlf, $self->_make_as($from));
466 foreach my $j (@join) {
470 # check whether a join type exists
471 my $to_jt = ref($to) eq 'ARRAY' ? $to->[0] : $to;
473 if (ref($to_jt) eq 'HASH' and defined($to_jt->{-join_type})) {
474 $join_type = $to_jt->{-join_type};
475 $join_type =~ s/^\s+ | \s+$//xg;
478 $join_type = $self->{_default_jointype} if not defined $join_type;
480 my $join_clause = sprintf ('%s JOIN ',
481 $join_type ? ' ' . uc($join_type) : ''
483 push @sqlf, $join_clause;
485 if (ref $to eq 'ARRAY') {
486 push(@sqlf, '(', $self->_recurse_from(@$to), ')');
488 push(@sqlf, $self->_make_as($to));
490 push(@sqlf, ' ON ', $self->_join_condition($on));
492 return join('', @sqlf);
496 my ($self, $sqlbind) = @_;
498 my @sqlbind = @$$sqlbind; # copy
499 my $sql = shift @sqlbind;
500 push @{$self->{from_bind}}, @sqlbind;
506 my ($self, $from) = @_;
507 return join(' ', map { (ref $_ eq 'SCALAR' ? $$_
508 : ref $_ eq 'REF' ? $self->_fold_sqlbind($_)
510 } reverse each %{$self->_skip_options($from)});
514 my ($self, $hash) = @_;
516 $clean_hash->{$_} = $hash->{$_}
517 for grep {!/^-/} keys %$hash;
521 sub _join_condition {
522 my ($self, $cond) = @_;
523 if (ref $cond eq 'HASH') {
528 croak (ref($v) . qq{ reference arguments are not supported in JOINS - try using \"..." instead'})
529 if ref($v) ne 'SCALAR';
533 my $x = '= '.$self->_quote($v); $j{$_} = \$x;
536 return scalar($self->_recurse_where(\%j));
537 } elsif (ref $cond eq 'ARRAY') {
538 return join(' OR ', map { $self->_join_condition($_) } @$cond);
540 die "Can't handle this yet!";
545 my ($self, $label) = @_;
546 return '' unless defined $label;
547 return $$label if ref($label) eq 'SCALAR';
548 return "*" if $label eq '*';
549 return $label unless $self->{quote_char};
550 if(ref $self->{quote_char} eq "ARRAY"){
551 return $self->{quote_char}->[0] . $label . $self->{quote_char}->[1]
552 if !defined $self->{name_sep};
553 my $sep = $self->{name_sep};
554 return join($self->{name_sep},
555 map { $self->{quote_char}->[0] . $_ . $self->{quote_char}->[1] }
556 split(/\Q$sep\E/,$label));
558 return $self->SUPER::_quote($label);
563 $self->{limit_dialect} = shift if @_;
564 return $self->{limit_dialect};
567 # Set to an array-ref to specify separate left and right quotes for table names.
568 # A single scalar is equivalen to [ $char, $char ]
571 $self->{quote_char} = shift if @_;
572 return $self->{quote_char};
575 # Character separating quoted table names.
578 $self->{name_sep} = shift if @_;
579 return $self->{name_sep};