JezK
Edit File: SQLMaker.pm
package DBIx::Class::SQLMaker; use strict; use warnings; =head1 NAME DBIx::Class::SQLMaker - An SQL::Abstract-based SQL maker class =head1 DESCRIPTION This module is a subclass of L<SQL::Abstract> and includes a number of DBIC-specific workarounds, not yet suitable for inclusion into the L<SQL::Abstract> core. It also provides all (and more than) the functionality of L<SQL::Abstract::Limit>, see L<DBIx::Class::SQLMaker::LimitDialects> for more info. Currently the enhancements to L<SQL::Abstract> are: =over =item * Support for C<JOIN> statements (via extended C<table/from> support) =item * Support of functions in C<SELECT> lists =item * C<GROUP BY>/C<HAVING> support (via extensions to the order_by parameter) =item * Support of C<...FOR UPDATE> type of select statement modifiers =back =cut use base qw/ DBIx::Class::SQLMaker::LimitDialects SQL::Abstract DBIx::Class /; use mro 'c3'; use Sub::Name 'subname'; use DBIx::Class::Carp; use namespace::clean; __PACKAGE__->mk_group_accessors (simple => qw/quote_char name_sep limit_dialect/); sub _quoting_enabled { ( defined $_[0]->{quote_char} and length $_[0]->{quote_char} ) ? 1 : 0 } # for when I need a normalized l/r pair sub _quote_chars { # in case we are called in the old !!$sm->_quote_chars fashion return () if !wantarray and ( ! defined $_[0]->{quote_char} or ! length $_[0]->{quote_char} ); map { defined $_ ? $_ : '' } ( ref $_[0]->{quote_char} ? (@{$_[0]->{quote_char}}) : ( ($_[0]->{quote_char}) x 2 ) ) ; } # FIXME when we bring in the storage weaklink, check its schema # weaklink and channel through $schema->throw_exception sub throw_exception { DBIx::Class::Exception->throw($_[1]) } BEGIN { # reinstall the belch()/puke() functions of SQL::Abstract with custom versions # that use DBIx::Class::Carp/DBIx::Class::Exception instead of plain Carp no warnings qw/redefine/; *SQL::Abstract::belch = subname 'SQL::Abstract::belch' => sub (@) { my($func) = (caller(1))[3]; carp "[$func] Warning: ", @_; }; *SQL::Abstract::puke = subname 'SQL::Abstract::puke' => sub (@) { my($func) = (caller(1))[3]; __PACKAGE__->throw_exception("[$func] Fatal: " . join ('', @_)); }; } # the "oh noes offset/top without limit" constant # limited to 31 bits for sanity (and consistency, # since it may be handed to the like of sprintf %u) # # Also *some* builds of SQLite fail the test # some_column BETWEEN ? AND ?: 1, 4294967295 # with the proper integer bind attrs # # Implemented as a method, since ::Storage::DBI also # refers to it (i.e. for the case of software_limit or # as the value to abuse with MSSQL ordered subqueries) sub __max_int () { 0x7FFFFFFF }; # we ne longer need to check this - DBIC has ways of dealing with it # specifically ::Storage::DBI::_resolve_bindattrs() sub _assert_bindval_matches_bindtype () { 1 }; # poor man's de-qualifier sub _quote { $_[0]->next::method( ( $_[0]{_dequalify_idents} and ! ref $_[1] ) ? $_[1] =~ / ([^\.]+) $ /x : $_[1] ); } sub _where_op_NEST { carp_unique ("-nest in search conditions is deprecated, you most probably wanted:\n" .q|{..., -and => [ \%cond0, \@cond1, \'cond2', \[ 'cond3', [ col => bind ] ], etc. ], ... }| ); shift->next::method(@_); } # Handle limit-dialect selection sub select { my ($self, $table, $fields, $where, $rs_attrs, $limit, $offset) = @_; ($fields, @{$self->{select_bind}}) = $self->_recurse_fields($fields); if (defined $offset) { $self->throw_exception('A supplied offset must be a non-negative integer') if ( $offset =~ /\D/ or $offset < 0 ); } $offset ||= 0; if (defined $limit) { $self->throw_exception('A supplied limit must be a positive integer') if ( $limit =~ /\D/ or $limit <= 0 ); } elsif ($offset) { $limit = $self->__max_int; } my ($sql, @bind); if ($limit) { # this is legacy code-flow from SQLA::Limit, it is not set in stone ($sql, @bind) = $self->next::method ($table, $fields, $where); my $limiter; if( $limiter = $self->can ('emulate_limit') ) { carp_unique( 'Support for the legacy emulate_limit() mechanism inherited from ' . 'SQL::Abstract::Limit has been deprecated, and will be removed when ' . 'DBIC transitions to Data::Query. If your code uses this type of ' . 'limit specification please file an RT and provide the source of ' . 'your emulate_limit() implementation, so an acceptable upgrade-path ' . 'can be devised' ); } else { my $dialect = $self->limit_dialect or $self->throw_exception( "Unable to generate SQL-limit - no limit dialect specified on $self" ); $limiter = $self->can ("_$dialect") or $self->throw_exception(__PACKAGE__ . " does not implement the requested dialect '$dialect'"); } $sql = $self->$limiter ( $sql, { %{$rs_attrs||{}}, _selector_sql => $fields }, $limit, $offset ); } else { ($sql, @bind) = $self->next::method ($table, $fields, $where, $rs_attrs); } push @{$self->{where_bind}}, @bind; # this *must* be called, otherwise extra binds will remain in the sql-maker my @all_bind = $self->_assemble_binds; $sql .= $self->_lock_select ($rs_attrs->{for}) if $rs_attrs->{for}; return wantarray ? ($sql, @all_bind) : $sql; } sub _assemble_binds { my $self = shift; return map { @{ (delete $self->{"${_}_bind"}) || [] } } (qw/pre_select select from where group having order limit/); } my $for_syntax = { update => 'FOR UPDATE', shared => 'FOR SHARE', }; sub _lock_select { my ($self, $type) = @_; my $sql; if (ref($type) eq 'SCALAR') { $sql = "FOR $$type"; } else { $sql = $for_syntax->{$type} || $self->throw_exception( "Unknown SELECT .. FOR type '$type' requested" ); } return " $sql"; } # Handle default inserts sub insert { # optimized due to hotttnesss # my ($self, $table, $data, $options) = @_; # SQLA will emit INSERT INTO $table ( ) VALUES ( ) # which is sadly understood only by MySQL. Change default behavior here, # until SQLA2 comes with proper dialect support if (! $_[2] or (ref $_[2] eq 'HASH' and !keys %{$_[2]} ) ) { my @bind; my $sql = sprintf( 'INSERT INTO %s DEFAULT VALUES', $_[0]->_quote($_[1]) ); if ( ($_[3]||{})->{returning} ) { my $s; ($s, @bind) = $_[0]->_insert_returning ($_[3]); $sql .= $s; } return ($sql, @bind); } next::method(@_); } sub _recurse_fields { my ($self, $fields) = @_; my $ref = ref $fields; return $self->_quote($fields) unless $ref; return $$fields if $ref eq 'SCALAR'; if ($ref eq 'ARRAY') { my (@select, @bind); for my $field (@$fields) { my ($select, @new_bind) = $self->_recurse_fields($field); push @select, $select; push @bind, @new_bind; } return (join(', ', @select), @bind); } elsif ($ref eq 'HASH') { my %hash = %$fields; # shallow copy my $as = delete $hash{-as}; # if supplied my ($func, $rhs, @toomany) = %hash; # there should be only one pair if (@toomany) { $self->throw_exception( "Malformed select argument - too many keys in hash: " . join (',', keys %$fields ) ); } if (lc ($func) eq 'distinct' && ref $rhs eq 'ARRAY' && @$rhs > 1) { $self->throw_exception ( 'The select => { distinct => ... } syntax is not supported for multiple columns.' .' Instead please use { group_by => [ qw/' . (join ' ', @$rhs) . '/ ] }' .' or { select => [ qw/' . (join ' ', @$rhs) . '/ ], distinct => 1 }' ); } my ($rhs_sql, @rhs_bind) = $self->_recurse_fields($rhs); my $select = sprintf ('%s( %s )%s', $self->_sqlcase($func), $rhs_sql, $as ? sprintf (' %s %s', $self->_sqlcase('as'), $self->_quote ($as) ) : '' ); return ($select, @rhs_bind); } elsif ( $ref eq 'REF' and ref($$fields) eq 'ARRAY' ) { return @{$$fields}; } else { $self->throw_exception( $ref . qq{ unexpected in _recurse_fields()} ); } } # this used to be a part of _order_by but is broken out for clarity. # What we have been doing forever is hijacking the $order arg of # SQLA::select to pass in arbitrary pieces of data (first the group_by, # then pretty much the entire resultset attr-hash, as more and more # things in the SQLA space need to have more info about the $rs they # create SQL for. The alternative would be to keep expanding the # signature of _select with more and more positional parameters, which # is just gross. All hail SQLA2! sub _parse_rs_attrs { my ($self, $arg) = @_; my $sql = ''; if ($arg->{group_by}) { if ( my ($group_sql, @group_bind) = $self->_recurse_fields($arg->{group_by}) ) { $sql .= $self->_sqlcase(' group by ') . $group_sql; push @{$self->{group_bind}}, @group_bind; } } if (defined $arg->{having}) { my ($frag, @bind) = $self->_recurse_where($arg->{having}); push(@{$self->{having_bind}}, @bind); $sql .= $self->_sqlcase(' having ') . $frag; } if (defined $arg->{order_by}) { $sql .= $self->_order_by ($arg->{order_by}); } return $sql; } sub _order_by { my ($self, $arg) = @_; # check that we are not called in legacy mode (order_by as 4th argument) if (ref $arg eq 'HASH' and not grep { $_ =~ /^-(?:desc|asc)/i } keys %$arg ) { return $self->_parse_rs_attrs ($arg); } else { my ($sql, @bind) = $self->next::method($arg); push @{$self->{order_bind}}, @bind; return $sql; } } sub _split_order_chunk { my ($self, $chunk) = @_; # strip off sort modifiers, but always succeed, so $1 gets reset $chunk =~ s/ (?: \s+ (ASC|DESC) )? \s* $//ix; return ( $chunk, ( $1 and uc($1) eq 'DESC' ) ? 1 : 0, ); } sub _table { # optimized due to hotttnesss # my ($self, $from) = @_; if (my $ref = ref $_[1] ) { if ($ref eq 'ARRAY') { return $_[0]->_recurse_from(@{$_[1]}); } elsif ($ref eq 'HASH') { return $_[0]->_recurse_from($_[1]); } elsif ($ref eq 'REF' && ref ${$_[1]} eq 'ARRAY') { my ($sql, @bind) = @{ ${$_[1]} }; push @{$_[0]->{from_bind}}, @bind; return $sql } } return $_[0]->next::method ($_[1]); } sub _generate_join_clause { my ($self, $join_type) = @_; $join_type = $self->{_default_jointype} if ! defined $join_type; return sprintf ('%s JOIN ', $join_type ? $self->_sqlcase($join_type) : '' ); } sub _recurse_from { my $self = shift; return join (' ', $self->_gen_from_blocks(@_) ); } sub _gen_from_blocks { my ($self, $from, @joins) = @_; my @fchunks = $self->_from_chunk_to_sql($from); for (@joins) { my ($to, $on) = @$_; # check whether a join type exists my $to_jt = ref($to) eq 'ARRAY' ? $to->[0] : $to; my $join_type; if (ref($to_jt) eq 'HASH' and defined($to_jt->{-join_type})) { $join_type = $to_jt->{-join_type}; $join_type =~ s/^\s+ | \s+$//xg; } my @j = $self->_generate_join_clause( $join_type ); if (ref $to eq 'ARRAY') { push(@j, '(', $self->_recurse_from(@$to), ')'); } else { push(@j, $self->_from_chunk_to_sql($to)); } my ($sql, @bind) = $self->_join_condition($on); push(@j, ' ON ', $sql); push @{$self->{from_bind}}, @bind; push @fchunks, join '', @j; } return @fchunks; } sub _from_chunk_to_sql { my ($self, $fromspec) = @_; return join (' ', do { if (! ref $fromspec) { $self->_quote($fromspec); } elsif (ref $fromspec eq 'SCALAR') { $$fromspec; } elsif (ref $fromspec eq 'REF' and ref $$fromspec eq 'ARRAY') { push @{$self->{from_bind}}, @{$$fromspec}[1..$#$$fromspec]; $$fromspec->[0]; } elsif (ref $fromspec eq 'HASH') { my ($as, $table, $toomuch) = ( map { $_ => $fromspec->{$_} } ( grep { $_ !~ /^\-/ } keys %$fromspec ) ); $self->throw_exception( "Only one table/as pair expected in from-spec but an exra '$toomuch' key present" ) if defined $toomuch; ($self->_from_chunk_to_sql($table), $self->_quote($as) ); } else { $self->throw_exception('Unsupported from refkind: ' . ref $fromspec ); } }); } sub _join_condition { my ($self, $cond) = @_; # Backcompat for the old days when a plain hashref # { 't1.col1' => 't2.col2' } meant ON t1.col1 = t2.col2 if ( ref $cond eq 'HASH' and keys %$cond == 1 and (keys %$cond)[0] =~ /\./ and ! ref ( (values %$cond)[0] ) ) { carp_unique( "ResultSet {from} structures with conditions not conforming to the " . "SQL::Abstract syntax are deprecated: you either need to stop abusing " . "{from} altogether, or express the condition properly using the " . "{ -ident => ... } operator" ); $cond = { keys %$cond => { -ident => values %$cond } } } elsif ( ref $cond eq 'ARRAY' ) { # do our own ORing so that the hashref-shim above is invoked my @parts; my @binds; foreach my $c (@$cond) { my ($sql, @bind) = $self->_join_condition($c); push @binds, @bind; push @parts, $sql; } return join(' OR ', @parts), @binds; } return $self->_recurse_where($cond); } # This is hideously ugly, but SQLA does not understand multicol IN expressions # FIXME TEMPORARY - DQ should have native syntax for this # moved here to raise API questions # # !!! EXPERIMENTAL API !!! WILL CHANGE !!! sub _where_op_multicolumn_in { my ($self, $lhs, $rhs) = @_; if (! ref $lhs or ref $lhs eq 'ARRAY') { my (@sql, @bind); for (ref $lhs ? @$lhs : $lhs) { if (! ref $_) { push @sql, $self->_quote($_); } elsif (ref $_ eq 'SCALAR') { push @sql, $$_; } elsif (ref $_ eq 'REF' and ref $$_ eq 'ARRAY') { my ($s, @b) = @$$_; push @sql, $s; push @bind, @b; } else { $self->throw_exception("ARRAY of @{[ ref $_ ]}es unsupported for multicolumn IN lhs..."); } } $lhs = \[ join(', ', @sql), @bind]; } elsif (ref $lhs eq 'SCALAR') { $lhs = \[ $$lhs ]; } elsif (ref $lhs eq 'REF' and ref $$lhs eq 'ARRAY' ) { # noop } else { $self->throw_exception( ref($lhs) . "es unsupported for multicolumn IN lhs..."); } # is this proper...? $rhs = \[ $self->_recurse_where($rhs) ]; for ($lhs, $rhs) { $$_->[0] = "( $$_->[0] )" unless $$_->[0] =~ /^ \s* \( .* \) \s* $/xs; } \[ join( ' IN ', shift @$$lhs, shift @$$rhs ), @$$lhs, @$$rhs ]; } =head1 FURTHER QUESTIONS? Check the list of L<additional DBIC resources|DBIx::Class/GETTING HELP/SUPPORT>. =head1 COPYRIGHT AND LICENSE This module is free software L<copyright|DBIx::Class/COPYRIGHT AND LICENSE> by the L<DBIx::Class (DBIC) authors|DBIx::Class/AUTHORS>. You can redistribute it and/or modify it under the same terms as the L<DBIx::Class library|DBIx::Class/COPYRIGHT AND LICENSE>. =cut 1;