X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FDBIx%2FClass%2FSQLAHacks.pm;h=ee3f156c5a7517e4dd6710cc640523fdf220fa62;hb=64ae166780d0cb2b9577e506da9b9b240c146d20;hp=429be4feee8c93a2e0e233f85e75dcaa54186ad0;hpb=517f91301e206be0246389f608ece68f3906f6de;p=dbsrgits%2FDBIx-Class.git diff --git a/lib/DBIx/Class/SQLAHacks.pm b/lib/DBIx/Class/SQLAHacks.pm index 429be4f..ee3f156 100644 --- a/lib/DBIx/Class/SQLAHacks.pm +++ b/lib/DBIx/Class/SQLAHacks.pm @@ -1,578 +1,6 @@ package # Hide from PAUSE DBIx::Class::SQLAHacks; -# This module is a subclass of SQL::Abstract::Limit and includes a number -# of DBIC-specific workarounds, not yet suitable for inclusion into the -# SQLA core - -use base qw/SQL::Abstract::Limit/; -use strict; -use warnings; -use Carp::Clan qw/^DBIx::Class|^SQL::Abstract/; - -BEGIN { - # reinstall the carp()/croak() functions imported into SQL::Abstract - # as Carp and Carp::Clan do not like each other much - no warnings qw/redefine/; - no strict qw/refs/; - for my $f (qw/carp croak/) { - - my $orig = \&{"SQL::Abstract::$f"}; - *{"SQL::Abstract::$f"} = sub { - - local $Carp::CarpLevel = 1; # even though Carp::Clan ignores this, $orig will not - - if (Carp::longmess() =~ /DBIx::Class::SQLAHacks::[\w]+ .+? called \s at/x) { - __PACKAGE__->can($f)->(@_); - } - else { - $orig->(@_); - } - } - } -} - - -# Tries to determine limit dialect. -# -sub new { - my $self = shift->SUPER::new(@_); - - # This prevents the caching of $dbh in S::A::L, I believe - # If limit_dialect is a ref (like a $dbh), go ahead and replace - # it with what it resolves to: - $self->{limit_dialect} = $self->_find_syntax($self->{limit_dialect}) - if ref $self->{limit_dialect}; - - $self; -} - - -# Slow but ANSI standard Limit/Offset support. DB2 uses this -sub _RowNumberOver { - my ($self, $sql, $order, $rows, $offset ) = @_; - - $offset += 1; - my $last = $rows + $offset - 1; - my ( $order_by ) = $self->_order_by( $order ); - - $sql = <<"SQL"; -SELECT * FROM -( - SELECT Q1.*, ROW_NUMBER() OVER( ) AS ROW_NUM FROM ( - $sql - $order_by - ) Q1 -) Q2 -WHERE ROW_NUM BETWEEN $offset AND $last - -SQL - - return $sql; -} - -# Crappy Top based Limit/Offset support. MSSQL uses this currently, -# but may have to switch to RowNumberOver one day -sub _Top { - my ( $self, $sql, $order, $rows, $offset ) = @_; - - # mangle the input sql so it can be properly aliased in the outer queries - $sql =~ s/^ \s* SELECT \s+ (.+?) \s+ (?=FROM)//ix - or croak "Unrecognizable SELECT: $sql"; - my $sql_select = $1; - my @sql_select = split (/\s*,\s*/, $sql_select); - - # we can't support subqueries (in fact MSSQL can't) - croak - if (@sql_select != @{$self->{_dbic_rs_attrs}{select}}) { - croak (sprintf ( - 'SQL SELECT did not parse cleanly - retrieved %d comma separated elements, while ' - . 'the resultset select attribure contains %d elements: %s', - scalar @sql_select, - scalar @{$self->{_dbic_rs_attrs}{select}}, - $sql_select, - )); - } - - my $name_sep = $self->name_sep || '.'; - my $esc_name_sep = "\Q$name_sep\E"; - my $col_re = qr/ ^ (?: (.+) $esc_name_sep )? ([^$esc_name_sep]+) $ /x; - - my $rs_alias = $self->{_dbic_rs_attrs}{alias}; - my $quoted_rs_alias = $self->_quote ($rs_alias); - - # construct the new select lists, rename(alias) some columns if necessary - my (@outer_select, @inner_select, %seen_names, %col_aliases, %outer_col_aliases); - - for (@{$self->{_dbic_rs_attrs}{select}}) { - next if ref $_; - my ($table, $orig_colname) = ( $_ =~ $col_re ); - next unless $table; - $seen_names{$orig_colname}++; - } - - for my $i (0 .. $#sql_select) { - - my $colsel_arg = $self->{_dbic_rs_attrs}{select}[$i]; - my $colsel_sql = $sql_select[$i]; - - # this may or may not work (in case of a scalarref or something) - my ($table, $orig_colname) = ( $colsel_arg =~ $col_re ); - - my $quoted_alias; - # do not attempt to understand non-scalar selects - alias numerically - if (ref $colsel_arg) { - $quoted_alias = $self->_quote ('column_' . (@inner_select + 1) ); - } - # column name seen more than once - alias it - elsif ($orig_colname && - ($seen_names{$orig_colname} && $seen_names{$orig_colname} > 1) ) { - $quoted_alias = $self->_quote ("${table}__${orig_colname}"); - } - - # we did rename - make a record and adjust - if ($quoted_alias) { - # alias inner - push @inner_select, "$colsel_sql AS $quoted_alias"; - - # push alias to outer - push @outer_select, $quoted_alias; - - # Any aliasing accumulated here will be considered - # both for inner and outer adjustments of ORDER BY - $self->__record_alias ( - \%col_aliases, - $quoted_alias, - $colsel_arg, - $table ? $orig_colname : undef, - ); - } - - # otherwise just leave things intact inside, and use the abbreviated one outside - # (as we do not have table names anymore) - else { - push @inner_select, $colsel_sql; - - my $outer_quoted = $self->_quote ($orig_colname); # it was not a duplicate so should just work - push @outer_select, $outer_quoted; - $self->__record_alias ( - \%outer_col_aliases, - $outer_quoted, - $colsel_arg, - $table ? $orig_colname : undef, - ); - } - } - - my $outer_select = join (', ', @outer_select ); - my $inner_select = join (', ', @inner_select ); - - %outer_col_aliases = (%outer_col_aliases, %col_aliases); - - # deal with order - croak '$order supplied to SQLAHacks limit emulators must be a hash' - if (ref $order ne 'HASH'); - - $order = { %$order }; #copy - - my $req_order = $order->{order_by}; - - # examine normalized version, collapses nesting - my $limit_order; - if (scalar $self->_order_by_chunks ($req_order)) { - $limit_order = $req_order; - } - else { - $limit_order = [ map - { join ('', $rs_alias, $name_sep, $_ ) } - ( $self->{_dbic_rs_attrs}{_source_handle}->resolve->primary_columns ) - ]; - } - - my ( $order_by_inner, $order_by_outer ) = $self->_order_directions($limit_order); - my $order_by_requested = $self->_order_by ($req_order); - - # generate the rest - delete $order->{order_by}; - my $grpby_having = $self->_order_by ($order); - - # short circuit for counts - the ordering complexity is needless - if ($self->{_dbic_rs_attrs}{-for_count_only}) { - return "SELECT TOP $rows $inner_select $sql $grpby_having $order_by_outer"; - } - - # we can't really adjust the order_by columns, as introspection is lacking - # resort to simple substitution - for my $col (keys %outer_col_aliases) { - for ($order_by_requested, $order_by_outer) { - $_ =~ s/\s+$col\s+/ $outer_col_aliases{$col} /g; - } - } - for my $col (keys %col_aliases) { - $order_by_inner =~ s/\s+$col\s+/ $col_aliases{$col} /g; - } - - - my $inner_lim = $rows + $offset; - - $sql = "SELECT TOP $inner_lim $inner_select $sql $grpby_having $order_by_inner"; - - if ($offset) { - $sql = <<"SQL"; - - SELECT TOP $rows $outer_select FROM - ( - $sql - ) $quoted_rs_alias - $order_by_outer -SQL - - } - - if ($order_by_requested) { - $sql = <<"SQL"; - - SELECT $outer_select FROM - ( $sql ) $quoted_rs_alias - $order_by_requested -SQL - - } - - $sql =~ s/\s*\n\s*/ /g; # parsing out multiline statements is harder than a single line - return $sql; -} - -# action at a distance to shorten Top code above -sub __record_alias { - my ($self, $register, $alias, $fqcol, $col) = @_; - - # record qualified name - $register->{$fqcol} = $alias; - $register->{$self->_quote($fqcol)} = $alias; - - return unless $col; - - # record unqualified name, undef (no adjustment) if a duplicate is found - if (exists $register->{$col}) { - $register->{$col} = undef; - } - else { - $register->{$col} = $alias; - } - - $register->{$self->_quote($col)} = $register->{$col}; -} - - - -# While we're at it, this should make LIMIT queries more efficient, -# without digging into things too deeply -sub _find_syntax { - my ($self, $syntax) = @_; - return $self->{_cached_syntax} ||= $self->SUPER::_find_syntax($syntax); -} - -my $for_syntax = { - update => 'FOR UPDATE', - shared => 'FOR SHARE', -}; -# Quotes table names, handles "limit" dialects (e.g. where rownum between x and -# y), supports SELECT ... FOR UPDATE and SELECT ... FOR SHARE. -sub select { - my ($self, $table, $fields, $where, $order, @rest) = @_; - - $self->{"${_}_bind"} = [] for (qw/having from order/); - - if (not ref($table) or ref($table) eq 'SCALAR') { - $table = $self->_quote($table); - } - - local $self->{rownum_hack_count} = 1 - if (defined $rest[0] && $self->{limit_dialect} eq 'RowNum'); - @rest = (-1) unless defined $rest[0]; - croak "LIMIT 0 Does Not Compute" if $rest[0] == 0; - # and anyway, SQL::Abstract::Limit will cause a barf if we don't first - my ($sql, @where_bind) = $self->SUPER::select( - $table, $self->_recurse_fields($fields), $where, $order, @rest - ); - if (my $for = delete $self->{_dbic_rs_attrs}{for}) { - $sql .= " $for_syntax->{$for}" if $for_syntax->{$for}; - } - - return wantarray ? ($sql, @{$self->{from_bind}}, @where_bind, @{$self->{having_bind}}, @{$self->{order_bind}} ) : $sql; -} - -# Quotes table names, and handles default inserts -sub insert { - my $self = shift; - my $table = shift; - $table = $self->_quote($table); - - # 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 (! $_[0] or (ref $_[0] eq 'HASH' and !keys %{$_[0]} ) ) { - return "INSERT INTO ${table} DEFAULT VALUES" - } - - $self->SUPER::insert($table, @_); -} - -# Just quotes table names. -sub update { - my $self = shift; - my $table = shift; - $table = $self->_quote($table); - $self->SUPER::update($table, @_); -} - -# Just quotes table names. -sub delete { - my $self = shift; - my $table = shift; - $table = $self->_quote($table); - $self->SUPER::delete($table, @_); -} - -sub _emulate_limit { - my $self = shift; - if ($_[3] == -1) { - return $_[1].$self->_order_by($_[2]); - } else { - return $self->SUPER::_emulate_limit(@_); - } -} - -sub _recurse_fields { - my ($self, $fields, $params) = @_; - my $ref = ref $fields; - return $self->_quote($fields) unless $ref; - return $$fields if $ref eq 'SCALAR'; - - if ($ref eq 'ARRAY') { - return join(', ', map { - $self->_recurse_fields($_) - .(exists $self->{rownum_hack_count} && !($params && $params->{no_rownum_hack}) - ? ' AS col'.$self->{rownum_hack_count}++ - : '') - } @$fields); - } - elsif ($ref eq 'HASH') { - my %hash = %$fields; - - my $as = delete $hash{-as}; # if supplied - - my ($func, $args) = each %hash; - delete $hash{$func}; - - if (lc ($func) eq 'distinct' && ref $args eq 'ARRAY' && @$args > 1) { - croak ( - 'The select => { distinct => ... } syntax is not supported for multiple columns.' - .' Instead please use { group_by => [ qw/' . (join ' ', @$args) . '/ ] }' - .' or { select => [ qw/' . (join ' ', @$args) . '/ ], distinct => 1 }' - ); - } - - my $select = sprintf ('%s( %s )%s', - $self->_sqlcase($func), - $self->_recurse_fields($args), - $as - ? sprintf (' %s %s', $self->_sqlcase('as'), $as) - : '' - ); - - # there should be nothing left - if (keys %hash) { - croak "Malformed select argument - too many keys in hash: " . join (',', keys %$fields ); - } - - return $select; - } - # Is the second check absolutely necessary? - elsif ( $ref eq 'REF' and ref($$fields) eq 'ARRAY' ) { - return $self->_fold_sqlbind( $fields ); - } - else { - croak($ref . qq{ unexpected in _recurse_fields()}) - } -} - -sub _order_by { - my ($self, $arg) = @_; - - if (ref $arg eq 'HASH' and keys %$arg and not grep { $_ =~ /^-(?:desc|asc)/i } keys %$arg ) { - - my $ret = ''; - - if (my $g = $self->_recurse_fields($arg->{group_by}, { no_rownum_hack => 1 }) ) { - $ret = $self->_sqlcase(' group by ') . $g; - } - - if (defined $arg->{having}) { - my ($frag, @bind) = $self->_recurse_where($arg->{having}); - push(@{$self->{having_bind}}, @bind); - $ret .= $self->_sqlcase(' having ').$frag; - } - - if (defined $arg->{order_by}) { - my ($frag, @bind) = $self->SUPER::_order_by($arg->{order_by}); - push(@{$self->{order_bind}}, @bind); - $ret .= $frag; - } - - return $ret; - } - else { - my ($sql, @bind) = $self->SUPER::_order_by ($arg); - push(@{$self->{order_bind}}, @bind); - return $sql; - } -} - -sub _order_directions { - my ($self, $order) = @_; - - # strip bind values - none of the current _order_directions users support them - return $self->SUPER::_order_directions( [ map - { ref $_ ? $_->[0] : $_ } - $self->_order_by_chunks ($order) - ]); -} - -sub _table { - my ($self, $from) = @_; - if (ref $from eq 'ARRAY') { - return $self->_recurse_from(@$from); - } elsif (ref $from eq 'HASH') { - return $self->_make_as($from); - } else { - return $from; # would love to quote here but _table ends up getting called - # twice during an ->select without a limit clause due to - # the way S::A::Limit->select works. should maybe consider - # bypassing this and doing S::A::select($self, ...) in - # our select method above. meantime, quoting shims have - # been added to select/insert/update/delete here - } -} - -sub _recurse_from { - my ($self, $from, @join) = @_; - my @sqlf; - push(@sqlf, $self->_make_as($from)); - foreach my $j (@join) { - my ($to, $on) = @$j; - - - # 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; - } - - $join_type = $self->{_default_jointype} if not defined $join_type; - - my $join_clause = sprintf ('%s JOIN ', - $join_type ? ' ' . uc($join_type) : '' - ); - push @sqlf, $join_clause; - - if (ref $to eq 'ARRAY') { - push(@sqlf, '(', $self->_recurse_from(@$to), ')'); - } else { - push(@sqlf, $self->_make_as($to)); - } - push(@sqlf, ' ON ', $self->_join_condition($on)); - } - return join('', @sqlf); -} - -sub _fold_sqlbind { - my ($self, $sqlbind) = @_; - - my @sqlbind = @$$sqlbind; # copy - my $sql = shift @sqlbind; - push @{$self->{from_bind}}, @sqlbind; - - return $sql; -} - -sub _make_as { - my ($self, $from) = @_; - return join(' ', map { (ref $_ eq 'SCALAR' ? $$_ - : ref $_ eq 'REF' ? $self->_fold_sqlbind($_) - : $self->_quote($_)) - } reverse each %{$self->_skip_options($from)}); -} - -sub _skip_options { - my ($self, $hash) = @_; - my $clean_hash = {}; - $clean_hash->{$_} = $hash->{$_} - for grep {!/^-/} keys %$hash; - return $clean_hash; -} - -sub _join_condition { - my ($self, $cond) = @_; - if (ref $cond eq 'HASH') { - my %j; - for (keys %$cond) { - my $v = $cond->{$_}; - if (ref $v) { - croak (ref($v) . qq{ reference arguments are not supported in JOINS - try using \"..." instead'}) - if ref($v) ne 'SCALAR'; - $j{$_} = $v; - } - else { - my $x = '= '.$self->_quote($v); $j{$_} = \$x; - } - }; - return scalar($self->_recurse_where(\%j)); - } elsif (ref $cond eq 'ARRAY') { - return join(' OR ', map { $self->_join_condition($_) } @$cond); - } else { - die "Can't handle this yet!"; - } -} - -sub _quote { - my ($self, $label) = @_; - return '' unless defined $label; - return $$label if ref($label) eq 'SCALAR'; - return "*" if $label eq '*'; - return $label unless $self->{quote_char}; - if(ref $self->{quote_char} eq "ARRAY"){ - return $self->{quote_char}->[0] . $label . $self->{quote_char}->[1] - if !defined $self->{name_sep}; - my $sep = $self->{name_sep}; - return join($self->{name_sep}, - map { $self->{quote_char}->[0] . $_ . $self->{quote_char}->[1] } - split(/\Q$sep\E/,$label)); - } - return $self->SUPER::_quote($label); -} - -sub limit_dialect { - my $self = shift; - $self->{limit_dialect} = shift if @_; - return $self->{limit_dialect}; -} - -# Set to an array-ref to specify separate left and right quotes for table names. -# A single scalar is equivalen to [ $char, $char ] -sub quote_char { - my $self = shift; - $self->{quote_char} = shift if @_; - return $self->{quote_char}; -} - -# Character separating quoted table names. -sub name_sep { - my $self = shift; - $self->{name_sep} = shift if @_; - return $self->{name_sep}; -} +use base qw/DBIx::Class::SQLMaker/; 1;