X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FDBIx%2FClass%2FSQLMaker%2FLimitDialects.pm;h=84cc5a3d2f9408bf0884303198b15284c2a2f7ea;hb=5f11e54f1dc812354b8d160d5b286502cc227cbf;hp=6bb7b9282f7964b74e300f5892a6f4b3a6e7192f;hpb=7cec43565df63cdbf6320721c7d7c33cb6ce6e96;p=dbsrgits%2FDBIx-Class.git diff --git a/lib/DBIx/Class/SQLMaker/LimitDialects.pm b/lib/DBIx/Class/SQLMaker/LimitDialects.pm index 6bb7b92..84cc5a3 100644 --- a/lib/DBIx/Class/SQLMaker/LimitDialects.pm +++ b/lib/DBIx/Class/SQLMaker/LimitDialects.pm @@ -96,34 +96,35 @@ sub _RowNumberOver { my ($self, $sql, $rs_attrs, $rows, $offset ) = @_; # get selectors, and scan the order_by (if any) - my ($stripped_sql, $in_sel, $out_sel, $alias_map, $extra_order_sel) - = $self->_subqueried_limit_attrs ( $sql, $rs_attrs ); + my $sq_attrs = $self->_subqueried_limit_attrs ( $sql, $rs_attrs ); # make up an order if none exists my $requested_order = (delete $rs_attrs->{order_by}) || $self->_rno_default_order; + + # the order binds (if any) will need to go at the end of the entire inner select + local $self->{order_bind}; my $rno_ord = $self->_order_by ($requested_order); + push @{$self->{select_bind}}, @{$self->{order_bind}}; # this is the order supplement magic - my $mid_sel = $out_sel; - if ($extra_order_sel) { + my $mid_sel = $sq_attrs->{selection_outer}; + if (my $extra_order_sel = $sq_attrs->{order_supplement}) { for my $extra_col (sort { $extra_order_sel->{$a} cmp $extra_order_sel->{$b} } keys %$extra_order_sel ) { - $in_sel .= sprintf (', %s AS %s', + $sq_attrs->{selection_inner} .= sprintf (', %s AS %s', $extra_col, $extra_order_sel->{$extra_col}, ); - - $mid_sel .= ', ' . $extra_order_sel->{$extra_col}; } } # and this is order re-alias magic - for ($extra_order_sel, $alias_map) { - for my $col (keys %$_) { + for my $map ($sq_attrs->{order_supplement}, $sq_attrs->{outer_renames}) { + for my $col (sort { (length $b) <=> (length $a) } keys %{$map||{}} ) { my $re_col = quotemeta ($col); - $rno_ord =~ s/$re_col/$_->{$col}/; + $rno_ord =~ s/$re_col/$map->{$col}/; } } @@ -137,9 +138,9 @@ sub _RowNumberOver { return <{selection_outer} FROM ( SELECT $mid_sel, ROW_NUMBER() OVER( $rno_ord ) AS $idx_name FROM ( - SELECT $in_sel ${stripped_sql}${group_having} + SELECT $sq_attrs->{selection_inner} $sq_attrs->{query_leftover}${group_having} ) $qalias ) $qalias WHERE $idx_name >= ? AND $idx_name <= ? @@ -245,12 +246,24 @@ Supported by B. sub _RowNum { my ( $self, $sql, $rs_attrs, $rows, $offset ) = @_; - my ($stripped_sql, $insel, $outsel) = $self->_subqueried_limit_attrs ($sql, $rs_attrs); + my $sq_attrs = $self->_subqueried_limit_attrs ($sql, $rs_attrs); my $qalias = $self->_quote ($rs_attrs->{alias}); my $idx_name = $self->_quote ('rownum__index'); my $order_group_having = $self->_parse_rs_attrs($rs_attrs); + + # if no offset (e.g. first page) - we can skip one of the subqueries + if (! $offset) { + push @{$self->{limit_bind}}, [ $self->__rows_bindtype => $rows ]; + + return <{selection_outer} FROM ( + SELECT $sq_attrs->{selection_inner} $sq_attrs->{query_leftover}${order_group_having} +) $qalias WHERE ROWNUM <= ? +EOS + } + # # There are two ways to limit in Oracle, one vastly faster than the other # on large resultsets: https://decipherinfosys.wordpress.com/2007/08/09/paging-and-countstopkey-optimization/ @@ -266,38 +279,26 @@ sub _RowNum { $rs_attrs->{order_by} and $rs_attrs->{_rsroot_rsrc}->storage->_order_by_is_stable( - $rs_attrs->{from}, $rs_attrs->{order_by} + @{$rs_attrs}{qw/from order_by where/} ) ) { - # if offset is 0 (first page) the we can skip a subquery - if (! $offset) { - push @{$self->{limit_bind}}, [ $self->__rows_bindtype => $rows ]; + push @{$self->{limit_bind}}, [ $self->__total_bindtype => $offset + $rows ], [ $self->__offset_bindtype => $offset + 1 ]; - return <{limit_bind}}, [ $self->__total_bindtype => $offset + $rows ], [ $self->__offset_bindtype => $offset + 1 ]; - - return <{selection_outer} FROM ( + SELECT $sq_attrs->{selection_outer}, ROWNUM $idx_name FROM ( + SELECT $sq_attrs->{selection_inner} $sq_attrs->{query_leftover}${order_group_having} ) $qalias WHERE ROWNUM <= ? ) $qalias WHERE $idx_name >= ? EOS - } } else { push @{$self->{limit_bind}}, [ $self->__offset_bindtype => $offset + 1 ], [ $self->__total_bindtype => $offset + $rows ]; return <{selection_outer} FROM ( + SELECT $sq_attrs->{selection_outer}, ROWNUM $idx_name FROM ( + SELECT $sq_attrs->{selection_inner} $sq_attrs->{query_leftover}${order_group_having} ) $qalias ) $qalias WHERE $idx_name BETWEEN ? AND ? EOS @@ -309,26 +310,49 @@ sub _prep_for_skimming_limit { my ( $self, $sql, $rs_attrs ) = @_; # get selectors - my (%r, $alias_map, $extra_order_sel); - ($r{inner_sql}, $r{in_sel}, $r{out_sel}, $alias_map, $extra_order_sel) - = $self->_subqueried_limit_attrs ($sql, $rs_attrs); + my $sq_attrs = $self->_subqueried_limit_attrs ($sql, $rs_attrs); my $requested_order = delete $rs_attrs->{order_by}; - $r{order_by_requested} = $self->_order_by ($requested_order); - - # make up an order unless supplied - my $inner_order = ($r{order_by_requested} - ? $requested_order - : [ map - { "$rs_attrs->{alias}.$_" } - ( $rs_attrs->{_rsroot_rsrc}->_pri_cols ) - ] - ); + $sq_attrs->{order_by_requested} = $self->_order_by ($requested_order); + $sq_attrs->{grpby_having} = $self->_parse_rs_attrs ($rs_attrs); + + # without an offset things are easy + if (! $rs_attrs->{offset}) { + $sq_attrs->{order_by_inner} = $sq_attrs->{order_by_requested}; + } + else { + $sq_attrs->{quoted_rs_alias} = $self->_quote ($rs_attrs->{alias}); - # localise as we already have all the bind values we need - { + # localise as we already have all the bind values we need local $self->{order_bind}; - $r{order_by_inner} = $self->_order_by ($inner_order); + + # make up an order unless supplied or sanity check what we are given + my $inner_order; + if ($sq_attrs->{order_by_requested}) { + $self->throw_exception ( + 'Unable to safely perform "skimming type" limit with supplied unstable order criteria' + ) unless ($rs_attrs->{_rsroot_rsrc}->schema->storage->_order_by_is_stable( + $rs_attrs->{from}, + $requested_order, + $rs_attrs->{where}, + )); + + $inner_order = $requested_order; + } + else { + $inner_order = [ map + { "$rs_attrs->{alias}.$_" } + ( @{ + $rs_attrs->{_rsroot_rsrc}->_identifying_column_set + || + $self->throw_exception(sprintf( + 'Unable to auto-construct stable order criteria for "skimming type" limit ' + . "dialect based on source '%s'", $rs_attrs->{_rsroot_rsrc}->name) ); + } ) + ]; + } + + $sq_attrs->{order_by_inner} = $self->_order_by ($inner_order); my @out_chunks; for my $ch ($self->_order_by_chunks ($inner_order)) { @@ -336,48 +360,54 @@ sub _prep_for_skimming_limit { $ch =~ s/\s+ ( ASC|DESC ) \s* $//ix; my $dir = uc ($1||'ASC'); - push @out_chunks, \join (' ', $ch, $dir eq 'ASC' ? 'DESC' : 'ASC' ); } - $r{order_by_reversed} = $self->_order_by (\@out_chunks); - } - - # this is the order supplement magic - $r{mid_sel} = $r{out_sel}; - if ($extra_order_sel) { - for my $extra_col (sort - { $extra_order_sel->{$a} cmp $extra_order_sel->{$b} } - keys %$extra_order_sel - ) { - $r{in_sel} .= sprintf (', %s AS %s', - $extra_col, - $extra_order_sel->{$extra_col}, - ); + $sq_attrs->{order_by_middle} = $self->_order_by (\@out_chunks); + + # this is the order supplement magic + $sq_attrs->{selection_middle} = $sq_attrs->{selection_outer}; + if (my $extra_order_sel = $sq_attrs->{order_supplement}) { + for my $extra_col (sort + { $extra_order_sel->{$a} cmp $extra_order_sel->{$b} } + keys %$extra_order_sel + ) { + $sq_attrs->{selection_inner} .= sprintf (', %s AS %s', + $extra_col, + $extra_order_sel->{$extra_col}, + ); + + $sq_attrs->{selection_middle} .= ', ' . $extra_order_sel->{$extra_col}; + } - $r{mid_sel} .= ', ' . $extra_order_sel->{$extra_col}; + # Whatever order bindvals there are, they will be realiased and + # reselected, and need to show up at end of the initial inner select + push @{$self->{select_bind}}, @{$self->{order_bind}}; + + # if this is a part of something bigger, we need to add back all + # the extra order_by's, as they may be relied upon by the outside + # of a prefetch or something + if ($rs_attrs->{_is_internal_subuery}) { + $sq_attrs->{selection_outer} .= sprintf ", $extra_order_sel->{$_} AS $_" + for sort + { $extra_order_sel->{$a} cmp $extra_order_sel->{$b} } + grep { $_ !~ /[^\w\-]/ } # ignore functions + keys %$extra_order_sel + ; + } } - # Whatever order bindvals there are, they will be realiased and - # need to show up in front of the entire initial inner subquery - push @{$self->{pre_select_bind}}, @{$self->{order_bind}}; - } - - # and this is order re-alias magic - for my $map ($extra_order_sel, $alias_map) { - for my $col (keys %$map) { - my $re_col = quotemeta ($col); - $_ =~ s/$re_col/$map->{$col}/ - for ($r{order_by_reversed}, $r{order_by_requested}); + # and this is order re-alias magic + for my $map ($sq_attrs->{order_supplement}, $sq_attrs->{outer_renames}) { + for my $col (sort { (length $b) <=> (length $a) } keys %{$map||{}}) { + my $re_col = quotemeta ($col); + $_ =~ s/$re_col/$map->{$col}/ + for ($sq_attrs->{order_by_middle}, $sq_attrs->{order_by_requested}); + } } } - # generate the rest of the sql - $r{grpby_having} = $self->_parse_rs_attrs ($rs_attrs); - - $r{quoted_rs_alias} = $self->_quote ($rs_attrs->{alias}); - - \%r; + $sq_attrs; } =head2 Top @@ -402,31 +432,32 @@ when $limit+$offset > total amount of rows in the resultset. sub _Top { my ( $self, $sql, $rs_attrs, $rows, $offset ) = @_; - my %l = %{ $self->_prep_for_skimming_limit($sql, $rs_attrs) }; + my $lim = $self->_prep_for_skimming_limit($sql, $rs_attrs); $sql = sprintf ('SELECT TOP %u %s %s %s %s', $rows + ($offset||0), - $l{in_sel}, - $l{inner_sql}, - $l{grpby_having}, - $l{order_by_inner}, + $offset ? $lim->{selection_inner} : $lim->{selection_original}, + $lim->{query_leftover}, + $lim->{grpby_having}, + $lim->{order_by_inner}, ); $sql = sprintf ('SELECT TOP %u %s FROM ( %s ) %s %s', $rows, - $l{mid_sel}, + $lim->{selection_middle}, $sql, - $l{quoted_rs_alias}, - $l{order_by_reversed}, + $lim->{quoted_rs_alias}, + $lim->{order_by_middle}, ) if $offset; - $sql = sprintf ('SELECT TOP %u %s FROM ( %s ) %s %s', - $rows, - $l{out_sel}, + $sql = sprintf ('SELECT %s FROM ( %s ) %s %s', + $lim->{selection_outer}, $sql, - $l{quoted_rs_alias}, - $l{order_by_requested}, - ) if ( ($offset && $l{order_by_requested}) || ($l{mid_sel} ne $l{out_sel}) ); + $lim->{quoted_rs_alias}, + $lim->{order_by_requested}, + ) if $offset and ( + $lim->{order_by_requested} or $lim->{selection_middle} ne $lim->{selection_outer} + ); return $sql; } @@ -456,31 +487,33 @@ when $limit+$offset > total amount of rows in the resultset. sub _FetchFirst { my ( $self, $sql, $rs_attrs, $rows, $offset ) = @_; - my %l = %{ $self->_prep_for_skimming_limit($sql, $rs_attrs) }; + my $lim = $self->_prep_for_skimming_limit($sql, $rs_attrs); $sql = sprintf ('SELECT %s %s %s %s FETCH FIRST %u ROWS ONLY', - $l{in_sel}, - $l{inner_sql}, - $l{grpby_having}, - $l{order_by_inner}, + $offset ? $lim->{selection_inner} : $lim->{selection_original}, + $lim->{query_leftover}, + $lim->{grpby_having}, + $lim->{order_by_inner}, $rows + ($offset||0), ); $sql = sprintf ('SELECT %s FROM ( %s ) %s %s FETCH FIRST %u ROWS ONLY', - $l{mid_sel}, + $lim->{selection_middle}, $sql, - $l{quoted_rs_alias}, - $l{order_by_reversed}, + $lim->{quoted_rs_alias}, + $lim->{order_by_middle}, $rows, ) if $offset; - $sql = sprintf ('SELECT %s FROM ( %s ) %s %s FETCH FIRST %u ROWS ONLY', - $l{out_sel}, + + $sql = sprintf ('SELECT %s FROM ( %s ) %s %s', + $lim->{selection_outer}, $sql, - $l{quoted_rs_alias}, - $l{order_by_requested}, - $rows, - ) if ( ($offset && $l{order_by_requested}) || ($l{mid_sel} ne $l{out_sel}) ); + $lim->{quoted_rs_alias}, + $lim->{order_by_requested}, + ) if $offset and ( + $lim->{order_by_requested} or $lim->{selection_middle} ne $lim->{selection_outer} + ); return $sql; } @@ -504,9 +537,9 @@ sub _RowCountOrGenericSubQ { return $self->_GenericSubQ(@_) if $offset; - return sprintf <<"EOF", $rows, $sql; + return sprintf <<"EOF", $rows, $sql, $self->_parse_rs_attrs( $rs_attrs ); SET ROWCOUNT %d -%s +%s %s SET ROWCOUNT 0 EOF } @@ -536,75 +569,52 @@ sub _GenericSubQ { my $root_rsrc = $rs_attrs->{_rsroot_rsrc}; my $root_tbl_name = $root_rsrc->name; - my ($order_by, @rest) = do { + my ($first_order_by) = do { local $self->{quote_char}; - $self->_order_by_chunks ($rs_attrs->{order_by}) - }; - - unless ( - $order_by - && - ! @rest - && - ( ! ref $order_by - || - ( ref $order_by eq 'ARRAY' and @$order_by == 1 ) - ) - ) { - $self->throw_exception ( - 'Generic Subquery Limit does not work on resultsets without an order, or resultsets ' - . 'with complex order criteria (multicolumn and/or functions). Provide a single, ' - . 'unique-column order criteria.' - ); - } - - ($order_by) = @$order_by if ref $order_by; + local $self->{order_bind}; + map { ref $_ ? $_->[0] : $_ } $self->_order_by_chunks ($rs_attrs->{order_by}) + } or $self->throw_exception ( + 'Generic Subquery Limit does not work on resultsets without an order. Provide a single, ' + . 'unique-column order criteria.' + ); - $order_by =~ s/\s+ ( ASC|DESC ) \s* $//ix; + $first_order_by =~ s/\s+ ( ASC|DESC ) \s* $//ix; my $direction = lc ($1 || 'asc'); - my ($unq_sort_col) = $order_by =~ /(?:^|\.)([^\.]+)$/; - - my $inf = $root_rsrc->storage->_resolve_column_info ( - $rs_attrs->{from}, [$order_by, $unq_sort_col] - ); + my ($first_ord_alias, $first_ord_col) = $first_order_by =~ /^ (?: ([^\.]+) \. )? ([^\.]+) $/x; - my $ord_colinfo = $inf->{$order_by} || $self->throw_exception("Unable to determine source of order-criteria '$order_by'"); - - if ($ord_colinfo->{-result_source}->name ne $root_tbl_name) { - $self->throw_exception(sprintf - "Generic Subquery Limit order criteria can be only based on the root-source '%s'" - . " (aliased as '%s')", $root_rsrc->source_name, $rs_attrs->{alias}, - ); - } + $self->throw_exception(sprintf + "Generic Subquery Limit order criteria can be only based on the root-source '%s'" + . " (aliased as '%s')", $root_rsrc->source_name, $rs_attrs->{alias}, + ) if ($first_ord_alias and $first_ord_alias ne $rs_attrs->{alias}); - # make sure order column is qualified - $order_by = "$rs_attrs->{alias}.$order_by" - unless $order_by =~ /^$rs_attrs->{alias}\./; + $first_ord_alias ||= $rs_attrs->{alias}; - my $is_u; - my $ucs = { $root_rsrc->unique_constraints }; - for (values %$ucs ) { - if (@$_ == 1 && "$rs_attrs->{alias}.$_->[0]" eq $order_by) { - $is_u++; - last; - } - } $self->throw_exception( - "Generic Subquery Limit order criteria column '$order_by' must be unique (no unique constraint found)" - ) unless $is_u; - - my ($stripped_sql, $in_sel, $out_sel, $alias_map, $extra_order_sel) - = $self->_subqueried_limit_attrs ($sql, $rs_attrs); + "Generic Subquery Limit first order criteria '$first_ord_col' must be unique" + ) unless $root_rsrc->_identifying_column_set([$first_ord_col]); + + my $sq_attrs = do { + # perform the mangling only using the very first order crietria + # (the one we care about) + local $rs_attrs->{order_by} = $first_order_by; + $self->_subqueried_limit_attrs ($sql, $rs_attrs); + }; my $cmp_op = $direction eq 'desc' ? '>' : '<'; my $count_tbl_alias = 'rownum__emulation'; - my $order_sql = $self->_order_by (delete $rs_attrs->{order_by}); + my ($order_sql, @order_bind) = do { + local $self->{order_bind}; + my $s = $self->_order_by (delete $rs_attrs->{order_by}); + ($s, @{$self->{order_bind}}); + }; my $group_having_sql = $self->_parse_rs_attrs($rs_attrs); + my $in_sel = $sq_attrs->{selection_inner}; + # add the order supplement (if any) as this is what will be used for the outer WHERE - $in_sel .= ", $_" for keys %{$extra_order_sel||{}}; + $in_sel .= ", $_" for keys %{$sq_attrs->{order_supplement}}; my $rownum_cond; if ($offset) { @@ -623,10 +633,15 @@ sub _GenericSubQ { ; } + # even though binds in order_by make no sense here (the rs needs to be + # ordered by a unique column first) - pass whatever there may be through + # anyway + push @{$self->{limit_bind}}, @order_bind; + return sprintf (" -SELECT $out_sel +SELECT $sq_attrs->{selection_outer} FROM ( - SELECT $in_sel ${stripped_sql}${group_having_sql} + SELECT $in_sel $sq_attrs->{query_leftover}${group_having_sql} ) %s WHERE ( SELECT COUNT(*) FROM %s %s WHERE %s $cmp_op %s ) $rownum_cond $order_sql @@ -634,8 +649,8 @@ $order_sql $rs_attrs->{alias}, $root_tbl_name, $count_tbl_alias, - "$count_tbl_alias.$unq_sort_col", - $order_by, + "$count_tbl_alias.$first_ord_col", + "$first_ord_alias.$first_ord_col", )); } @@ -688,6 +703,7 @@ sub _subqueried_limit_attrs { my $sql_alias = (ref $s) eq 'HASH' ? $s->{-as} : undef; push @sel, { + arg => $s, sql => $sql_sel, unquoted_sql => do { local $self->{quote_char}; @@ -702,7 +718,9 @@ sub _subqueried_limit_attrs { , }; - $in_sel_index->{$sql_sel}++; + # anything with a placeholder in it needs re-selection + $in_sel_index->{$sql_sel}++ unless $sql_sel =~ / (?: ^ | \W ) \? (?: \W | $ ) /x; + $in_sel_index->{$self->_quote ($sql_alias)}++ if $sql_alias; # record unqualified versions too, so we do not have @@ -718,26 +736,32 @@ sub _subqueried_limit_attrs { # unless we are dealing with the current source alias # (which will transcend the subqueries as it is necessary # for possible further chaining) - my (@in_sel, @out_sel, %renamed); + # same for anything we do not recognize + my ($sel, $renamed); for my $node (@sel) { + push @{$sel->{original}}, $node->{sql}; + if ( + ! $in_sel_index->{$node->{sql}} + or $node->{as} =~ / (?{unquoted_sql} =~ / (?{as} = $self->_unqualify_colname($node->{as}); my $quoted_as = $self->_quote($node->{as}); - push @in_sel, sprintf '%s AS %s', $node->{sql}, $quoted_as; - push @out_sel, $quoted_as; - $renamed{$node->{sql}} = $quoted_as; + push @{$sel->{inner}}, sprintf '%s AS %s', $node->{sql}, $quoted_as; + push @{$sel->{outer}}, $quoted_as; + $renamed->{$node->{sql}} = $quoted_as; } else { - push @in_sel, $node->{sql}; - push @out_sel, $self->_quote ($node->{as}); + push @{$sel->{inner}}, $node->{sql}; + push @{$sel->{outer}}, $self->_quote (ref $node->{arg} ? $node->{as} : $node->{arg}); } } + # see if the order gives us anything - my %extra_order_sel; + my $extra_order_sel; for my $chunk ($self->_order_by_chunks ($rs_attrs->{order_by})) { # order with bind $chunk = $chunk->[0] if (ref $chunk) eq 'ARRAY'; @@ -745,20 +769,17 @@ sub _subqueried_limit_attrs { next if $in_sel_index->{$chunk}; - $extra_order_sel{$chunk} ||= $self->_quote ( - 'ORDER__BY__' . scalar keys %extra_order_sel + $extra_order_sel->{$chunk} ||= $self->_quote ( + 'ORDER__BY__' . scalar keys %{$extra_order_sel||{}} ); } - return ( - $proto_sql, - (map { join (', ', @$_ ) } ( - \@in_sel, - \@out_sel) - ), - \%renamed, - keys %extra_order_sel ? \%extra_order_sel : (), - ); + return { + query_leftover => $proto_sql, + (map {( "selection_$_" => join (', ', @{$sel->{$_}} ) )} keys %$sel ), + outer_renames => $renamed, + order_supplement => $extra_order_sel, + }; } sub _unqualify_colname {