X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?p=dbsrgits%2FDBIx-Class.git;a=blobdiff_plain;f=lib%2FDBIx%2FClass%2FResultSet.pm;h=f231f4e3c8e615ee9963bd4f04fe1d67aa55cf4b;hp=574b2da18f3dea55c4e8ae5d5065e472921e3ce5;hb=fd8076c89806c4e6222b032e5cc8f5b45e02c6e8;hpb=c97338007ede15e7c62095a642b3de382a3508bd diff --git a/lib/DBIx/Class/ResultSet.pm b/lib/DBIx/Class/ResultSet.pm index 574b2da..f231f4e 100644 --- a/lib/DBIx/Class/ResultSet.pm +++ b/lib/DBIx/Class/ResultSet.pm @@ -207,11 +207,23 @@ automatically get one from e.g. a L called in scalar context: my $rs = $schema->resultset('CD')->search({ title => '100th Window' }); -IMPORTANT: If called on an object, proxies to new_result instead so +=over + +=item WARNING + +If called on an object, proxies to L instead, so my $cd = $schema->resultset('CD')->new({ title => 'Spoon' }); -will return a CD object, not a ResultSet. +will return a CD object, not a ResultSet, and is equivalent to: + + my $cd = $schema->resultset('CD')->new_result({ title => 'Spoon' }); + +Please also keep in mind that many internals call C directly, +so overloading this method with the idea of intercepting new result object +creation B. See also warning pertaining to L. + +=back =cut @@ -1748,18 +1760,15 @@ sub _rs_update_delete { my $attrs = { %{$self->_resolved_attrs} }; - # "needs" is a strong word here - if the subquery is part of an IN clause - no point of - # even adding the group_by. It will really be used only when composing a poor-man's - # multicolumn-IN equivalent OR set - my $needs_group_by_subq = defined $attrs->{group_by}; + my $existing_group_by = delete $attrs->{group_by}; + my $needs_subq = defined $existing_group_by; + + # simplify the joinmap and maybe decide if a subquery is necessary + my $relation_classifications = {}; - # simplify the joinmap and maybe decide if a grouping (and thus subquery) is necessary - my $relation_classifications; if (ref($attrs->{from}) eq 'ARRAY') { - if (@{$attrs->{from}} == 1) { - # not a fucking JOIN at all, quit with the dickery - $relation_classifications = {}; - } else { + # if we already know we need a subq, no point of classifying relations + if (!$needs_subq and @{$attrs->{from}} > 1) { $attrs->{from} = $storage->_prune_unused_joins ($attrs->{from}, $attrs->{select}, $cond, $attrs); $relation_classifications = $storage->_resolve_aliastypes_from_select_args ( @@ -1767,32 +1776,33 @@ sub _rs_update_delete { $attrs->{select}, $cond, $attrs - ) unless $needs_group_by_subq; # we already know we need a group, no point of resolving them + ); } } else { - $needs_group_by_subq ||= 1; # if {from} is unparseable assume the worst + $needs_subq ||= 1; # if {from} is unparseable assume the worst } - $needs_group_by_subq ||= exists $relation_classifications->{multiplying}; - - # if no subquery - life is easy-ish - unless ( - $needs_group_by_subq - or - keys %$relation_classifications # if any joins at all - need to wrap a subq - or - $self->_has_resolved_attr(qw/rows offset/) # limits call for a subq + # do we need anything like a subquery? + if ( + ! $needs_subq + and + ! keys %{ $relation_classifications->{restricting} || {} } + and + ! $self->_has_resolved_attr(qw/rows offset/) # limits call for a subq ) { # Most databases do not allow aliasing of tables in UPDATE/DELETE. Thus # a condition containing 'me' or other table prefixes will not work # at all. Tell SQLMaker to dequalify idents via a gross hack. - my $sqla = $rsrc->storage->sql_maker; - local $sqla->{_dequalify_idents} = 1; + my $cond = do { + my $sqla = $rsrc->storage->sql_maker; + local $sqla->{_dequalify_idents} = 1; + \[ $sqla->_recurse_where($self->{cond}) ]; + }; return $rsrc->storage->$op( $rsrc, $op eq 'update' ? $values : (), - $self->{cond}, + $cond, ); } @@ -1804,7 +1814,6 @@ sub _rs_update_delete { $rsrc->source_name, ) ); - my $existing_group_by = delete $attrs->{group_by}; # make a new $rs selecting only the PKs (that's all we really need for the subq) delete $attrs->{$_} for qw/collapse _collapse_order_by select _prefetch_selector_range as/; @@ -1835,13 +1844,15 @@ sub _rs_update_delete { ); } else { + # if all else fails - get all primary keys and operate over a ORed set # wrap in a transaction for consistency # this is where the group_by starts to matter - my $subq_group_by; - if ($needs_group_by_subq) { - $subq_group_by = $attrs->{columns}; - + if ( + $existing_group_by + or + keys %{ $relation_classifications->{multiplying} || {} } + ) { # make sure if there is a supplied group_by it matches the columns compiled above # perfectly. Anything else can not be sanely executed on most databases so croak # right then and there @@ -1854,7 +1865,7 @@ sub _rs_update_delete { if ( join ("\x00", sort @current_group_by) ne - join ("\x00", sort @$subq_group_by ) + join ("\x00", sort @{$attrs->{columns}} ) ) { $self->throw_exception ( "You have just attempted a $op operation on a resultset which does group_by" @@ -1865,12 +1876,14 @@ sub _rs_update_delete { ); } } + + $subrs = $subrs->search({}, { group_by => $attrs->{columns} }); } my $guard = $storage->txn_scope_guard; my @op_condition; - for my $row ($subrs->search({}, { group_by => $subq_group_by })->cursor->all) { + for my $row ($subrs->cursor->all) { push @op_condition, { map { $idcols->[$_] => $row->[$_] } (0 .. $#$idcols) @@ -2308,7 +2321,11 @@ Passes the hashref of input on to L. sub new_result { my ($self, $values) = @_; - $self->throw_exception( "new_result needs a hash" ) + + $self->throw_exception( "new_result takes only one argument - a hashref of values" ) + if @_ > 2; + + $self->throw_exception( "new_result expects a hashref" ) unless (ref $values eq 'HASH'); my ($merged_cond, $cols_from_relations) = $self->_merge_with_rscond($values); @@ -2598,7 +2615,6 @@ This can be applied recursively, and will work correctly for a structure with an arbitrary depth and width, as long as the relationships actually exists and the correct column data has been supplied. - Instead of hashrefs of plain related data (key/value pairs), you may also pass new or inserted objects. New objects (not inserted yet, see L), will be inserted into their appropriate tables. @@ -2643,7 +2659,8 @@ it is a simple shortcut for C<< $self->new_result($attrs)->insert >>, a lot of the internals simply never call it, so your override will be bypassed more often than not. Override either L or L depending on how early in the -L process you need to intervene. +L process you need to intervene. See also warning pertaining to +L. =back @@ -2721,7 +2738,7 @@ database! year => 2005, }); - if( $cd->in_storage ) { + if( !$cd->in_storage ) { # do some stuff $cd->insert; } @@ -2792,20 +2809,6 @@ L and L instead. Don't forget to call L to save the newly created row to the database! - my $cd = $schema->resultset('CD')->update_or_new( - { - artist => 'Massive Attack', - title => 'Mezzanine', - year => 1998, - }, - { key => 'cd_artist_title' } - ); - - if( $cd->in_storage ) { - # do some stuff - $cd->insert; - } - =cut sub update_or_create { @@ -3999,6 +4002,12 @@ to Earth' and a cd with title 'Popular'. If you want to fetch related objects from other tables as well, see C below. + NOTE: An internal join-chain pruner will discard certain joins while + constructing the actual SQL query, as long as the joins in question do not + affect the retrieved result. This for example includes 1:1 left joins + that are not part of the restriction specification (WHERE/HAVING) nor are + a part of the query selection. + For more help on using joins with search, see L. =head2 prefetch @@ -4293,7 +4302,7 @@ attribute, this setting is ignored and an appropriate warning is issued. Adds to the WHERE clause. # only return rows WHERE deleted IS NULL for all searches - __PACKAGE__->resultset_attributes({ where => { deleted => undef } }); ) + __PACKAGE__->resultset_attributes({ where => { deleted => undef } }); Can be overridden by passing C<< { where => undef } >> as an attribute to a resultset. @@ -4324,12 +4333,13 @@ L. =over 4 -=item Value: ( 'update' | 'shared' ) +=item Value: ( 'update' | 'shared' | \$scalar ) =back Set to 'update' for a SELECT ... FOR UPDATE or 'shared' for a SELECT -... FOR SHARED. +... FOR SHARED. If \$scalar is passed, this is taken directly and embedded in the +query. =cut