[Bast-commits] r6275 - in
DBIx-Class/0.08/branches/joined_count/lib/DBIx/Class: . Storage
ribasushi at dev.catalyst.perl.org
ribasushi at dev.catalyst.perl.org
Fri May 15 21:35:06 GMT 2009
Author: ribasushi
Date: 2009-05-15 21:35:06 +0000 (Fri, 15 May 2009)
New Revision: 6275
Modified:
DBIx-Class/0.08/branches/joined_count/lib/DBIx/Class/ResultSet.pm
DBIx-Class/0.08/branches/joined_count/lib/DBIx/Class/Storage/DBI.pm
Log:
A workable fix for the resultset multicol update/delete debacle - by default fallback to per-row deletions, with the ability to overide this behavior for various storage drivers
Modified: DBIx-Class/0.08/branches/joined_count/lib/DBIx/Class/ResultSet.pm
===================================================================
--- DBIx-Class/0.08/branches/joined_count/lib/DBIx/Class/ResultSet.pm 2009-05-15 21:21:24 UTC (rev 6274)
+++ DBIx-Class/0.08/branches/joined_count/lib/DBIx/Class/ResultSet.pm 2009-05-15 21:35:06 UTC (rev 6275)
@@ -1326,6 +1326,18 @@
return $_[0]->reset->next;
}
+
+# _update_delete_via_subq
+#
+# Presence of some rs attributes requires a subquery to reliably
+# update/deletre
+#
+
+sub _update_delete_via_subq {
+ return $_[0]->_has_attr (qw/join seen_join group_by row offset page/);
+}
+
+
# _cond_for_update_delete
#
# update/delete require the condition to be modified to handle
@@ -1340,18 +1352,6 @@
# No-op. No condition, we're updating/deleting everything
return $cond unless ref $full_cond;
- # Some attributes when present require a subquery
- # This might not work on some database (mysql), but...
- # it won't work without the subquery either so who cares
- if ($self->_has_attr (qw/join seen_join group_by row offset page/) ) {
-
- foreach my $pk ($self->result_source->primary_columns) {
- $cond->{$pk} = { -in => $self->get_column($pk)->as_query };
- }
-
- return $cond;
- }
-
if (ref $full_cond eq 'ARRAY') {
$cond = [
map {
@@ -1391,7 +1391,7 @@
else {
$self->throw_exception("Can't update/delete on resultset with condition unless hash or array");
}
-
+
return $cond;
}
@@ -1414,9 +1414,14 @@
sub update {
my ($self, $values) = @_;
- $self->throw_exception("Values for update must be a hash")
+ $self->throw_exception('Values for update must be a hash')
unless ref $values eq 'HASH';
+ # rs operations with subqueries are Storage dependent - delegate
+ if ($self->_update_delete_via_subq) {
+ return $self->result_source->storage->subq_update_delete($self, 'update', $values);
+ }
+
my $cond = $self->_cond_for_update_delete;
return $self->result_source->storage->update(
@@ -1441,7 +1446,7 @@
sub update_all {
my ($self, $values) = @_;
- $self->throw_exception("Values for update must be a hash")
+ $self->throw_exception('Values for update_all must be a hash')
unless ref $values eq 'HASH';
foreach my $obj ($self->all) {
$obj->set_columns($values)->update;
@@ -1472,10 +1477,15 @@
=cut
sub delete {
- my ($self) = @_;
- $self->throw_exception("Delete should not be passed any arguments")
- if $_[1];
+ my $self = shift;
+ $self->throw_exception('delete does not accept any arguments')
+ if @_;
+ # rs operations with subqueries are Storage dependent - delegate
+ if ($self->_update_delete_via_subq) {
+ return $self->result_source->storage->subq_update_delete($self, 'delete');
+ }
+
my $cond = $self->_cond_for_update_delete;
$self->result_source->storage->delete($self->result_source, $cond);
@@ -1498,7 +1508,10 @@
=cut
sub delete_all {
- my ($self) = @_;
+ my $self = shift;
+ $self->throw_exception('delete_all does not accept any arguments')
+ if @_;
+
$_->delete for $self->all;
return 1;
}
Modified: DBIx-Class/0.08/branches/joined_count/lib/DBIx/Class/Storage/DBI.pm
===================================================================
--- DBIx-Class/0.08/branches/joined_count/lib/DBIx/Class/Storage/DBI.pm 2009-05-15 21:21:24 UTC (rev 6274)
+++ DBIx-Class/0.08/branches/joined_count/lib/DBIx/Class/Storage/DBI.pm 2009-05-15 21:35:06 UTC (rev 6275)
@@ -1051,6 +1051,85 @@
return $self->_execute('delete' => [], $source, $bind_attrs, @_);
}
+# We were sent here because the $rs contains a complex search
+# which will require a subquery to select the correct rows
+# (i.e. joined or limited resultsets)
+#
+# Genarating a single PK column subquery is trivial and supported
+# by all RDBMS. However if we have a multicolumn PK, things get ugly.
+# Look at multipk_update_delete()
+sub subq_update_delete {
+ my $self = shift;
+ my ($rs, $op, $values) = @_;
+
+ if ($rs->result_source->primary_columns == 1) {
+ return $self->_onepk_update_delete (@_);
+ }
+ else {
+ return $self->_multipk_update_delete (@_);
+ }
+}
+
+# Generally a single PK resultset operation is trivially expressed
+# with PK IN (subquery). However some databases (mysql) do not support
+# modification of a table mentioned in the subselect. This method
+# should be overriden in the appropriate storage class to be smarter
+# in such situations
+sub _onepk_update_delete {
+
+ my $self = shift;
+ my ($rs, $op, $values) = @_;
+
+ my $rsrc = $rs->result_source;
+ my @pcols = $rsrc->primary_columns;
+
+ return $self->$op (
+ $rsrc,
+ $op eq 'update' ? $values : (),
+ { $pcols[0] => { -in => $rs->get_column ($pcols[0])->as_query } },
+ );
+}
+
+# ANSI SQL does not provide a reliable way to perform a multicol-PK
+# resultset update/delete involving subqueries. So resort to simple
+# (and inefficient) delete_all style per-row opearations, while allowing
+# specific storages to override this with a faster implementation.
+#
+# We do not use $row->$op style queries, because resultset update/delete
+# is not expected to cascade (this is what delete_all/update_all is for).
+#
+# There should be no race conditions as the entire operation is rolled
+# in a transaction.
+sub _multipk_update_delete {
+ my $self = shift;
+ my ($rs, $op, $values) = @_;
+
+ my $rsrc = $rs->result_source;
+ my @pcols = $rsrc->primary_columns;
+
+ my $guard = $self->txn_scope_guard;
+
+ my $subrs_cur = $rs->search ({}, { columns => \@pcols })->cursor;
+ while (my @pks = $subrs_cur->next) {
+
+ my $cond;
+ for my $i (0.. $#pcols) {
+ $cond->{$pcols[$i]} = $pks[$i];
+ }
+
+ $self->$op (
+ $rsrc,
+ $op eq 'update' ? $values : (),
+ $cond,
+ );
+ }
+
+ $guard->commit;
+
+ return 1;
+}
+
+
sub _select {
my $self = shift;
my $sql_maker = $self->sql_maker;
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