Add automatic naming of unique constraints

[dbsrgits/DBIx-Class.git] / lib / DBIx / Class / ResultSource.pm

diff --git a/lib/DBIx/Class/ResultSource.pm b/lib/DBIx/Class/ResultSource.pm
index eb58dd5..a5da754 100644 (file)
--- a/lib/DBIx/Class/ResultSource.pm
+++ b/lib/DBIx/Class/ResultSource.pm
@@ -292,13 +292,24 @@ constraint.
     constraint_name => [ qw/column1 column2/ ],
   );
 
+Alternatively, you can specify only the columns:
+
+  __PACKAGE__->add_unique_constraint([ qw/column1 column2/ ]);
+
+This will result in a unique constraint named C<table_column1_column2>, where
+C<table> is replaced with the table name.
+
 Unique constraints are used, for example, when you call
 L<DBIx::Class::ResultSet/find>. Only columns in the constraint are searched.
 
 =cut
 
 sub add_unique_constraint {
-  my ($self, $name, $cols) = @_;
+  my $self = shift;
+  my $cols = pop @_;
+  my $name = shift;
+
+  $name ||= $self->name_unique_constraint($cols);
 
   foreach my $col (@$cols) {
     $self->throw_exception("No such column $col on table " . $self->name)
@@ -310,6 +321,22 @@ sub add_unique_constraint {
   $self->_unique_constraints(\%unique_constraints);
 }
 
+=head2
+
+Return a name for a unique constraint containing the specified columns. These
+names consist of the table name and each column name, separated by underscores.
+
+For example, a constraint on a table named C<cd> containing the columns
+C<artist> and C<title> would result in a constraint name of C<cd_artist_title>.
+
+=cut
+
+sub name_unique_constraint {
+  my ($self, $cols) = @_;
+
+  return join '_', $self->name, @$cols;
+}
+
 =head2 unique_constraints
 
 Read-only accessor which returns the list of unique constraints on this source.