18 die new Eexception("Referenced table must be an instance of a table object") if not UNIVERSAL::isa($args{'ReferencedTable'},'IMPL::SQL::Schema::Table');
20 die new Exception("Referenced columns must be a not empty list of columns") if not UNIVERSAL::isa($args{'ReferencedColumns'},'ARRAY') or not scalar(@{$args{'ReferencedColumns'}});
28 die new Exception('A foreing key columns doesn\'t match refenced columns') if grep { not $_->Type->isSame((shift @ColumnsCopy)->Type)} @{$this->Columns};
31 die new Exception('The foreign key must match to the primary key of the referenced table',$this->Name) if grep { not $_->Type->isSame(shift(@ColumnsCopy)->Type)} @{$ForeingPK->Columns};