function onDeleteDelete(Model $model) { $modelPk = Model::primaryKeyName($model); if (!isset($this->through)) { $relatedClass = $this->foreignClass; } else { $relatedClass = $this->through; } $queryBuilder = new SqlBuilder(); $queryBuilder->from(Model::tableFor($relatedClass))->equal($this->foreignKey, $model->{$modelPk}); $source = Model::sourceFor($model); $source->executeStatement($queryBuilder->delete(), $queryBuilder->getPdoArguments()); }