detachPivot method

Future<void> detachPivot(String relName, dynamic relatedId)

Detach from pivot table by related model ID. Deleted from DB immediately.

Implementation

Future<void> detachPivot(
  String relName,
  dynamic relatedId,
) async {
  final rel = relations()[relName];

  if (rel == null) {
    throw Exception(
      "Relation '$relName' is not defined on $runtimeType."
    );
  }

  if (rel.type != RelationType.belongsToMany) {
    throw Exception(
      "detachPivotById() can only be used with belongsToMany relations. "
      "'$relName' is ${rel.type}."
    );
  }

  final parentId = toMap()[primaryKey];

  if (parentId == null) {
    throw Exception(
      "Cannot detachPivotById('$relName'): parent model is not saved."
    );
  }

  if (relatedId == null) {
    throw Exception(
      "Cannot detachPivotById('$relName'): relatedId is null."
    );
  }

  await dbService.delete(
    rel.pivotTable!,
    where:
      '${rel.pivotForeignKey} = ? AND ${rel.pivotRelatedKey} = ?',
    params: [parentId, relatedId],
  );

  // Optional: keep in-memory relation consistent if already loaded
  final current = getRelation(relName);
  if (current is List) {
    current.removeWhere(
      (e) =>
        (e as dynamic).toMap()[rel.child.primaryKey] == relatedId,
    );
  }
}