#BelongsToManyRepository

BelongsToManyRepository is a Relation Repository for handling BelongsToMany relationships.

Unlike other relationship types, BelongsToMany relationships need to be recorded through a junction table. When defining an association relationship in NocoBase, a junction table can be created automatically, or it can be explicitly specified.

#Class Methods

#find()

Finds associated objects

Signature

• async find(options?: FindOptions): Promise<M[]>

Details

The query parameters are consistent with Repository.find().

#findOne()

Finds an associated object, returning only one record

Signature

• async findOne(options?: FindOneOptions): Promise<M>

#count()

Returns the number of records that match the query conditions

Signature

• async count(options?: CountOptions)

Type

interface CountOptions
  extends Omit<SequelizeCountOptions, 'distinct' | 'where' | 'include'>,
    Transactionable {
  filter?: Filter;
}

#findAndCount()

Queries the database for a dataset and the total count under specific conditions.

Signature

• async findAndCount(options?: FindAndCountOptions): Promise<[any[], number]>

Type

type FindAndCountOptions = CommonFindOptions;

#create()

Creates an associated object

Signature

• async create(options?: CreateOptions): Promise<M>

#update()

Updates associated objects that meet the conditions

Signature

• async update(options?: UpdateOptions): Promise<M>

#destroy()

Deletes associated objects that meet the conditions

Signature

• async destroy(options?: TargetKey | TargetKey[] | DestroyOptions): Promise<Boolean>

#add()

Adds new associated objects

Signature

• async add( options: TargetKey | TargetKey[] | PrimaryKeyWithThroughValues | PrimaryKeyWithThroughValues[] | AssociatedOptions ): Promise<void>

Type

type PrimaryKeyWithThroughValues = [TargetKey, Values];

interface AssociatedOptions extends Transactionable {
  tk?:
    | TargetKey
    | TargetKey[]
    | PrimaryKeyWithThroughValues
    | PrimaryKeyWithThroughValues[];
}

Details

You can directly pass the targetKey of the associated object, or pass the targetKey along with the field values of the junction table.

Example

const t1 = await Tag.repository.create({
  values: { name: 't1' },
});

const t2 = await Tag.repository.create({
  values: { name: 't2' },
});

const p1 = await Post.repository.create({
  values: { title: 'p1' },
});

const PostTagRepository = new BelongsToManyRepository(Post, 'tags', p1.id);

// Pass targetKey
PostTagRepository.add([t1.id, t2.id]);

// Pass junction table fields
PostTagRepository.add([
  [t1.id, { tagged_at: '123' }],
  [t2.id, { tagged_at: '456' }],
]);

#set()

Sets associated objects

Signature

• async set( options: TargetKey | TargetKey[] | PrimaryKeyWithThroughValues | PrimaryKeyWithThroughValues[] | AssociatedOptions, ): Promise

Details

Parameters are the same as add()

#remove()

Removes the association with the given objects

Signature

• async remove(options: TargetKey | TargetKey[] | AssociatedOptions)

Type

interface AssociatedOptions extends Transactionable {
  tk?: TargetKey | TargetKey[];
}

#toggle()

Toggles associated objects.

In some business scenarios, it is often necessary to toggle associated objects. For example, a user can favorite a product, unfavorite it, and favorite it again. The toggle method can be used to quickly implement such functionality.

Signature

• async toggle(options: TargetKey | { tk?: TargetKey; transaction?: Transaction }): Promise<void>

Details

The toggle method automatically checks if the associated object already exists. If it exists, it is removed; if not, it is added.