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BelongsToMany

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publicclass| source

BelongsToMany

Extends:

Association → BelongsToMany

Many-to-many association with a join table.

When the join table has additional attributes, these can be passed in the options object:

UserProject = sequelize.define('user_project', {
  role: Sequelize.STRING
});
User.belongsToMany(Project, { through: UserProject });
Project.belongsToMany(User, { through: UserProject });
// through is required!

user.addProject(project, { through: { role: 'manager' }});

All methods allow you to pass either a persisted instance, its primary key, or a mixture:

Project.create({ id: 11 }).then(project => {
  user.addProjects([project, 12]);
});

If you want to set several target instances, but with different attributes you have to set the attributes on the instance, using a property with the name of the through model:

p1.UserProjects = {
  started: true
}
user.setProjects([p1, p2], { through: { started: false }}) // The default value is false, but p1 overrides that.

Similarly, when fetching through a join table with custom attributes, these attributes will be available as an object with the name of the through model.

user.getProjects().then(projects => {
  let p1 = projects[0]
  p1.UserProjects.started // Is this project started yet?
})

In the API reference below, add the name of the association to the method, e.g. for User.belongsToMany(Project) the getter will be user.getProjects().

See:

Method Summary

| Public Methods | | public |

add(sourceInstance: Model, newInstances: Model | Model[] | string[] | string | number[] | number, options: Object): Promise

Associate one or several rows with source instance.

| | | public |

count(instance: Model, options: Object): Promise<number>

Count everything currently associated with this, using an optional where clause.

| | | public |

create(sourceInstance: Model, values: Object, options: Object): Promise

Create a new instance of the associated model and associate it with this.

| | | public |

get(instance: Model, options: Object): Promise<Array<Model>>

Get everything currently associated with this, using an optional where clause.

| | | public |

has(sourceInstance: Model, instances: Model | Model[] | string[] | string | number[] | number, options: Object): Promise<boolean>

Check if one or more instance(s) are associated with this.

| | | public |

remove(sourceInstance: Model, oldAssociatedObjects: Model | Model[] | string | string[] | number | number[], options: Object): Promise

Un-associate one or more instance(s).

| | | public |

set(sourceInstance: Model, newAssociatedObjects: Model | Model[] | string[] | string | number[] | number, options: Object): Promise

Set the associated models by passing an array of instances or their primary keys.

| |

Inherited Summary

| From class Association | | public |

associationType: string

The type of the association.

| | | public |

source: Model

| | | public |

target: Model

| |

Public Methods

publicadd(sourceInstance: Model, newInstances: Model | Model[] | string[] | string | number[] | number, options: Object): Promise source

Associate one or several rows with source instance. It will not un-associate any already associated instance that may be missing from newInstances.

Params:

| Name | Type | Attribute | Description | | sourceInstance | Model | |

source instance to associate new instances with

| | newInstances | Model | Model[] | string[] | string | number[] | number |

  • optional

|

A single instance or primary key, or a mixed array of persisted instances or primary keys

| | options | Object |

  • optional

|

Options passed to through.findAll, bulkCreate and update

| | options.validate | Object |

  • optional

|

Run validation for the join model.

| | options.through | Object |

  • optional

|

Additional attributes for the join table.

|

Return:

| Promise |

publiccount(instance: Model, options: Object): Promise<number> source

Count everything currently associated with this, using an optional where clause.

Params:

| Name | Type | Attribute | Description | | instance | Model | |

instance

| | options | Object |

  • optional

|

find options

| | options.where | Object |

  • optional

|

An optional where clause to limit the associated models

| | options.scope | string | boolean |

  • optional

|

Apply a scope on the related model, or remove its default scope by passing false

|

Return:

| Promise<number> |

publiccreate(sourceInstance: Model, values: Object, options: Object): Promise source

Create a new instance of the associated model and associate it with this.

Params:

| Name | Type | Attribute | Description | | sourceInstance | Model | |

source instance

| | values | Object |

  • optional

|

values for target model

| | options | Object |

  • optional

|

Options passed to create and add

| | options.through | Object |

  • optional

|

Additional attributes for the join table

|

Return:

| Promise |

publicget(instance: Model, options: Object): Promise<Array<Model>> source

Get everything currently associated with this, using an optional where clause.

Params:

| Name | Type | Attribute | Description | | instance | Model | |

instance

| | options | Object |

  • optional

|

find options

| | options.where | Object |

  • optional

|

An optional where clause to limit the associated models

| | options.scope | string | boolean |

  • optional

|

Apply a scope on the related model, or remove its default scope by passing false

| | options.schema | string |

  • optional

|

Apply a schema on the related model

|

Return:

| Promise<Array<Model>> |

See:

  • Model for a full explanation of options

publichas(sourceInstance: Model, instances: Model | Model[] | string[] | string | number[] | number, options: Object): Promise<boolean> source

Check if one or more instance(s) are associated with this. If a list of instances is passed, the function returns true if all instances are associated

Params:

| Name | Type | Attribute | Description | | sourceInstance | Model | |

source instance to check for an association with

| | instances | Model | Model[] | string[] | string | number[] | number |

  • optional

|

Can be an array of instances or their primary keys

| | options | Object |

  • optional

|

Options passed to getAssociations

|

Return:

| Promise<boolean> |

publicremove(sourceInstance: Model, oldAssociatedObjects: Model | Model[] | string | string[] | number | number[], options: Object): Promise source

Un-associate one or more instance(s).

Params:

| Name | Type | Attribute | Description | | sourceInstance | Model | |

instance to un associate instances with

| | oldAssociatedObjects | Model | Model[] | string | string[] | number | number[] |

  • optional

|

Can be an Instance or its primary key, or a mixed array of instances and primary keys

| | options | Object |

  • optional

|

Options passed to through.destroy

|

Return:

| Promise |

publicset(sourceInstance: Model, newAssociatedObjects: Model | Model[] | string[] | string | number[] | number, options: Object): Promise source

Set the associated models by passing an array of instances or their primary keys. Everything that it not in the passed array will be un-associated.

Params:

| Name | Type | Attribute | Description | | sourceInstance | Model | |

source instance to associate new instances with

| | newAssociatedObjects | Model | Model[] | string[] | string | number[] | number |

  • optional

|

A single instance or primary key, or a mixed array of persisted instances or primary keys

| | options | Object |

  • optional

|

Options passed to through.findAll, bulkCreate, update and destroy

| | options.validate | Object |

  • optional

|

Run validation for the join model

| | options.through | Object |

  • optional

|

Additional attributes for the join table.

|

Return:

| Promise |