Managing relations through the REST API

Defining relations between content-types (that are designated as entities in the database layers) is connecting entities with each other.

Relations between content-types can be managed through the admin panel or through REST requests sent to the Content API.

Relations can be connected, disconnected or set through the Content API by passing parameters in the body of the request:

Parameter name	Description	Type of update
connect	Connects new entities. Can be used in combination with disconnect. Can be used with positional arguments to define an order for relations.	Partial
disconnect	Disconnects entities. Can be used in combination with connect.	Partial
set	Set entities to a specific set. Using set will overwrite all existing connections to other entities. Cannot be used in combination with connect or disconnect.	Full

connect

Using connect in the body of a request performs a partial update, connecting the specified relations.

connect accepts either a shorthand or a longhand syntax. In the following examples, numbers refers to entity ids:

Syntax type	Syntax example
shorthand	connect: [2, 4]
longhand	connect: [{ id: 2 }, { id: 4 }]

You can also use the longhand syntax to reorder relations.

connect can be used in combination with disconnect.

caution

connect can not be used for media attributes.

Shorthand syntax example

Sending the following request updates the restaurant entity with id 1, using the categories attribute to connect the entity with entities with id 2 and 4:

Example request using the shorthand syntax

PUT http://localhost:1337/api/restaurants/1

{
  data: {
    categories: { 
      connect: [2, 4],
    }
  }
}

Longhand syntax example

Sending the following request updates the restaurant entity with id 1, using the categories attribute to connect the entity with entities with id 2 and 4:

Example request using the longhand syntax

PUT http://localhost:1337/api/restaurants/1

{
  data: {
    categories: { 
      connect: [
        { id: 2 },
        { id: 4 }
      ], 
    }
  }
}

Relations reordering

Positional arguments can be passed to the longhand syntax of connect to define the order of relations.

The longhand syntax accepts an array of objects, each object containing the id of the entry to be connected and an optional position object to define where to connect the relation.

Different syntaxes for different relations

The syntaxes described in this documentation are useful for one-to-many, many-to-many and many-ways relations.
For one-to-one, many-to-one and one-way relations, the syntaxes are also supported but only the last relation will be used, so it's preferable to use a shorter format (e.g.: { data: { category: 2 } }, see REST API documentation).

To define the position for a relation, pass one of the following 4 different positional attributes:

Parameter name and syntax	Description	Type
before: id	Positions the relation before the given id.	Entry id
after: id	Positions the relation after the given id.	Entry id
start: true	Positions the relation at the start of the existing list of relations.	Boolean
end: true	Positions the relation at the end of the existing list of relations.	Boolean

The position argument is optional and defaults to position: { end: true }.

Sequential order

Since connect is an array, the order of operations is important as they will be treated sequentially (see combined example below).

caution

The same relation should not be connected more than once, otherwise it would return a Validation error by the API.

Basic example

Consider the following record in the database:

categories: [
  { id: 1 }
  { id: 2 }
]

Sending the following request updates the restaurant entity with id 1, connecting a relation of entity with id 3 for the categories attribute and positioning it before the entity with id 2:

Example request to update the position of one relation

PUT http://localhost:1337/api/restaurants/1

{
  data: {
    categories: {
      connect: [
        { id: 3, position: { before: 2 } },
      ]
    }
  }
}

Combined example

Consider the following record in the database:

categories: [
  { id: 1 }
  { id: 2 }
]

Sending the following example in the request body of a PUT request updates multiple relations:

Example request to reorder several relations

PUT http://localhost:1337/api/restaurants/1

{
  data: {
    categories: {
      connect: [
        { id: 6, position: { after: 1} },
        { id: 7, position: { before: 2 } },
        { id: 8, position: { end: true } },
        { id: 9 },
        { id: 10, position: { start: true } },
      ]
    }
  }
}

Omitting the position argument (as in id: 9) defaults to position: { end: true }. All other relations are positioned relative to another existing id (using after or before) or relative to the list of relations (using start or end). Operations are treated sequentially in the order defined in the connect array, so the resulting database record will be the following:

categories: [
  { id: 10 },
  { id: 1 },
  { id: 6 },
  { id: 7 },
  { id: 2 },
  { id: 8 },
  { id: 9 }
]

disconnect

Using disconnect in the body of a request performs a partial update, disconnecting the specified relations.

disconnect accepts either a shorthand or a longhand syntax. In the following examples, numbers refers to entity ids:

Syntax type	Syntax example
shorthand	disconnect: [2, 4]
longhand	disconnect: [{ id: 2 }, { id: 4 }]

disconnect can be used in combination with connect.

Shorthand syntax example

Sending the following request updates the restaurant entity with id 1, disconnecting the relations with entities with id 2 and 4:

Example request using the shorthand syntax

PUT http://localhost:1337/api/restaurants/1

{
  data: {
    categories: { 
      disconnect: [2, 4],
    }
  }
}

Longhand syntax example

Sending the following request updates the restaurant entity with id 1, disconnecting the relations with entities with id 2 and 4:

Example request using the longhand syntax

PUT http://localhost:1337/api/restaurants/1

{
  data: {
    categories: { 
      disconnect: [
        { id: 2 },
        { id: 4 }
      ], 
    }
  }
}

set

Using set performs a full update, replacing all existing relations with the ones specified, in the order specified.

set accepts a shorthand or a longhand syntax. In the following examples, numbers refers to entity ids:

Syntax type	Syntax example
shorthand	set: [2, 4]
longhand	set: [{ id: 2 }, { id: 4 }]

As set replaces all existing relations, it should not be used in combination with other parameters. To perform a partial update, use connect and disconnect.

Omitting set

Omitting any parameter is equivalent to using set.
For instance, the following 3 syntaxes are all equivalent:

• data: { categories: set: [{ id: 2 }, { id: 4 }] }}
• data: { categories: set: [2, 4] }}
• data: { categories: [2, 4] } (as used in the REST API documentation)

Shorthand syntax example

Sending the following request updates the restaurant entity with id 1, replacing all previously existing relations and using the categories attribute to connect the entity with entities with id 2 and 4:

Example request using the shorthand syntax with set

PUT http://localhost:1337/api/restaurants/1

{
  data: {
    categories: { 
      set: [2, 4],
    }
  }
}

Longhand syntax example

Sending the following request updates the restaurant entity with id 1, replacing all previously existing relations and using the categories attribute to connect the entity with entities with id 2 and 4:

Example request using the longhand syntax with set

PUT http://localhost:1337/api/restaurants/1

{
  data: {
    categories: { 
      set: [
        { id: 2 },
        { id: 4 }
      ], 
    }
  }
}