Version: 0.15.x

Mutations

Graphback provides three mutation types for every model.

  • create<Type>: create a new item in the database of and return the created object in the response.
  • update<Type>: update an existing item in the database and return the updated object in the response.
  • delete<Type>: delete a single item in the database and return the deleted object in the response.

Create#

The create mutation allows the client to insert a new item in the database.

The mutation follows the naming format create<Type>:

type Mutation {
createNote(input: CreateNoteInput!): Note
}

Arguments:

  • input: input type created by Graphback for creating a new Note object.

Graphback creates a Create<Type>Input input type for each of the data models you define, where the create configuration is enabled. Relationship object fields in models map to the foreign key field in the database.

Each input field in Create<Type>Input directly maps to the fields in the model. With the exception of the primary field, each field added to the input type preserves field nullability from the original model.

note

Primary fields will be nullable in the input type as they are often auto-generated by the database.

Take the following Note model as an example.

""" @model """
type Note {
id: ID!
title: String!
description: String
"""
@manyToOne(field: 'notes', key: 'authorId')
"""
author: User
}
input CreateNoteInput {
id: ID
title: String!
description: String
authorId: ID
}

The CreateNoteInput input type is created from the Note model.

Example of a typical create mutation on Note:

mutation {
createNote(input: {
title: "Do shopping",
description: "Get groceries for party",
authorId: 19
}) {
id
title
description
author {
id
name
}
}
}

You can also perform create mutations on models with GraphQL type fields which map to a JSON column or an embedded document (MongoDB):

""" @model """
type Note {
id: ID!
title: String!
description: String
metadata: NoteMetadata
}
"""Regular non-model GraphQL type"""
type NoteMetadata {
createdAt: String
updatedAt: String
}
input CreateNoteInput {
id: ID
title: String!
description: String
metadata: CreateNoteMetadataInput
}
input CreateNoteMetadataInput {
createdAt: String
updatedAt: String
}

Graphback generates the appropriate input types for regular types that do not map to any database table/collection but are used as a field in a model.

You can create a new Note with NoteMetadata in a single mutation:

mutation {
createNote(input: {
title: "Do shopping",
description: "Get groceries for party",
metadata: {
createdAt: "2340324024",
updatedAt: "2340324024"
}
}) {
id
title
description
metadata {
createdAt
updatedAt
}
}
}

Update#

The update mutation allows the client to update an existing item in the database.

The mutation follows the naming format update<Type>:

type Mutation {
updateNote(input: MutateNoteInput!): Note
}

Arguments:

  • input: input type created by Graphback for updating an existing Note object.

Graphback creates a Mutate<Type>Input input type for each of the data models you define, where either the update or delete configuration is enabled. Relationship object fields in models map to the foreign key field in the database.

With the exception of the primary field, all input fields are set to nullable to allow for partial updates. Graphback uses the primary field to ensure the correct item is being updated.

Take the following Note model as an example.

""" @model """
type Note {
id: ID!
title: String!
description: String
"""
@manyToOne(field: 'notes', key: 'authorId')
"""
author: User
}
input MutateNoteInput {
id: ID!
title: String
description: String
authorId: ID
}

The MutateNoteInput input type is created from the Note model.

Example of a typical create mutation on Note:

mutation {
updateNote(input: {
id: 10,
description: "Get remainder of groceries"
}) {
id
title
description
author {
id
name
}
}
}

You can also perform update mutations on models with GraphQL type fields which map to a JSON column or an embedded document (MongoDB):

""" @model """
type Note {
id: ID!
title: String!
description: String
metadata: NoteMetadata
}
"""Regular non-model GraphQL type"""
type NoteMetadata {
createdAt: String
updatedAt: String
}
input MutateNoteInput {
id: ID!
title: String
description: String
metadata: MutateNoteMetadataInput
}
input MutateNoteMetadataInput {
createdAt: String
updatedAt: String
}

Graphback generates the appropriate input types for regular GraphQL types that do not map to any database table/collection but are used as a field in a model.

You can update an existing Note with NoteMetadata in a single mutation:

mutation {
updateNote(input: {
id: 10,
description: "Get prosecco for party",
metadata: {
createdAt: "2340349036",
updatedAt: "2340349036"
}
}) {
id
title
description
metadata {
createdAt
updatedAt
}
}
}

Delete#

The delete mutation allows the client to delete an existing item from the database.

The mutation follows the naming format delete<Type>:

type Mutation {
deleteNote(input: MutateNoteInput!): Note
}

Arguments:

  • input: input type created by Graphback for updating an existing Note object.

Graphback creates a Mutate<Type>Input input type for each of the data models you define, when either the the delete or update CRUD configuration is enabled.

With the exception of the primary field, all input fields are set to nullable. Graphback uses the value from the primary field to ensure the correct is being deleted.

Take the following Note model as an example.

""" @model """
type Note {
id: ID!
title: String!
description: String
}
input MutateNoteInput {
id: ID!
title: String
description: String
}

The MutateNoteInput input type is created from the Note model. Each input field in MutateNoteInput maps to the fields defined in Note.

Example of a typical delete mutation on Note:

mutation {
deleteNote(input: {
id: 10
}) {
id
}
}
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