Upsert mutation

An upsert query will insert an object into the database in case there is no conflict with another row in the table. In case there is a conflict with one or more rows, it will either update the fields of the conflicted rows or ignore the request.

Convert insert mutation to upsert

Note

Only tables with update permissions are upsertable. i.e. a table’s update permissions are respected before updating an existing row in case of a conflict.

To convert an insert mutation into an upsert, you need to specify a unique or primary key constraint and the columns to be updated in the case of a violation of that constraint using the on_conflict argument. You can specify a constraint using the constraint field and choose the columns to update using the update_columns field of the argument. The value of the update_columns field determines the behaviour of the upsert request in case of conflicts.

Fetching Postgres constraint names

You can fetch the name of unique or primary key constraints by querying the information_schema.table_constraints table. GraphQL Engine will automatically generate constraint names as enum values for constraint (try autocompleting in GraphiQL). Typically, the constraint is automatically named as <table-name>_<column-name>_key.

Update selected columns on conflict

Insert a new object in the author table or, if the primary key constraint, author_pkey, is violated, update the columns specified in update_columns:

mutation upsert_author {
  insert_author(
    objects: [
      {name: "John", id: 10}
    ],
    on_conflict: {
      constraint: author_pkey,
      update_columns: [name]
    }
  ) {
    affected_rows
    returning{
      id
      name
    }
  }
}
mutation upsert_author { insert_author( objects: [ {name: "John", id: 10} ], on_conflict: { constraint: author_pkey, update_columns: [name] } ) { affected_rows returning{ id name } } }
{ "data": { "insert_author": { "affected_rows": 1, "returning": [ { "name": "John", "id": 10 } ] } } }

Ignore request on conflict

If update_columns is an empty array then GraphQL Engine ignore changes on conflict. Insert a new object into the author table or, if the unique constraint, author_name_key, is violated, ignore the request

mutation upsert_author {
  insert_author(
    objects: [
      {name: "John", id: 10}
    ],
    on_conflict: {
      constraint: author_name_key,
      update_columns: []
    }
  ) {
    affected_rows
  }
}
mutation upsert_author { insert_author( objects: [ {name: "John", id: 10} ], on_conflict: { constraint: author_name_key, update_columns: [] } ) { affected_rows } }
{ "data": { "insert_author": { "affected_rows": 0 } } }

In this case, the insert mutation is ignored because there is a conflict.

Upsert in nested mutations

You can specify on_conflict clause while inserting nested objects

mutation upsert_author_article {
  insert_author(
    objects: [
      {
        id: 10,
        name: "John",
        articles: {
          data: [
            {
              id: 1,
              title: "Article 1 title",
              content: "Article 1 content"
            }
          ],
          on_conflict: {
            constraint: article_pkey,
            update_columns: [title, content]
          }
        }
      }
    ]
  ) {
    affected_rows
  }
}
mutation upsert_author_article { insert_author( objects: [ { id: 10, name: "John", articles: { data: [ { id: 1, title: "Article 1 title", content: "Article 1 content" } ], on_conflict: { constraint: article_pkey, update_columns: [title, content] } } } ] ) { affected_rows } }
{ "data": { "insert_author": { "affected_rows": 2 } } }

Edge-cases

Nested upserts will fail when:

  • In case of an array relationship, parent upsert does not affect any rows (i.e. update_columns: [] for parent and a conflict occurs)
  • In case of an object relationship, nested object upsert does not affect any row (i.e. update_columns: [] for nested object and a conflict occurs)

To allow upserting in these cases, set update_columns: [<conflict-column>]. By doing this, in case of a conflict, the conflicted column will be updated with the new value (which is the same value it had before and hence will effectively leave it unchanged) and will allow the upsert to go through.