When there is a parent-child relationship between GQL schemas, you can create a single query to retrieve parent documents and their children documents using a special field in the projection called **\_children**. With **\_children**, you can formulate the child query with the child schema using arguments similarly as with regular GQL queries. 

Example:

The following example shows the parent query is used with the **StartPage** schema and the child query is used with the **BiographyPage** schema.

**Response**

The following example shows the parent query is used with the **BloglistPageType** schema and the child query is used with the **BlogitemPageType** schema. So for every matching parent item in the blog list, the items for each parent are retrieved and shown in a single response.