Untitled :: DataStax Astra DB Classic Documentation

Delete data

A mutation can be turned into a delete operation by starting the mutation name with delete or remove. A mutation will also be a delete operation if it is annotated with @cql_delete. The mutation must take a single argument that is an input type for a mapped entity, or individual primary key arguments like retrieving operations. If successful, the mutation will return a Boolean value.

At runtime, all partition key fields must be present, and a prefix of the clustering columns can be present (if using a single object argument, other fields will be ignored). The delete operation targets a single row if it operates on a full primary key, or multiple rows otherwise.

Let’s add another book "Pride and Prejudice" with an insertBook(), so that you can delete the book using deleteBook() to illustrate deleting data:

insert book
delete book
delete result

mutation insertAnotherBook {
 insertBook(book: {
   title: "Pride and Prejudice",
   isbn: "", author: "Jane Austen" }
  ) {
      title
      isbn
      author
  }
}

mutation deletepap {
  deleteBook(book: { title:"Pride and Prejudice"})
}

{
  "data": {
    "deleteBook": true
  }
}

To check for the existence of a record before deleting, use either method discussed above. This example shows the use of the directive @cql_delete( ifExists: true):

mutation
insert library collection
delete book with ifExists
delete result

deleteLibCollection(libColl: LibCollectionInput!): Boolean @cql_delete(ifExists: true)

mutation insertCSRMPhoto {
  insertLibColl(libColl: { type: "photo", lib_id: 12345, lib_name: "CSRM" }) {
    type
    lib_id
    lib_name
  }
}

mutation insertCSRMBook {
  insertLibColl(libColl: { type: "book", lib_id: 12345, lib_name: "CSRM" }) {
    type
    lib_id
    lib_name
  }
}
mutation insertWSacPhoto {
  insertLibColl(libColl: { type: "photo", lib_id: 12543, lib_name: "West Sacramento Historical Society" }) {
    type
    lib_id
    lib_name
  }
}

mutation insertDavisBook {
  insertLibColl(libColl: { type: "book", lib_id: 66666, lib_name: "Davis Historical Museum" }) {
    type
    lib_id
    lib_name
  }
}

# Note that the lib_id is INCORRECT,
# SO THIS delete operation will fail
mutation deleteDHM {
  deleteLibCollection(libColl: {
    type:"book",
    lib_id: 66665,
    lib_name: "Davis Historical Museum"
  })
}

  "data": {
    "deleteLibCollection": false
  }
}