Tutorial 11 - Using Mutations to Delete an Item

Introduction

In this article we'll look at how to delete a record with a GraphQL mutation, but first of all, let's look at what deleting a record means (and how to undo it!).

What is Soft Deletion?

When we delete records with GraphQL, they are soft-deleted by default.

If you accidentally delete data, it may have been "soft deleted", and you may be able to recover it if you act quickly.

Think of soft-deletion as being a bit like a recycle bin:

• Records are given a deleted_at property with a date in 30 days time in platformOS's datetime format (ISO 8601)

• When the date is reached, the record will be permanently deleted.

• They are removed from the results of all queries by default (this includes all Siteglide tags)

• You can get ordinary recordsqueries to display soft-deleted records (only), see below:

query seeDeletedRecords {
  records(
    per_page: 20,
    filter: {
      deleted_at: {
        exists: true
      }
    },
    sort: {
      deleted_at: {
        order: ASC
      }
    }
  ) {
    results {
      id
      deleted_at
    }
  }
}

The results will be the same as in a normal query; it's helpful to add deleted_at to the results so you can see when they will be permanently deleted:

{
  "data": {
    "record_delete": {
      "id": "3",
      "deleted_at": "2024-01-02T15:15:55.666Z"
    }
  }
}

Recovering Soft Deleted Records

If a record has been soft-deleted by mistake, and has not yet been permanently deleted, you can recover it by setting the deleted_at property to null. Make sure to use the query above to find the ID of the record you want to recover and pass it in as a variable to the mutation below.

mutation recoverSoftDeletedRecord($id: ID!) {
  record_update(id: $id, record: {deleted_at: "null"}) {
    id
    deleted_at
  }
}

After changing deleted_at to null, the record becomes an ordinary record. It appears in queries and is no longer scheduled to be deleted. The mutation results should confirm that deleted_at is no longer set:

{
  "data": {
    "record_update": {
      "id": "3",
      "deleted_at": null
    }
  }
}

If you want to extend the amount of time the record stays in soft-deleted state, you can change the deleted_at property to set the deletion date to be further in the future (but this is an advanced method we won't cover here).

Deleting a Record

Building a record_delete mutation in explorer

Step 1) Find the ID of the Record you wish to Delete

Use another query to find the ID.

Step 2) Add the mutation keyword and a name

mutation deleteRecord {

}

Step 3) Add the records_delete mutation type

mutation deleteRecord {
  record_delete() {}
}

Step 4) Add the id of the record you wish to delete, with a variable if you like

mutation deleteRecord($id: ID!) {
  record_delete(
    id: $id
  ) {}
}

Step 5) Add a result to confirm the mutation's success

mutation deleteRecord($id: ID!) {
  record_delete(
    id: $id
  ) {
    id
    deleted_at
  }
}

A successful deletion may look like this:

{
  "data": {
    "record_delete": {
      "id": "3",
      "deleted_at": "2024-01-02T15:15:55.666Z"
    }
  }
}

Summary and Further Learning

You've now learned how to perform all four CRUD operations using GraphQL:

1. Create

2. Read (query)

3. Update

4. Delete

If you wish to programatically create, update or delete multiple records at once, it may be more efficient to use the following mutation types instead of looping:

• records_create_all

• records_update_all

• records_delete_all

Be very careful with those and make sure you test with data which is backed up. We recommend using any_table: false as a precaution.

In these mutation types, you use a filter to determine which records should be affected instead of only passing id. You need to add count to the results.

Next Time

Next time we'll look at how you can use a query to access data from multiple relational database tables, or in other words, view data from Siteglide datasources.