---
title: "Atomic Data Modifications for Data Connect"
description: "Atomic Data Modifications for Data Connect"
published: "2025-05-06"
last_updated: "2025-05-06"
authors:
  - "Andrea Wu (Developer Advocate)"
categories:
  - "SQL Connect"
  - "GraphQL"
canonical_url: "https://firebase.blog/posts/2025/05/dataconnect-atomic-data-modifications"
---

# Atomic Data Modifications for Data Connect

*Published May 6, 2025 by Andrea Wu (Developer Advocate)*

---
> **Note:** Firebase Data Connect has been renamed to SQL Connect. Learn more in the [SQL Connect announcement](https://firebase.blog/posts/2026/04/whats-new-sql-connect).

When using databases, you need to ensure data consistency and prevent race conditions - especially in collaborative or high-traffic applications. Now, Data Connect has atomic operations that let you manage counters, lists, and other data structures:
- `inc` and `dec` to increment and decrement a field by the specified amount for `Int`, `Int64`, `Float`, `Date`, and `Timestamp` data types
- `add` and `remove` to add and remove items positionally to list types, except Vector lists
- `append`  and `prepend` to add to the end and beginning to list types, except Vector lists
This blog post will go through each one with an example.

### INC and DEC operators
Let’s say you’re building a banking app, and you need to increment and decrement the balance amounts in an account.

`inc` increments the field by the specified amount:

```graphql
mutation BankUpdateAmount($amount: Int!) {
  bank_update: {
    data: {
      balance_update: {
        inc: $amount
      }
    }
  }
}
```

`dec` decrements the field by the specified amount:

```graphql
mutation BankUpdateAmount($amount: Int!) {
  bank_update: {
    data: {
      balance_update: {
        dec: $amount
      }
    }
  }
}
```

### List operators
Now, let’s say you’re creating a todo list app, and a user needs to add and remove items to the to-do list.

`prepend` adds an item to the start of a list:

```graphql
mutation AddItemToStart($id: UUID!, $item: String!) {
  todoList_update: {
    id: $id,
    data: {
      items_update: { prepend: [$item] }
    }
  }
}
```

`append` adds an item to the end of a list:

```graphql
mutation AddItemToEnd($id: UUID!, $item: String!) {
  todoList_update: {
    id: $id,
    data: {
      items_update: { append: [$item] }
    }
  }
}
```

`add` adds to the end of the list only if the item doesn’t already exist in the list. To differentiate `add` from `append`, `append` will always add to the list, even if the item already exists in the list:

```graphql
mutation AddItemIfDNE($id: UUID!, $item: String!) {
  todoList_update: {
    id: $id,
    data: {
      items_update: {add: [$string]}
    }
  }
}
```

`remove` removes an item from a list if the list contains the value. If there is more than one entry with the value, the list removes all of them:

```graphql
mutation RemoveItem($id: UUID!, $item: String!) {
  todoList_update: {
    id: $id,
    data: {
      items_update: {remove: [$string]}
    }
  }
}
```

### Try it out!
These new features and improvements are designed to unlock new use cases and make Data Connect a more capable database service for your apps. We're excited to see what you build with it and these new features. Happy coding!