Writing Data

Write data to the local SQLite database and manage the upload queue with the PowerSync SDK.

Write data using SQL INSERT, UPDATE, or DELETE statements. PowerSync automatically queues these writes and uploads them to your backend via the uploadData() function in your backend connector.

Basic Write Operations

TypeScript

// Insert a new todo
await db.execute(
  'INSERT INTO todos (id, created_at, list_id, description) VALUES (uuid(), date(), ?, ?)',
  [listId, 'Buy groceries']
);

// Update a todo
await db.execute(
  'UPDATE todos SET completed = 1, completed_at = date() WHERE id = ?',
  [todoId]
);

// Delete a todo
await db.execute('DELETE FROM todos WHERE id = ?', [todoId]);

Best practice: Use UUIDs when inserting new rows on the client side. UUIDs can be generated offline/locally, allowing for unique identification of records created in the client database before they are synced to the server. See Client ID for more details.

ORM Support

PowerSync integrates with popular ORM libraries, which provide type safety and additional tooling. Using an ORM is often preferable to writing raw SQL queries, especially for common operations.

See ORM Support to learn which ORMs PowerSync supports and how to get started.

Write Operations and Upload Queue

PowerSync automatically queues writes and uploads them to your backend. The upload queue stores three types of operations:

Operation	Purpose	Contents	SQLite Statement
PUT	Create new row	Contains the value for each non-null column	Generated by INSERT statements.
PATCH	Update existing row	Contains the row id, and value of each changed column.	Generated by UPDATE statements.
DELETE	Delete existing row	Contains the row id	Generated by DELETE statements.

The SDK automatically processes this queue by calling your uploadData() function. For a detailed breakdown of when and how uploadData() is called, including triggers, throttling, retry behavior, and error handling, see When uploadData() is Called.

For details on how to structure your backend to accept these writes, see Writing Client Changes.

Advanced Topics

• Usage Examples - Code examples for common use cases