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Writing Data

Mutations can insert, update, and remove data from database tables.

Inserting new documents​

You can create new documents in the database with the db.insert method:

export default mutation(async ({ db }, { name }) => {
  const taskId = await db.insert("tasks", { name });
  …

The second argument to db.insert is a JavaScript object with data for the new document.

The same types of values that can be passed into and returned from queries and mutations can be written into the database. See Field Values for the full list of supported types.

The insert method returns a globally unique ID for the newly inserted document.

Updating existing documents​

Given an existing document ID the document can be updated using the following methods:

  1. The db.patch method will add new fields and override existing fields of the existing document:
export default mutation(async ({ db }, { id, tag }) => {
  const task = await db.get(id);
  console.log(task); // prints {name: "Foo"}
  await db.patch("tasks", id, {tag});
  const task = await db.get(id);
  console.log(task); // prints {name: "Foo", tag: "Bar"}
  …
  1. The db.replace method will replace the existing document entirely, potentially removing existing fields:
export default mutation(async ({ db }, { id, tag }) => {
  const task = await db.get(id);
  console.log(task); // prints {name: "Foo"}
  await db.replace("tasks", id, {tag});
  const task = await db.get(id);
  console.log(task); // prints {tag: "Bar"}
  …

Deleting documents​

Given an existing document ID the document can be removed from the table with the db.delete method.

export default mutation(async ({ db }, { id }) => {
  await db.delete(id);
});