_invalidation.md

The mutation hooks generated by ZenStack automatically invalidates the queries that are potentially affected by the changes. For example, if you create a Post, the client.post.useFindMany() query will be automatically invalidated when the mutation succeeds. Invalidation causes cache to be purged and fresh data to be refetched.

The automatic invalidation takes care of nested read, write, and delete cascading.

1. Nested Read

Nested reads are also subject to automatic invalidation. For example, if you create a Post, the query made by

client.user.useFindUnique({ where: { id: userId }, include: { posts: true } });

will be invalidated.

2. Nested Write

Similarly, nested writes also trigger automatic invalidation. For example, if you create a Post in a nested update to User like:

updateUser.mutate({ where: { id: userId }, posts: { create: { title: 'post1' } } });

The mutation will cause queries like client.post.useFindMany() to be invalidated.

3. Delete Cascade

In ZModel, relations can be configured to cascade delete, e.g.:

model User {
    ...
    posts Post[]
}

model Post {
    ...
    user User @relation(fields: [userId], references: [id], onDelete: Cascade)
    userId Int
}

When a User is deleted, the Post entities it owns will be deleted automatically. The generated hooks takes cascade delete into account. For example, if you delete a User, Post model will be considered as affected and queries like client.post.useFindMany() will be invalidated.