Update

The update operation changes property values on nodes or edges that match a where predicate. Updates are validated against the schema before they commit.

Basic syntax

An update has three parts: the target type, a set block with the new values, and a where clause that selects which rows to change.

query complete_task($slug: String) {
    update Task set {
        status: "completed"
    }
    where slug = $slug
}

omnigraph change --uri ./graph.omni \
    --query mutations.gq \
    --name complete_task \
    --params '{"slug": "auth"}'

Or via the HTTP API:

curl -X POST http://localhost:8080/change \
    -H "Content-Type: application/json" \
    -d '{
        "query_source": "query complete_task($slug: String) { update Task set { status: \"completed\" } where slug = $slug }",
        "query_name": "complete_task",
        "params": {"slug": "auth"},
        "branch": "main"
    }'

Updating multiple properties

The set block accepts any number of properties. All listed properties are updated atomically in a single transaction:

query reassign_task($slug: String, $new_title: String, $new_status: String) {
    update Task set {
        title: $new_title,
        status: $new_status
    }
    where slug = $slug
}

Properties not listed in set are left unchanged.

now() is a valid value in both set and where:

query touch_task($slug: String) {
    update Task set { last_seen_at: now() }
    where slug = $slug
}

Where clause operators

The where clause supports the following comparison operators:

Examples:

query bump_ages() {
    update Person set { age: 0 }
    where age < 0
}

query clear_old_bios($cutoff: Date) {
    update Person set { bio: null }
    where created_at < $cutoff
}

One where predicate per update

Each update operation takes exactly one where predicate. To filter on multiple conditions, select the relevant keys with a read query first and then issue narrower updates.

query complete_task($slug: String) {
    update Task set { status: "completed" }
    where slug = $slug
}

Key properties are immutable

Properties annotated with @key cannot be changed after insertion. Attempting to include a @key property in a set block produces a compile-time error:

node Task {
    slug: String @key
    title: String @index
    status: enum(pending, in_progress, completed)
}

# This will fail at compile time:
query rename_task($slug: String, $new_slug: String) {
    update Task set { slug: $new_slug }
    where slug = $slug
}

To change a key value, delete the old node and insert a new one.

Edge updates are not supported

update only applies to nodes. Mutating an edge's properties is rejected at typecheck time. To change an edge's properties, run two separate mutations on the same branch, first a delete, then an insert with the new values. Combining the two in one mutation is rejected by rule D2 (see Mutations overview).

Transactional guarantees

If any row fails validation during an update. For example, setting a value outside a @range constraint or violating a @unique constraint. The entire update is rolled back. Either all matching rows are updated or none are.