materialize

function materialize<TContext>(query): MaterializeWrapper<GetInlineResult<TContext>, TContext extends SingleResult ? true : false>;

Defined in: packages/db/src/query/builder/functions.ts:878

Materialize an includes subquery into a plain value on the parent row.

• For multi-row subqueries, the parent receives an Array<T> snapshot (equivalent to toArray()).
• For findOne() subqueries, the parent receives a single T | undefined value — undefined when no child matches.

The snapshot updates reactively: parent rows re-emit when the underlying children change.

Type Parameters

TContext

TContext extends Context

Parameters

query

QueryBuilder<TContext>

Returns

MaterializeWrapper<GetInlineResult<TContext>, TContext extends SingleResult ? true : false>

Example

// Multi-row: produces Array<Issue> on each project
select(({ p }) => ({
  ...p,
  issues: materialize(
    q.from({ i: issues }).where(({ i }) => eq(i.projectId, p.id)),
  ),
}))

// Singleton: produces Author | undefined on each post
select(({ p }) => ({
  ...p,
  author: materialize(
    q.from({ a: authors }).where(({ a }) => eq(a.id, p.authorId)).findOne(),
  ),
}))