# ContextSchema

# Type Alias: ContextSchema

```ts
type ContextSchema = Record<string, unknown>;
```

Defined in: [packages/db/src/query/builder/types.ts:68](https://github.com/TanStack/db/blob/main/packages/db/src/query/builder/types.ts#L68)

ContextSchema - The shape of available tables/collections in a query context

This is simply a record mapping table aliases to their TypeScript types.
It evolves as the query progresses:
- Initial: Just the `from()` table
- After joins: Includes all joined tables with proper optionality
- In subqueries: May be a subset of the outer query's schema