voluptasmollitia/docs-exp/firestore_lite.queryconstraint.md

Monorepo for the Firebase JavaScript SDK

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[Home](./index.md) &gt; [@firebase/firestore](./firestore.md) &gt; [lite](./firestore_lite.md) &gt; [QueryConstraint](./firestore_lite.queryconstraint.md)

## QueryConstraint class

A `QueryConstraint` is used to narrow the set of documents returned by a Firestore query. `QueryConstraint`<!-- -->s are created by invoking [where()](./firestore_.where.md)<!-- -->, [orderBy()](./firestore_.orderby.md)<!-- -->, [startAt()](./firestore_.startat.md)<!-- -->, [startAfter()](./firestore_.startafter.md)<!-- -->, , [endAt()](./firestore_.endat.md)<!-- -->, [limit()](./firestore_.limit.md) or [limitToLast()](./firestore_.limittolast.md) and can then be passed to [query()](./firestore_.query.md) to create a new query instance that also contains this `QueryConstraint`<!-- -->.

<b>Signature:</b>

```typescript
export declare abstract class QueryConstraint 
```

## Properties

|  Property | Modifiers | Type | Description |
|  --- | --- | --- | --- |
|  [type](./firestore_lite.queryconstraint.type.md) |  | [QueryConstraintType](./firestore_lite.queryconstrainttype.md) | The type of this query constraints |