new QueryPartition()
A split point that can be used in a query as a starting and/or end point for the query results. The cursors returned by #startAt and #endBefore can only be used in a query that matches the constraint of query that produced this partition.
Members
endBefore
The cursor that defines the first result after this partition or
undefined if this is the last partition. The cursor value must be
destructured when passed to endBefore() (for example with
query.endBefore(...queryPartition.endBefore)).
Example
```
const query = firestore.collectionGroup('collectionId');
for await (const partition of query.getPartitions(42)) {
let partitionedQuery = query.orderBy(FieldPath.documentId());
if (partition.startAt) {
partitionedQuery = partitionedQuery.startAt(...partition.startAt);
}
if (partition.endBefore) {
partitionedQuery = partitionedQuery.endBefore(...partition.endBefore);
}
const querySnapshot = await partitionedQuery.get();
console.log(`Partition contained ${querySnapshot.length} documents`);
}
```startAt
The cursor that defines the first result for this partition or undefined
if this is the first partition. The cursor value must be
destructured when passed to startAt() (for example with
query.startAt(...queryPartition.startAt)).
Example
```
const query = firestore.collectionGroup('collectionId');
for await (const partition of query.getPartitions(42)) {
let partitionedQuery = query.orderBy(FieldPath.documentId());
if (partition.startAt) {
partitionedQuery = partitionedQuery.startAt(...partition.startAt);
}
if (partition.endBefore) {
partitionedQuery = partitionedQuery.endBefore(...partition.endBefore);
}
const querySnapshot = await partitionedQuery.get();
console.log(`Partition contained ${querySnapshot.length} documents`);
}
```Methods
toQuery() → {Query.<T>}
Returns a query that only encapsulates the documents for this partition.
Returns:
| Type | Description |
|---|---|
| Query.<T> |
A query partitioned by a Query#startAt and Query#endBefore cursor. |