V
- the type of the results value.public interface QueryResults<V> extends Iterator<V>
getResultClass()
value.
Results are loaded lazily in batches, where batch size is set by Cloud Datastore. As a result, it
is possible to get a DatastoreException
upon hasNext
or next
calls.Modifier and Type | Method and Description |
---|---|
Cursor |
getCursorAfter()
Returns the Cursor for the point after the value returned in the last
Iterator.next() call. |
com.google.datastore.v1.QueryResultBatch.MoreResultsType |
getMoreResults()
Returns MoreResults state of the query after the current batch.
|
Class<?> |
getResultClass()
Returns the actual class of the result's values.
|
int |
getSkippedResults()
Returns the number of results skipped, typically because of an offset.
|
forEachRemaining, hasNext, next, remove
Class<?> getResultClass()
Cursor getCursorAfter()
Iterator.next()
call. This
cursor can be used to issue subsequent queries (with the same constraints) that may return
additional results.
A simple use case:
Query<Entity> query = Query.newEntityQueryBuilder()
.setKind("Person")
.setFilter(PropertyFilter.eq("favoriteFood", "pizza"))
.build();
QueryResults<Entity> results = datastore.run(query);
// Consume some results (using results.next()) and do any other actions as necessary.
query = query.toBuilder().setStartCursor(results.getCursorAfter()).build();
results = datastore.run(query); // now we will iterate over all entities not yet consumed
int getSkippedResults()
A simple use case to count entities:
Query<Key> query = Query.newKeyQueryBuilder().setOffset(Integer.MAX_VALUE).build();
QueryResults<Key> result = datasore.datastore.run(query);
if (!result.hasNext()) {
int numberOfEntities = result.getSkippedResults();
}
com.google.datastore.v1.QueryResultBatch.MoreResultsType getMoreResults()
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