queryIterator()
This method returns a query iterator to iterate data.
public QueryIterator queryIterator(QueryIteratorReq request)
Request Syntax
queryIterator(QueryIteratorReq.builder()
.databaseName(String databaseName)
.collectionName(String collectionName)
.partitionNames(List<String> partitionNames)
.outputFields(List<String> outputFields)
.expr(String expr)
.consistencyLevel(ConsistencyLevel consistencyLevel)
.offset(long offset)
.limit(long limit)
.ignoreGrowing(boolean ignoreGrowing)
.timezone(String timezone)
.batchSize(long batchSize)
.reduceStopForBest(boolean reduceStopForBest)
.filterTemplateValues(Map<String, Object> filterTemplateValues)
.build()
);
BUILDER METHODS:
-
databaseName(String databaseName)-The name of the database. Defaults to the current database if not specified.
-
collectionName(String collectionName)-The name of the target collection.
-
partitionNames(List<String> partitionNames)-A list of partition names to target.
-
outputFields(List<String> outputFields)-A list of field names to include in the output.
-
expr(String expr)-A boolean expression to filter results.
-
consistencyLevel(ConsistencyLevel consistencyLevel)-The consistency level for the operation.
-
offset(long offset)-The number of results to skip before returning.
-
limit(long limit)-The maximum number of results to return.
-
ignoreGrowing(boolean ignoreGrowing)-Whether to ignore growing segments during the operation.
-
timezone(String timezone)-The timezone string for time-related filters.
-
batchSize(long batchSize)-The batch size for iterator operations.
-
reduceStopForBest(boolean reduceStopForBest)-Whether to stop iteration when the best result is found.
-
filterTemplateValues(Map<String, Object> filterTemplateValues)-A map of template variable values for parameterized filters.
RETURNS:
QueryIterator
QueryIterator
EXCEPTIONS:
-
MilvusClientException
This exception will be raised when any error occurs during this operation.
Example
import io.milvus.orm.iterator.QueryIterator;
import io.milvus.response.QueryResultsWrapper;
import io.milvus.v2.service.vector.request.QueryIteratorReq;
import io.milvus.v2.common.ConsistencyLevel;
import java.util.Arrays;
import java.util.List;
// Create a query iterator to retrieve results in batches
QueryIterator queryIterator = client.queryIterator(QueryIteratorReq.builder()
.collectionName("my_collection")
.expr("userID < 3000")
.outputFields(Arrays.asList("userID", "userAge"))
.batchSize(100)
.offset(0)
.limit(10000)
.consistencyLevel(ConsistencyLevel.BOUNDED)
.build());
// Iterate through all results
int counter = 0;
while (true) {
List<QueryResultsWrapper.RowRecord> res = queryIterator.next();
if (res.isEmpty()) {
queryIterator.close();
break;
}
for (QueryResultsWrapper.RowRecord record : res) {
System.out.println(record);
counter++;
}
}
System.out.printf("%d query results returned%n", counter);