queryIterator()

Addedv2.4.xModifiedv2.6.x

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

A QueryIterator object to iterate data.

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.client.ConnectConfig;
import io.milvus.v2.client.MilvusClientV2;
import io.milvus.v2.common.ConsistencyLevel;
import io.milvus.v2.service.vector.request.QueryIteratorReq;

// 1. Set up a client
ConnectConfig connectConfig = ConnectConfig.builder()
        .uri("YOUR_CLUSTER_ENDPOINT")
        .token("YOUR_CLUSTER_TOKEN")
        .build();
        
MilvusClientV2 client = new MilvusClientV2(connectConfig);

// 2. Iterator data
QueryIterator queryIterator = client.queryIterator(QueryIteratorReq.builder()
        .collectionName("test")
        .expr("id < 300")
        .outputFields(Lists.newArrayList("id", "vector"))
        .batchSize(50L)
        .offset(5)
        .limit(400)
        .consistencyLevel(ConsistencyLevel.BOUNDED)
        .build());

while (true) {
    List<QueryResultsWrapper.RowRecord> res = queryIterator.next();
    if (res.isEmpty()) {
        System.out.println("query iteration finished, close");
        queryIterator.close();
        break;
    }

    for (QueryResultsWrapper.RowRecord record : res) {
        System.out.println(record);
    }
}