query()
A MilvusClient interface. This method filters entities by a boolean expression. Note that the order of the returned entities can not be guaranteed.
R<QueryResponse> query(QuerySimpleParam requestParam);
QuerySimpleParam
Use the QuerySimpleParam.Builder to construct a QuerySimpleParam object.
import io.milvus.param.highlevel.dml.QuerySimpleParam;
QuerySimpleParam.Builder builder = QuerySimpleParam.newBuilder();
Methods of QuerySimpleParam.Builder:
| Method | Description | Parameters |
|---|---|---|
withCollectionName(String collectionName) | Sets the name of the target collection. The value cannot be empty or null. | collectionName: Name of the collection against which the query is conducted. |
withOutputFields(List<String> outputFields) | Sets the names of the fields to return. If this value is set, the query result contains the values of these fields. | outputFields: Fields to include in the query result. |
withFilter(String filter) | Sets an expression to filter entities. For more information, refer to this doc. | filter: A boolean expression to filter entities. |
withOffset(Long offset) | Sets a position prior to which entities are to ignore in the query. | offset: A position prior to which entities are to ignore. |
withLimit(Long limit) | Sets the number or entities to return. The value should be 0 or a positive integer. The value defaults to 0, which lifts the limits on the number of entities to return. | limit: Number of entities to return. |
withConsistencyLevel(ConsistencyLevelEnum consistencyLevel) | Sets the consistency level of the collection to query against. If not specified, the default consistency level is to be used. For details, please refer to ConsistencyLevelEnum in Misc. | consistencyLevel: The consistency level of the collection to query against. |
build() | Constructs a QuerySimpleParam object. | N/A |
The QuerySimpleParam.Builder.build() method can throw the following exceptions:
ParamExceptionis raised if the parameter is invalid.
Returns
This method catches all the exceptions and returns an R<QueryResponse> object.
- If the API fails on the server side, it returns the error code and message from the server.
- If the API fails by RPC exception, it returns
R.Status.Unknowand the error message of the exception. - If the API succeeds, it returns valid
QueryResponseheld by the R template.
Example
import io.milvus.param.*;
import io.milvus.response.QueryResultsWrapper;
import io.milvus.response.FieldDataWrapper;
import io.milvus.grpc.QueryResults;
QuerySimpleParam querySimpleParam = QuerySimpleParam.newBuilder()
.withCollectionName(COLLECTION_NAME)
.withOutFields(Lists.newArrayList("*"))
.withFilter(filter)
.withLimit(100L)
.withOffset(0L)
.build();
R<QueryResponse> response = client.query(param)
if (response.getStatus() != R.Status.Success.getCode()) {
System.out.println(response.getMessage());
}
for (QueryResultsWrapper.RowRecord rowRecord : response.getData().getRowRecords()) {
System.out.println(rowRecord);
}