com.google.cloud.bigquery

Class QueryRequest

java.lang.Object

com.google.cloud.bigquery.QueryRequest

All Implemented Interfaces:

Serializable

public final class QueryRequest
extends Object
implements Serializable

Google Cloud BigQuery Query Request. This class can be used to run a BigQuery SQL query and return results if the query completes within a specified timeout. The query results are saved to a temporary table that is deleted approximately 24 hours after the query is run. The query is run through a BigQuery Job whose identity can be accessed via QueryResponse.jobId(). If the query does not complete within the provided QueryRequest.Builder.maxWaitTime(Long), the response returned by BigQuery.query(QueryRequest) will have QueryResponse.jobCompleted() set to false and QueryResponse.result() set to null. To obtain query results you can use BigQuery.getQueryResults(JobId, BigQuery.QueryResultsOption...) until QueryResponse.jobCompleted() returns true.

Example usage of a query request:

 // Substitute "field", "table" and "dataset" with real field, table and dataset identifiers
 QueryRequest request = QueryRequest.builder("SELECT field FROM table")
     .defaultDataset(DatasetId.of("dataset"))
     .maxWaitTime(60000L)
     .pageSize(1000L)
     .build();
 QueryResponse response = bigquery.query(request);
 while (!response.jobCompleted()) {
   Thread.sleep(1000);
   response = bigquery.getQueryResults(response.jobId());
 }
 List<BigQueryError> executionErrors = response.executionErrors();
 // look for errors in executionErrors
 QueryResult result = response.result();
 Iterator<List<FieldValue>> rowIterator = result.iterateAll();
 while(rowIterator.hasNext()) {
   List<FieldValue> row = rowIterator.next();
   // do something with row
 }
 

See Also:

Query, Query Reference, Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	QueryRequest.Builder

Method Summary

Methods

Modifier and Type	Method and Description
static QueryRequest.Builder	builder(String query) Creates a builder for a QueryRequest given the BigQuery SQL query to be executed.
DatasetId	defaultDataset() Returns the default dataset to assume for any unqualified table names in the query.
Boolean	dryRun() Returns whether the query has to be dry run or not.
boolean	equals(Object obj)
int	hashCode()
Long	maxWaitTime() Returns how long to wait for the query to complete, in milliseconds, before the request times out and returns.
static QueryRequest	of(String query) Creates a QueryRequest object given the BigQuery SQL query to be executed.
Long	pageSize() Returns the maximum number of rows of data to return per page of results.
String	query() Sets the BigQuery query to be executed.
QueryRequest.Builder	toBuilder() Returns a builder for the QueryRequest object.
String	toString()
Boolean	useQueryCache() Returns whether to look for the result in the query cache.

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Method Detail

query

public String query()

Sets the BigQuery query to be executed.

pageSize

public Long pageSize()

Returns the maximum number of rows of data to return per page of results.

defaultDataset

public DatasetId defaultDataset()

Returns the default dataset to assume for any unqualified table names in the query.

maxWaitTime

public Long maxWaitTime()

Returns how long to wait for the query to complete, in milliseconds, before the request times out and returns. Note that this is only a timeout for the request, not the query. If the query takes longer to run than the timeout value, the call returns without any results and with the QueryResponse.jobCompleted() set to false. You can call BigQuery.getQueryResults(JobId, BigQuery.QueryResultsOption...) to wait for the query to complete and read the results. If not set, a wait time of 10000 milliseconds (10 seconds) is used.

dryRun

public Boolean dryRun()

Returns whether the query has to be dry run or not. If set, the query is not executed. If the query is valid statistics are returned on how many bytes would be processed. If the query is invalid an error is returned. If not set the query is executed.

useQueryCache

public Boolean useQueryCache()

Returns whether to look for the result in the query cache. The query cache is a best-effort cache that will be flushed whenever tables in the query are modified. If not specified the query cache is used.

See Also:

Query Caching

toBuilder

public QueryRequest.Builder toBuilder()

Returns a builder for the QueryRequest object.

toString

public String toString()

Overrides:

toString in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object

equals

public boolean equals(Object obj)

Overrides:

equals in class Object

builder

public static QueryRequest.Builder builder(String query)

Creates a builder for a QueryRequest given the BigQuery SQL query to be executed.

of

public static QueryRequest of(String query)

Creates a QueryRequest object given the BigQuery SQL query to be executed.