Struct parameters

Run a query with struct parameters.

Documentation pages that include this code sample

Code Sample

Go

Before trying this sample, follow the Go setup instructions in the BigQuery Quickstart Using Client Libraries. For more information, see the BigQuery Go API reference documentation.

import (
	"context"
	"fmt"
	"io"

	"cloud.google.com/go/bigquery"
	"google.golang.org/api/iterator"
)

// queryWithStructParam demonstrates running a query and providing query parameters that include struct
// types.
func queryWithStructParam(w io.Writer, projectID string) error {
	// projectID := "my-project-id"
	ctx := context.Background()
	client, err := bigquery.NewClient(ctx, projectID)
	if err != nil {
		return fmt.Errorf("bigquery.NewClient: %v", err)
	}
	defer client.Close()

	type MyStruct struct {
		X int64
		Y string
	}
	q := client.Query(
		`SELECT @struct_value as s;`)
	q.Parameters = []bigquery.QueryParameter{
		{
			Name:  "struct_value",
			Value: MyStruct{X: 1, Y: "foo"},
		},
	}
	// Run the query and print results when the query job is completed.
	job, err := q.Run(ctx)
	if err != nil {
		return err
	}
	status, err := job.Wait(ctx)
	if err != nil {
		return err
	}
	if err := status.Err(); err != nil {
		return err
	}
	it, err := job.Read(ctx)
	for {
		var row []bigquery.Value
		err := it.Next(&row)
		if err == iterator.Done {
			break
		}
		if err != nil {
			return err
		}
		fmt.Fprintln(w, row)
	}
	return nil
}

Java

Before trying this sample, follow the Java setup instructions in the BigQuery Quickstart Using Client Libraries. For more information, see the BigQuery Java API reference documentation.

import com.google.cloud.bigquery.BigQuery;
import com.google.cloud.bigquery.BigQueryException;
import com.google.cloud.bigquery.BigQueryOptions;
import com.google.cloud.bigquery.QueryJobConfiguration;
import com.google.cloud.bigquery.QueryParameterValue;
import com.google.cloud.bigquery.TableResult;
import java.util.HashMap;
import java.util.Map;

public class QueryWithStructsParameters {

  public static void main(String[] args) {
    queryWithStructsParameters();
  }

  public static void queryWithStructsParameters() {
    try {
      // Initialize client that will be used to send requests. This client only needs to be created
      // once, and can be reused for multiple requests.
      BigQuery bigquery = BigQueryOptions.getDefaultInstance().getService();

      // Create struct
      Map<String, QueryParameterValue> struct = new HashMap<>();
      struct.put("booleanField", QueryParameterValue.bool(true));
      struct.put("integerField", QueryParameterValue.string("test-stringField"));
      struct.put("stringField", QueryParameterValue.int64(10));
      QueryParameterValue recordValue = QueryParameterValue.struct(struct);

      String query = "SELECT STRUCT(@recordField) AS record";
      QueryJobConfiguration queryConfig =
          QueryJobConfiguration.newBuilder(query)
              .setUseLegacySql(false)
              .addNamedParameter("recordField", recordValue)
              .build();

      TableResult results = bigquery.query(queryConfig);

      results
          .iterateAll()
          .forEach(row -> row.forEach(val -> System.out.printf("%s", val.toString())));

      System.out.println("Query with struct parameter performed successfully.");
    } catch (BigQueryException | InterruptedException e) {
      System.out.println("Query not performed \n" + e.toString());
    }
  }
}

Node.js

Before trying this sample, follow the Node.js setup instructions in the BigQuery Quickstart Using Client Libraries. For more information, see the BigQuery Node.js API reference documentation.

// Run a query using struct query parameters

// Import the Google Cloud client library
const {BigQuery} = require('@google-cloud/bigquery');
const bigquery = new BigQuery();

async function queryParamsStructs() {
  // The SQL query to run
  const sqlQuery = 'SELECT @struct_value AS struct_obj;';

  const options = {
    query: sqlQuery,
    // Location must match that of the dataset(s) referenced in the query.
    location: 'US',
    params: {struct_value: {x: 1, y: 'foo'}},
  };

  // Run the query
  const [rows] = await bigquery.query(options);

  console.log('Rows:');
  rows.forEach(row => console.log(row.struct_obj.y));
}

Python

Before trying this sample, follow the Python setup instructions in the BigQuery Quickstart Using Client Libraries. For more information, see the BigQuery Python API reference documentation.

from google.cloud import bigquery

# Construct a BigQuery client object.
client = bigquery.Client()

query = "SELECT @struct_value AS s;"
job_config = bigquery.QueryJobConfig(
    query_parameters=[
        bigquery.StructQueryParameter(
            "struct_value",
            bigquery.ScalarQueryParameter("x", "INT64", 1),
            bigquery.ScalarQueryParameter("y", "STRING", "foo"),
        )
    ]
)
query_job = client.query(query, job_config=job_config)  # Make an API request.

for row in query_job:
    print(row.s)