Run a query with struct parameters.

## Explore further


For detailed documentation that includes this code sample, see the following:

- [Run parameterized queries](https://docs.cloud.google.com/bigquery/docs/parameterized-queries)

## Code sample

### Go


Before trying this sample, follow the Go setup instructions in the
[BigQuery quickstart using
client libraries](https://docs.cloud.google.com/bigquery/docs/quickstarts/quickstart-client-libraries).


For more information, see the
[BigQuery Go API
reference documentation](https://godoc.org/cloud.google.com/go/bigquery).


To authenticate to BigQuery, set up Application Default Credentials.
For more information, see

[Set up authentication for client libraries](https://docs.cloud.google.com/bigquery/docs/authentication#client-libs).

    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: %w", err)
    	}
    	defer client.Close()

    	type MyStruct struct {
    		X int64
    		Y string
    	}
    	q := client.Query(
    		`SELECT @struct_value as s;`)
    	q.Parameters = []bigquery.https://docs.cloud.google.com/go/docs/reference/cloud.google.com/go/bigquery/latest/index.html#cloud_google_com_go_bigquery_QueryParameter{
    		{
    			Name:  "struct_value",
    			Value: MyStruct{X: 1, Y: "foo"},
    		},
    	}
    	// Run the query and process the returned row iterator.
    	it, err := q.Read(ctx)
    	if err != nil {
    		return fmt.Errorf("query.Read(): %w", err)
    	}
    	for {
    		var row []bigquery.https://docs.cloud.google.com/go/docs/reference/cloud.google.com/go/bigquery/latest/index.html#cloud_google_com_go_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](https://docs.cloud.google.com/bigquery/docs/quickstarts/quickstart-client-libraries).


For more information, see the
[BigQuery Java API
reference documentation](https://docs.cloud.google.com/java/docs/reference/google-cloud-bigquery/latest/overview).


To authenticate to BigQuery, set up Application Default Credentials.
For more information, see

[Set up authentication for client libraries](https://docs.cloud.google.com/bigquery/docs/authentication#client-libs).

    import com.google.cloud.bigquery.https://docs.cloud.google.com/java/docs/reference/google-cloud-bigquery/latest/com.google.cloud.bigquery.BigQuery.html;
    import com.google.cloud.bigquery.https://docs.cloud.google.com/java/docs/reference/google-cloud-bigquery/latest/com.google.cloud.bigquery.BigQueryException.html;
    import com.google.cloud.bigquery.https://docs.cloud.google.com/java/docs/reference/google-cloud-bigquery/latest/com.google.cloud.bigquery.BigQueryOptions.html;
    import com.google.cloud.bigquery.https://docs.cloud.google.com/java/docs/reference/google-cloud-bigquery/latest/com.google.cloud.bigquery.QueryJobConfiguration.html;
    import com.google.cloud.bigquery.https://docs.cloud.google.com/java/docs/reference/google-cloud-bigquery/latest/com.google.cloud.bigquery.QueryParameterValue.html;
    import com.google.cloud.bigquery.https://docs.cloud.google.com/java/docs/reference/google-cloud-bigquery/latest/com.google.cloud.bigquery.TableResult.html;
    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.
          https://docs.cloud.google.com/java/docs/reference/google-cloud-bigquery/latest/com.google.cloud.bigquery.BigQuery.html bigquery = https://docs.cloud.google.com/java/docs/reference/google-cloud-bigquery/latest/com.google.cloud.bigquery.BigQueryOptions.html.getDefaultInstance().getService();

          // Create struct
          Map<String, QueryParameterValue> struct = new HashMap<>();
          https://docs.cloud.google.com/java/docs/reference/google-cloud-bigquery/latest/com.google.cloud.bigquery.QueryParameterValue.html#com_google_cloud_bigquery_QueryParameterValue_struct_java_util_Map_java_lang_String_com_google_cloud_bigquery_QueryParameterValue__.put("x", https://docs.cloud.google.com/java/docs/reference/google-cloud-bigquery/latest/com.google.cloud.bigquery.QueryParameterValue.html.https://docs.cloud.google.com/java/docs/reference/google-cloud-bigquery/latest/com.google.cloud.bigquery.QueryParameterValue.html#com_google_cloud_bigquery_QueryParameterValue_int64_java_lang_Integer_(1));
          https://docs.cloud.google.com/java/docs/reference/google-cloud-bigquery/latest/com.google.cloud.bigquery.QueryParameterValue.html#com_google_cloud_bigquery_QueryParameterValue_struct_java_util_Map_java_lang_String_com_google_cloud_bigquery_QueryParameterValue__.put("y", https://docs.cloud.google.com/java/docs/reference/google-cloud-bigquery/latest/com.google.cloud.bigquery.QueryParameterValue.html.https://docs.cloud.google.com/java/docs/reference/google-cloud-bigquery/latest/com.google.cloud.bigquery.QueryParameterValue.html#com_google_cloud_bigquery_QueryParameterValue_string_java_lang_String_("foo"));
          https://docs.cloud.google.com/java/docs/reference/google-cloud-bigquery/latest/com.google.cloud.bigquery.QueryParameterValue.html recordValue = https://docs.cloud.google.com/java/docs/reference/google-cloud-bigquery/latest/com.google.cloud.bigquery.QueryParameterValue.html.https://docs.cloud.google.com/java/docs/reference/google-cloud-bigquery/latest/com.google.cloud.bigquery.QueryParameterValue.html#com_google_cloud_bigquery_QueryParameterValue_struct_java_util_Map_java_lang_String_com_google_cloud_bigquery_QueryParameterValue__(struct);

          String query = "SELECT STRUCT(@recordField) AS s";
          https://docs.cloud.google.com/java/docs/reference/google-cloud-bigquery/latest/com.google.cloud.bigquery.QueryJobConfiguration.html queryConfig =
              https://docs.cloud.google.com/java/docs/reference/google-cloud-bigquery/latest/com.google.cloud.bigquery.QueryJobConfiguration.html.newBuilder(query)
                  .https://docs.cloud.google.com/java/docs/reference/google-cloud-bigquery/latest/com.google.cloud.bigquery.QueryJobConfiguration.Builder.html#com_google_cloud_bigquery_QueryJobConfiguration_Builder_addNamedParameter_java_lang_String_com_google_cloud_bigquery_QueryParameterValue_("recordField", recordValue)
                  .build();

          https://docs.cloud.google.com/java/docs/reference/google-cloud-bigquery/latest/com.google.cloud.bigquery.TableResult.html results = bigquery.https://docs.cloud.google.com/java/docs/reference/google-cloud-bigquery/latest/com.google.cloud.bigquery.BigQuery.html#com_google_cloud_bigquery_BigQuery_query_com_google_cloud_bigquery_QueryJobConfiguration_com_google_cloud_bigquery_BigQuery_JobOption____(queryConfig);

          results
              .https://docs.cloud.google.com/java/docs/reference/google-cloud-bigquery/latest/com.google.cloud.bigquery.TableResult.html#com_google_cloud_bigquery_TableResult_iterateAll__()
              .forEach(row -> row.forEach(val -> System.out.printf("%s", val.toString())));

          System.out.println("Query with struct parameter performed successfully.");
        } catch (https://docs.cloud.google.com/java/docs/reference/google-cloud-bigquery/latest/com.google.cloud.bigquery.BigQueryException.html | InterruptedException e) {
          System.out.println("Query not performed \n" + e.toString());
        }
      }
    }

### Python


Before trying this sample, follow the Python setup instructions in the
[BigQuery quickstart using
client libraries](https://docs.cloud.google.com/bigquery/docs/quickstarts/quickstart-client-libraries).


For more information, see the
[BigQuery Python API
reference documentation](https://docs.cloud.google.com/python/docs/reference/bigquery/latest).


To authenticate to BigQuery, set up Application Default Credentials.
For more information, see

[Set up authentication for client libraries](https://docs.cloud.google.com/bigquery/docs/authentication#client-libs).

    from google.cloud import https://docs.cloud.google.com/python/docs/reference/bigquery/latest

    # Construct a BigQuery client object.
    client = https://docs.cloud.google.com/python/docs/reference/bigquery/latest.https://docs.cloud.google.com/python/docs/reference/bigquery/latest/google.cloud.bigquery.client.Client.html()

    query = "SELECT @struct_value AS s;"
    job_config = https://docs.cloud.google.com/python/docs/reference/bigquery/latest.https://docs.cloud.google.com/python/docs/reference/bigquery/latest/google.cloud.bigquery.job.QueryJobConfig.html(
        query_parameters=[
            https://docs.cloud.google.com/python/docs/reference/bigquery/latest.https://docs.cloud.google.com/python/docs/reference/bigquery/latest/google.cloud.bigquery.query.StructQueryParameter.html(
                "struct_value",
                https://docs.cloud.google.com/python/docs/reference/bigquery/latest.https://docs.cloud.google.com/python/docs/reference/bigquery/latest/google.cloud.bigquery.query.ScalarQueryParameter.html("x", "INT64", 1),
                https://docs.cloud.google.com/python/docs/reference/bigquery/latest.https://docs.cloud.google.com/python/docs/reference/bigquery/latest/google.cloud.bigquery.query.ScalarQueryParameter.html("y", "STRING", "foo"),
            )
        ]
    )
    results = client.https://docs.cloud.google.com/python/docs/reference/bigquery/latest/google.cloud.bigquery.client.Client.html#google_cloud_bigquery_client_Client_query_and_wait(
        query, job_config=job_config
    )  # Make an API request and waits for results.

    for row in results:
        print(row.s)

### Rust

    use google_cloud_bigquery::client::BigQuery;
    use google_cloud_bigquery::query::FromRow;
    use google_cloud_bigquery_v2::model::{
        QueryParameter, QueryParameterStructType, QueryParameterType, QueryParameterValue,
    };

    #[derive(FromRow, Debug)]
    struct NameCount {
        name: String,
        number: i64,
    }

    pub async fn sample(project_id: &str) -> anyhow::Result<()> {
        let client = BigQuery::builder().build().await?;

        let mut rows = client
            .query(
                "SELECT name, number \
            FROM `bigquery-public-data.usa_names.usa_1910_2013` \
            WHERE state = @record.state AND gender = @record.gender \
            LIMIT 10",
            )
            .with_project_id(project_id)
            .set_parameter_mode("NAMED")
            .set_query_parameters([QueryParameter::new()
                .set_name("record")
                .set_parameter_type(
                    QueryParameterType::new()
                        .set_type("STRUCT")
                        .set_struct_types([
                            QueryParameterStructType::new()
                                .set_name("state")
                                .set_type(QueryParameterType::new().set_type("STRING")),
                            QueryParameterStructType::new()
                                .set_name("gender")
                                .set_type(QueryParameterType::new().set_type("STRING")),
                        ]),
                )
                .set_parameter_value(QueryParameterValue::new().set_struct_values([
                    ("state", QueryParameterValue::new().set_value("TX")),
                    ("gender", QueryParameterValue::new().set_value("F")),
                ]))])
            .set_location("US")
            .until_done()
            .await?
            .read();

        while let Some(row) = rows.next().await.transpose()? {
            let name_count: NameCount = row.try_into()?;
            println!("Name: {}, Number: {}", name_count.name, name_count.number);
        }
        Ok(())
    }

## What's next


To search and filter code samples for other Google Cloud products, see the
[Google Cloud sample browser](https://docs.cloud.google.com/docs/samples?product=bigquery).