Method QueryConn

backend/plugin/db/bigquery/bigquery.go:112–216

QueryConn queries a SQL statement in a given connection.

(ctx context.Context, _ *sql.Conn, statement string, queryContext db.QueryContext)

// QueryConn queries a SQL statement in a given connection.
func (d *Driver) QueryConn(ctx context.Context, _ *sql.Conn, statement string, queryContext db.QueryContext) ([]*v1pb.QueryResult, error) {
	// For BigQuery, interpret Explain as dry run (BigQuery doesn't support EXPLAIN)
	if queryContext.Explain {
		return d.dryRunQuery(ctx, statement, queryContext)
	}

	statements, err := util.SanitizeSQL(statement)
	if err != nil {
		return nil, err
	}

	var results []*v1pb.QueryResult
	for _, statement := range statements {
		startTime := time.Now()
		queryResult, err := func() (*v1pb.QueryResult, error) {
			if util.IsSelect(statement) {
				if queryContext.Limit > 0 {
					statement = getStatementWithResultLimit(statement, queryContext.Limit)
				}
				q := d.client.Query(statement)
				if queryContext.OperatorEmail != "" {
					q.Labels = map[string]string{"operator_email": encodeOperatorEmail(queryContext.OperatorEmail)}
				}
				q.DefaultDatasetID = d.databaseName
				it, err := q.Read(ctx)
				if err != nil {
					return nil, err
				}

				result := &v1pb.QueryResult{}
				readOnce := false
				var fieldTypes []bigquery.FieldType
				for {
					var values []bigquery.Value
					err := it.Next(&values)
					if err == iterator.Done {
						break
					}
					if err != nil {
						return nil, err
					}

					// Get schema columns.
					if !readOnce {
						readOnce = true
						for _, s := range it.Schema {
							result.ColumnNames = append(result.ColumnNames, s.Name)
							result.ColumnTypeNames = append(result.ColumnTypeNames, string(s.Type))
							fieldTypes = append(fieldTypes, s.Type)
						}
					}

					row := &v1pb.QueryRow{}
					for i, v := range values {
						row.Values = append(row.Values, convertValue(v, fieldTypes[i]))
					}
					result.Rows = append(result.Rows, row)
					n := len(result.Rows)