Method Execute

statement.go:238–274

(ctx context.Context, session *Session)

}

func (s *SelectStatement) Execute(ctx context.Context, session *Session) (*Result, error) {
	stmt := spanner.NewStatement(s.Query)

	iter, roTxn := session.RunQueryWithStats(ctx, stmt)
	defer iter.Stop()

	rows, columnNames, err := parseQueryResult(iter)
	if err != nil {
		if session.InReadWriteTransaction() && spanner.ErrCode(err) == codes.Aborted {
			// Need to call rollback to free the acquired session in underlying google-cloud-go/spanner.
			rollback := &RollbackStatement{}
			rollback.Execute(ctx, session)
		}
		return nil, err
	}
	result := &Result{
		ColumnNames: columnNames,
		Rows:        rows,
	}
	result.ColumnTypes = iter.Metadata.GetRowType().GetFields()

	queryStats := parseQueryStats(iter.QueryStats)
	rowsReturned, err := strconv.Atoi(queryStats.RowsReturned)
	if err != nil {
		return nil, fmt.Errorf("rowsReturned is invalid: %v", err)
	}

	result.AffectedRows = rowsReturned
	result.Stats = queryStats

	// ReadOnlyTransaction.Timestamp() is invalid until read.
	if roTxn != nil {
		result.Timestamp, _ = roTxn.Timestamp()
	}

	return result, nil
}

// extractColumnNames extract column names from ResultSetMetadata.RowType.Fields.
func extractColumnNames(fields []*pb.StructType_Field) []string {