Method Execute

statement.go:543–567

Execute processes `EXPLAIN` statement for queries and DMLs.

(ctx context.Context, session *Session)

// Execute processes `EXPLAIN` statement for queries and DMLs.
func (s *ExplainStatement) Execute(ctx context.Context, session *Session) (*Result, error) {
	queryPlan, timestamp, _, err := runAnalyzeQuery(ctx, session, spanner.NewStatement(s.Explain), s.IsDML)
	if err != nil {
		return nil, err
	}

	if queryPlan == nil {
		return nil, errors.New("EXPLAIN statement is not supported for Cloud Spanner Emulator.")
	}

	rows, predicates, err := processPlanWithoutStats(queryPlan)
	if err != nil {
		return nil, err
	}

	result := &Result{
		ColumnNames:  explainColumnNames,
		AffectedRows: len(rows),
		Rows:         rows,
		Timestamp:    timestamp,
		Predicates:   predicates,
	}

	return result, nil
}

type DescribeStatement struct {
	Statement string