Method QueryConn

backend/plugin/db/spanner/spanner.go:325–390

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) {
	if queryContext.Explain {
		return d.explainStatement(ctx, statement)
	}

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

	var results []*v1pb.QueryResult
	for _, statement := range stmts {
		startTime := time.Now()
		queryResult, err := func() (*v1pb.QueryResult, error) {
			if util.IsSelect(statement) {
				// Only apply limit wrapper for SELECT statements
				limitedStatement := statement
				if queryContext.Limit > 0 {
					limitedStatement = getStatementWithResultLimit(statement, queryContext.Limit)
				}
				return d.queryStatement(ctx, limitedStatement, queryContext)
			}
			if util.IsDDL(statement) {
				op, err := d.dbClient.UpdateDatabaseDdl(ctx, &databasepb.UpdateDatabaseDdlRequest{
					Database:   getDSN(d.config.DataSource.Host, d.databaseName),
					Statements: []string{statement},
				})
				if err != nil {
					return nil, err
				}
				if err := op.Wait(ctx); err != nil {
					return nil, err
				}
				return &v1pb.QueryResult{}, nil
			}
			var rowCount int64
			if _, err := d.client.ReadWriteTransaction(ctx, func(ctx context.Context, rwt *spanner.ReadWriteTransaction) error {
				count, err := rwt.Update(ctx, spanner.NewStatement(statement))
				if err != nil {
					return err
				}
				rowCount = count
				return nil
			}); err != nil {
				return nil, err
			}
			return util.BuildAffectedRowsResult(rowCount, nil), nil
		}()
		stop := false
		if err != nil {
			queryResult = &v1pb.QueryResult{
				Error: err.Error(),
			}
			stop = true
		}
		queryResult.Statement = statement
		queryResult.Latency = durationpb.New(time.Since(startTime))
		queryResult.RowsCount = int64(len(queryResult.Rows))