Function prepareTransformation

backend/plugin/parser/tsql/backup.go:191–242

(databaseName, statement string)

}

func prepareTransformation(databaseName, statement string) ([]statementInfo, error) {
	parsedStatements, err := parseTSQLStatements(statement)
	if err != nil {
		return nil, errors.Wrap(err, "failed to parse statement")
	}

	var dmls []statementInfo
	for _, parsedStatement := range parsedStatements {
		node, ok := GetOmniNode(parsedStatement.AST)
		if !ok || node == nil {
			continue
		}
		var (
			table         *TableReference
			statementType StatementType
			err           error
		)
		switch n := node.(type) {
		case *ast.UpdateStmt:
			table, err = resolveDMLTargetTable(n.Relation, n.FromClause, databaseName)
			statementType = StatementTypeUpdate
		case *ast.DeleteStmt:
			table, err = resolveDMLTargetTable(n.Relation, n.FromClause, databaseName)
			statementType = StatementTypeDelete
		default:
			continue
		}
		if err != nil {
			return nil, err
		}
		if table == nil {
			return nil, errors.Errorf("failed to resolve DML target table")
		}
		if strings.HasPrefix(table.Table, "#") {
			slog.Info("prior backup: skipping DML targeting temp table",
				"table", table.Table,
				"statementType", statementType)
			continue
		}
		table.StatementType = statementType
		loc := dmlNodeLoc(node)
		dmls = append(dmls, statementInfo{
			statement:     parsedStatement.Text,
			node:          node,
			table:         table,
			startPosition: positionFromByteOffset(parsedStatement.Start, parsedStatement.Text, loc.Start),
			endPosition:   positionFromByteOffset(parsedStatement.Start, parsedStatement.Text, dmlEndOffset(parsedStatement.Text, loc)),
		})
	}

	return dmls, nil
}

func resolveDMLTargetTable(relation ast.TableExpr, fromClause *ast.List, databaseName string) (*TableReference, error) {
	table, err := tableReferenceFromTableExpr(relation, databaseName, defaultSchema)