Method Expand

internal/x/expander/expander.go:43–70

Expand takes a SQL query, and if it contains * in SELECT or RETURNING clause, expands it to use explicit column names. Returns the expanded query string.

(ctx context.Context, query string)

// Expand takes a SQL query, and if it contains * in SELECT or RETURNING clause,
// expands it to use explicit column names. Returns the expanded query string.
func (e *Expander) Expand(ctx context.Context, query string) (string, error) {
	// Parse the query
	stmts, err := e.parser.Parse(strings.NewReader(query))
	if err != nil {
		return "", fmt.Errorf("failed to parse query: %w", err)
	}

	if len(stmts) == 0 {
		return query, nil
	}

	stmt := stmts[0].Raw.Stmt

	// Check if there's any star in the statement (including CTEs, subqueries, etc.)
	if !hasStarAnywhere(stmt) {
		return query, nil
	}

	// Expand all stars in the statement recursively
	if err := e.expandNode(ctx, stmt); err != nil {
		return "", err
	}

	// Format the modified AST back to SQL
	expanded := ast.Format(stmts[0].Raw, e.dialect)

	return expanded, nil
}

// expandNode recursively expands * in all parts of the statement
func (e *Expander) expandNode(ctx context.Context, node ast.Node) error {