Method expandSelectStmt

internal/x/expander/expander.go:94–143

expandSelectStmt expands * in a SELECT statement including CTEs and subqueries

(ctx context.Context, stmt *ast.SelectStmt)

// expandSelectStmt expands * in a SELECT statement including CTEs and subqueries
func (e *Expander) expandSelectStmt(ctx context.Context, stmt *ast.SelectStmt) error {
	// First expand any CTEs - must be done in order since later CTEs may depend on earlier ones
	if stmt.WithClause != nil && stmt.WithClause.Ctes != nil {
		for _, cteNode := range stmt.WithClause.Ctes.Items {
			cte, ok := cteNode.(*ast.CommonTableExpr)
			if !ok {
				continue
			}
			cteSelect, ok := cte.Ctequery.(*ast.SelectStmt)
			if !ok {
				continue
			}
			if hasStarInList(cteSelect.TargetList) {
				// Get column names for this CTE
				columns, err := e.getCTEColumnNames(ctx, stmt, cte)
				if err != nil {
					return err
				}
				cteSelect.TargetList = rewriteTargetList(cteSelect.TargetList, columns)
			}
			// Recursively handle nested CTEs/subqueries in this CTE
			if err := e.expandSelectStmtInner(ctx, cteSelect); err != nil {
				return err
			}
		}
	}

	// Expand subqueries in FROM clause
	if stmt.FromClause != nil {
		for _, fromItem := range stmt.FromClause.Items {
			if err := e.expandFromClause(ctx, fromItem); err != nil {
				return err
			}
		}
	}

	// Expand the target list if it has stars
	if hasStarInList(stmt.TargetList) {
		// Format the current state to get columns
		tempRaw := &ast.RawStmt{Stmt: stmt}
		tempQuery := ast.Format(tempRaw, e.dialect)
		columns, err := e.getColumnNames(ctx, tempQuery)
		if err != nil {
			return fmt.Errorf("failed to get column names: %w", err)
		}
		stmt.TargetList = rewriteTargetList(stmt.TargetList, columns)
	}

	return nil
}

// expandSelectStmtInner expands nested structures without re-processing the target list
func (e *Expander) expandSelectStmtInner(ctx context.Context, stmt *ast.SelectStmt) error {