Rename the parent pointer to root, as the pointer often references expression multiple layers above the current expression.

mysql/with_statement.go

@@ -35,7 +35,7 @@ func CTE(name string, columns ...jet.ColumnExpression) CommonTableExpression {
 		CommonTableExpression:      jet.CTE(name, columns...),
 	}
 
-	cte.parent = cte
+	cte.root = cte
 
 	return cte
 }