## GROUP分組查詢和Having子句 有時候我們要進行分組查詢，如以下SQL： ``` SELECT * FROM `user` WHERE `id` IN(1637, 1639, 1640 ) GROUP BY name ``` 在BeetlSql中直接拼條件調用group方法，傳入字段即可： ``` Query<User> query = sqlManager.query(User.class); List<User> list = query .andIn("id", Arrays.asList(1637, 1639, 1640)) .groupBy("name") .select(); ``` 在分組查詢之后，我們可能還要進行having篩選，只需要在后面調用having方法，傳入條件即可。 ``` SELECT * FROM `user` WHERE `id` IN( 1637, 1639, 1640 ) GROUP BY name HAVING `create_time` IS NOT NULL ``` ``` Query<User> query = sqlManager.query(User.class); List<User> list = query .andIn("id", Arrays.asList(1637, 1639, 1640)) .groupBy("name") .having(query.condition().andIsNotNull("create_time")) .select(); ```