SELECT * FROM demo_group_class_group_mapper WHERE id_ = #{id} SELECT * FROM demo_group_class_group_mapper ORDER BY id_ INSERT INTO demo_group_class_group_mapper (id_,demo_group_id_,class_group_id_,create_time_) VALUES(#{id},#{demoGroupId},#{classGroupId},#{createTime}) UPDATE demo_group_class_group_mapper id_ = #{id}, class_group_id_ = #{classGroupId}, demo_group_id_ = #{demoGroupId}, create_time_ = #{createTime}, WHERE id_ = #{id} DELETE FROM demo_group_class_group_mapper WHERE id_ = #{id} SELECT * FROM demo_group_class_group_mapper ORDER BY id_ SELECT COUNT(*) FROM demo_group_class_group_mapper