SELECT * FROM subject WHERE id_ = #{id} SELECT * FROM subject ORDER BY id_ INSERT INTO subject (id_,name_,code_,parent_subject_id_,create_time_,update_time_,del_flag_) VALUES(#{id},#{name},#{code},#{parentSubjectId},#{createTime},#{updateTime},#{delFlag,typeHandler=com.ym.mec.common.dal.CustomEnumTypeHandler}) UPDATE subject del_flag_ = #{delFlag,typeHandler=com.ym.mec.common.dal.CustomEnumTypeHandler}, parent_subject_id_ = #{parentSubjectId}, code_ = #{code}, update_time_ = #{updateTime}, name_ = #{name}, WHERE id_ = #{id} DELETE FROM subject WHERE id_ = #{id} SELECT * FROM subject ORDER BY id_ SELECT COUNT(*) FROM subject SELECT s.* FROM music_group_subject_plan mgsp LEFT JOIN `subject` s ON mgsp.subject_id_ = s.id_ WHERE mgsp.music_group_id_ = #{musicGroupId}