insert into tb_selection_dormitory(
dormitory_id,
clazz_id
)values(
#{dormitoryId},
#{clazzId}
)
delete from tb_selection_dormitory where id = #{id}
update tb_selection_dormitory set
dormitory_id=#{dormitoryId},
clazz_id=#{clazzId}
where id = #{id}
update tb_selection_dormitory set
dormitory_id = #{dormitoryId},
clazz_id = #{clazzId}
where id = #{id}
and id = #{id}and dormitory_id = #{dormitoryId}and clazz_id = #{clazzId}
delete from tb_selection_dormitory where clazz_id = #{clazzId}