我这里用的是mybatis，批量修改。
工作中遇到的，希望能帮助同样困惑的人
【sql技巧】mysql修改时，动态指定要修改的字段 update `table` set (case when ....) = 1 where id = xx
标签：set list collect question over t-sql dia com div
【sql技巧】mysql修改时，动态指定要修改的字段 update `table` set (case when ....) = 1 where id = xx
message
SET send_status = (CASE WHEN sender_id = #{userId, jdbcType=BIGINT} THEN 2 ELSE send_status END),
receive_status = (CASE WHEN receiver_id = #{userId, jdbcType=BIGINT} THEN 2 ELSE receive_status END)
WHERE dialog_id IN (
<foreach collection="list" item="item" index="index" separator="," >
#{item, jdbcType=BIGINT}
</foreach>
)