概述
有两张表【user】和【city】，user表的
city_uuid、city_no和 city 表的city_uuid、city_no一一对应，但是 user 表只有city_uuid，这时候需要将 city 对应的city_no批量更新到 user 表中
批量更新方式
第一种方式（inner join 内连接）
update u set u.city_no = c.city_no from user u inner join city c on u.city_uuid = c.city_uuid where u.city_uuid is not null and u.city_no is null 第二种方式（子查询）
update u set u.city_no = (select c.city_no from city c where u.city_uuid = c.city_uuid) from user u 第三种方式：（笛卡尔积）
update u set u.city_no = c.city_no from [user] u, city c where u.city_uuid = c.city_uuid update 多表更新
update table1 t1,table2 t2, table3 t3, ... , tablen tn set t1.column= ?, t2.column, t3.column = ?, ... , tn.column = ? where t1.xx= ?, t2.xx = ?, ... , tn.xx = ? 案例：（conditionUuid是user表的外键，每个conditionUuid对应两条user记录，将producter记录覆盖consumer记录的指定字段值)
update r2 set r2.userUuid = r1.userUuid, r2.userName = r1.userName , r2.age = r1.age, r2.updatedTime = '2021-02-22 22:22:22.222' from user r1 inner join user r2 on r1.conditionUuid = r2.conditionUuid where r1.conditionValue = 'condition-consumer-00000000000000000' and r1.userName is not null and r2.conditionValue = 'condition-producter-0000000000000000' and r2.userName is not null 版权声明：本文内容由互联网用户自发贡献，该文观点仅代表作者本人。本站仅提供信息存储空间服务，不拥有所有权，不承担相关法律责任。如发现本站有涉嫌侵权/违法违规的内容， 请联系我们举报，一经查实，本站将立刻删除。
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