更新表语法：查询在mysql中工作，但不在oracle或mssql中

Question

update t_one t1 
join t_two t2 on (t2.f1 = t1.f1)
join t_three t3 on (t1.f4 = t3.f4 and t2.f5 = t3.f5) 
set t1.f6 = t3.f6 
where t1.f6 is null

我想用t_three中相应的值更新t_on.f6，该值取决于连接。查询在mysql中运行得很好，但是我得到了

ORACLE中的错误

  

ORA-00971：缺少SET关键字

和MSSQL

  

查询错误：'t1'附近的语法不正确

我该怎么办？

Answer 1

我永远不会记得各种条款出现在哪个顺序，但这是

的内容

update t1 
set t1.f6 = t3.f6 
from t_one t1
join t_two t2 on (t2.f1 = t1.f1)
join t_three t3 on (t1.f4 = t3.f4 and t2.f5 = t3.f5) 
where t1.f6 is null

您可能不需要t1或set条款中的where别名，但它们可能不会受到伤害。

Answer 2

对于SQL Server，您需要更多类似的东西：

UPDATE t1 
   SET t1.f6 = t3.f6 
  FROM t_one t1 
       INNER JOIN t_two t2 ON t2.f1 = t1.f1
       INNER JOIN t_three t3 ON t1.f4 = t3.f4 AND t2.f5 = t3.f5 
 WHERE t1.f6 is null

Answer 3

在SQL Server中：

update  t1 
set t1.f6 = t3.f6 
from t_one t1
join t_two t2 on (t2.f1 = t1.f1)
join t_three t3 on (t1.f4 = t3.f4 and t2.f5 = t3.f5) 
where t1.f6 is null