SQL-Server 2014. UPDATE 连接两个表并使用表别名

Question

我有两张几乎一模一样的桌子。 当它是NULL 时，需要更新 TABLE_03 中的每个Postal 没有要使用的 ID 或主键，所以我将它们与列 Link、Name 和 PhoneNum /（TABLE_ALL 中的 Phone）链接起来

尝试过的SQL：

 UPDATE TABLE_03 a
   join TABLE_ALL b 
   ON   a.Link = b.Link,
        a.Name = b.Name,
        a.PhoneNum = b.Phone
   SET a.Postal = b.PostalCode
  WHERE a.Postal IS NULL;

SQL Server 报错

Incorrect syntax near 'a'.

没有别名：

  UPDATE TABLE_03 
   join TABLE_ALL 
   ON   TABLE_03.Link = TABLE_ALL.Link,
        TABLE_03.Name = TABLE_ALL.Name,
        TABLE_03.PhoneNum = TABLE_ALL.Phone
   SET TABLE_03.Postal = TABLE_ALL.PostalCode
  WHERE TABLE_03.Postal IS NULL; 

给出错误：

Incorrect syntax near the keyword 'join'.

Answer 1

您的语法错误，主要是JOIN ON 子句。它应该像下面使用AND 运算符

UPDATE TABLE_03 a
   join TABLE_ALL b 
   ON   a.Link = b.Link AND
        a.Name = b.Name AND
        a.PhoneNum = b.Phone
   SET a.Postal = b.PostalCode
  WHERE a.Postal IS NULL;

使用正确的SQL Server 语法

UPDATE a
SET a.Postal = b.PostalCode
FROM TABLE_03 a
   join TABLE_ALL b 
   ON   a.Link = b.Link AND
        a.Name = b.Name AND
        a.PhoneNum = b.Phone   
  WHERE a.Postal IS NULL;

Answer 2

试试这个

       UPDATE TABLE_03 
 SET TABLE_03.Postal = TABLE_ALL.PostalCode
 from TABLE_ALL 
 where  TABLE_03.Link = TABLE_ALL.Link AND 
    TABLE_03.Name = TABLE_ALL.NAME AND 
    TABLE_03.PhoneNum = TABLE_ALL.Phone and

   TABLE_03.Postal IS NULL; 

Answer 3

试试这个：

 UPDATE a
   SET a.Postal = b.PostalCode
   FROM TABLE_03 a
   join TABLE_ALL b 
   ON   a.Link = b.Link,
        a.Name = b.Name,
        a.PhoneNum = b.Phone
  WHERE a.Postal IS NULL;