Question

我正在使用SQL Server 2012。

我想更新表格中的一行，使其等于同一表格中除主键字段之外的另一行的值，请参阅下面的示例。这样做的最佳方式是什么？

 Primary Key      Field One     Field Two    Field Three
 ABS              5             6            2
 NJK              3             2            3

因此更新查询应该返回一个看起来像

的结果

 Primary Key      Field One     Field Two    Field Three
 ABS              5             6            2
 NJK              5             6            2

Answer 1

UPDATE  A
SET     A.[Field One] = B.[Field One],
        A.[Field Two] = B.[Field Two],   
        A.[Field Three] = B.[Field Three]
FROM    [table] A
CROSS JOIN (SELECT * FROM [table] WHERE [Primary Key] = 'ABS') B

Answer 2

UPDATE x
SET
  x.[Field One] = y.[Field One],
  x.[Field Two] = y.[Field Two],
  x.[Field Three] = y.[Field Three]
FROM 
  <tablename> x
JOIN 
  <tablename> y
ON
  x.[Primary Key] = 'NJK' AND
  y.[Primary Key] = 'ABS'

在主键列之外的同一个表中设置一行等于另一行

2 个答案: