如何更新每个记录的PK

Question

我有两个完全相同的表，除了一列。两个表都有相同数量的记录和相同数量的列，并且所有数据都是相同的。

Table A: 
+--------------------------------------+--------+--------+---------+ 
|     GUID     | Animal | Person | Vehicle | 
+--------------------------------------+--------+--------+---------+ 
| 1D001609-7071-4DBB-9E65-0000B3EEF751 | cat | matt | car  | 
| 90260783-E3C3-4A9B-BEA0-000388EA41E1 | dog | rich | truck | 
| DD18FCFA-99BD-4FBC-AFC2-00058EF95D0A | zebra | alex | van  | 
+--------------------------------------+--------+--------+---------+ 



Table B: 
+--------------------------------------+--------+--------+---------+ 
|     GUID     | Animal | Person | Vehicle | 
+--------------------------------------+--------+--------+---------+ 
| F67A3079-8589-4304-AA3C-000688696BAA | cat | matt | car  | 
| C71710EC-492F-424E-805D-00068AFE4E82 | dog | rich | truck | 
| 5F830142-F4CC-4580-974D-000710F1AB5F | zebra | alex | van  | 
+--------------------------------------+--------+--------+---------+ 

我需要一个表的GUID来进行更新，以等于表B的东西的GUID像这样将工作：

update a 
set a.guid=b.guid 
from tablea a 
join tableb b 
on a.animal=b.animal 
and a.person=b.person 
and a.vehicle=b.vehicle 

但上述方案不会为我工作。我实际上有大约50列和大约100万条记录。

关于如何更有效地更新表A中的GUID，您还有其他建议吗？

Answer 1

UPDATE A 
SET [GUID] = (
    SELECT [GUID] 
    FROM B 
    WHERE EXISTS (
    SELECT A.Animal,A.Person,A.Vehicle 
    INTERSECT 
    SELECT B.Animal,B.Person,B.Vehicle 
) 
) 

Answer 2

如果你想表是相同的，这个怎么样：

DROP TABLE B 

SELECT * 
INTO B 
FROM A