检查更新数据是否与SQL Server中以前的数据相同

Question

I have a table Table1 :

 ID | RefID |  Answer | Points | 
----+-------+---------+--------+
 1  |   1   |    1    |   5    | 
 2  |   1   |    2    |   0    | 
 3  |   1   |    3    |   3    | 
 4  |   2   |    1    |   4    | 

I have a result set in temp table Temp1 with same structure and have update Table1 only if for refID answer and points have changed, otherwise there should be deletion for this record.

I tried:

update table1 
set table1.answer = temp1.answer,
    table1.points = temp1.points 
from table1 
join temp1 on table1.refid = temp1.refid 
where table1.answer != temp1.answer or table1.points != temp1.points

Here is a fiddle http://sqlfiddle.com/#!18/60424/1/1

However this is not working and don't know how to add the delete condition. Desired result should be if tables not the same ex. (second row answer 2 points3):

 ID | RefID |  Answer | Points | 
----+-------+---------+--------+
 1  |   1   |    1    |   5    | 
 2  |   1   |    2    |   3    | 
 3  |   1   |    3    |   3    | 
 4  |   2   |    1    |   4    | 

if they are same all records with refID are deleted.

Explanation when temp1 has this data

     ID  | RefID |  Answer | Points | 
     ----+-------+---------+--------+
     12  |   1   |    1    |   5    | 
     13  |   1   |    2    |   0    | 
     14  |   1   |    3    |   3    | 

EDIT: adding another id column questionid solved the update by adding this also in join.

Table structure is now:

 ID | RefID |  Qid |Answer | Points | 
----+-------+------+-------+--------+
 1  |   1   |  10  |  1    |   5    | 
 2  |   1   |  11  |  2    |   0    | 
 3  |   1   |  12  |  3    |   3    | 
 4  |   2   |  11  |  1    |   4    | 

SQL for update is: (fiddle http://sqlfiddle.com/#!18/00f87/1/1 ) :

update table1 
set table1.answer = temp1.answer,
   table1.points = temp1.points 
from table1 
join temp1 on table1.refid = temp1.refid and table1.qid = temp1.qid 
where table1.answer != temp1.answer or table1.points != temp1.points;

SELECT ID, refid, answer, points 
FROM table1

How can I make the deletion case, if data is same ?

Answer 1

You need to add one more condition in the join to exactly match the column.Try this one.

update table1 
set table1.answer=temp1.answer,
    table1.points=temp1.points 
from
table1 join temp1 on table1.refid=temp1.refid and **table1.ID=temp1.ID**
where table1.answer!=temp1.answer or table1.points!=temp1.points

Answer 2

我认为从我的理解来看，如果id是唯一的，则需要使用id而不是refid或两者都使用

Answer 3

I would first do the delete, and only then the update.
The reason for this is that once you've deleted all the records where the three columns are the same, your update statement becomes simpler - you only need the join, and no where clause:

DELETE t1
FROM table1 AS t1
JOIN temp1 ON t1.refid = temp1.refid
          AND t1.qid = temp1.qid
          AND t1.answer=temp1.answer
          AND t1.points=temp1.points 

UPDATE t1 
SET answer = temp1.answer,
    points = temp1.points 
FROM table1 AS t1 
JOIN temp1 ON t1.refid=temp1.refid 
          AND t1.qid = temp1.qid