MySQL将值赋给一个空别名(MySQL assigning value to a null alias)

 结果表格： 
 
result_event | name          |  position
-------------+---------------+------------
1            | Jason Smith   |  1
1            | David Johnson |  2
1            | Randy White   |  3
1            | Billy Hansen  |  4 
2            | Wally Mann    |  1
2            | Jason Smith   |  2
2            | Billy Hansen  |  3
2            | David Johnson |  4
2            | Randy White   |  5
 
 我有一张比赛结果如上表。 我想通过他们在两场比赛中的组合位置来排序车手。 （例如1号加2号= 3号，2号加4号= 6号等）。赛车手“Wally Mann”没有参加第一场比赛，即使他赢得了第二场比赛，他也应该在所有其他比赛中进球。 
 
 预期结果： 
 
Name          | Race1  | Race2
--------------+--------+-------
Jason Smith   |   1    |   2
David Johnson |   2    |   4
Billy Hansen  |   4    |   3 
Randy White   |   3    |   5
Wally Mann    |   NULL |   1
 
 当前查询： 
 
SELECT name,
     CASE(WHEN result_event=1 then position else 0 END) Race1,
     CASE(WHEN result_event=2 then position else 0 END) Race2,
     SUM(position) eventscore
FROM results
GROUP BY name
ORDER BY eventscore DESC
 
 在我当前的查询中，“Wally Mann”是第一个列表，因为（Null + 1）<（1 + 2）。 我能做些什么来使所有有两个结果的参赛者进入（Null + 1）结果？ 

results table:
 
result_event | name          |  position
-------------+---------------+------------
1            | Jason Smith   |  1
1            | David Johnson |  2
1            | Randy White   |  3
1            | Billy Hansen  |  4 
2            | Wally Mann    |  1
2            | Jason Smith   |  2
2            | Billy Hansen  |  3
2            | David Johnson |  4
2            | Randy White   |  5
 
I have a table with race results as above. I want to sort the riders by their combined placement in the two races. (eg 1st plus 2nd = 3, 2nd plus 4th = 6, etc.) Racer "Wally Mann" did not race the first race so even though he won the second race, he should be scored behind all others.
 
Desired Result:
 
Name          | Race1  | Race2
--------------+--------+-------
Jason Smith   |   1    |   2
David Johnson |   2    |   4
Billy Hansen  |   4    |   3 
Randy White   |   3    |   5
Wally Mann    |   NULL |   1
 
Current query:
 
SELECT name,
     CASE(WHEN result_event=1 then position else 0 END) Race1,
     CASE(WHEN result_event=2 then position else 0 END) Race2,
     SUM(position) eventscore
FROM results
GROUP BY name
ORDER BY eventscore DESC
 
In my current query, "Wally Mann" is first in the list because (Null + 1) < (1+2). What can I do to make the (Null + 1) result sort AFTER all the racers who have two results? 

原文：https://stackoverflow.com/questions/50494618