如何只选择具有多个给定字段值的行

Is there some elegant way to do that, without a big WHERE with lots of AND and OR? For example there are 4 columns: A, B, C, D. For each row the columns have random integer values. I need to select only those rows which have more than one column with a non-zero value. For example (1,2,3,4) and (3,4,0,0) should get selected, however (0,0,7,0) should not be selected (there are no rows that have zeros only).

有没有一种优雅的方式去做这件事，没有一个很大的，有很多很多的，或者?例如，有4列:A、B、C、d。对于每一行，列都有随机整数值。我只需要选择那些具有非零值的列的行。例如(1,2,3,4)和(3,4,0,0)应该被选中，但是(0,7,0)不应该被选中(没有只有零的行)。

PS. I know how this looks but the funny thing is that this is not exam or something, it's a real query which I need to use in a real app :D

我知道这是什么样子，但有趣的是，这不是考试之类的，这是一个真正的查询，我需要在真正的应用中使用:D

3 个解决方案

#1

There. No WHERE, no OR and no AND:

在那里。不，不，不，不，和:

SELECT
   IF(`column1` != 0,1,0) +
   IF(`column2` != 0,1,0) +
   IF(`column3` != 0,1,0) +
   IF(`column4` != 0,1,0) AS `results_sum`
FROM `table`
HAVING
   `results_sum` > 1

#2

SELECT  *
FROM    mytable
WHERE   (0, 0, 0) NOT IN ((a, b, c), (a, b, d), (a, c, d), (b, c, d))

This I believe is this shortest way, though not necessarily the most efficient.

我相信这是一条最短的路，虽然不一定是最有效的路。

#3

Try

试一试

select *
from table t
where ( abs(sign(A))
      + abs(sign(B))
      + abs(sign(C))
      + abs(sign(D))
      ) > 0

#1