mysql - MySQL Set First值是否为-1？

我有一个数据表：
player1, player2, player3, player4
它们都是默认为int的-1。我该如何设置第一个（-1为player1，player4为最后一个）数字-1？

例：
player1, player2, player3, player4
-1, -1, -1, -1
player1是第一个值为-1的值，因此我们将其设置为4。

最佳答案

这是你想要的？

update table t
    set player1 = (case when player1 = -1
                        then <a number> else player1 end),
        player2 = (case when player1 <> -1 and player2 = -1
                        then <a number> else player2 end),
        player3 = (case when player1 <> -1 and player2 <> -1 and player3 = -1
                        then <a number> else player3 end),
        player4 = (case when player1 <> -1 and player2 <> -1 and player3 <> -1 and player4 = -1
                        then <a number> else player4 end);

关于mysql - MySQL Set First值是否为-1？，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/23123313/