php - 在 php 或 mysql 中使用数字中的内部数组对数组进行排序

Question

我有一个这样的数组，

array[0][0],[1][0],[2][0] 是问题，array[0][1],[1][1],[2][1] 是问题这些问题的答案。
现在我想根据答案的数量对这个数组进行排序。
第一个问题只有一个答案，并且 第二个有两个答案，第三个有三个答案。
排序后的数组应根据该问题的答案数量降序排列。 无论如何在sql中实现这个？或者我们如何在 php 中排序？希望我的问题很清楚。先感谢您。

Array
(
    [0] => Array
        (
            [0] => Array
                (
                    [0] => 12
                    [1] => 110
                    [2] => Tom
                    [3] => Tom@gmail.com
                    [4] => Hello tom how are you?
                    [5] => 2013-01-03 14:54:07
                )

            [1] => Array
                (
                    [0] => Array
                        (
                            [0] => 12
                            [1] => Yes i am fine.
                            [2] => Arun
                            [3] => arun@gmail.com
                            [4] => 2013-01-03 14:55:22
                        )
                )
        )
    [1] => Array
        (
            [0] => Array
                (
                    [0] => 12
                    [1] => 110
                    [2] => Tom
                    [3] => Tom@gmail.com
                    [4] => Hello tom how are you.
                    [5] => 2013-01-03 14:54:07
                )

            [1] => Array
                (
                    [0] => Array
                        (
                            [0] => 12
                            [1] => Yes i am fine
                            [2] => Arun
                            [3] => arun@gmail.com
                            [4] => 2013-01-03 14:55:22
                        )
                    [1] => Array
                        (
                            [0] => 12
                            [1] => Yes i am fine
                            [2] => Arun
                            [3] => arun@gmail.com
                            [4] => 2013-01-03 14:55:22
                        )
                )
        )
    [2] => Array
        (
            [0] => Array
                (
                    [0] => 12
                    [1] => 110
                    [2] => Tom
                    [3] => Tom@gmail.com
                    [4] => Hello tom how are you.
                    [5] => 2013-01-03 14:54:07
                )
            [1] => Array
                (
                    [0] => Array
                        (
                            [0] => 12
                            [1] => Yes i am fine
                            [2] => Arun
                            [3] => arun@gmail.com
                            [4] => 2013-01-03 14:55:22
                        )
                    [1] => Array
                        (
                            [0] => 12
                            [1] => Yes i am fine
                            [2] => Arun
                            [3] => arun@gmail.com
                            [4] => 2013-01-03 14:55:22
                        )
                [2] => Array
                        (
                            [0] => 12
                            [1] => Yes i am fine
                            [2] => Arun
                            [3] => arun@gmail.com
                            [4] => 2013-01-03 14:55:22
                        )
                )
        )

Answer 1

这应该有效:

function cmp($a, $b)
{
    return count($a[1]) > count($b[1]) ? -1 : 1;
}

usort($data, 'cmp');

或者，如果您使用的是 PHP 5.3.0 或更高版本，您可以使用:

usort($data, function ($a, $b) {
    return count($a[1]) > count($b[1]) ? -1 : 1;
});