php排序数组有三个维度

我有一个三维数组,我想在第一维中对第三维中的值进行排序.
如下：

Array
(
[0] => Array
    (
        [0] => Array
            (
                [data] => 7
                [field] => 1
                [type] => string
            )

        [1] => Array
            (
                [data] => 2011/07/13
                [field] => -2
                [sort] => 1310594015
            )

        [2] => Array
            (
                [data] => admin
                [field] => -1
                [sort] => admin
            )
    )

[1] => Array
    (
        [0] => Array
            (
                [data] => 6
                [field] => 1
                [type] => string
            )

        [1] => Array
            (
                [data] => 2011/07/14
                [field] => -2
                [sort] => 1310667194
            )

        [2] => Array
            (
                [data] => admin
                [field] => -1
                [sort] => admin
            )
    )
)

我想根据’data’键的值在第一级(即第三级)对数组进行排序(即只有2个).在这种情况下,第一级的两个数组应该交换,因此’data’的值为6的数组位于带有7的数组之前.
包含’data’键的数组将始终位于第二级的位置[0].

解决方法:

usort($allArray,function($a,$b){
     return $a[0]['data']-$b[0]['data'];
})