PHP对多数组进行排序并创建一个新数组

Question

我有这样一个多维数组：

Array
(
    [0] => Array
        (
            [date] => 2017-11-22
            [triger] => triger1
            [count] => 6
        )

    [1] => Array
        (
            [date] => 2017-11-11
            [triger] => triger2
            [count] => 16
        )
    [2] => Array
        (
            [date] => 2017-11-15
            [triger] => triger2
            [count] => 8
        )

)

我希望每个触发器键创建一个单独的子数组，其中包含给定键的所有数据。我想对其进行排序，并从结果中创建一个如下所示的新外观：

Array
(
    [triger1] => Array
        (
            [0] => Array
                 (
                    [date] => 2017-11-22
                    [triger] => triger1
                    [count] => 6
                  )
        )
    [triger2] => Array
        (
            [0] => Array
                 (
                    [date] => 2017-11-11
                    [triger] => triger2
                    [count] => 16
                  )
            [1] => Array
                 (
                    [date] => 2017-11-15
                    [triger] => triger2
                    [count] => 8
                  )
        )
)