只保留PHP中重複值數組的最小值？

Question

我有一個數組，它是這樣的：

Array 
(
    [0] => Array 
     (
      [date] => 2015-11-01 
      [price] => 95 
     ) 

    [1] => Array 
     (
      [date] => 2015-11-08 
      [price] => 95 
     ) 

    [2] => Array 
     (
      [date] => 2015-11-15 
      [price] => 95 
     ) 

    [3] => Array 
     (
      [date] => 2015-11-03 
      [price] => 90 
     ) 

    [4] => Array 
     (
      [date] => 2015-11-04 
      [price] => 90 
     ) 

    [5] => Array 
     (
      [date] => 2015-11-05 
      [price] => 90 
     ) 

    [6] => Array 
     (
      [date] => 2015-11-06 
      [price] => 90 
     ) 

    [7] => Array 
     (
      [date] => 2015-11-07 
      [price] => 90 
     ) 

    [8] => Array 
     (
      [date] => 2015-11-08 
      [price] => 90 
     ) 

    [9] => Array 
     (
      [date] => 2015-11-09 
      [price] => 90 
     ) 

    [10] => Array 
     (
      [date] => 2015-11-10 
      [price] => 90 
     ) 

    [11] => Array 
     (
      [date] => 2015-11-11 
      [price] => 90 
     ) 

    [12] => Array 
     (
      [date] => 2015-11-12 
      [price] => 90 
     ) 

    [13] => Array 
     (
      [date] => 2015-11-13 
      [price] => 90 
     ) 

    [14] => Array 
     (
      [date] => 2015-11-14 
      [price] => 90 
     ) 

    [15] => Array 
     (
      [date] => 2015-11-15 
      [price] => 90 
     ) 
) 

我想要複製的日期字段的只有最低的價格值出現。它需要是這樣的。

Array(

    [0] => Array 
     (
      [date] => 2015-11-01 
      [price] => 95 
     ) 

    [1] => Array 
     (
      [date] => 2015-11-03 
      [price] => 90 
     ) 

    [2] => Array 
     (
      [date] => 2015-11-04 
      [price] => 90 
     ) 

    [3] => Array 
     (
      [date] => 2015-11-05 
      [price] => 90 
     ) 

    [4] => Array 
     (
      [date] => 2015-11-06 
      [price] => 90 
     ) 

    [5] => Array 
     (
      [date] => 2015-11-07 
      [price] => 90 
     ) 

    [6] => Array 
     (
      [date] => 2015-11-08 
      [price] => 90 
     ) 

    [7] => Array 
     (
      [date] => 2015-11-09 
      [price] => 90 
     ) 

    [8] => Array 
     (
      [date] => 2015-11-10 
      [price] => 90 
     ) 

    [9] => Array 
     (
      [date] => 2015-11-11 
      [price] => 90 
     ) 

    [10] => Array 
     (
      [date] => 2015-11-12 
      [price] => 90 
     ) 

    [11] => Array 
     (
      [date] => 2015-11-13 
      [price] => 90 
     ) 

    [12] => Array 
     (
      [date] => 2015-11-14 
      [price] => 90 
     ) 

    [13] => Array 
     (
      [date] => 2015-11-15 
      [price] => 90 
     ) 
) 

請幫忙嗎？

Answer 1

如果有人有同樣的問題。這裏是我最終制作的代碼。

for ($row = 0; $row < $p; $row++) { 
    $id = $arr[$row]['id']; 
    $date1 = $arr[$row]['date']; 
    $price1 = $arr[$row]['price']; 

    for ($row2 = 0; $row2 < $p; $row2++) { 
     $id2 = $arr[$row2]['id']; 

     if($id != $id2) 
     { 
      $date2 = $arr[$row2]['date']; 
      $price2 = $arr[$row2]['price']; 
      if($date1 == $date2) 
      { 
       if($price1 > $price2) 
       { 

        unset($arr[$row]); 
       } 
      } 
     } 

    } } 

$ arr = array_values（$ arr）;