php - 将具有相同标识符的数组中的 ROWS 分组

Question

如何在 foreach 循环内运行下面的这个数组，并将共享相同 section_id 的行组合在一起？

我用注释 block 标记了所有行和部分。

这是数组

Array ( 
    [0] => Array ( // Row 1
        [assessment_selection_id] => 63 
        [assessment_id] => 32 
        [section_id] => 1 // Section 1
        [question_id] => 1 
        [selection] => 2 
        [timestamp] => 1368160586 
   ) 
   [1] => Array ( // Row 2
        [assessment_selection_id] => 61 
        [assessment_id] => 32 
        [section_id] => 2 // Section 2
        [question_id] => 1 
        [selection] => 3 
        [timestamp] => 1368160510 
   )
   [2] => Array ( // Row 3
        [assessment_selection_id] => 61 
        [assessment_id] => 32 
        [section_id] => 2 // Section 2
        [question_id] => 1 
        [selection] => 3 
        [timestamp] => 1368160510 
   ) 

   [3] => Array ( // Row 4
        [assessment_selection_id] => 61 
        [assessment_id] => 32 
        [section_id] => 2 // Section 2
        [question_id] => 1 
        [selection] => 3 
        [timestamp] => 1368160510 
   ) 
)

预期结果

Array ( 
   [0] => Array ( // Section 1
        [0] => Array ( // Row 1 
            [assessment_selection_id] => 63 
            [assessment_id] => 32 
            [section_id] => 1 
            [question_id] => 1 
            [selection] => 2 
            [timestamp] => 1368160586 
        )
    )
    [1] => Array ( // Section 2
        [0] => Array ( // Row 1
            [assessment_selection_id] => 61 
            [assessment_id] => 32 
            [section_id] => 2 
            [question_id] => 1 
            [selection] => 2 
            [timestamp] => 1368160586 
        )
       [1] => Array ( // Row 2
            [assessment_selection_id] => 61 
            [assessment_id] => 32 
            [section_id] => 2 
            [question_id] => 1 
            [selection] => 2 
            [timestamp] => 1368160586 
        )
       [2] => Array ( // Row 3
            [assessment_selection_id] => 61 
            [assessment_id] => 32 
            [section_id] => 2 
            [question_id] => 1 
            [selection] => 2 
            [timestamp] => 1368160586 
        )
    )
)

没有数组的预期结果

第 1 部分

• 第 1 行

  assessment_selection_id,评估_id，section_id,问题编号，选择，时间戳

第 2 部分

• 第 1 行

  assessment_selection_id,评估_id，section_id,问题编号，选择，时间戳

• 第 2 行

  assessment_selection_id,评估_id，section_id,问题编号，选择，时间戳

• 第 3 行

  assessment_selection_id,评估_id，section_id,问题编号，选择，时间戳

Answer 1

假设您将数组保存在 $myArray 中这样做:

$newArray=array();
foreach($myArray as $val){
    $newKey=$val['section_id'];
    $newArray[$newKey][]=$val
}
print_r($newArray);