PHP implements a method of reorganizing a two-dimensional array of MySQL duplicate ID into a three-dimensional array

This article describes the PHP method of reorganizing a two-dimensional array of MySQL duplicate ID into a three-dimensional array. Share it for your reference, as follows:

Application scenarios

When MYSQL uses association query, for example, product table is associated with product picture table, and multiple product pictures of a product, the association query results are as follows:

$arr=[
  ['id'=>1,'img'=>'img1'],
  ['id'=>1,'img'=>'img2'],
  ['id'=>1,'img'=>'img3'],
  ['id'=>2,'img'=>'img1'],
  ['id'=>2,'img'=>'img2'],
  ['id'=>2,'img'=>'img3'],
  ['id'=>3,'img'=>'img1'],
  ['id'=>3,'img'=>'img2'],
  ['id'=>3,'img'=>'img3'],
]

Then, the result we want is generally like this, as follows:

$arr=[
  ['id'=>1,'img'=>['img1','img2','img3']],
  ['id'=>2,'img'=>['img1','img2','img3']],
  ['id'=>3,'img'=>['img1','img2','img3']],
]

Solution

$arr=[
    ['id'=>1,'img'=>'img1'],
    ['id'=>1,'img'=>'img2'],
    ['id'=>1,'img'=>'img3'],
    ['id'=>2,'img'=>'img1'],
    ['id'=>2,'img'=>'img2'],
    ['id'=>2,'img'=>'img3'],
    ['id'=>3,'img'=>'img1'],
    ['id'=>3,'img'=>'img2'],
    ['id'=>3,'img'=>'img3'],
]
$arr1=array();
foreach ($arr as $key => $value) {
    if( in_array($value['id'], $value)){
     $arr1[$value['id']]['id']=$value['id'];
     $arr1[$value['id']]['img'][]=$value['img'];
    }   
}
var_dump($arr1);

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