PHP Array Blacklist and Whitelist Instance Code Detailed Explanation

In php, the data often obtained through join query will have this situation:

$data = [
  {id=>1,name=>a,age=>a},
  {id=>1,name=>b,age=>b},
  {id=>2,name=>c,age=>c},
  {id=>3,name=>f,age=>f},
  {id=>2,name=>d,age=>d},
];

Data in this format is actually very common. In fact, the data effect we want is:

$data = [
  [id=>1,user_info=>[[name=>a,age=>a],[name=>b,age=>b]]],
  [id=>2,user_info=>[[name=>c,age=>c],[name=>d,age=>d]]],
  [id=>3,user_info=>[[name=>f,age=>f]]],
];

So we need all kinds of foreach to deal with the functions;

Here, under 1, two functions

Blacklist of arrays:

/**
 *  Array to get the data in the blacklist 
 * @param array $arr  Source array 
 * @param array $list  White list 
 * @return array
 * @example
 * $arr = ['a'=>1,'b'=>2,'c'=>3,'d'=>4]
 * $list = ['d','c'];
 * $return = ['a'=>1,'b'=>2];
 */
public function array_black_list(Array $arr, Array $list)
{
  return array_diff_key($arr, array_flip($list));
}

White list of arrays

/**
 *  Array to get the data in the white list 
 * @param array $arr  Source array 
 * @param array $list  White list 
 * @return array
 * @example
 * $arr = ['a'=>1,'b'=>2,'c'=>3,'d'=>4]
 * $list = ['d','c'];
 * $return = ['c'=>3,'d'=>4];
 */
public function array_white_list(Array $arr, Array $list)
{
  return array_intersect_key($arr, array_flip($list));
}

Using blacklist and whitelist, the above data format conversion can be easily realized:

/**
 * repeat Data processing (1 Like is leftJoin Perfect data structure )
 * leftJoin  Multiple sets of data queried ,  According to primary_id Modify the data structure ,  Save as   Field =>[{},{},{}] Similar structure 
 *  Effect :$data = [{id=>1,name=>a,age=>a},{id=>1,name=>b,age=>b},{id=>2,name=>c,age=>c},{id=>3,name=>null,age=>null}],$fieldArr = ['name','age']
 * return [{id=>1,repeat_info=>[{name=>a,age=>a},{name=>b,age=>b}]},{id=>2,repeat_info=>[{name=>c,age=>c}]},{id=>3,repeat_info=>[]}]
 * @param $data  array  Original data ;
 * @param $fieldArr array  Required fields ,
 * @param string $primary_key  Duplicate data   Vouchers ;(1 General primary key id)
 * @param string $repeat_name  Duplicate data should be saved in the array   Field name 
 * @return array
 */
public function dealRepeatData(Array $data, Array $fieldArr, $primary_key = 'id', $repeat_name = 'repeat_info')
{
  $res = [];
  // Get non-duplicate values through blacklist ,  Merge to press id In the classified array ;
  foreach ($data as $nre) {
    $res[$nre[$primary_key]] = $res[$nre[$primary_key]] ?? $this->array_black_list($nre, $fieldArr);
  }
  // Get duplicate values through white list ,  Merged into the blacklist $repeat_name  In the field ;
  foreach ($data as $re) {
    $res[$re[$primary_key]][$repeat_name][] = $this->array_white_list($re, $fieldArr);
  }
  return array_values($res);
}

Summarize