php 把多维数组中，某值相同的项合并，重组数据(不用再愁postgres中无mysql中的group_concat()功能)

对数组$array重组：

$array = array(
array('id'=>1,'name'=>'aa','pwd'=>'12'),
array('id'=>1,'name'=>'bb','pwd'=>'56'),
array('id'=>1,'name'=>'saa','pwd'=>'89'),

array('id'=>2,'name'=>'cc','pwd'=>'78')
);
实现代码如下：

$tmpArray = array();
        foreach ($array as $row) {
            
            $key = $row['id'];
            if (array_key_exists($key, $tmpArray)) {
//$tmpArray[$key]['pwd'] = $tmpArray[$key]['pwd']  . ',' . $row['pwd'];  //用这句的话下面有关pwd的条件语句都要删掉，实现其字符串形式
                if (is_array($tmpArray[$key]['name'])) {
                    $tmpArray[$key]['name'][] = $row['name'];
                } else {
                    $tmpArray[$key]['name'] = array($tmpArray[$key]['name'], $row['name']);
                }
                if (is_array($tmpArray[$key]['pwd'])) {
                    $tmpArray[$key]['pwd'][] = $row['pwd'];
                } else {
                    $tmpArray[$key]['pwd'] = array($tmpArray[$key]['pwd'], $row['pwd']);
                }
            } else {
                $tmpArray[$key] = array('id'=>$row['id'],'name'=>array($row['name']),'pwd'=>array($row['pwd'])); //此句要注意，可设置
                // $tmpArray[$key] = $row; // 有字段相加时可能会代替上面一句
            }
        }

        echo "<pre>";
        var_dump($tmpArray);

打印结果为：

array (size=2)
  1 =>
    array (size=3)
      'id' => int 1
      'name' =>
        array (size=3)
          0 => string 'aa' (length=2)
          1 => string 'bb' (length=2)
          2 => string 'saa' (length=3)
      'pwd' =>
        array (size=3)
          0 => string '12' (length=2)
          1 => string '56' (length=2)
          2 => string '89' (length=2)
  2 =>
    array (size=3)
      'id' => int 2
      'name' =>
        array (size=1)
          0 => string 'cc' (length=2)
      'pwd' =>
        array (size=1)
          0 => string '78' (length=2)

// $field 为一维数字数组，$field[0]为用于分组的单一字段。  

public function combine($array,$field){
$tmpArray = array();
$distinct_field = $field[0];
unset($field[0]);
foreach ($array as $row) {
$key = $row[$distinct_field];
if (array_key_exists($key, $tmpArray)) {
foreach($field as $value){
if (is_array($tmpArray[$key][$value])) {
$tmpArray[$key][$value][] = $row[$value];
} else {
$tmpArray[$key][$value] = array($tmpArray[$key][$value], $row[$value]);
}
}
} else {
$tmpArray[$key][$distinct_field] = $row[$distinct_field];
foreach ($field as $value){
$tmpArray[$key][$value] = array($row[$value]);
}
}
}
return $tmpArray;
}