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)


      

实现了用上面的id值来分组。

 // $field 为一维数字数组，$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;
        }