php - 缩短代码、ORDER BY 和 SWITCH

Question

你能帮我缩短代码吗？要点是，我想根据给定的 $T 以不同的顺序从数据库中获取数据。任何想法？

public function rewriteQuery($T){

switch ($T) {

    case 0:
        $query="SELECT id, title FROM kshome WHERE del=0 AND active=1 ORDER BY FIELD(id,1,2,3,4,5,6)";  
        break;
     case 1:
        $query="SELECT id, title FROM kshome WHERE del=0 AND active=1 ORDER BY FIELD(id,2,3,4,5,6,1)";  
        break;
     case 2:
        $query="SELECT id, title FROM kshome WHERE del=0 AND active=1 ORDER BY FIELD(id,3,4,5,6,1,2)";    
        break;
     case 3:
       $query="SELECT id, title FROM kshome WHERE del=0 AND active=1 ORDER BY FIELD(id,4,5,6,1,2,3)";  
        break;
     case 4:
      $query="SELECT id, title FROM kshome WHERE del=0 AND active=1 ORDER BY FIELD(id,5,6,1,2,3,4)";  
        break;
    default:
       $query="SELECT id, title FROM kshome WHERE del=0 AND active=1 ORDER BY FIELD(id,6,1,2,3,4,5)";  
    break;

    }        

  return $query;             

} 

Answer 1

缩短此过程的一种方法是创建一个返回order by字段的数组。

类似这样的事情:

$order_by_array = array(
  0 => "(id,1,2,3,4,5,6)", 
  1 => "(id,2,3,4,5,6,1)", 
  2 => "(id,3,4,5,6,1,2)", 
  3 => "(id,4,5,6,1,2,3)", 
  4 => "(id,5,6,1,2,3,4)"
);

然后你的rewriteQuery($T)函数可以重写为:

public function rewriteQuery($T){
  $order_by = "(id,6,1,2,3,4,5)"; // Default
  if (array_key_exists($T, $order_by_array)) {
    $order_by = $order_by_array[$T];
  }

  $query = "SELECT id, title FROM kshome WHERE del=0 AND active=1 ORDER BY FIELD{$order_by}";
  ...
}