laravel 模型查询按照whereIn排序的示例

来源：jb51　　时间：2019/10/17 9:04:38　　对本文有异议

实例如下所示：

$ids = [5,7,3,1,2];
$data = Content::whereIn('id',$ids)
    ->select('id')
    ->get();
//查询结果是想按照wherein的顺序排序
//正确写法
$data = Content::whereIn('id',$ids)
    ->select('id')
//   ->orderBy(\DB::raw('FIND_IN_SET(id, "' . implode(",", $ids) . '"' . ")"))
//   ->orderBy(DB::raw("FIND_IN_SET(id, '" . implode(',', $ids) . "'" . ')'))
//   ->orderByRaw("FIND_IN_SET(id, '" . implode(',', $ids) . "'" . ')')
    ->orderBy(\DB::raw('FIND_IN_SET(id, "' . implode(",", $ids) . '"' . ")"))
    ->get();

中午没睡觉一直调试，心塞...

错误写法

//错误写法
$data = Content::whereIn('id',$ids)
    ->select('id')
    ->orderByRaw("FIND_IN_SET('id', "' . implode(",", $ids) . '"' . ")")
    ->get();
//该写法查询顺序是按照id大小正序排序

原因解析

//正确写法的sql语句为
select `id` from `contents`
order by FIND_IN_SET(id, "5,6,7,4,2,1") asc
//错误写法的sql语句为
select `id` from `contents`
order by 'FIND_IN_SET(id, "5,6,7,4,2,1")' asc
//或者
select `id` from `contents`
order by `FIND_IN_SET(id, "5,6,7,4,2,1")` asc
 
//FIND_IN_SET()方法外面不要添加任何符号