php - Laravel运行Select Exists查询

我有这样的查询：

    $query = "Select EXISTS(SELECT * FROM grp_user AS pivot JOIN groups
AS g ON pivot.grp_id = g.id JOIN vote ON g.id = vote.grp_id WHERE
pivot.grp_id = :grp_id AND pivot.user_id = :user_id)";

我想运行它。所以我尝试了：

$res = DB::select($query,array("grp_id"=>250,"user_id"=>1));

理想情况下，res应该具有布尔值，但是它具有类似以下的数组：

[{"EXISTS(SELECT * FROM grp_user AS pivot JOIN groups AS g ON pivot.grp_id = g.id JOIN vote ON g.id = vote.grp_id WHERE pivot.grp_id = ? AND pivot.user_id = ?)":1}]

请注意最后的1，即我感兴趣的值（它为1或0）。

我该如何进行这项工作，或以“ laravel”方式实现这一目标？

最佳答案

为什么不检查它是否为空：

$query = "Select * FROM grp_user AS pivot JOIN groups
AS g ON pivot.grp_id = g.id JOIN vote ON g.id = vote.grp_id WHERE
pivot.grp_id = :grp_id AND pivot.user_id = :user_id LIMIT 1";

$res = DB::select($query,array("grp_id"=>250,"user_id"=>1));

return (count($res) > 0) ? 1 : 0;

关于php - Laravel运行Select Exists查询，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/38104608/