laravel验证批次列中的唯一值

Question

I have table that have role column, i have to check and validate for every type need only one manager like this :

| id |   role | type | name 
_______________________________
| 1 | manager | 1    | Pedram 
| 2 | member  | 1    | Parham
| 3 | member  | 2    | Pedram 
| 4 | member  | 1    | Parham

i have to do this with Laravel unique: validation.

i wrote a custom validation and it works :

    public function validateUniqueValue($attribute, $value, $parameters)
{
    $query = DB::table($parameters[0])->where($parameters[1], $value);
    if (array_key_exists(2, $parameters)) {
        $query->where($parameters[2], $parameters[3]);
    }
    if ($query->count() > 0) {
        return false;
    }
    else {
        return true;
    }
}

but, how can i do something like this ?

Answer 1

If you want to validate input for distinct values then you can use unique:tablename constraint in Validator. However we can also add conjunctions in the constraint. So in your example you could do the following:

$validator = Validator::make
(
      ['type' => $typeval], 
      ['type' => 'unique:table,role,' . $role_value]
);

if($validator->fails()) //not distinct role, type pair
else //distinct

Which would produce the SQL:

SELECT COUNT(*) FROM `table` WHERE `type` = ? AND `role` = ?

So this will obviously allow all distinct pairs for any role/type and not just manager/type pairs but if you just want to check for distinct manager/type pairs you would need to let $role_value = 'manager'