Laravel默认的auth表

How do i change where laravel does it queries on functions like :

 $request->validate([
        'username' => 'required|string',
        'email' => 'required|string|email|unique:users',
        'password' => 'required|string'
    ]);?

It always does it queries on the table 'users' which is a laravel default table that I don't use

It make the query on the users table because when you use the unique validation rule you can pass the name of the table on which eloquent must search for the input value which is being validate.

$request->validate([
    'username' => 'required|string',
    'email' => 'required|string|email|unique:users',
    'password' => 'required|string'
]);?

Your validation rule for email will search for the existance of the given email in the users table because it's the name of table which you pass as the first argument of unique. You can change it.

The unique rule take parameters like this unique:table_name:column_name