Failed to attach database, unable to upgrade database because it is a read-only __ database

Attachment database, the old problem, and later found a solution on the internet, recorded.

The following is reproduced from the network:

After consulting the data, found that is not a file read-only problem, strictly speaking should be a "permission" problem, the current SQL Server login account does not have to attach files to write permission, there will be the above "read-only" hint, the solution has the following several ways:

1. Copy the attached file to the SQL Server default Data directory, at which point the add-on will succeed;

2. At logon authentication, choose Windows Authentication instead of SQL Server authentication, even if your login account is sa;

3. If you must use SQL Server authentication, change the permissions on the login account to have full operational rights to the file you want to attach;

4. Change the account logon status of SQL Server service from Network service to local service;