Mssqlserver error: 15405 special entity sa unavailable

Solution 1

1) set the logon mode to "hybrid authentication" (right-click the Server and choose "security"> Click "SQL Server" and "Windows identity authentication)

The premise is that the hybrid authentication of the database has been enabled, that is, the sa user has been enabled.

3) set sa account (Database-> Security (not the same as above, this does not need to be right-clicked) -> login name-> sa Account-> password-> User ing-> map to your database

3) restart SQL server. (net stop mssqlserver)

Solution 2

Check whether the database has mixed identity authentication, and check that the sa user is enabled. If all of them are enabled, set them as shown in the following figure.

Right-click the database property: file --> owner --> select user sa to log on to the database with this sa user.

After the preceding method is set, it can be used.