Some issues with SQL Server SA login

SQL Server SA login cannot connect to (local)?

When you encounter this problem, make sure that the SQL Master service is turned on:

OK then replace the server name with the computer name \ Instance name again using SA login as follows:

Is it possible?

If you want to use "(local)", "." To log in, you can set it to SQL Server Configuration Manager:

Right click on "Alias"--New Alias
Protocol, select "Named Pipes", and then enter "(local)" In the alias, the server input "machine name \ server name", such as: "Oiar7rfic62jx36\sqlexpress", then click on the application, then select the SQL Server service, the SQL The Server service restarts.
You can then use (local) to log in and use the same "." The way it can be.

How do I turn on sa login mode?
First log in with Windows mode, then right click on the database click Properties.

Turn on SA and Windows Mixed mode.

Security ==> Login ==>sa Right-click the ==> property
Set the SA password as follows

Then enable the SA account:

So far, the problem of SA landing can be solved roughly.

Some issues with SQL Server SA login