If you need to check if a login exists in SQL Server , you can use query the master.dbo.syslogins for it.
How to Check if a login exists in SQL Server ?
Here’s a sample query demonstrating how you can query master.dbo.syslogins to find out if the login exists in SQL Server.
Select * from master.dbo.syslogins where name = 'sa'
This would retreive all the details of the loginid ‘sa’.
