This post is a guide on how to connect to SQL Server with Windows Authentication, but using a different Domain User rather than your own.
The regular Windows SQL Server User connects & runs their queries via SQL Server Management Studio (SSMS). If you’re in a corporate environment, you’ll likely be logged into your computer with an Active Directory (AD) User. In this example, if we open SSMS we will likely connect with our currently logged-in AD account.
This guide shows how to authenticate to MSSQL using an AD account that is not the same as your own logged-in user, which is particularly useful for testing newly created SQL Server AD User access and permissions.
Open SSMS with Other Domain User
A regular SQL Server Management Studio (SSMS) user in Windows has the application pinned to their taskbar. Search with the Windows button and follow the same on the SSMS app icon.
Right-Click SSMS Icon –> Hold CTRL + Right-Click Icon –> Select Run As Different User
Simple as that. No need for much longer explanations. All I can refer you to is the new SSMS Tips Tag for more posts on this topic.