Cannot connect to LocalDB with Power BI Desktop

Hi kennykhor ,

To connect to a shared instance of LocalDB add .\ (dot + backslash) to the connection string to reference the namespace reserved for shared instances. For example, to connect to a shared instance of LocalDB named AppData use a connection string such as (localdb)\.\AppData as part of the connection string. A user connecting to a shared instance of LocalDB that they do not own must have a Windows Authentication or SQL Server Authentication login.

So, Please try (localdb)\.\MSSQLLocalDB

If this doesn't work, try to use domain\username to replace (localdb).

For example: use .\username or local:\username to replace  (localdb).

Besides, you can use whoami in windows commands to findout your username

For more details, please refer to:

How to connect and use Microsoft SQL Server Express LocalDB

SQL Server 2012 Express LocalDB  

whoami | Microsoft Docs 

Best Regards,

Jianbo Li

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