How can a SharePoint SQL connection be set to query by the current login name?

I have a SQL table that needs to be queried by the login name. So, using SharePoint designer I successfully created a database connection, but I can't use the properties exposed by Profile nor Session as input parameters because they are not supported (A dialog pops up with a message indicating this)

How else can I query a SQL da开发者_Python百科tasource by using the current login?

-Edit

To create the data connection, proceed as follows

1. Open the data source library
2. Expand database connections and click on connect to a database
3. Enter the database settings
4. Select "specify custom Select, Update, Insert, and Delete"
5. Click on Edit Command
6. Add a parameter and select Profile and enter UserName as the property name

An error will follow stating that this is not supported.

Unfortunately, you don't give many details but I think you're looking for the LOGON_USER Server Variable: Data View / Data Form: Parameters You Don’t Know About.