When I try to access SQL Database 2014. It shows an error:

“An exception occurred while executing a Transact-SQL statement or batch. (Microsoft.SqlServer.ConnectionInfo)
Msg 924, Level 14, State 1, Line 1
Database ‘db_name’ is already open and can only have one user at a time.”

I searched over internet and found these resources.

But, the above sources are not freeware. Please Guide!