A network-related or instance-specific error occurred while establishing a connection to SQL Server.

Question

can anyone give the permanent solution of this problem

Answer 1

Try to ping your server where SQL Server is installed, or if it's installed in your development machine check if the service is running. Can you describe what triggered this? also make sure it's non-code fault.

Hth, cmiiw

Answer 2

Okay, so is SQL Server installed on your machine or another? have you tried my first suggestion? tell me how it goes.

Answer 3

there is no fault in code