system.invalidcastexception specified cast is not valid. c#

Question

Hi to all

              Sir i have a problem 'system.invalidcastexception specified cast is not valid. c#" 

                      

                sqlConnection.Open();

                SqlCommand command = new SqlCommand(query, sqlConnection);

                int i = (int)command.ExecuteScalar();

                sqlConnection.Close();

Please solve my problem

Regards

NagaRaju T