Handling ExecuteScalar() when no results are returned

Question

I am using the following SQL query and the ExecuteScalar() method to fetch data from an Oracle database:

sql = \"select username from usermst wh         


        

Answer 1

I have seen in VS2010 string getusername = command.ExecuteScalar(); gives compilation error, Cannot implicitly convert type object to string. So you need to write string getusername = command.ExecuteScalar().ToString(); when there is no record found in database it gives error Object reference not set to an instance of an object and when I comment '.ToString()', it is not give any error. So I can say ExecuteScalar not throw an exception. I think anserwer given by @Rune Grimstad is right.