How can i get output in true or false in SQL

Question

Please help me i want to get my output i boolean result true or false how can i do this in this query I'm retrieving the data which will tell me whether this class and section is in my department or not this query is doing as i want but how do i write when i do it in C# winforms if data is exist save it otherwise it shows me a message class doesn't exists in the department please help me if you can i am very thankful to you.