Query Strings our some times Shows Your Whole Logic (What You Are Trying to do with Database) in Asp.net. Is Asp.net project is running on internet then its Ok because now We have SSL (Security Socket Layer) But When We Run it on LAN (Local Area Networks) in Any Organization then it is possible That your Query Strings can Helps to Understand Your Logic.

For the better Understanding Follow These Steps.

1-Open new Project and Select Class Library from New Project Modules Showing on Right Side of window. 

2-Make your Connection string in that class.

3-Now make the connection function given below:

Now if You Run And Use it will fulfill your Simple Delete Requirements. But sometime we need to make where Clause more then one Field Then we have to create Overloaded Function Which is Just Differ by no of Fields.