I agree with
Christian Graus[
^] and still if you want to do it manually only on your database then....
Let make your sql query easier.
Get Necessary Tokens from sentence.
Ex.
"What is session in C#??" tokens : Session,C#.
"What is WCF webService & how to implement it?" tokens : WCF,WebService,implement.
(I have done this once my project)
And then fire query with "like" in sql.