you can post your query on javatpoint forum. www.javatpoint.com/forum

you can solve your problem by this tutorial. this tutorial may be helpful to you. http://www.javatpoint.com/abstract-class-in-java[^]

plz visit here this tutorial may be helpful to you. http://www.javatpoint.com/sql-delete-duplicate-rows[^]

Dear if you want to learn sql by online free tutorial. this tutorial may be helpful to you. www.javatpoint.com/sql-tutorial post your queries on javatpoint forum. www.javatpoint.com/forum