title: a query to show name of the bus and busno, where source of a bus is the destination of another bus and vice versa
body: <p>There are two tables, one is <strong>Buses</strong>, where the bus names and bus no.s will be available and another is <strong>schedule</strong> , where the bus no.s, sources of the buses and destinations of the buses will be available. So basically, here we need to display the name and no of two buses as the final output, where bus X has the destination of bus Y as its source and bus Y has the source of bus X as its destination. Since the source and destination are in the same table, I don't know how to form the logic. And the concept essentially to be used for this problem is Joins. </p>