Consider the following relational database that stores information about bars and customers: Drinker (name, address) Bar (name, address) Beer (name, brewer) Frequents (drinker, bar, times a week) Likes (drinker, beer) Serves (bar, beer, price) Write the following queries in relational algebra: 1. Find all drinkers who frequent only those bars that serve some beers they like. 2. Find all drinkers who frequent every bar that serves some beers they like.3. Find those drinkers who enjoy exactly the same set of beers as Amy.
