Answer the following in SQL and relational algebra

Beers(name,manf)  Bars(name,licence,address)
Drinkers(name,address,phone)  Likes(drinker,beer)
Frequents(drinker,bar)  Sells(bar,beer,price)


* details of all bars in The Rocks

select name,licence from Bars where address = 'Rocks';

Proj[name,licence](Sel[address='Rocks'](Bars))



* beers made by Sierra Nevada

select name from Beers where manf = 'SN';

Proj[name](Sel[manf='SN'](Beers))



* beers sold in the Coogee Bay Hotel

select beer from Sells where bar = 'CBH';

Proj[beer](Sel[bar='CBH'](Sells))