Bars and Beers 1

Consider the following database consisting of six relations:

Beers(name, manf): stores information about beers, including the manufacturer of each beer.

Bars(name, city, addr, license, phone): stores information about bars including their city, street address, phone number and their operating license.

Drinkers(name, city, addr, phone): stores information about drinkers, including their city, street address and phone number.

Likes (drinker, beer): indicates which drinker likes which beers (note that a drinker may like many beers and many drinkers may like the same beer).

Sells (bar, beer, price): indicates the price of each beer sold at each bar (note that each bar can sell many beers and many bars can sell the same beer, at possibly different prices).

Frequents (drinker, bar): indicates which drinker frequents which bars (note that each drinker may frequent many bars and many drinkers may frequent the same bar).

Attribute types: All attributes are of string type (e.g., Drinkers.name can be 'John McDonald'), except Sells.price is a number (e.g., Sells.price can be 2.25). Write SQL queries to answer the following:

Find the names of all beers, and their prices, served by the bar 'Blue Angel'.

Find the name and phone number of every drinker who likes the beer 'Budweiser'.

Find all bars frequented by both 'Vince' and 'Herb'.

Find all bars in 'Chicago' (and display all attributes) for which we know either the address (i.e., addr in our schema) or the phone number but not both.