Examples of SQL Having & SQL Group By

SQL Having         SQL Group By   Null in SQL Group By

Some of the examples found on the Internet:

Find the average sales price for each beer.

Sells (bar, beer, price)

SELECT beer, AVG (price)

FROM Sells

GROUP BY beer;

Find, for each drinker, the average price of Bud at the bars they frequent.

Sells (bar, beer, price)

Frequents (drinker, bar)

SELECT drinker, AVG (price)

FROM Frequents, Sells

WHERE beer = 'Bud' AND

Frequents.bar = Sells.bar

GROUP BY drinker;

Find the average price of those beers that are either served in at least 3 bars or manufactured by Anheuser-Busch.

Beers (name, manf)

Sells (bar, beer, price)

SELECT beer, AVG (price)

FROM Sells

GROUP BY beer

HAVING

COUNT (*) > = 3 OR

beer IN(

SELECT name

FROM Beers

WHERE manf = 'Anheuser-Busch');