> Hello, > > > Worksheet number 2 has a question that goes as follows: > > Q) Display credit code, and the count of publishers in a column called Number of > publishers. Then group according to the creditcode for all the cases where either the > count is greater than 2 or the city or phone is not empty. Then apply ascending order. > > Solution: > > SELECT creditcode, count(cust_id) AS 'Number of Publishers' > FROM publishers > GROUP BY creditcode > HAVING count(cust_id) > 2 and city OR phone IS NOT NULL > ORDER BY creditcode ASC; > > > My query is that: > > 1) In the HAVING clause, shouldn't the answer by "OR city OR phone IS NOT NULL"? Why is it and when the question explicitly states "either or" > > 2) Can we have an alternative solution that goes like this, using the where clause: > > select creditcode, count(cust_id) as "number of publishers" > from publishers > where city or phone is NOT NULL > group by creditcode > having count(cust_id)>2 > order by count(cust_id) desc; > > Would this be incorrect? If so then why? > > Thanks