Beginning SQL

Chapter 9
280
SalesPersonId MemberId
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2 10
Although you now have the answer to the question, it would be a whole lot nicer to see the names rather
than SalesPersonId and MemberId. To display the names, create a join between the SalesPerson and
MemberDetails tables:
SELECT SalesPerson.SalesPersonId,
SalesPerson.FirstName,
SalesPerson.LastName,
MemberDetails.MemberId,
MemberDetails.FirstName,
MemberDetails.LastName
FROM (Orders INNER JOIN MemberDetails
ON Orders.MemberId = MemberDetails.MemberId)
INNER JOIN SalesPerson
ON Orders.SalesPersonId = SalesPerson.SalesPersonId
GROUP BY SalesPerson.SalesPersonId,
SalesPerson.FirstName,
SalesPerson.LastName,
MemberDetails.MemberId,
MemberDetails.FirstName,
MemberDetails.LastName
HAVING COUNT(Orders.MemberId) > 1
ORDER BY SalesPerson.SalesPersonId
Although you added a lot of new code, it’s just a result of joining two new tables, MemberDetails and
SalesPerson. The various names and IDs of the salespeople and members have been added to the
SELECT column list, as shown in the following:
SELECT SalesPerson.SalesPersonId,
SalesPerson.FirstName,
SalesPerson.LastName,
MemberDetails.MemberId,
MemberDetails.FirstName,
MemberDetails.LastName
The column names appear in more than one of the tables, so each has to be prefixed by the name of the
table the column comes from. The GROUP BY clause requires that columns in the SELECT column list also
appear in the GROUP BY list, so you added them there also: