Beginning SQL

Chapter 3
96
You’re one step further, but now you need to get rid of the MemberId and replace it with the members’
first and last names. To do this, you need to link to the MemberDetails table and get the data from there,
which involves a second INNER JOIN:
SELECT Category.Category, MemberDetails.FirstName, MemberDetails.LastName
FROM FavCategory INNER JOIN Category
ON FavCategory.CategoryId = Category.CategoryId
INNER JOIN MemberDetails
ON FavCategory.MemberId = MemberDetails.MemberId
ORDER BY MemberDetails.LastName, MemberDetails.FirstName;
The preceding code includes a second INNER JOIN statement after the first one. The ON statement links
to the first INNER JOIN by linking the FavCategory and MemberDetails tables. The ORDER BY statement
orders the results by last name and then first name to identify which member likes which categories.
Note that if you’re using MS Access, you must change the SQL slightly. Access is happy with just one
join but insists that you put brackets around each additional join. So the preceding code needs to be
rewritten as follows:
SELECT Category.Category, MemberDetails.FirstName, MemberDetails.LastName
FROM (FavCategory INNER JOIN Category
ON FavCategory.CategoryId = Category.CategoryId)
INNER JOIN MemberDetails
ON FavCategory.MemberId = MemberDetails.MemberId
ORDER BY MemberDetails.LastName, MemberDetails.FirstName;
Notice the brackets around the first inner join. The second inner join, which joins to the results of the
first, doesn’t need brackets. Note that this code works on the other database systems but that the brackets
aren’t required around the additional joins.
The results so far are as follows:
Category FirstName LastName
Thriller Stuart Dales
War Stuart Dales
Historical Stuart Dales
Horror William Doors
Sci-fi William Doors
Sci-fi Steve Gee
War Jamie Hills
Horror Jamie Hills
Sci-fi Jamie Hills