Beginning Microsoft SQL Server 2008 ... - S3 Tech Training

Chapter 4: JOINs
Figure 4-1
As always, let’s take a look at this with an example or two.
Try It Out UNION
108
Select Col1 FROM
Table1
Row1
Row2
Row3
Row4
Row5
Row6
Select Col5 FROM
Table2
RowA
RowB
RowC
RowD
RowE
RowF
First, let’s look at a UNION that has some practical use to it. (It’s something I could see happening in the
real world — albeit not all that often.) For this example, we’re going to assume that AdventureWorks is
moving to a new facility and we want to send out an email to all of our customers and vendors. We want
to return a list of names and email addresses to our address update. We can do this in just one query
with something like this:
USE AdventureWorks2008
SELECT FirstName + ‘ ‘ + LastName AS Name, pe.EmailAddress
EmailAddress
FROM Person.Person pp
JOIN Person.EmailAddress pe
ON pp.BusinessEntityID = pe.BusinessEntityID
Select Col1 FROM
Table1
UNION
Select Col5 FROM
Table2
Row1
Row2
Row3
Row4
Row5
Row6
RowA
RowB
RowC
RowD
RowE
RowF