Beginning SQL

Chapter 3
Executing this SQL provides the following results:
LastName FirstName DateOfBirth
Night Doris 1997-05-28
Doors William 1994-05-28
Hills Jamie 1992-07-17
Smith Katie 1977-01-09
Jackson John 1974-05-27
Gee Steve 1967-10-05
Botts Seymour 1956-10-21
Dales Stuart 1956-08-07
Jones Jenny 1953-08-25
Jones John 1952-10-05
Johnson Jack 1945-06-09
Simons Susie 1937-01-20
The next section looks at how columns in the results set can be joined together, for example, returning
FirstName and LastName columns as one column called FullName.
Joining Columns — Concatenation
Not only does SQL allow you to query various columns, but it also allows you to combine one or more
columns and give the resulting column an alias. Note that using an alias has no effect on the table itself;
you’re not really creating a new column in the table, only one for the results set. When you join columns
together, you concatenate them. For example, if you have the data ABC and concatenate it to DEF, you get
ABCDEF.
This chapter only attempts to concatenate text literals or columns that have the char or varchar data
type. Joining text with a number can cause errors. Chapter 5 shows you how to convert data types and
use this to convert numbers to text and then concatenate.
So how do you go about concatenating text? Unfortunately, concatenating text varies depending on the
database system you’re using. Because there are significant differences among the five database systems
covered in this chapter, each is taken in turn, starting with SQL Server and MS Access. You simply need
to read the section relevant to the database system you’re using — feel free to skip over the others.
MS SQL Server and MS Access
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Both SQL Server and Access concatenate columns and data in the same manner — with the concatenation
operator, which on these systems is the plus (+) sign. So, in order to return the full name, that is first
and last name, of members, you’d write the following:
SELECT FirstName + ‘ ‘ + LastName AS FullName FROM MemberDetails;