16.2: SELECT Statement

The SELECT statement, or command, allows the user to extract data from tables, based on specific criteria. It is processed according to the following sequence:

SELECT DISTINCT item(s)
FROM  table(s)
WHERE  predicate
GROUP BY  field(s)
ORDER BY fields

We can use the SELECT statement to generate an employee phone list from the Employees table as follows:

SELECT  FirstName, LastName, phone
FROM Employees
ORDER BY LastName

This action will display employee’s last name, first name, and phone number from the Employees table, seen in Table \(\PageIndex{1}\).

Last Name	First Name	Phone Number
Hagans	Jim	604-232-3232
Wong	Bruce	604-244-2322

Table \(\PageIndex{1}\): Employees table. (Copyright; author via source)

 

In this next example, we will use a Publishers table (Table \(\PageIndex{2}\)). (You will notice that Canada is mispelled in the Publisher Country field for Example Publishing and ABC Publishing. To correct mispelling, use the UPDATE statement to standardize the country field to Canada – see UPDATE statement later in this chapter.)

Publisher Name	Publisher City	Publisher Province	Publisher Country
Acme Publishing	Vancouver	BC	Canada
Example Publishing	Edmonton	AB	Cnada
ABC Publishing	Toronto	ON	Canda

Table \(\PageIndex{2}\): Publishers table. (Copyright; author via source)

If you add the publisher’s name and city, you would use the SELECT statement followed by the fields name separated by a comma:

SELECT PubName, city
FROM Publishers

This action will display the publisher’s name and city from the Publishers table.

If you just want the publisher’s name under the display name city, you would use the SELECT statement with no comma separating pub_name and city:

SELECT PubName city
FROM Publishers

Performing this action will display only the pub_name from the Publishers table with a “city” heading.  If you do not include the comma, SQL Server assumes you want a new column name for pub_name.