Selecting columns and rows

Often, you are interested in only columns in a table. For example, to make up birthday cards for employees you might want to see the Surname, DepartmentID and BirthDate columns.

Listing last name, department, and birth date of each employee

In this section, you will select each employee's birth date, last name, and department ID. Type the following:

SELECT Surname, DepartmentID, BirthDate
FROM Employees

Surname

DepartmentID

BirthDate

Whitney

100

1958-06-05

Cobb

100

1960-12-04

Chin

200

1966-10-30

Jordan

300

1951-12-13

Breault

100

1947-05-13

Rearranging columns

The three columns appear in the order in which you typed them in the SELECT command. To rearrange the columns, simply change the order of the column names in the command. For example, to put the BirthDate column on the left, use the following command:

SELECT BirthDate, Surname, DepartmentID
FROM Employees

Ordering rows

You can order rows and look at only certain columns at the same time as follows:

SELECT BirthDate, Surname, DepartmentID
FROM Employees
ORDER BY Surname

The asterisk in

SELECT * FROM Employees

is a short form for all columns in the table.

NoteQueries involving columns that have a significant number of NULL values run faster than in previous releases. The process of inserting or updating data in a table, however, may take longer (compared with previous releases) in cases where a significant number of NULL values are being inserted into the table.