Selecting, Arranging, and Renaming Columns 

You can select specific columns in the query and arrange and rename these columns in the results table.

Prerequisites

You require the demo data for the SQL Tutorial.

Start the query tool SQL Studio as database administrator MONA with password RED and log on to the demo database instance DEMODB.

Selecting Specific Columns

To select columns from a table, specify the desired column name after the keyword SELECT. Use commas to separate the column names in this list. Blank characters are optional.

 

SELECT firstname, name
  FROM hotel.customer

Displaying the first and last names of all customers

Result

FIRSTNAME	NAME
Jenny	Porter
Peter	Brown
?	Datasoft
Rose	Brian
Mary	Griffith
Martin	Randolph
Sally	Smith
Mike	Jackson
Rita	Doe
George	Howe
Frank	Miller
Susan	Baker
Joseph	Peters
?	TOOLware
Antony	Jankins

Selecting All Columns

Instead of the list of column names, you can also enter *.

 

SELECT *
  FROM hotel.customer

The system displays the contents of the entire customer table. The columns are displayed in the order you defined when you created the table.

Arranging Columns

You can arrange the columns to be displayed in any order you desire. To do so, enter the column names in the desired order after the keyword SELECT.

 

SELECT name, firstname
  FROM hotel.customer

Displaying the last and first names of all customers

Result

NAME	FIRSTNAME
Porter	Jenny
Brown	Peter
Datasoft	?
Brian	Rose
Griffith	Mary
Randolph	Martin
Smith	Sally
Jackson	Mike
Doe	Rita
Howe	George
Miller	Frank
Baker	Susan
Peters	Joseph
TOOLware	?
Jankins	Antony

 

Renaming Columns

You can rename the columns to be displayed.

 

SELECT zip, name city_name
  FROM hotel.city
    WHERE state = 'NY'

Displaying the zip code and city/place name of all cities/places in the state of NY

Result

ZIP	CITY_NAME
10019	New York
10580	New York
11788	Long Island
12203	Albany

 

See also:

SQL  Reference Manual, QUERY Expression (query_expression), Selected Column (select_column), Table Expression (table_expression)

More examples for Data Query