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 can use the demo data for the SQL tutorial. Start the Database Studio as database administrator MONA with the password RED and log on to demo database DEMODB: Logging On to a Database.

Activities

You can use Database Studio to enter and execute SQL statements. More information: Working with SQL Statements: Overview

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`

More Information

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

More examples for Data Query