CHOOSE Function On SQL Server

Ekrem Önsoy

5 years ago

Did you know the CHOOSE function in SQL Server? This function introduced with SQL Server 2012.

SELECT ..., 'xxx' = CASE WHEN yyy = 1 THEN 'xy' ... END ...

1	SELECT ..., 'xxx' = CASE WHEN yyy = 1 THEN 'xy' ... END ...

The CHOOSE command can provide practical use for situations such as the example above.

For example:

SELECT CHOOSE (field1, 'Manager', 'Director', 'Developer', 'Tester' ) AS Result FROM myTable1;

1	SELECT CHOOSE (field1, 'Manager', 'Director', 'Developer', 'Tester' ) AS Result FROM myTable1;

Here is the CASE WHEN version of the command I wrote above with CHOOSE:

SELECT 'Result' = CASE WHEN field1= 1 THEN 'Manager'  
WHEN field1= 2 THEN 'Director' 
WHEN field1= 3 THEN 'Developer' 
WHEN field1= 4 THEN 'Tester' 
END FROM myTable1

SELECT 'Result' = CASE WHEN field1= 1 THEN 'Manager'

WHEN field1= 2 THEN 'Director'

WHEN field1= 3 THEN 'Developer'

WHEN field1= 4 THEN 'Tester'

END FROM myTable1

It doesn’t contribute to performance, but as I said, it makes it easy to write code.