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CHOOSE Function On SQL Server

Ekrem Önsoy December 26, 2018 MSSQL

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

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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.

About Ekrem Önsoy

The original article was written in Turkish by Ekrem Önsoy and translated to English by dbtut with the consent of the author. The copyright of the article belongs to the author. The author shall not be liable in any way for any defect caused by translation.

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