Example for CASE Function in SQL

Create a Table

CREATE TABLE SimpleTable (ID INT, NAME VARCHAR(MAX))
GO
Insert some value into table
INSERT INTO SimpleTable (ID, NAME)
SELECT 1, 'LAKSHMI'
UNION ALL
SELECT 2, 'NARAYANAN'
UNION ALL
SELECT 3, 'NARAYANAN'
GO

CASE Funciton:

UPDATE SimpleTable
SET Gender = CASE NAME WHEN 'NARAYANAN' THEN 'LAKSHMI' ELSE 'NARAYANAN' END
GO
SELECT *
FROM SimpleTable
GO