CASE IN statement with multiple values
You can return the same value from several matches:
SELECT
CASE c.Number
WHEN '1121231' THEN 1
WHEN '31242323' THEN 1
WHEN '234523' THEN 2
WHEN '2342423' THEN 2
END AS Test
FROM tblClient c
This will probably result in the same execution plan as Martins suggestion, so it's more a matter of how you want to write it.
Yes. You need to use the "Searched" form rather than the "Simple" form of the CASE
expression
SELECT CASE
WHEN c.Number IN ( '1121231', '31242323' ) THEN 1
WHEN c.Number IN ( '234523', '2342423' ) THEN 2
END AS Test
FROM tblClient c