SQL case substring problem. please help

[ciqeane]

here is the sample data

CREATE TABLE Boo (
keycol INT PRIMARY KEY,
datacol VARCHAR(20));

INSERT INTO Boo VALUES(1, 'DM/B19S/7281520');
INSERT INTO Boo VALUES(2, 'NW/L11U/BALL 10/300');
INSERT INTO Boo VALUES(3, 'RK/H11S/65-2511RK');
INSERT INTO Boo VALUES(4, 'FI/G21U/0004/BN5-12');
INSERT INTO Boo VALUES(5, 'FN/199U/FABRICATE');

Here is my query, please help me figure out what is the error

SELECT keycol,
CASE
WHEN SUBSTRING(datacol, 1, 2) IN ('FI','FN') THEN REG
WHEN SUBSTRING(datacol, 1, 2) IN ('FV') THEN VALV
WHEN SUBSTRING(datacol, 1, 2) IN ('RK') THEN RIKE
ELSE NULL
END AS col2
FROM Boo;

this error appear when i execute.

Msg 207, Level 16, State 1, Line 6
Invalid column name 'REG'.
Msg 207, Level 16, State 1, Line 7
Invalid column name 'VALV'.
Msg 207, Level 16, State 1, Line 8
Invalid column name 'RIKE'.

whats that mean?
helpp. thanks in advance:-)

[deepuv04]

the query is treating REG, VALV, AND RIKE AS Column names in the table. Use single quotes.

Thanks

[NeoPa]

It looks like you are intending to set the values as strings. As it is, there is nothing there to indicate what REG, VALV and RIKE are. Try instead :

SELECT keycol,
CASE
WHEN SUBSTRING(datacol, 1, 2) IN ('FI','FN') THEN 'REG'
WHEN SUBSTRING(datacol, 1, 2) IN ('FV') THEN 'VALV'
WHEN SUBSTRING(datacol, 1, 2) IN ('RK') THEN 'RIKE'
ELSE NULL
END AS col2
FROM Boo;

[ciqeane]

oh my God, it works when i use the single quote!!
thanks a bunch all.:-)