Sybase proc throws "Incorrect syntax near '='" - sql

Question

I have the following piece of a SELECT query inside a stored procedure i'm developing:
AND (
CASE S.SWITCH
WHEN 'A' THEN P.TEST = T.OPTION_1
WHEN 'C' THEN P.TEST = T.OPTION_1 + T.OPTION_2
WHEN 'G' THEN P.TEST = T.OPTION_3
WHEN 'N' THEN TRUE
ELSE FALSE
END
)
I'm getting an Incorrect syntax near '=' error. Why would it complain about the first equals sign? It's a Sybase server if anyone is interested.

Answer 1

You case comparison should be something like below, if you are testing P.TEST value based on S.SWITCH case.
AND (
P.TEST =
CASE
WHEN S.SWITCH = 'A' THEN T.OPTION_1
WHEN S.SWITCH = 'C' THEN T.OPTION_1 + T.OPTION_2
WHEN S.SWITCH = 'G' THEN T.OPTION_3
WHEN S.SWITCH = 'N' THEN TRUE
ELSE FALSE
END
)
If you are comparing based on P.TEST and S.SWITCH, you can do either of following
Blorgbeard already provided this answer
AND
(
(S.SWITCH = 'A' AND P.TEST = T.OPTION_1) OR
(S.SWITCH = 'C' AND T.OPTION_1 + T.OPTION_2) OR
(S.SWITCH = 'G' AND P.TEST = T.OPTION_3) OR
(S.SWITCH = 'N')
)
If you want to make case statement work for this, following could be a possible solution.
AND (
CASE 1 =
WHEN S.SWITCH = 'A' AND P.TEST = T.OPTION_1 THEN 1
WHEN S.SWITCH = 'C' AND P.TEST = T.OPTION_1 + T.OPTION_2 THEN 1
WHEN S.SWITCH = 'G' AND P.TEST = T.OPTION_3 THEN 1
WHEN S.SWITCH = 'N' THEN 1
ELSE 0
END
)

Answer 2

Boolean expressions don't work like that in SQL. You can reformulate your switch like this:
AND (
(S.SWITCH = 'A' AND P.TEST = T.OPTION_1) OR
(S.SWITCH = 'C' AND T.OPTION_1 + T.OPTION_2) OR
(S.SWITCH = 'G' AND P.TEST = T.OPTION_3) OR
(S.SWITCH = 'N')
)

Answer 3

I know this is more of a comment than an answer, but hopefully this will lead to an answer, and I need to do formatted code for this so...
I tried this in Mysql and it worked. Could you try something like this in Sybase and see what it returns? The point being, extract the part that failed and test it out and see if you can figure out exactly what is wrong. It may be that Sybase is pointing to that equal sign but something else is really what is confusing it.
set #miller:='C';
set #mtime:=2;
select CASE #miller
WHEN 'A' THEN #mtime = 1
WHEN 'C' THEN #mtime = 2
WHEN 'G' THEN #mtime = 3
WHEN 'N' THEN TRUE
ELSE FALSE
END
This returns a 1 since miller = 'C' takes it to check if mtime = 2, which is true, and that means a 1 or true in Mysql.
Could you try and isolate this bit of code like this in Sybase?