SQL或在WHEN中（在CASE中）

Question

Strangely i could not find this on the web, I need an OR within a when clause in a case statement, something like:

SELECT type,color,brand,CASE type WHEN "foo" OR "BAR" OR "somethingelse" THEN SELECT ... FROM .... WHERE .... > ....;

I just cant find a way to make it work, i have tried enclosing it in parenthesys:

SELECT type,color,brand,CASE type WHEN ("foo" OR "BAR" OR "somethingelse") THEN SELECT ... FROM .... WHERE .... > ....;

Or in square brackets:

SELECT type,color,brand,CASE type WHEN ["foo" OR "BAR" OR "somethingelse"] THEN SELECT ... FROM .... WHERE .... > ....;

The problem is that i have more groups of options to check, and make a single WHEN for each of them, will make my query super long. Nothing, any advice?

Answer 1

In CASE you cannot start a separate SELECT without brackets ... and the OR is possible with the following:

CASE WHEN type IN ("foo","BAR","somethingelse") THEN ... ELSE END

If you want to get the target value from a select call (subquery) then do this in the THEN section

... THEN ( SELECT col1 FROM tble WHERE ... ) ELSE END

Answer 2

case has two forms Only one can use Or

1. case x when val1 then result1 when val2 then result2 else defaultResult end
2. case when x = val1 then result1 When y = val2 then result2 Else DefaultResult end , or, more generally:
   case when [boolExp1] then reslt1 when [boolExp2] then reslt2 else defltReslt end

the second form can use Or , or any other Boolean operator for that matter (except Exists as I recall)

 case when x = val1 or y = val2 or z in (val3, val4, val5) then result1 
      else defaultResult end