Reputation: 13
Can I use case expression to build where like this?
select *
from table
where
case
when x=y then z= j and t=v
when x=k then q= p and s=l
end
;
I need change where clause depending on the value of x variable.
Upvotes: 0
Views: 76
Reputation: 167982
An alternative to using OR
is to use nested CASE
statements:
SELECT *
FROM table_name
WHERE CASE
WHEN x = y THEN CASE WHEN z = j AND t = v THEN 1 ELSE 0 END
WHEN x = k THEN CASE WHEN q = p AND s = l THEN 1 ELSE 0 END
ELSE 0
END = 1;
or you could simplify it to:
SELECT *
FROM table_name
WHERE CASE
WHEN x = y AND z = j AND t = v THEN 1
WHEN x = k AND q = p AND s = l THEN 1
ELSE 0
END = 1;
However, you should check whether Oracle can use column indexes or if a separate function-based index is required with these solutions.
Upvotes: 0
Reputation: 222462
Use or
:
select *
from table
where (x = y and z = j and t = v) or (x = k and q = p and s = l);
Upvotes: 2