Thanks all for your response.

Gail's blog recommends using dynamic SQL

but our boss doesn't like it at all.

I have to learn how to handle it either with CASE

or IF. My problem with IF was when there are

a lot of conditions IF becomes messy so I try to find out

if I can write logic in WHERE clause more accurate, easy to understand.

I'm talking about something like this:

Pseudo Java:

IF @account = '' OR LEN(@account) = 0 OR @account IS NULL

whereStmt = "WHERE Id1 BETWEEN 'AA' AND 'KK' AND Id2 IS NULL"

ELSEIF @account <> '' AND LEN(@account) > 0 AND @account IS NOT NULL

whereStmt = "WHERE Id1 BETWEEN 'MM' AND 'ZZ' AND Id2 IS NOT NULL"

ELSEIF @account > 100

whereStmt = "WHERE ......." and so on