InstantForum.NET v4.1.4Teradata Forumshttp://www.teradata.com/teradataforum/info@teradata.comTue, 14 Oct 2008 09:42:40 GMT20http://www.teradata.com/teradataforum/Topic11386-5-1.aspxHi Jack,Teradata supports Scalar Subqueries only in some special cases within WHERE/HAVING.You'll have to rewrite it to (Outer) Joins.DieterThu, 08 May 2008 10:53:17 GMTdnoethhttp://www.teradata.com/teradataforum/Topic11386-5-1.aspxhi,WHEN search conditions cannot contain SELECT statements.try using a derived table instead.thxThu, 08 May 2008 09:47:52 GMTSNhttp://www.teradata.com/teradataforum/Topic11386-5-1.aspxPlease look at the query belowselect ename from emp e where not exists(select 'x' from dept d where d.deptno=case when d.deptname in (select deptname from xdepartments ) then 20 else 50 end );In the place of subquery "select deptname from xdepartments" , if I use hardcoded values like 100,200,3000 then it is working fine but I don't know why It is not working if I use subquery like above It's giving an error message..Please Help me out...I am using teradata SQL Assistant 7.1and getting Error message as : Illegal expression in when clause of case expression.Please help me outThanx Regards,jackThu, 08 May 2008 09:18:40 GMTJACKSON