Help: About Charindex Function Doesn't Work With Variable

Hello to all,

I hope that somebody can help me.

I have written a sql query to search Partner.  I have a wtcomValidRelationships Table. There are two Fields (IDMember(type: Int) and RelationshipIDs(type: varchar(1000)) in this table.

Example: 3418 has 3422 RelationshipID and 3422 has 4088 RelationshipID, if i want to check if there is a relationship between 3418 and 4088. 

declare @IDM int;

declare @IDO char(100);

set @IDM = 3418;

set @IDO = '4088';

select B.IDMember

from wtcomValidRelationships as A, wtcomValidRelationships as B

where A.IDMember = @IDM and charindex(cast(B.IDMember as char(100)),A.RelationshipIDS) > 0

and charindex(@IDO,B.RelationshipIDs) > 0

Using this query i get nothing.

I try to use constant in charindex and i get result.

declare @IDM int;

declare @IDO char(100);

set @IDM = 3418;

set @IDO = '4088';

select B.IDMember

from wtcomValidRelationships as A, wtcomValidRelationships as B

where A.IDMember = @IDM and charindex('3422',A.RelationshipIDS) > 0

and charindex('4088',B.RelationshipIDs) > 0

So i think that charindex doesn't work with variable. But I must use variable. Can someone help me? What should i do ?

Thanks

Best Regards

Pinsha