c# - relationship one to one EntityFramework error -

i create 2 table in sql server 2008

table 1 : user( userid,name, firstname,login, password...) , pk : userid
table 2 : sessionuser(userid, date, adress) , pk : userid

the relationship between 2 tables set in sql server 2008, 1 1 relationship , foreign key in table sessionuser (fk: userid)
there users in user table (full lines)
when tried add session in session table shows me error:

entities in 'distributionssentities.sessionuser ' participate in 'fk_sessionuser_user ' relationship. 0 related 'user ' found. 1 'user ' expected.

code:

distributionssentities db = new distributionssentities(); sessionuser sessionuser = new sessionuser();              sessionuser.userid = 12; // id existe in user table             sessionuser.date = "12-12-2012";             sessionuser.adressip = "192.168.1.1";               db.addtosessionuser(sessionuser);             db.savechanges(); 

how resolve problem thanx.

just setting userid won't trick.

you can either:
- select user database , set user property
- create new user desired id , attach context
- or, set foreign key reference directly:

sessionuser.userreference.entitykey = new system.data.entitykey(sessionuser.userreference.relationshipset.entitycontainer.name + "." + sessionuser.userreference.targetrolename, "id", id); 

it's bit long, can make extension method comes in handy.