Question

I’m having trouble using LINQ method calls with multiple joins. I’m trying to do something like this:

            if (!isDepSelect)
            {                
                query = (from Items in db.DEPARTMENTs
                             select Items);
            }
            else
            {                    
                    query = (from Items in db.DEPARTMENTs
                             from gDept in db.DEPT_PROFILE
                             from wAccess in db.WEB_ACCESS
                             where Items.DEPT_CODE == gDept.DEPT_CODE && gDept.USER_ID == wAccess.USER_ID && wAccess.EMP_ID == id
                             select Items);
            }

I had done this:

IQueryable<DEPARTMENT> query = db.DEPARTMENTs;


            if (isDepSelect)
            { 
                query = query.Join(db.DEPT_PROFILE,depts => depts.DEPT_CODE,prof => prof.DEPT_CODE,(depts, prof) => depts);    
            }

But now I don’t know how to add the JOIN of DEPT_PROFILE table with the WEB_ACCESS table and the condition of the EMP_ID = id.

The reason I’m doing this is that the isDepSelect boolean is not the only condition that this query will change its relations and I need someway to add this relations without repeating my LINQ for each of my conditions.

Thank you for your time.

Answer 1

Try with,

List<DEPARTMENTs> list =   db.DEPARTMENTs.Join(db.DEPT_PROFILE, dept => dept.DEPT_CODE, prof => prof.DEPT_CODE, (dept,prof) => new {dept, prof})
            .Join(Wdb.WEB_ACCESS, depts => depts.prof.USER_ID,web => web.USER_ID,(depts,web) => new { depts, web})
            .Where(result => result.web.EMP_ID== id).Select(s => s.depts.dept).ToList<DEPARTMENTs>();