Question

I tried using “Exist” and “IN”. Not only did I not succeed, it didn’t seem as an efficient solution.

Here is a simplified example:

TblMyTable

UserName1  –  Grade  –  UserName2  –  Grade

I need a query where there is a mutual relation / existence.

What I mean is that the returned result from the query will only include the users where on the same row there is both UserName1 and UserName2 mutually (see image below for a better example / explanation).

Any user can work with any other user.

So the result will be (the order doesn’t matter) ideally in one line:

John – 5000  —  Mary – 3000

or

Mary – 3000  —  John – 5000

The punchline is, it’s one dynamically changing table with active Users using the F.Key to the main User’s table, which has the P.Key.

Please see image below for a better example / explanation.

Database is SQL 2005.

Many thanx in advance

* Edit: Screenshot that hopefully help explain it all.

The end result should be 2 rows, because only they have a mutual relation in TblDynamicUserList:

ana – Phone – 3000   —   RanAbraGmail – Wifi – 2000

and

anaHeb – Phone – 5000   —   RoyP – Phone – 4000


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Answer 1

Would something like this work for you:

With ManagerWorkers As
    (
    -- get managers with workers
    Select Managers.WorkerUsername As ManagerUsername, Workers.WorkerUsername
    From tblMyTable As Managers
        Join tblMyTable As Workers
            On Workers.ManagerUsername = Managers.WorkerUsername
    ) 
Select *
From ManagerWorkers
Union All
-- get workers that have a manager in the above list
Select WorkerUsername, ManagerUsername
From tblMyTable
Where Exists(   Select 1
                From ManagerWorkers
                Where ManagerWorkers.ManagerUsername = tblMyTable.ManagerUsername
                )   

EDIT: Given the update to the question how about the following query:

Select D1.u_username, U1.Permission, U1.Grade, D1.f_username, U2.Permission, U2.Grade
from tblDynamicUserList As D1
    Join tblDynamicUserList As D2
        On D2.u_username = D1.f_username
            And D2.f_username = D1.u_username
    Join tblUsers As U1
        On U1.u_username = D1.u_username
    Join tblUsers As U2
        On U2.u_username = D2.u_username