SQL Server : Compare One Row with Multiple Rows of Same Table

Question

I have data which is something like below:

id       docid     fname      lname 
1        1         x          y
2        1         x          y
3        1         x          y

I need result of same document id with matching rows condition for docid 1 at the same time I want to compare id 3 with id 2 and 1 and get the matching record(s) only, but not for id 3. Something Like:

id       docid      fname     lname
1        1         x          y
2        1         x          y

Good news for me is comparing with single documentid only and I have that for example 1. Also, I have comparing record. Say id:3, which has to be compared with other two records.

There are two cases below, consider compare id as 6:

id       docid     fname      lname 
4        2         p          q
5        2         r          s
6        2         p          q

id       docid     fname     lname
4        2         p          q

If none of the records match, then empty is the result.

I tried something like below:

SELECT ta.id,ta.docid,ta.fname,ta.lname FROM tbldoc ta 
      WHERE (SELECT COUNT(*)FROM tbldoc ta2 
           WHERE ISNULL(ta.id,'') = ISNULL(ta2.id,'') AND
                 ISNULL(ta.docid,'') = ISNULL(ta2.docid,'') AND
                 ISNULL(ta.fname,'') = ISNULL(ta2.fname ,'') AND
                 ISNULL(ta.lname,'') = ISNULL(ta2.lname ,'')
            )>1 AND docid=1 And id<>3 

But, its failing when all the columns have null value(s).

Update : above is the sample one here is my real scenario table schema and data

create table tbldoc (Created int,Checkn nvarchar(max),Account nvarchar(max),EONumber nvarchar(max),Voucher nvarchar(max),Invoice nvarchar(max),Total decimal,Venue nvarchar(max),Reference nvarchar(max),Sign bit,Room nvarchar(max),Page int);
insert into tbldoc values(59,1234,NULL,NULL,NULL,NULL,40,3,NULL,1,NULL,NULL);
insert into tbldoc values(62,1234,NULL,NULL,NULL,NULL,40,3,NULL,1,NULL,NULL);
insert into tbldoc values(68,1234,NULL,NULL,NULL,NULL,40,3,NULL,1,NULL,NULL);

Answer 1

Try this :

select a.* from tbldoc as a right join
(select * from tbldoc where id = 3) as b
on a.docid = b.docid
and a.fname = b.fname
and a.lname = b.lname
and a.id != b.id

You are defining the criteria in second line (select * from tbldoc where id = 3) as b

OR

select a.* 
from tbldoc as a right join tbldoc as b
on a.docid = b.docid
and a.fname = b.fname
and a.lname = b.lname
and a.id != b.id
where b.id = 3

You are defining the criteria in last line where id = 3

--EDIT--

This is for your real table :

select a.* 
from tbldoc as a right join tbldoc as b
on (a.checkn = b.checkn or b.checkn is NULL)
and (a.Account = b.Account or b.Account is NULL) 
and (a.EONumber = b.EONumber or b.EONumber is NULL) 
and (a.Invoice = b.Invoice or b.Invoice is NULL) 
and (a.Total = b.Total or b.Total is NULL) 
and (a.Venue = b.Venue or b.Venue is NULL) 
and (a.Reference = b.Reference or b.Reference is NULL) 
and (a.Sign = b.Sign or b.Sign is NULL) 
and (a.Room = b.Room or b.Room is NULL) 
and (a.Page = b.Page or b.Page is NULL) 
and a.created != b.created
where b.created = 68