>Hi all,
>I'm trying to write a routine to identify duplicate records. I have a select statement that uses certain criteria to compare each record with all the others in the table. This seems to work but foreach record that produces a match I also get a match when I get to the matched record a compare that. Is there some way to prevent this?
>
>My results look something like

>id1 id2
>1   2
>2   1

>All I really want in this instance is one entry.
>This is the select statement

>SELECT Addresses.iid, Addresses_a.iid;
> FROM duplicates!addresses, duplicates!addresses Addresses_a;
> WHERE Addresses.iid <> Addresses_a.iid;
>   AND Addresses.csurname == Addresses_a.csurname;
>   AND Addresses.cforename == Addresses_a.cforename;
>   AND (Addresses.caddress_1 == Addresses_a.caddress_1;
>   OR (Addresses.cpostcode == Addresses_a.cpostcode));
> ORDER BY Addresses.csurname, Addresses.cforename
>

>Many thanks in anticipation.

Create Cursor crsDupes (myID i, surname c(10), address c(10))

lcAddress = Sys(2015)
lcSurname = Sys(2015)

For ix = 1 to 20
	If Int(Rand()*1000)%2=0
	lcAddress = Sys(2015)
	lcSurname = Sys(2015)
	endif
	Insert into crsDupes values (ix,lcSurName ,lcAddress )
EndFor
browse title 'My Table'

Select c1.myID as ID1, c3.myID as ID2  ;
   from crsDupes c1 ;
	inner join crsDupes c3 ;
	on c1.myID < c3.myID and ;
	c1.surname = c3.surname and ;
	c1.address = c3.address

*Or more compact
Select c1.myID as ID1, c3.myID as ID2  ;
   from crsDupes c1 ;
	inner join crsDupes c3 ;
	on c1.myID < c3.myID and ;
	c1.surname = c3.surname and ;
	c1.address = c3.address ;
	where c1.myID =  ;
	(select Min(c2.myID) ;
	from crsDupes c2 ;
	where c1.surname = c2.surname and ;
	c1.address = c2.address)

Cetin