I forgot, just put NVL() across all aNodes and bNodes fields, just in case the values you have in links table didn't exists in nodes one.

>Sure.
>Nodes table contains 3 fields.
>N X Y
>3467 172653 298723
>2173 172550 298834
>2257 172403 298653
>
>The Links table only has 3 fields that Matter.
>A B ST_Name
>3467 2173 1st St.
>2173 2257 2nd St.
>2257 3467 3rd St.
>
>The result would look like this:
>A B St_Name X1 Y1 X2 Y2 DX DY
>3467 2173 1st St. 172653 298723 172550 298834 103 111
>2173 2257 2nd St. 172550 298834 172403 298653 147 181
>2257 3467 3rd St. 172403 298653 172653 298723 250 70
>
>
>
>
>
>>Don,
>>Can you post some simple data from both tables and desired result?
>>
>>
>>
>>>Thanks Sergy and Borislav -
>>>I guess my original question did not fully explain what I am trying to do. Sergey's answer gets me close but not quite there. Say there are 2 tables Links and Nodes. Each record of the Links table contains the the node numbers for the endpoints of a line. The Nodes table contains the x,y coordinates for each of the nodes. The task is to select all the records from the Links table and add the x and y coordinates for the 2 ends of the line. Thus X1 and Y1 define the first endpoint and X2 and Y2 define the second endpoint. We also want to compute the deltaX and delta Y for the 2 endpoints so we can tell if the line is mostly horizontal or mostly verticle. Based on Sergey's response I have coded:
>>>

>>>cd \foxpro\networkupdate
>>>close tables all
>>>use linkdata in 0 alias links
>>>use xydata in 0 alias nodes
>>>use xydata in 0 alias nodes2 again
>>>	>select dt1.*, nodes2.x as x2, nodes2.y as y2, ;
>>>abs(dt1.x1-nodes2.x) as dx, abs(dt1.y1-nodes2.y) as dy ;
>>>from ( ;
>>>	select links.*, nodes.n, nodes.x as x1, nodes.y as y1 ;
>>>	from nodes ;
>>>	right outer join links ;
>>>	on nodes.n = links.a ;
>>>	where st_name <> ' ' ;
>>>	) dt1 ;
>>>right outer join dt1 ;
>>>on dt1.n = nodes2.n ;
>>>where dt1.st_name <> ' '	
>>>

>>>Which gets me almost there but not quite because the outside SELECT wants to see dt1 as a preexisting table. Can either of you tell me where to go from here?
>>>
>>>Thanks
>>>
>>>
>>>
>>>>That what we get when assuming anything. :)
>>>>Now lets wait and see who's assumption is correct.
>>>>
>>>>>But I am not referencing X2 and Y2, I am referencing nodes.x and nodes.y.
>>>>>If they are calculated fields, you are right, but they are not (if the example SELECT is correct).
>>>>>
>>>>>>It's not going to work. You cannot reference calculated fields in consequent calculations in the same list. You can use derived table

>>>>>>SELECT *, ABS(dt1.x2-dt2.y2) AS dx ;
>>>>>>  FROM ( ;
>>>>>>select temp1.*,nodes.x as x2, nodes.y as y2,
>>>>>>	from UPDNETATR!xydata nodes ;
>>>>>>	right outer join temp1 ;
>>>>>>	on  nodes.n = temp1.b;
>>>>>>	where st_name <> ' ' ;
>>>>>>	order by temp1.st_name ;
>>>>>>       ) dt1
>>>>>>

>>>>>>>Yes it is:
>>>>>>>BTW the result contains x2 and Y2 :-)
>>>>>>>of course if you didn't have X1 in Temp1
>>>>>>>

>>>>>>>select temp1.*,nodes.x as x2, nodes.y as y2, ABS(nodes.x-nodes.y) AS dx;
>>>>>>>	from UPDNETATR!xydata nodes ;
>>>>>>>	right outer join temp1 ;
>>>>>>>	on  nodes.n = temp1.b;
>>>>>>>	where st_name <> ' ' ;
>>>>>>>	order by temp1.st_name
>>>>>>>