People: A couple of MapInfo gurus recently answered Stefano Felici's question about the formulation of a MapInfo query to select those objects from one table that don't intersect any objects in another table. The answer is of course DOES NOT INTERSECT Select RedTab.Id From RedTab Where Not RedTab.Obj intersects any (select BlueTab.Obj from BlueTab) In MapInfo, +ACI-intersects+ACI- actually means both +ACI-touches+ACI- and +ACI-overlaps+ACI-, so you can formulate three related queries, depending on how precise you need to be. Note that the following TOUCHES and OVERLAPS queries refine the basic INTERSECTS query. INTERSECTS Select RedTab.Id , BlueTab.Id From RedTab , BlueTab Where RedTab.Obj intersects BlueTab.Obj TOUCHES Select RedTab.Id , BlueTab.Id From RedTab , BlueTab Where RedTab.Obj intersects BlueTab.Obj And (Area (Overlap (RedTab.Obj, BlueTab.Obj ), +ACI-sq mi+ACI- ) +AD0- 0 ) OVERLAPS Select RedTab.Id , BlueTab.Id From RedTab , BlueTab Where RedTab.Obj intersects BlueTab.Obj And (Area (Overlap (RedTab.Obj, BlueTab.Obj ), +ACI-sq mi+ACI- ) +AD4- 0 ) Now, following this approach, is it possible to formulate a DOES NOT OVERLAP query in MapInfo by refining the DOES NOT INTERSECT query? It might look something like this pseudo-code: Select RedTab.Id From RedTab Where +ADw-RedTab.Obj does not intersect anything in BlueTab+AD4- Or +ADw-RedTab.Obj intersects but does not overlap anything in BlueTab+AD4- This is not an entirely frivolous question. Suppose you were the United Nations and you wanted to use MapInfo to find those countries that are not having a territorial border dispute with their neighbors. The proposed DOES NOT OVERLAP query should find them. Island countries such as mine would be selected by the first term (does not intersect). Peaceful neighbors such as USA and Canada would be selected by the second term (intersects but does not overlap). However India and Pakistan would be rejected because, right now, their maps overlap in Kashmir. Anyhow, I conjecture that a one-pass DOES NOT OVERLAP query cannot be formulated in MapInfo. David M Haycraft Phone/Fax: 61 +- 2 +- 6231 8104 Information Analysis Assocs P/L Mobile: 0412 001 134 ACN 085 516 105 Email: d.haycraft+AEA-acslink.aone.net.au 1 Cumming Place, Wanniassa Web: www.acslink.aone.net.au/actaa/iaa.htm A.C.T. 2903, Australia A MapInfo Partner ---------------------------------------------------------------------- To unsubscribe from this list, send e-mail to [EMAIL PROTECTED] and put "unsubscribe MAPINFO-L" in the message body, or contact [EMAIL PROTECTED]