If you were trying to do that operation using the "modify structure" menu command, you will find that you cannot remove all the columns. MI requires that at least one column remains in the structure. I do not know if that constraint would exist programmatically but if you get in trouble with the suggested code, I would simply start by adding the first new column (or any dummy column) before deleting all the old ones (and deleting the dummy after having added the new ones)
Jacques Paris e-mail [EMAIL PROTECTED] MapBasic-MapInfo support http://www.paris-pc-gis.com -----Original Message----- From: Terry McDonnell [mailto:[EMAIL PROTECTED] Sent: June 21, 2005 04:45 To: mapinfo-l@lists.directionsmag.com Subject: RE: MI-L Drop and replace all columns? Ross, I've not done this programmatically before but, if I did, below is how I'd do it. Not sure whether the Obj column is protected in a "drop" so I've put the test in for it. Of coursre, you'd well back up your table before trying it!!!!! HTH Terry ___________________________________ Dim lnNumCols, lnColNum As SmallInt lcColName, lcCol as String Open Table "YourTable" lnNumCols = TableInfo( "YourTable", TAB_INFO_NCOLS) For lnColNum = 1 to lnNumCols lcCol = "Col" + Rtrim$( Str$( lnColNum)) If Ucase$( lcColName) <> "OBJ" then lcColName = ColumnInfo( "YourTable", lcColName, COL_INFO_NAME) Alter Table YourTable Drop lcColName End If Next Alter table YourTable Add NewCol ... Etc. -----Original Message----- From: Ross Nixon [mailto:[EMAIL PROTECTED] Sent: 21 June 2005 04:01 To: Terry McDonnell Subject: MI-L Drop and replace all columns? I want to Alter a table by dropping all existing columns (without losing the objects) and add several new columns. Can I do this in one or two mapbasic "Alter Table" statements? Thanks, Ross Nixon Manawatu Aerial Photo Services P.O. Box 75 Palmerston North www.forestrymaps.co.nz Ph/Fax. 06 355 1431 --------------------------------------------------------------------- List hosting provided by Directions Magazine | www.directionsmag.com | To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] Message number: 16847 --------------------------------------------------------------------- List hosting provided by Directions Magazine | www.directionsmag.com | To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] Message number: 16849
