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delphidelphi-2010paradox

Delphi TTable.Exists fails on Paradox table even if database tables exist

When I create a table object (Table1) from scratch and assign the TableName property to an existing table on disk, the Table1.Exist function fails. I'm using Delphi2010 and it is a Paradox 7 table.

filename := ZipMaster1.DirEntry[i].FileName;
if Pos('.DB', UpperCase(filename)) > 0 then
begin
  Table1 := TTable.Create(FormArchiveFileSelector);
  Table1.TableName := IncludeTrailingPathDelimiter(ExtractDir) + ExtractFileName(filename);
  if Table1.Exists then
    Table1.DeleteTable;
  Table1.Free;
end;

When I replace Table1.Exists with FileExists(Table1.TableName), this returns true. Does anyone have any explanantion for this?

Solution code

Followed suggestions, below is some 'correct' sample code: 

filename := 'C:\Temp\tables\XXX_1.db';
Table1.DatabaseName := ExtractFilePath(filename);
Table1.Tablename := ExtractFileName(filename);
if Table1.Exists then MessageDlg('Exists', mtInformation, [mbOK], 0)
else MessageDlg('Missing', mtInformation, [mbOK], 0);

Note: Even setting Table1.Tablename to the full path and tablename while setting DatabaseName properly cause the Exists function to fail. TableName must be without the path, always.

Solution

  • You need to separately set the DatabaseName and FileName. 

    Table1 := TTable.Create(whatever);
Table1.DatabaseName := ExtractDir;
Table1.TableName := ExtractFileName(filename);

    (You should really get away from the BDE and Paradox files (as well as TTable). The BDE has been deprecated for more than a decade now, and may not ship in future versions of Delphi. There are serious issues with the latest versions of Windows as well.)