Hello,

When I have a table with one field of type date and indexed by this field, if I do TEdbtable.Locate with a TDate variable value I get the following error : ElevateDB Error #1011 An error occurred with the value 42105 (A conversion error occurred with the value 42105).

Here there is an easy sample to reproduce the problem :

// I have a form with the following components :
   Db1: TEDBDatabase;
   Tb1: TEDBTable;
   Session1: TEDBSession;
// and this is the FormCreate for the above form :
procedure TForm1.FormCreate(Sender: TObject);
var
 L : TStringList;
 dDate : TDate;
begin
 Session1.SessionName := 'Session1';
 Session1.SessionType := stLocal;
 Session1.LoginUser := 'Administrator';
 Session1.LoginPassword := 'EDBDefault';
 Session1.LocalConfigPath := ExtractFileDir( Application.ExeName );
 edbcomps.Engine.ConfigPath := Session1.LocalConfigPath;
 Session1.Open;
 Db1.Database := 'TEST';
 Db1.DatabaseName := Db1.Database;
 Db1.SessionName := Session1.SessionName;
 Tb1.DatabaseName := Db1.DatabaseName;
 Tb1.TableName := 'TESTDATE';
 Tb1.SessionName := Session1.SessionName;
 L := TStringList.Create;
 try
   Session1.GetDatabases( L );
   if L.IndexOf( Db1.Database ) = -1 then
     Session1.Execute( 'CREATE DATABASE "' + Db1.Database + '"  PATH ' + QuotedStr( Session1.LocalConfigPath ) );
   Db1.Open;
   L.Clear;
   Session1.GetTableNames( Db1.Database, L );
   if L.IndexOf( Tb1.TableName ) = -1 then
   begin
     Db1.Execute( 'CREATE TABLE "' + Tb1.TableName + '" ( "DATEFIELD" DATE )' );
     Db1.Execute( 'CREATE INDEX "iDate" ON "' + Tb1.TableName + '" ("DATEFIELD")' );
   end;
 finally
   L.Free;
 end;
 Tb1.Open;
 Tb1.IndexName := 'iDate';
 dDate := Date;
 // test FindKey
 if not Tb1.FindKey( [ dDate ] ) then
 begin
   Tb1.Append;
   Tb1.FieldByName( 'DATEFIELD' ).Value := dDate;
   Tb1.Post;
 end;
 // test FindKey again
 Tb1.FindKey( [ dDate ] ) ;
 // test Locate -------> THIS WILL RAISE EXCEPTION : ElevateDB Error #1011 An error occurred with the value   
 // 42105 (A conversion error occurred with the value 42105)
 Tb1.Locate( 'DATEFIELD', dDate, [] );
end;

Initially, the problem is in the declaration of the dDate variable. If you declare the dDate variable as TDate, an exception is thrown, but if you declare the dDate variable as TDateTime, all is ok.

I think that the problem is that the VarType( dFecha ) = varDouble when you declare the dDate variable as TDate. But if you declare the dDate variable as TDateTime, VarType( dFecha ) = varDate. The problem is that TEDBValue.SetAsVariant does not have in account that you can use a variable of type TDate as a parameter of a Locate, it only have in account the type of the variant passed value and it will raise an exception, because is treating this value as a double value and not as a TDate value. I think that the solution could be to correct the procedure TEDBValue.SetAsVariant having in account that if VarType of value passed is varDouble and DataType is TYPE_DATE call to AsDateTime:=TDateTime(Value).  It is a problem in the elevatedb sources, and it is easy to correct.

What do you think about it, Tim Young?.

Thank you and best regards.

I think that another solution is to take in account it in the procedure SetAsDouble, doing the following modification :

procedure TEDBValue.SetAsDouble(const Value: Double);
var
  TempLargeInt: Int64;
begin
  SetNull(False);
  case FDataType of
     TYPE_FLOAT:
.............
     // take in account a TDate value
     TYPE_DATE :
         SetInteger(NativeDateToDate(TDateTime(Value)));
end;

Or in the TEDBValue.SetAsVariant when you :

case VarType(Value) of
 ....
 ....
 varSingle:
    AsDouble:=Double(Value);
 varDouble :
    // CORRECT FOR TDate value assigned to a variant and the field is DATE
    if FDataType = TYPE_DATE then
       AsDateTime:=TDateTime(Value)
    else
        AsDouble:=Double(Value);
 .......
 ........
end;

Both solutions does work, but you are the expert, not me.

Thank you and best regards.

macc2010


This sort of problem is best addressed by raising a support ticket on Elevate's web site. These are user supported newsgroups and whilst Tim does drop in occasionally he's currently focused on EWB and may not notice this for some time.

Roy Lambert

Thank you Roy, I will do as you are telling me.