EAssertionFailed with message 'Unknown data type

Hey from Greenland

I am contemplating moving some of my BDE projects over to dbExpress.

I use the MSSql component from Timur Islamov. I have not Registered
yeta as I wanted to see if I could get it to work

The project I am trying to move to dbExpress is a read only projects,
just for wieving data.

I have great problems though and hope someone can help

The problems is that I get an error I do not understand and I am
stucked

1. Query
No appearent problem

 with QLQuery1 do
 begin
    Close;
    SQL.Clear;
    SQL.Add('SELECT  A.NUMBER_, B.NUMBER_');
    SQL.Add('FROM PURPOSE A, CENTRE B');
    SQL.Add('WHERE A.DATASET =:SET');
    SQL.Add('AND A.ACCESSCODE > :BNUM');
    SQL.Add('AND A.NUMBER_ = B.NUMBER_');
    SQL.Add('ORDER BY A.ACCOUNT');
    ParamByName('BNUM').Value := 0;
    ParamByName('SET').Value := 'DAT';
    Open;

2. Query
I get an error ...... raised exception class EAssertionFailed with
message 'Unknown data type
(D:\Projects\Delphi\DBExp\Source\dbexp.pas,line 755)' Process stopped
......

with SQLQuery1 do
begin
   Close;
   SQL.Clear;
   SQL.Add('SELECT B.PURCHASENUMBER, A.PURCHASENAME, A.ORDERACCOUNT,
A.ORDERPLACING,');
   SQL.Add('A.CREATEDATE, A.DELMODE, A.PROJ, A.DELREMARKS1,
A.DEPARTMENT, A.CENTRE, A.EXCHANGECODE,');
   SQL.Add('A.PURPOSE, A.DELIVERYDATE, A.CREDITORGRP, A.L_INVOICE,
SUM(B.LINEAMOUNT) TOTAL  FROM PURCHTABLE A ,');
   SQL.Add('PURCHTRANS B');
   SQL.Add('WHERE A.DATASET = :SET');
   SQL.Add('AND B.DATASET = :SET');
   SQL.Add('AND A.CREATEDATE >= :BDATE');
   SQL.Add('AND A.CREATEDATE <= :EDATE');
   SQL.Add('AND A.CENTRE LIKE :CNTR');
   SQL.Add('AND B.PURCHASENUMBER = A.PURCHASENUMBER');
   SQL.Add('GROUP BY A.PURCHASENUMBER, A.PURPOSE, A.DEPARTMENT,
B.PURCHASENUMBER,');
   SQL.Add('A.PURCHASENAME, A.ORDERACCOUNT, A.CREATEDATE, A.PROJ,
A.SECTION, A.EXCHANGECODE,');
   SQL.Add('A.DELREMARKS1, A.DEPARTMENT, A.CENTRE, A.PURPOSE,
A.L_INVOICE, A.ORDERPLACING,');
   SQL.Add('A.DELIVERYDATE, A.DELMODE, A.CREDITORGRP');
   SQL.Add('ORDER BY B.PURCHASENUMBER');
   ParamByName('SET').Value := 'DAT';
   ParamByName('CNTR').Value := '%'+ACRN+'%';
   ParamByName('BDATE').Value := DStart;
   ParamByName('EDATE').Value := DStop;
   Open;

I hope someone can help

TIA

Dino
J-O Nyboe Nielsen
Pituffik
Greenland