IBX ...TIBQuery read only result set ???

I have just moved from BDE to  the IBX componet set in Delphi.

I need to insert a blob, which I have previously done by getting a BDE
resultset into insert mode (requestlive = true and open a select)  , then
using
TBlobField(MyTfield).LoadFromStream(Stream) ......setting the TField

With TIBQUERY,  I cannot get past "read only dataset"...trying to use
.INSERT or  .EDIT methods , so I can set the Tfields and then POST.

I is sometimes very usefull to be able to get into EDIT or INSERT mode, just
assign values to the Tfileds and then post , instead of writing update sql
and then using EXECSQL.

How do you do this ... am I missing something simple.

Dennis Cons