If you are assembling all this stuff to insert or update data, use
TIB_DSQL or TIB_Cursor not TIBOQuery - the query does lots of other
stuff related to user interation, which is not only unnecessary but
can also get in the way of simple insert/update processing.

So instead of all the complex stuff you are doing by creating TField
definitions just do something like...

t1 := TIB_DSQL.Create(Self);
t1.IB_Connection := ibconn1;
t1.IB_Transaction := ibt1;
t1.SQL.Add( 'UPDATE GRAPHICSTREAM' );
t1.SQL.Add( 'SET GRAPHIC=:GRAPHIC' );
t1.SQL.Add( 'WHERE GRAPHICNAME=:GRAPHICNAME AND' );
t1.SQL.Add( ' VERSION=:VERSION' );
t1.Prepare;
t1.ParamByName( 'GRAPHICNAME' ).AsString :=
extractFileName(edit1.text);
t1.ParamByName( 'VERSION' ).AsInteger := 1;
t1.ParamByName( 'GRAPHIC' ).LoadFromFile(edit1.text);
t1.Execute;

HTH

Geoff Worboys
Telesis Computing