Hello.

completes the internal query as "inner join" so when we have a relation that has null values in the main table key the relation is not shown.

I have valued three ways to avoiding this limitation:

1 .- Fill null values with a special value that has an interrelation in the other table. Id zero value or something like that.
2.- Sub-classing QSqlRelationalTableModel.
3.- Direct modify qsqlrelationaltablemodel.cpp and qsqlrelationaltablemodel.h and add a function for select de join mode.

Is there any way simpler to do this in editable data models?