Updating a cell/cells to a database

I have a grid that I need to enable users to edit the row data via a dialog. I have attached an event to the row that opens my dialog and populates it with the grid values.
On submitting the changes to the grid I use:

grid.cellById(row_id, cell).setValue(myValue);

This works ok and the value in the grid cell is updated but the changes are not being written back to the database - it appears no event is being fired on the connector to replicate the change(s) so they are being lost.

How can I achieve this - I tried:
grid.selectCell(row_id, cell);
grid.cellById(row_id, cell).setValue(myValue);

but this left me with an empty cell…