How to handle asp:formview edititemtemplate with checkboxlist control

[mark d.]

I'm using a formview control to display/edit/insert data that is
populated from an sqldatasource. One of the values is a pipe delimited
string that represents multiple items. Within the edititemtemplate for
this field I have a label and checkboxlist. Within the checkboxlist
databound event I take the label and split up the string then set the
appropriate checkboxes to selected.

My question is how to update this field. I've looked into the
formview_itemupdating event and can intercept the value of the label
and set it to the selected fields in the checkboxlist using e.value =
''
but the item doesn't update. Do I have to call upate from within the
formview itemupdating sub or does it get called automatically after?