Thanks for that confirmation, we'll have a think about how to change the logic of our code to not rely on it, as I really like the 'update from' syntax. The virtual table page [](https://sqlite.org/vtab.html) may be a bit misleading here though and I think it's why I misunderstood: > If the xUpdate method is performing an UPDATE, then sqlite3_value_nochange(X) can be used to discover which columns of the virtual table were actually modified by the UPDATE statement. The sqlite3_value_nochange(X) interface returns true for columns that do not change. Thanks everyone for all the help.