How can I lock the data

In every field you want to lock, You can put "not yourYESNOfield" without the quotes in the fields preferences.

I'm a newb, and have a different but related question: how do i prevent a table being written to?

I have a few tables that will only need to be updated on occasion, if at all, so want to prevent records being added by accident.

I've already had this happen a few times, so want to stop this from happening.

Are you saying:

1) you can't lock date table-wide - you have to do it field by field

2) if i have to go field by field, what do i enter in the Writeable If field, given my fields are not Yes/No?

Sorry, i see that's the table, ok. What do i put in that field?

If you lock the whole table like here above, you must have a second table where you can switch this On or Off (with a yes/No field. Let's say you have a table "Settings" with only one record(*1) (Id is always 1) and a Yes/No field "Lock Table X".(And maybe other fields also for settings purposes) you can always point to these fields like record(Table,Id).Field

(*1) to achieve this, you can put "delete this" in the trigger on create of that Settings table after you've created 1 record.

Now,  in that table X you can put the folowing in the Writable only field : not record(Settings,1).'Lock Table X'

If you put "null" (without the quotes) in writable if then these fields will be locked for editing.

Ok, thank you.