Before this revision,
using a selection field with as possible keys `0`,
such as `require_payment` in `website_quote`,
resulted to the records field values to be stored
as `NULL` instead of `0` in the database.
This leads to the inability:
- To distinguish records with this selection field not set
or set to `0` (as both are stored as `NULL`)
- To search for records with the field set to `0`
(as they are considered not set)
For instance, while having `website_quote` installed,
search for sales orders with `Payment` set to
`Not mandatory on website quote validation`: It won't
return any result, even if you have some.
opw-697454