Thejas M Nair I found no standard regarding this. SQL standards define three literal values for boolean: TRUE, FALSE, and UNKNOWN . The standard is also controversial, and as a result, different DB has different implementations .
It seems that only Postgre SQL allows this. Other legacy data, such as that in MS Access, may also have this. That's why I think it makes sense to have a configuration or serde property to turn this on only if it's desired.