Re: [Firebird-devel] Adding NOT NULL fields with DEFAULT

[Vlad K. <hv...@us...>]

> Vlad Khorsun wrote:
>>> Records at format 1 (which does not have the field added in 2) should use the default value stored in format 2. 
>>> So 'ABC' should be written when updating to format 3 too.
>> 
>>     We have record, stored in format 1, without additional field. We have formats 2 and 3
>> with different default values for the same field. When engine read record it converts it into
>> most current format - format 3 in this case. The question is - what value should be in new
>> field, added with format 2 ? 'ABC' or '123' ? I think - 'ABC'.
>> 
> That's what I said, no? :-)
> 
> So a not-null field with NULL value (or not present), in format N, should return the default value of format 
> (N, N + 1, N + 2, ...) (the first that's found).

    Yes, and this makes things more complex.

> To rule above works, the field (not-null, with default) should have its value stored when updating the record 
> to a new format.

    This will be satisfied automatically as record must be read before update ;)

Regards,
Vlad