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

[Adriano d. S. F. <adr...@gm...>]

Ann W. Harrison wrote:
> 
> Here's the problem I see, and it may exist already.
> 
> Create a table, which creates format 1 for that table.
> Store a bunch of records.
> 
> Add a NOT NULL field with a default value of 'ABC',
> which creates format 2 for the table.  The new format
> includes the default value.
> 
> Now if you read records for that table, the new field's
> value is 'ABC'.
> 
That's ok.

> Now alter the table, changing the default value to '123',
> creating a new format 3 which includes the new default
> for that field.
> 
> Read the same records again and the value is probably going
> to be '123'.
> 
If the record format is 2, it should return 'ABC'. If the record is updated and written in the format 3, 'ABC' should be written to the field so it doesn't catch the format 3 value when reading it.


Adriano