Hi Alexander,

> > SQL> select myint2 from mytable2;
> >
> > shows the value 0 for myint2 for old records, so the database
> > *should* be in a restoreable state.
>
> Thomas, now try
>
> select * from mytable2 where myint2 is null;
>
> ;)) You see client-side null-interpretation of Not Null column. IIRC I
> even registered it in bug tracker once.

Ha, "catch me if you can", and yes, you did it ;-)).

Firebird 1.0 Build 796 and isql.exe.

A table with one record.

SQL> alter table mytable2 add myint3 integer not null;
SQL> commit;
SQL> select * from mytable2 where myint3 is null;

I get a result set of one record <= wrong

SQL> select * from mytable2 where myint3 is not null;

I get an empty result set <= still wrong

SQL> select * from mytable2 where myint3 = 0;

I get an empty result set <= again wrong

SQL> select * from mytable2;

I get a result set of one record <= correct


Regards,
Thomas.