> This won't work. You need to do this with a BEFORE INSERT trigger. See
> http://firebird.sourceforge.net/index.php?op=faq#q0011.dat

My fault. Sorry. Helen is right.

CREATE TABLE table [EXTERNAL [FILE] ’filespec’]
(<col_def> [, <col_def> | <tconstraint> …]);

<col_def> = col {<datatype> | COMPUTED [BY] (<expr>) | domain}
[DEFAULT {literal | NULL | USER}]
[NOT NULL]
[<col_constraint>]
[COLLATE collation]

What speaks against changing it to

<col_def> = ...
DEFAULT {literal | <expr> | NULL | USER}

Is there any conceptual issue here?

Roman