Re: [HACKERS] Serial and NULL values

Bruce Momjian <maillist(at)candle(dot)pha(dot)pa(dot)us> writes:
> test=> create table test (x int, y serial);
> CREATE
> test=> insert into test values (100, null);
> ERROR: ExecAppend: Fail to add null value in not null attribute y

gram.y thinks SERIAL is defined to mean NOT NULL:

| ColId SERIAL ColPrimaryKey
{
ColumnDef *n = makeNode(ColumnDef);
n->colname = $1;
n->typename = makeNode(TypeName);
n->typename->name = xlateSqlType("integer");
n->raw_default = NULL;
n->cooked_default = NULL;
=================> n->is_not_null = TRUE;
n->is_sequence = TRUE;
n->constraints = $3;

$$ = (Node *)n;
}

Offhand I don't see any fundamental reason why serial columns should
be restricted to be nonnull, but evidently someone did at some point.

regards, tom lane