> People may have problems with the NULL statements with some versions
> of PostgreSQL.  I have information about editing the applix macro
> on that creates the tables my web site:
>         http://www.radix.net/~cobrien/applix/applix.txt

Just in case someone cares ;)

The "NULL" constraint for a column definition is not defined in SQL92,
and is not necessary and could be dropped from Applix's definition of
the table. The default behavior of any column defined in SQL is to
allow NULL values. 

Postgres does not implement this redundant syntax extension because
yacc-style parsers such as the one used in Postgres find the use of
the bare NULL an ambiguous context. Presumably that is why SQL92 does
not define it.

However, I see that in a limited context, such as a bare NULL with no
other qualifiers, yacc can handle its use. I'll add it to Postgres'
next release...

                   - Thomas

-- 
Thomas Lockhart				lockhart@alumni.caltech.edu
South Pasadena, California

Fri, 12 Nov 1999 06:54:20 +0000
Thomas Lockhart <lockhart@alumni.caltech.edu>
Re: AWL: Re: tm1
> > People may have problems with the NULL statements with some versions
> > of PostgreSQL.  I have information about editing the applix macro
> > on that creates the tables my web site:
> >         http://www.radix.net/~cobrien/applix/applix.txt
> 
> Just in case someone cares ;)
> 
> The "NULL" constraint for a column definition is not defined in SQL92,
> and is not necessary and could be dropped from Applix's definition of
> the table. The default behavior of any column defined in SQL is to
> allow NULL values. 
> 
> Postgres does not implement this redundant syntax extension because
> yacc-style parsers such as the one used in Postgres find the use of
> the bare NULL an ambiguous context. Presumably that is why SQL92 does
> not define it.
> 
> However, I see that in a limited context, such as a bare NULL with no
> other qualifiers, yacc can handle its use. I'll add it to Postgres'
> next release...

Yes, we are hearing people use it.  Seems like we could just ignore the
NULL if possible.

-- 
  Bruce Momjian                        |  http://www.op.net/~candle
  maillist@candle.pha.pa.us            |  (610) 853-3000
  +  If your life is a hard drive,     |  830 Blythe Avenue
  +  Christ can be your backup.        |  Drexel Hill, Pennsylvania 19026

Fri, 12 Nov 1999 11:50:06 -0500 (EST)
Bruce Momjian <maillist@candle.pha.pa.us>
Re: [HACKERS] Re: AWL: Re: tm1