Re: What does this mean?

From: Jeff Zucker <jeff_at_vpservices.com>
Date: Thu, 01 Aug 2002 01:03:23 -0700
Message-ID: <3D48EB4B.1010607@vpservices.com>

Jonathan Leffler wrote:

> John Eggert wrote:
>

>> In Date's "manifesto" and "introduction to databases systems" he uses 
>> the following format
>>
>> <foo> ::=
>>         <bar>
>>
>> Could someone translate that into english for me?
>>
>> I.E. what the heck does ::= mean?

>
> It's a variation on BNF - Backus-Naur Form

 >
 > [good explanation snipped]
 >

> See also the web site http://www.cl.cam.ac.uk/~mgk25/iso-ebnf.html which
> discusses the ISO 14977:1996 Extended BNF, which I've never actually
> seen used.
>

Or, for even more fun, see the clickable, interactive BNF of the SQL92 draft at:

http://cui.unige.ch/db-research/Enseignement/analyseinfo/SQL7/BNFindex.html

-- 
Jeff

Received on Thu Aug 01 2002 - 03:03:23 CDT