Re: [HACKERS] JOIN syntax. Examples?
От | Hannu Krosing |
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Тема | Re: [HACKERS] JOIN syntax. Examples? |
Дата | |
Msg-id | 367562BC.D23FB4A7@trust.ee обсуждение исходный текст |
Ответ на | Re: [HACKERS] JOIN syntax. Examples? ("Oliver Elphick" <olly@lfix.co.uk>) |
Список | pgsql-hackers |
Thomas G. Lockhart wrote: > > > The book "The Practical SQL Handbook", which is often recommended on > > these lists, uses the syntax `*=' and `=*' for left and right outer > > joins (page 211). I think we ought to support this syntax as well, > > since it will save new users from confusion. > > This one conflicts with Postgres' operator extensibility features, since > it would look just like a legal operator. so does = Could it be possible to extend the operator extensibility features to achieve the behaviour of outer/cross joins ? > The two books I have at hand (besides my old Ingres docs) are A Guide to > the SQL Standard by Date and Darwen and Understanding the New SQL by > Melton and Simon. Both focus on SQL standard syntax, and neither mention > the various outer join syntaxes accepted by Oracle, Informix, or Sybase. Has anybody tried out DB2 ? I have downloaded it (for linux) but have not yet tried it. > An explanation for the lack of standards compliance by the big three > probably involves the fact that they predate the standard by a > significant number of years. Not to mention that both =* and =(+) are more concise and easier to follow, at least for one with my headshape. The standard is probably the 'worst common denominator' or something like that :( ----------------- Hannu
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