Re: Help - where is FROM clause in update?
Date: Thu, 18 Feb 1993 14:52:10 GMT
Message-ID: <1993Feb18.145210.7491_at_cbfsb.cb.att.com>
From article <1993Feb18.083746.22333_at_qiclab.scn.rain.com>, by tcox_at_qiclab.scn.rain.com (Thomas Cox):
> alaw_at_us.oracle.com writes:
>>danj_at_cbnewsg.cb.att.com (Dan Jackson) writes:
>>>I am use to using Ingres 6.4 which DOES have a 'from' clause >>>which makes this very easy. Does Oracle 7 have it? >>>Is there an ANSI standard?
>
> [example of update deleted -- thanks, Alvin.]
>
> My understanding of the ANSI standards (yes, that's plural) for SQL is
> that the UPDATE statement can *only* apply to one table, and furthermore
> that the UPDATE statement itself has no FROM clause. (Subqueries,
> however, certainly can have FROM clauses.)
>
> Either Ingres 6.4 violates the ANSI standards, *or* my understanding is
> wrong, *or* your memory of what Ingres 6.4 allows is faulty.
>
> I am interested in the actual answer on this. Could anyone supply it?
I am staring at the 1991 Ingres 6.4 SQL reference manual which has an *optional* from clause in the update statement. I use it and it works. However, the query can NOT be re-written without the from clause! At least I haven't been able to do it. The 'where' clause does NOT allow sub-queries. Only expressions.
The only reference to ANSI standards I found in the Ingres ref. manual was in the appendix, which gave a list of *proposed* ANSI standard SQL keywords to treat as reserved words to ensure compatibility with other SQL implementations.
Any ANSI folks out there who can clear this up????
-- Dan Jackson AT&T Somerset NJ, USA danj_at_cbnewsg.att.com (908)-805-1461Received on Thu Feb 18 1993 - 15:52:10 CET