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From:Matt Monaco Date:November 29 2005 5:22am
Subject:Re: comma-separated JOINS
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What would be the most efficient order to join in?  Say I have one main 
table with most columns (I assume this should be the main table of the 
query) then each table relates to the next, is it as simple as putting them 
in order?



"Peter Brawley" <peter.brawley@stripped> wrote in message 
news:438BAFCA.4030508@ style="color:#666">stripped...
> Matt,
>
> >When using JOINS by the simply supplying a comma separated list of
> tables in
> >the FROM clause, is the ON argument normally associated with a join
> intended
> >to be addressed in the WHERE clause, or should ON still be used?
>
> There's no ON clause for a join specified by a WHERE clause, and that's 
> one reason specifiying joins with JOIN ... ON ..  is almost always 
> preferable--it entirely disambiguates the join for the writer, readers, 
> and those others who later will have to divine what you meant :-) .
>
> PB
>
> -----
>
> Matt Monaco wrote:
>
>>When using JOINS by the simply supplying a comma separated list of tables 
>>in
>>the FROM clause, is the ON argument normally associated with a join 
>>intended
>>to be addressed in the WHERE clause, or should ON still be used?
>>
>>// Comma separated join
>>SELECT u.*, a.city FROM users u, addresses a WHERE u.id=a.user_id;
>>
>>// Actual JOIN clause
>>SELECT u.*, a.city FROM users u INNER JOIN addresses a ON u.id=a.user_id;
>>
>>
>>// Query style in question
>>SELECT u.*, a.city FROM users u, addresses a ON u.id=a.user_id;
>>
>>If not ON, is there at least another viable argument?  The reason I'm
>>interested is for a query involving 5 or 6 tables and WHERE arguments 
>>which
>>do not deal with the relationships.  I would like to assure the efficiency
>>of this query.
>>
>>
>>Thanks in advance,
>>Matt
>>
>>
>>
>
>
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Thread
comma-separated JOINSMatt Monaco29 Nov
  • Re: comma-separated JOINSPeter Brawley29 Nov
  • Re: comma-separated JOINSMatt Monaco29 Nov
    • Re: comma-separated JOINSSGreen29 Nov
    • Re: comma-separated JOINSMatt Monaco29 Nov