Re: Comma separated JOIN syntax
| From: | Marc Ferguson | Date: | Fri, 02 Dec 2005 19:58:22 +0000 |
| Subject: | Re: Comma separated JOIN syntax | ||
| References: | 1 | Groups: | php.db |
| Request: | Send a blank email to php-db+get-40749@lists.php.net to get a copy of this message | ||
Hi Matt,
For the query style you would replace "ON" with "WHERE". You won't use
"ON"
unless you use "JOIN"; they come together.
SELECT u.*, a.city FROM users u, addresses a WHERE u.id=a.user_id
Marc F.
""Matt Monaco"" <mmonaco3@jhu.edu> wrote in message
news:99.57.21657.2CE8B834@pb1.pair.com...
> 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