FW: [PHP] getting from one table listing from another
| From: | Jay Blanchard | Date: | Mon, 20 Aug 2007 11:26:27 +0000 |
| Subject: | FW: [PHP] getting from one table listing from another | ||
| Groups: | php.general | ||
| Request: | Send a blank email to php-general+get-261040@lists.php.net to get a copy of this message | ||
[snip]
Question -- is it redundant to say:
FROM table a LEFT OUTER JOIN table b
ON(a.column = b.column)
when "table a" appears first? Wouldn't that be the same as:
FROM table a OUTER JOIN table b
ON(a.column = b.column)
[/snip]
An OUTER JOIN is essentially a FULL OUTER JOIN which will include
matches and non-matches from both tables. The order of tables is only
important when specifying LEFT or RIGHT outer join. Some RDBMS implement
this differently so for clarity you should always be very specific.