QUICK JOINS question

[alphacooler]

I am unsure as to the proper order in which to do joins. When doing INNER JOINS (when many tables are involved), can I only join two tables that are placed back to back in order, or can I inner join table 1 with table 6 (1 and 6 being their order listed). Also does the same apply for LEFT JOINS, or can I join any two tables no matter where they come in order?

Thanks.

 

[r937]

my experience is that you should start with the table that has the most specificity, i.e. the table for which you have a WHERE condition

for example, to find all articles in a particular category, you would have

FROM categories
INNER
JOIN articles
ON articles.category_id = categories.id
WHERE categories.owner = 937

from this point forward, you may add additional tables, provided that each one you add has a join condition that references a table already mentioned

put all your INNER JOINs first, then your LEFT OUTER JOINs

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