Re: trouble figuring out joins, any gurus out there?
Posted by:
Rick James
Date: September 01, 2009 10:30PM
Plain 'ole JOIN.
INNER and OUTER -- usually just noise.
LEFT and RIGHT -- only useful for checking for missing rows in one of the tables.
STRAIGHT -- only when you thing you are smarter than the optimizer.
And, usually you don't need to worry about the order of tables.
SELECT p.project_name,
t.title
FROM project_tag pt
JOIN project p ON p.project_id = pt.project_id
JOIN tag t ON pt.tag_id = t.tag_id
JOIN todo_tag dt ON dt.tag_id = pt.tag_id
JOIN todo d ON t.todo_id = dt.todo_id
WHERE pt.project_id = 1
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Re: trouble figuring out joins, any gurus out there?
September 01, 2009 10:30PM
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