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Displaying posts with tag: right join (reset)

MySQL RIGHT OUTER JOIN Tutorial & Examples
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Here you find information about writing RIGHT JOINs (also referred to as RIGHT OUTER JOINs). This introduction into right joins includes a detailed description, syntax information and right outer join example statements. The Venn diagram on the left represents a result set that a statement with a right join produces. Please refer to the syntax examples below for an example. Links to additional information resources can be found at the end of this article.


Right Join syntax …


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Good SQL Querying
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By “Good SQL Querying”, I am not referring to “how to make your queries more perfomant.” I am about to go on a mini-rant about how to make readable and self-documenting SQL queries.

One practice that will get me instantly going on a rant is using a comma join. There is NO reason to do the following:

-- uses the sakila sample database
SELECT first_name, last_name, address
FROM customer,address;

What kind of join did the original author intend? A CROSS JOIN? Or did they really want an INNER JOIN and forget the WHERE clause?

The answer: you do not know for sure; you can only guess. Had the query been

SELECT …
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