Joined Tables

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The JOIN syntax provides methods of combining information in tables.

INNER JOINs, and LEFT and RIGHT OUTER JOINs are supported.

A join may be performed as a NATURAL JOIN or where the conditions for the join are more explicitly specified.

The different ways in which the various join options can be combined makes the overall JOIN syntax quite convoluted, so to simplify the explanation, each variant will be described on its own with an accompanying syntax diagram.

In order to understand the JOIN syntax generally, it is important to appreciate the difference between an INNER and an OUTER JOIN. It is also important to be aware of the three fundamental JOIN variants (NATURAL, JOIN USING and JOIN ON) which are mutually exclusive and apply equally to INNER and OUTER JOINs.

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