Here you find information about writing LEFT JOINs (also referred to as LEFT
OUTER JOINs). This introduction into left joins includes a
description, syntax information and example statements that use
left outer joins. The Venn diagram on the left represents a
result set that a statement with a left 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.
Left Join syntax
First of all, some syntax examples for the impatient:
-- left join with USING-clause SELECT * FROM <leftTable> LEFT JOIN <rightTable> USING(id)
-- left join with ON-clause SELECT * FROM <leftTable> a LEFT JOIN <rightTable> b ON a.name = b.authorName
As you can see, a join condition can be written …
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