left join vs left outer join

[kuridisanjeev]

Is there any difference between left join and left outer join??????

please clarify me..

[art297]

Yes.  A nice description, I think, is shown and described in the paper: http://www2.sas.com/proceedings/sugi30/249-30.pdf

It compares sql joins with data step merge operations, and shows the various merges and joins in terms of a venn diagram.

[LinusH · Accepted solution]

Well, the answer is No. From the paper:

"Often you will hear the "left outer join" referred to as just the "left join". This is because the code that creates the join uses only the keyword "left join". The terms, however, are synonymous. "

/Linus

[Howles]

It's documented (http://support.sas.com/documentation/cdl/en/sqlproc/63043/HTML/default/viewer.htm#p1bk7i6jqseje7n1li...😞

"Outer joins are inner joins that have been augmented with rows that did not match with any row from the other table in the join.".