topic left join vs left outer join in SAS Procedures

left join vs left outer join

kuridisanjeev — Sun, 22 Jan 2012 16:26:52 GMT

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

please clarify me..

left join vs left outer join

art297 — Sun, 22 Jan 2012 16:50:50 GMT

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.

Re: left join vs left outer join

Howles — Sun, 22 Jan 2012 18:01:57 GMT

It's documented (http://support.sas.com/documentation/cdl/en/sqlproc/63043/HTML/default/viewer.htm#p1bk7i6jqseje7n1lifcip8kzhpp.htm😞

"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.".

Re: left join vs left outer join

LinusH — Mon, 23 Jan 2012 14:13:07 GMT

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