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Re: GROUP_CONCAT question
Posted by: Peter Brawley
Date: August 17, 2014 12:29PM

We can't just make up the syntax we want.

First, ... Where tablename is not null ... makes no sense---the Where clause wants a column reference

Once that's fixed, ...a left Join b Where b.something is not null... is, logically, the same as ...a Inner Join b...

Third, ... Left Join Group_Concat(...) isn't going to work---you can't Join the comma-separated lists

Fourth, as the manual page for Joins says, don't mix comma joins and explicit joins

The table looks like an edge list (http://www.artfulsoftware.com/mysqlbook/sampler/mysqled1ch20.html), but how many levels of child-parent links do you need to report? Rather than we try to guess the intent of your query, how about posting the query requirement in plain English?

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August 17, 2014 02:14AM
Re: GROUP_CONCAT question
August 17, 2014 12:29PM
August 18, 2014 01:26AM
August 18, 2014 01:31AM
August 18, 2014 09:11AM


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