[Dbix-class] Left join with an extra condition

[Darren Duncan]

Bill Moseley wrote:
> Looking for how to add an addition condition on a join.  Here's an 
> example of the query with the extra condition in CAPS
> 
> select u.* <http://p.id/>, count(o.id <http://o.id>)
> from user u
> left outer join job j on   j.user = u.id <http://u.id> AND J.JOB_TYPE = 6
> where u.location  = ?
> group by u.*
> 
> So, wondering how to represent that along with the extra join condition.

What you are adding doesn't look like a normal join condition, as it isn't 
comparing values in the 2 tables being joined.

On the other hand, any straight equality test certainly is expressible as a 
join, if you consider the "6" to be a single-column,single-row table, and then 
you are joining 3 tables.

Is the syntax you propose supposed to be a shorthand for that?

What DBMSs would support this syntax, as I've never seen it before?

-- Darren Duncan