Counting records in a child table

[Mike Orr <sluggoster@xxxxxxxxx>]

I know how to do count(*)/group by on a single table, but how do I get
a count of related records in a child table? Some of the counts will
be zero.

SELECT
    parent.id AS id,
    parent.name AS name,
    parent.create_date AS create_date,
    COUNT(child.id) AS count
FROM parent LEFT JOIN child ON parent.id = child.parent_id
GROUP BY parent.id, parent.name, parent.create_date
ORDER by count desc;

Is this correct, and is it the simplest way to do it?

I used a left join to avoid skipping parent records that have no child
records. I grouped by parent.id because those are the result rows I
want. I added the other group by fields because psql refused to run
the query otherwise.

-- 
Mike Orr <sluggoster@xxxxxxxxx>

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