Andy Bennett wrote:
> I could use the inner join for the "entrys" join and the "items" join
> but not the "entry-items" join because each entry can have more than
> one item.
WITH a(id, name) AS (VALUES (1, 'A')),
b(id, name) AS (VALUES (1, 'B1'), (1, 'B2'))
SELECT * FROM a INNER JOIN b USING (id);
1|A|B1
1|A|B2
The only difference between inner and outer joins is how rows without
any match are handled.
> I started with an OUTER JOIN as I find it easier to show that it's
> doing the correct thing because I can search the output for errant
> NULLs. Trying to detect missing rows in an INNER JOIN is harder.
If the join columns have the same name, using USING is easier.
And it would be a good idea to enforce the relationships between the
tables with foreign key constraints: <https://www.sqlite.org/foreignkeys.html>
(However, constraints do not affect how you have to write your queries.)
Regards,
Clemens
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