Joining 3 tables
First off, sorry if this is a near enough duplicate. I've found this question, which nearly does what I want, but I couldn't wrap my head around how to alter it to my needs.
I've got these 3 tables:
cs_Accounts: +----+-----------------------------+-------------+ | id | email | username | +----+-----------------------------+-------------+ | 63 | jamasawaffles@googlil.com | jamwaffles2 | | 64 | jamwghghhfles@goomail.开发者_运维技巧com | jamwaffles3 | | 65 | dhenddfggdfgetal-pipdfg.com | dhendu9411 | | 60 | jwapldfgddfgfffles.co.uk | jamwaffles | +----+-----------------------------+-------------+ cs_Groups: +----+-----------+------------+-------------+ | id | low_limit | high_limit | name | +----+-----------+------------+-------------+ | 1 | 0 | 0 | admin | | 2 | 1 | 50 | developer | | 3 | 76 | 100 | reviewer | | 4 | 51 | 75 | beta tester | | 5 | 1 | 50 | contributor | +----+-----------+------------+-------------+ cs_Permissions: +----+---------+----------+ | id | user_id | group_id | +----+---------+----------+ | 4 | 60 | 4 | | 3 | 60 | 1 | | 5 | 60 | 2 | | 6 | 62 | 1 | | 7 | 62 | 3 | +----+---------+----------+
I've been wrestling with a 3 way join for hours now, and I can't get the results I want. I'm looking for this behaviour: a row will be returned for every user from cs_Accounts
where there is a row in cs_Permissions
that contains their ID and the ID of a group from cs_Groups
, as well as the group with the group_id
has a high_lmiit
and low_limit
in a range I can specify.
Using the data in the tables above, we might end up with something like this:
email username cs_Groups.name ---------------------------------------------------------- jwapldfgddfgfffles.co.uk jamwaffles admin jwapldfgddfgfffles.co.uk jamwaffles developer jwapldfgddfgfffles.co.uk jamwaffles beta tester dhenddfggdfgetal-pipdfg.com dhendu9411 admin dhenddfggdfgetal-pipdfg.com dhendu9411 reviewer
There is an extra condition, however. This condition is where rows are only selected if the group the user belongs to has a high_limit
and low_limit
with values I can specify using a WHERE
clause. As you can see, the table above only contains users with rows in the permissions table.
This feels a lot like homework but with a name like James I'm always willing to help.
select a.email,a.username,g.name
from cs_Accounts a
inner join cs_Permissions p on p.user_id = a.id
inner join cs_Groups g on g.id = p.Group_id
where g.low_limit > 70
and g.high_limt < 120
This is the query
SELECT ac.email, ac.username, gr.name
FROM cs_Accounts AS ac
LEFT JOIN cs_Permissions AS per ON per.user_id = ac.id
INNER JOIN cs_Groups AS gr ON per.user_id = gr.id
You can add a WHERE
clause to this query if you want
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