Field list in ambiguous in join with 4 tables - mysql

Question

Very confused why this is happening since I'm naming the specific tables as es and sub that it's complaining about (and I think that's how you fix that particular issue).
I've got:
users submissions_comments email_settings submissions tables
This query gives me what I want, but I now want to join this on my email_settings and submissions table which both have a user_id.
SELECT user_id,
submission_id,
comment,
users.*,
FROM submissions_comments
INNER JOIN
(SELECT submissions_comments.parent_id
FROM submissions_comments
WHERE id = 224) x ON submissions_comments.id = x.parent_id
LEFT JOIN users ON submissions_comments.user_id = users.id
Output:
user_id: 35
submission_id: 12
comment: fdasadfsdadfs
id: 35
email: bobcobb#gmail.com
username: bobcobb
name: Robert Cobb
about:
created: 2014-03-21 20:24:57
last_login: 2014-07-06 23:21:43
public_profile: 1
queued_photo: 0
But if I try to join on another table (which has a reference to a user_id) I get Column 'user_id' in field list is ambiguous
SELECT user_id,
submission_id,
comment,
users.*,
es.*,
sub.*
FROM submissions_comments
INNER JOIN
(SELECT submissions_comments.parent_id
FROM submissions_comments
WHERE id = 224) x ON submissions_comments.id = x.parent_id
LEFT JOIN users ON submissions_comments.user_id = users.id
LEFT JOIN submissions sub ON x.parent_id = sub.user_id
LEFT JOIN email_settings es ON x.parent_id = es.user_id;
As you can tell I'm joining all of these on the user_id returned from the inner select (e.g. x.parent_id).

Answer 1

You have to add the alias to the column name:
SELECT sub.user_id,...

Answer 2

SELECT submissions_comments.user_id,
submissions_comments.submission_id,
submissions_comments.comment,
users.*,
es.*,
sub.*
FROM submissions_comments
INNER JOIN
(SELECT submissions_comments.parent_id
FROM submissions_comments
WHERE id = 224) x ON submissions_comments.id = x.parent_id
LEFT JOIN users ON submissions_comments.user_id = users.id
LEFT JOIN submissions sub ON x.parent_id = sub.user_id
LEFT JOIN email_settings es ON x.parent_id = es.user_id;
you need to define which user_id you are referring on the select part as well.