Select rows which have no match in other table - mysql

Question

This query seemed pretty simple to start with.
#table - user
user_id - full_name - image
1 Jon-1 Jon-placeholder.png
2 Aax-2 Max-placeholder.png
3 Lie-3 Lie-placeholder.png
4 Man-4 Man-placeholder.png
5 Nik-5 Nik-placeholder.png
6 Led-6 Led-placeholder.png
7 Neo-7 Neo-placeholder.png
#table - user_contacts
id - user_id - contacts_id - created_date
1 1 2 2020-02-26 08:43:26
2 1 3 2020-02-26 08:43:26
3 1 5 2020-02-26 08:43:26
4 3 4 2020-02-26 08:43:26
5 3 5 2020-02-26 08:43:26
6 7 2 2020-02-26 08:43:26
What i am trying to a accomplish is retrieve all contacts_id from user_contacts where the user_id is not equal to user_id = 1 which user Jon-1 so this must looks like
#retrieved data
user_id - full_name - image
4 Man-4 Man-placeholder.png
6 Led-6 Led-placeholder.png
7 Neo-7 Neo-placeholder.png
user_ids 6,7,4 must be retrieved because user_id = 1 does not have those ids in the user_contact table under column contacts_id
First Query
SELECT u.user_id, u.full_name, u.image
FROM user u
NATURAL LEFT JOIN user_contacts cnt
WHERE cnt.contacts_id IS NULL
Second Query
SELECT user.user_id, user.full_name, user.image
FROM USER
WHERE user.user_id NOT IN (
SELECT user_contacts.contacts_id
FROM user_contacts
WHERE user_contacts.contacts_id IS NOT NULL)
Third Query
SELECT u.user_id, u.full_name, u.image
FROM user u
NATURAL LEFT JOIN user_contacts cnt
WHERE cnt.contacts_id IS NULL

Answer 1

dbfiddle
SELECT
user_id, full_name, image
FROM
user
WHERE NOT user_id in (SELECT contacts_id from user_contacts WHERE user_contacts.user_id=1)
AND user_id <> 1
WHERE NOT user_id in sub-query: The sub-query will get the contact for user=1.
AND user_id <> 1: this makes sure user 1 is not selected.

Answer 2

With NOT EXISTS:
select u.* from user u
where user_id <> 1
and not exists (
select 1 from user_contacts
where user_id = 1 and contacts_id = u.user_id
)
See the demo.
Results:
| user_id | full_name | image |
| ------- | --------- | ------------------- |
| 4 | Man-4 | Man-placeholder.png |
| 6 | Led-6 | Led-placeholder.png |
| 7 | Neo-7 | Neo-placeholder.png |

Answer 3

SELECT a.*
FROM user a
LEFT
JOIN
( SELECT uc.*
FROM user u
JOIN user_contacts uc
ON uc.user_id = u.user_id
WHERE u.full_name = 'Jon-1'
) b
ON b.contacts_id = a.user_id
WHERE a.full_name <> 'Jon-1'
AND b.id IS NULL;