Multiple table join with possible conditional matches - mysql

Question

I have several tables that I combine in an application I'm creating in PHP that essentially creates a check list. I realize I could solve this problem using a conditional in PHP, but am curious if MySQL is capable of accomplishing this and if so, how? Specifically, I have four tables which are queried using the following statement:
SELECT
cl_status.status,
users.user_first,
cl_status.date AS status_date,
cl_status.id AS status_id,
cl_status.criteria_id,
cl_criteria.id AS cid,
cl_criteria.description AS description
FROM cl_criteria
LEFT JOIN cl_lists
ON cl_criteria.cl_id = cl_lists.id
RIGHT JOIN cl_status
ON cl_criteria.id = cl_status.criteria_id
LEFT JOIN users
ON cl_status.user_id = users.user_id
WHERE cl_lists.id = '1'
Table one - cl_lists:
+----+------------------+------------+------------+-------+
| id | title | date | comp_level | owner |
+----+------------------+------------+------------+-------+
| 1 | Newcomer's guide | 1452473606 | 1 | 1 |
+----+------------------+------------+------------+-------+
Table two - cl_assign:
+----+-------+-------+------------+
| id | cl_id | owner | date |
+----+-------+-------+------------+
| 1 | 1 | 1 | 1455843514 |
+----+-------+-------+------------+
Table three - cl_status:
+----+-------------+---------+-------------+------------+--------+----------+
| id | criteria_id | user_id | description | date | status | comments |
+----+-------------+---------+-------------+------------+--------+----------+
| 2 | 66 | 1 | | NULL | 1 | NULL |
| 15 | 65 | 1 | | 1455842197 | 5 | NULL |
| 16 | 67 | 1 | | 1455842201 | 5 | NULL |
| 17 | 68 | 1 | | 1455842203 | 5 | NULL |
| 18 | 69 | 1 | | 1455842217 | 0 | NULL |
| 19 | 70 | 1 | | 1455842222 | 5 | NULL |
| 20 | 72 | 1 | | 1455842237 | 1 | NULL |
| 21 | 71 | 1 | | 1455842234 | 0 | NULL |
| 22 | 73 | 1 | | 1455842246 | 5 | NULL |
| 23 | 76 | 1 | | 1455842249 | 5 | NULL |
| 24 | 77 | 1 | | 1455842268 | 5 | NULL |
| 25 | 78 | 152 | | 1455854420 | 3 | NULL |
| 26 | 81 | 1 | | 1455843660 | 5 | NULL |
+----+-------------+---------+-------------+------------+--------+----------+
Table four - users:
+---------+------------+
| user_id | user_first |
+---------+------------+
| 1 | Mark |
| 2 | Test |
+---------+------------+
Ideally, I'd like the join to look like this:
+--------+------------+-------------+-----------+-------------+------+-----------------------------+
| status | user_first | status_date | status_id | criteria_id | cid | description |
+--------+------------+-------------+-----------+-------------+------+-----------------------------+
| 5 | Mark | 1455842197 | 15 | 65 | 65 | Tour of facility |
| 5 | Mark | 1455842201 | 16 | 67 | 67 | Tax forms |
| 5 | Mark | 1455842203 | 17 | 68 | 68 | 2 forms of ID |
| 0 | Mark | 1455842217 | 18 | 69 | 69 | Benefits | |
| 5 | Mark | 1455842246 | 22 | 73 | 73 | Intro to policies |
| 5 | Mark | 1455842249 | 23 | 76 | 76 | Setup email account |
| NULL | NULL | NULL | NULL | 78 | 78 | Setup Computer account |
+--------+------------+-------------+-----------+-------------+------+-----------------------------+
However, it looks like this:
+--------+------------+-------------+-----------+-------------+------+-----------------------------+
| status | user_first | status_date | status_id | criteria_id | cid | description |
+--------+------------+-------------+-----------+-------------+------+-----------------------------+
| 5 | Mark | 1455842197 | 15 | 65 | 65 | Tour of facility |
| 5 | Mark | 1455842201 | 16 | 67 | 67 | Tax forms |
| 5 | Mark | 1455842203 | 17 | 68 | 68 | 2 forms of ID |
| 0 | Mark | 1455842217 | 18 | 69 | 69 | Benefits |
| 5 | Mark | 1455842246 | 22 | 73 | 73 | Intro to policies |
| 5 | Mark | 1455842249 | 23 | 76 | 76 | Setup email account |
| 3 | Temp | 1455854420 | 25 | 78 | 78 | Setup Computer account |
+--------+------------+-------------+-----------+-------------+------+-----------------------------+
Is there a way to apply the conditional before the join? Or another way to accomplish the result set that I want?
EDIT
This is a screenshot of what the application looks like:
The criteria table will include steps of every checklist I have. The list table is a list of the various checklists. The status table allows every user (such as Mark, or Test) to look at the same checklist and complete it as if it was a separate document. It also populates the date/time that the item was updated by that user.

Answer 1

I suspect that the RIGHT JOIN you have in your query is causing the records you want to appear to be filtered out. Remember that t1 RIGHT JOIN t2 is the same as t2 LEFT JOIN t1, meaning that t1 will lose any record which does not appear in t2, with t2 keeping all its records. Try this:
SELECT cl_status.status, users.user_first, cl_status.date AS status_date,
cl_status.id AS status_id, cl_status.criteria_id, cl_criteria.id AS cid,
cl_criteria.description AS description
FROM cl_criteria LEFT JOIN cl_lists
ON cl_criteria.cl_id = cl_lists.id
LEFT JOIN cl_status
ON cl_criteria.id = cl_status.criteria_id
LEFT JOIN users
ON cl_status.user_id = users.user_id
WHERE cl_lists.id = '1'