SQL Query: 3 tables highest Value plus rest of row plus - mysql

Question

i'm currently stuck on a sql-query, trying to find a solution, but making me headache for 2 stays now. i've got 3 tables
user-table:
+-----+----------+-----------+
| pid | username | role |
+-----+----------+-----------+
| 1 | user1 | patient |
| 2 | user2 | patient |
| 3 | user3 | doc |
| 4 | user4 | assistant |
| 5 | user5 | patient |
+-----+----------+-----------+
base-dat:
+-----+---------+-------+------------+
| pid | surname | name | birthdate |
+-----+---------+-------+------------+
| 1 | smith | john | 1950-07-31 |
| 2 | jackson | sarah | 1948-08-15 |
+-----+---------+-------+------------+
med-dat:
+-----+-----+---------------+--------+--------+
| mid | pid | dateLastEntry | weight | pulse |
+-----+-----+---------------+--------+--------+
| 1 | 1 | 2017-12-01 | 86 | 65 |
| 2 | 1 | 2017-12-02 | 84 | 70 |
| 3 | 1 | 2017-12-03 | 80 | 67 |
| 4 | 2 | 2017-11-15 | 66 | 60 |
| 5 | 2 | 2017-11-17 | 60 | 64 |
+-----+-----+---------------+--------+--------+
I'm trying to get the max(dateLastEntry) for each user with role patient, showing their pid, name, surname, weight, pulse in a single row - , even if there is no med-data entry for the patient: something like this:
+-----+---------+-------+------------+--------+-------+
| pid | surname | name | lastEntry | weight | pulse |
+-----+---------+-------+------------+--------+-------+
| 1 | smith | john | 2017-12-02 | 84 | 70 |
| 2 | jackson | sarah | 2017-11-17 | 60 | 64 |
| 5 | NONE | NONE | NONE | NONE | NONE |
+-----+---------+-------+------------+--------+-------+
Atm my statement looks like this, but can't get the proper result:
select b.pid, s.surname, s.name, max(m.date) as lastEntry, m.weight, m.pulse
from users b
left join med-dat m on b.pid = m.pid
left join base-dat s on m.pid = s.pid
where b.role = 'Patient'
group by b.pid, s.surname, s.name, m.weight;

Answer 1

You can rewrite your query as below to get the desired output
select b.pid, s.surname, s.name, m.dateLastEntry as lastEntry, m.weight, m.pulse
from users b
left join med_dat m on b.pid = m.pid
left join base_dat s on m.pid = s.pid
left join med_dat m1 on m.pid = m1.pid
and m.dateLastEntry < m1.dateLastEntry
where m1.pid is null
and b.role = 'Patient'
DEMO
Edit from comment, join base_dat using pid from user table
select b.pid, s.surname, s.name, m.dateLastEntry as lastEntry, m.weight, m.pulse
from users b
left join med_dat m on b.pid = m.pid
left join base_dat s on b.pid = s.pid
left join med_dat m1 on m.pid = m1.pid and m.dateLastEntry < m1.dateLastEntry
where m1.pid is null
and b.role = 'Patient'
group by b.pid, s.surname, s.name, m.weight;
Demo