mySql INNER JOIN, MAX & DISTINCT - mysql

Question

I'm looking to return one row for each user of type "student" displaying their "name" and their latest "score" (in reverse chronological order).
I have two tables users & services
users Table
id name type
---|-------|-----
1 | Bob | student
2 | Dave | student
3 | Larry | student
4 | Kevin | master
services table
id score userId date
---|--------|-------|------------
1 | 14 | 1 | 2014-09-04
2 | 99 | 3 | 2014-09-03
3 | 53 | 2 | 2014-09-07
4 | 21 | 1 | 2014-09-08
5 | 79 | 2 | 2014-09-08
6 | 43 | 3 | 2014-09-10
7 | 72 | 3 | 2014-09-10
8 | 66 | 2 | 2014-09-01
9 | 43 | 3 | 2014-08-22
10 | 26 | 1 | 2014-08-22
Desired Result
id scores name date
---|--------|-------|------------
3 | 43 | Larry | 2014-09-10
1 | 21 | Bob | 2014-09-08
2 | 79 | Dave | 2014-09-08
What I have tried is:
SELECT users.id, users.name, services.date, services.score
FROM users
JOIN services ON users.id = services.userId
WHERE users.type='student'
ORDER BY services.date DESC
But this always returns the last date in the table for each user.
So i decided to try and tackle it from the other end like this:
SELECT servicesTemp.date, servicesTemp.score
FROM services servicesTemp
INNER JOIN
(SELECT userId, MAX(date) AS MaxExpDate
FROM services
GROUP BY clientId) servicesTempGrp
ON servicesTemp.userId = servicesTempGrp.userId
AND servicesTemp.MaxDate = servicesTempGrp.MaxDate
But realised that i would end up with duplicates if the dates were ever the same and i can only return one row per user (and double grouping didn't work).
I think i'm now over complicating this, so a life line would be much appreciated.

Answer 1

try:
SELECT users.id, users.name, services.date, services.score
FROM users
JOIN services ON users.id = services.userId
WHERE users.type='client'
AND services.date = (SELECT MAX(date) from services where userID = users.id)
ORDER BY services.date DESC

Answer 2

You can guarantee one row by using the substring_index()/group_concat() trick:
SELECT u.id, u.name, max(s.date) as date,
substring_index(group_concat(s.score order by date desc), ',', 1) as score
FROM users u JOIN
services s
ON u.id = s.userId
WHERE u.type = 'client'
GROUP BY u.id, u.name
ORDER BY s.date DESC;
Without using group by, another option for getting only one row per user is to use variables. Or, if you know the ids are being assigned sequentially, use the id instead of date:
SELECT u.id, u.name, s.date, s.score
FROM users u INNER JOIN
services s
on u.userId = s.userId INNER JOIN
(SELECT userId, MAX(id) AS MaxId
FROM services
GROUP BY userId
) smax
ON s.userId = smax.userId and s.Id = smax.MaxId
WHERE u.type = 'client';