MySQL retrieve employees presences - mysql

Question

I need to retrieve the employees presences for the day. There are two states in the presences: In & Out.
If the employee does not have a presence it should retrieve with the status of null.
I have two tables, Employees and Presences and I want to join them.
ID | name
1 John
2 Julie
3 Anthony
4 Joseph
Now the presences table has the following data:
ID | employee_id | presence_date | presence_hour | Movement
1 1 2016-08-30 08:55 In
2 2 2016-08-30 08:56 In
3 3 2016-08-30 08:57 In
4 1 2016-08-30 12:33 Out
5 2 2016-08-30 12:34 Out
As you can see in the presences data, the employee Anthony has not yet left the office and the employee Joseph has no entries in the table.
The result I'm expecting:
Employee | Movement
John Out
Julie Out
Anthony In
Joseph null
The query I'm using:
SELECT employee.name, presence.movement
FROM employees AS employee
LEFT JOIN presences AS presence ON presence.employee_id = employee.id
WHERE presence.presence_date = '2016-08-30' AND
employee.id IN (1, 2, 3, 4)
GROUP BY employee.id
ORDER BY employee.name, presence.id DESC
The problems I'm facing:
Joseph never appears in the data
presence.id DESC doesn't work

Answer 1

For Joseph presence.presence_date is null, so it is not matched by presence.presence_date = '2016-08-30'.
The order by presence.id makes no sense to me. You are grouping by employee, so all matching rows in presence for that employee are merged together. You want to sort all those according to presence.id and select the most recent rows movement value? This does not work the way you wrote it. One solution would be to use MAX(presence.id) in your query to get the id of the most recent row of presence for the current employee and then join the presence table again to get the data you want.
SELECT a.name, b.movement
FROM (
SELECT employee.name, MAX(presence.id) max_id
FROM employees AS employee
LEFT JOIN presences AS presence
ON presence.employee_id = employee.id WHERE presence.presence_date = '2016-08-30' AND
employee.id IN (1, 2, 3, 4)
GROUP BY employee.id
) a
LEFT JOIN presence b ON a.max_id = b.id
ORDER BY a.name
Although it might be not a good idea to assume that most recent is equivalent to biggest id, so one might select the row with the most recent date, but this is another "problem".

Answer 2

This is caused by applying the date filter in the where criteria. The where criteria is applied after the join, thus eliminating any records for Joseph, since he was not present that day. Move the date criteria to the join condition instead.
You got the whole group by wrong, your query is against the sql standards because you have columns in the select list that are not in the group by list and are not subject of an aggregate function, such as max(). MySQL allows such queries under certain sql mode settings only. Use max() on the movement and group by on employee name and date fields.
Sample query, assuming you can only have 1 in and one out per employee per day:
SELECT employee.name, max(presence.movement) as movement
FROM employees AS employee
LEFT JOIN presences AS presence ON presence.employee_id = employee.id and date(presence.presence_date) = '2016-08-30'
WHERE employee.id IN (1, 2, 3, 4)
GROUP BY employee.name, date(presence.presence_date)