MAX DATE with intermediate table - mysql

Question

I can't get the right results. I have 4 tables:
table: Aluno
id_aluno nome
1 Bruno
2 Carlos
table: Serie
id_serie id_aluno descricao
1 1 Tipo A
2 1 Tipo B
3 2 Tipo A
table: Treino
id_treino id_serie data
1 1 2015-12-10
2 2 2015-12-12
3 3 2015-12-10
table: Avaliacao
id_avaliacao id_aluno data_avaliacao
1 1 2015-12-07
2 1 2015-12-01
3 2 2015-12-05
4 2 2015-12-04
I want the following results:
nome descricao data data_avaliacao
Bruno TIPO B 2015-12-12 2015-12-07
Carlos TIPO A 2015-12-10 2015-12-05
The problem is that the GROUP BY clause should have column "id_aluno" but it's not foreign key of the table which has the date. There is a intermediate table between them (serie).
And I have this other table (avaliacao) which I also want the max DATE, but when I join them all, I got more than one result by aluno.
Query I tried:
SELECT a.nome, s.descricao, t.data, aa.data_avaliacao FROM Aluno a JOIN Serie s ON s.id_aluno = a.id_aluno JOIN Treino t ON t.id_serie = s.id_serie JOIN Avaliacao aa ON aa.id_aluno = a.id_aluno WHERE t.data = SELECT MAX(t1.data) FROM Aluno a1 JOIN Serie s1 ON s1.id_aluno = a1.id_aluno JOIN Treino t1 ON t1.id_serie = s1.id_serie WHERE s1.id_aluno = s.id_aluno )

Answer 1

If I give you this, can you work out the other part?
SELECT a.nome
, s.descricao
, t.data
, v.data_avaliacao
FROM aluno a
JOIN serie s
ON s.id_aluno = a.id_aluno
JOIN treino t
ON t.id_serie = s.id_serie
JOIN
( SELECT s.id_aluno
, MAX(t.data) max_data
FROM serie s
JOIN treino t
ON t.id_serie = s.id_serie
GROUP
BY id_aluno
) x
ON x.id_aluno = s.id_aluno
AND x.max_data = t.data
JOIN avaliacao v
ON v.id_aluno = a.id_aluno;

Answer 2

working with your own query check out the last part, adding only the group by
SELECT a.nome, s.descricao, t.data, aa.data_avaliacao FROM Aluno a
JOIN Serie s ON s.id_aluno = a.id_aluno
JOIN Treino t ON t.id_serie = s.id_serie
JOIN Avaliacao aa ON aa.id_aluno = a.id_aluno
WHERE t.data =
(SELECT MAX(t1.data)
FROM Aluno a1
JOIN Serie s1 ON s1.id_aluno = a1.id_aluno
JOIN Treino t1 ON t1.id_serie = s1.id_serie
WHERE s1.id_aluno = s.id_aluno ) group by a.nome
you can test it out in sqlfiddle

Answer 3

I think that the code of davejal works only if coincides that in the data the MAX date of the table treino correspond to MAX date of table avaliacao for every aluno, when don´t be like that the results won´t be the expected. Using the idea of
Strawberry
, finally would be
SELECT a.nome
, s.descricao
, t.data
, v.data_avaliacao
FROM aluno a
JOIN serie s
ON s.id_aluno = a.id_aluno
JOIN treino t
ON t.id_serie = s.id_serie
JOIN
( SELECT s.id_aluno
, MAX(t.data) max_data
FROM serie s
JOIN treino t
ON t.id_serie = s.id_serie
GROUP
BY id_aluno
) x
ON x.id_aluno = s.id_aluno
AND x.max_data = t.data
JOIN avaliacao v
ON s.id_aluno = v.id_aluno
WHERE v.data_avaliacao IN
( SELECT MAX(v.data_avaliacao) max_data1
FROM avaliacao v
GROUP
BY id_aluno
)
, hope this help