Question

Can anyone help me with this query?
I have three tables (A;B;C)

A <--1....N---> B  <--1....N--->  C

I want all A rows having C.dates (the greatest)

Answer 1

SELECT A.*, MAX(C.dates)
FROM A
JOIN B ON B.A_fk = A.id
JOIN C ON C.B_fk = B.id
GROUP BY A.id

This JOIN will exclude results which wont have LEFT join. That is, if any row from A wont have B row or any row from B wont have any C row, then the row wont show. To overcome this you can use LEFT JOIN instead of JOIN.

SELECT A.*, MAX(C.dates)
FROM A
LEFT JOIN B ON B.A_fk = A.id
LEFT JOIN C ON C.B_fk = B.id
GROUP BY A.id

EDIT: Sorry didnt noticed that you needed the greatest value of C.data. There you have it. You have to use MAX function in SELECT and GROUP BY A.id