You have a table called reports and you are extracting a table that consists of the id, user, item_id, and created fields. This new table will only have rows that contain the max value of created for each distinct item_id.
This part extracts the fields you want:
select a.id,
a.user,
a.item_id,
a.created
From a table called reports (a):
from reports as a
Only extract the rows that satisfy the condition:
where a.created = (select max(created)
from reports as b
where a.item_id = b.item_id)
3
solved Can someone explain this SQL for me?