How to get only latest record on filter of foreign key django

问题

I have a table like this Event table

| id | status | date |order(FK)|

| 1 | Planned | 05-02-2015 | 1 |

| 2 | Delivered | 04-02-2015 | 2 |

| 3 | Packed | 03-02-2015 | 3 |

| 4 | Return | 06-02-2015 | 1 |

I want output like this

| id | status | date |order(FK)|

| 2 | Delivered | 04-02-2015 | 2 |

| 3 | Packed | 03-02-2015 | 3 |

| 4 | Return | 06-02-2015 | 1 |

I tried with query = Event.objects.annotate(order_num=Max('date')) but didn't got the expected result. How can i achieve this output

回答1:

Try using the following:

from django.db.models import Max

Event.objects.annotate(max_date=Max('order__event__date')) \
             .filter(date=F('max_date'))

来源：https://stackoverflow.com/questions/46353695/how-to-get-only-latest-record-on-filter-of-foreign-key-django