python - Django 日期按月份过滤

Question

我需要编写一个查询，返回小于或等于某个月某天的所有对象。年份并不重要。获取特定日期/月份的对象非常容易(假设 now = datetime.datetime.now()):

posts = TodaysObject.objects.filter(publish_date__day=now.day, publish_date__month=now.month)

但是我不能这样做:

posts = TodaysObject.objects.filter(publish_date__day__lte=now.day, publish_date__month=now.month)

似乎 Django 认为我在组合多个字段查找时尝试进行连接 (publish_date__day__lte)。在 Django 中执行此操作的最佳方法是什么？

Answer 1

试试这个:

选项 1:

from django.db.models import Q

datafilter = Q()
for i in xrange(1, now.day+1):
    datafilter = datafilter | Q(publish_date__day=i)
datafilter = datafilter & Q(publish_date__month=now.month)
posts = TodaysObject.objects.filter(datafilter)

选项 2:

执行原始 sql 查询:

def query_dicts(query_string, *query_args):
    from django.db import connection
    cursor = connection.cursor()
    cursor.execute(query_string, query_args)
    col_names = [desc[0] for desc in cursor.description]
    while True:
        row = cursor.fetchone()
        if row is None:
            break
        row_dict = dict(izip(col_names, row))
        yield row_dict
    return
posts = query_dicts('SELECT * FROM tablename WHERE DAY(publish_date)<=%s AND MONTH(publish_date)=%s', now.day, now.month)

使用 extra() 函数:

posts = TodaysObject.objects.extra([where='DAY(publish_date)<=%d AND MONTH(publish_date)=%d' % (now.day, now.month)])

假设您正在使用 MySQL。对于 PostgreSQL，您需要将 DAY(publish_date) 和 MONTH(publish_date) 分别更改为 DATE_PART('DAY', publish_date) 和 DATE_PART('MONTH', publish_date)。