查询数据库某个字段不重复的值，按时间排序，如何写呢?

Question

文章模型如下

class Article(models.Model):

title = models.CharField(max_length=150, verbose_name='文章标题', unique=True)
content = models.TextField(verbose_name='文章内容')
describe = models.CharField(max_length=500, verbose_name='文章描述', blank=True, null=True)
date_publish = models.DateTimeField(auto_now_add=True, verbose_name="发布时间")
click_count = models.PositiveIntegerField(verbose_name='点击次数', blank=True, null=True, default=0)
keywords = models.ForeignKey(Keywords, blank=True, null=True, verbose_name='关键词')  

class Meta:
    verbose_name = '文章'
    verbose_name_plural = verbose_name
    ordering = ['-date_publish']

def __str__(self):
    return self.title

查询：若外键字段“keywords”下有多条数据，只取1条，多条数据按click_count取点击数最大的，再得到标题/内容/描述的值，输出到网页模板上。

想用一个查询语法完成，请问如何写呢

Answer 1

关键字mysql分析函数(开窗函数),由于mysql不支持max over只能写成如下:

SELECT tt.*
FROM table tt
  INNER JOIN (SELECT
                keyword,
                max(click_count) maxcount
              FROM table
              GROUP BY keyword) groupedtt ON tt.keyword = groupedtt.keyword AND tt.click_count = groupedtt.maxcount
ORDER BY tt.create_time