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我在 Django 2.2 中有这样的模型

class Post(models.Model):
    class Meta:
        verbose_name = _('Post')
        verbose_name_plural = _('Posts')

    phone_number = models.CharField(max_length=11, verbose_name=_('Phone number'), db_index=True)

    token = models.CharField(unique=True, max_length=20, verbose_name=_('Token'), db_index=True)
 
    post_state = models.SmallIntegerField(choices=[
        (PostState.NEW, _('New')),
        (PostState.PUBLISHED, _('Published')),
        (PostState.ARCHIVED, _('Archive')),
        (PostState.REMOVED_BEFORE_PUBLISH, _('Removed before publish')),
        (PostState.REJECTED_AFTER_PUBLISH, _('Rejected after publish')),
    ], default=PostState.NEW, verbose_name=_('Post state'), db_index=True)

我希望我在 phone_number 和 token 上的索引基于 post_state 值是部分的，我知道如何在 Postgres shell 中使用 SQL 命令来做到这一点，但我不知道如何在 django 模型中做到这一点，所以它进入了迁移文件也。

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2 回答 2

1

从Django 索引和索引选项中，您可以简单地将索引添加到模型元类：

from django.db.models import Index

class Meta:
        indexes = [
            Index(fields=['phone_number',], condition=Q(post_state__in=[PostState.NEW, PostState.PUBLISHED])),
            Index(fields=['token',], condition=Q(post_state__in=[PostState.NEW, PostState.PUBLISHED])),
            ... # other indexes
        ]
于 2021-06-12T21:06:49.383 回答
0

So I found the answer to this question.

class Post(models.Model):
    class Meta:
        verbose_name = _('Post')
        verbose_name_plural = _('Posts')
        indexes = (
            BTreeIndex(fields=('token',), condition=Q(post_state__in=[PostState.NEW, PostState.PUBLISHED])),
        )

    phone_number = models.CharField(max_length=11, verbose_name=_('Phone number'), db_index=True)

    token = models.CharField(unique=True, max_length=20, verbose_name=_('Token'))
 
    post_state = models.SmallIntegerField(choices=[
        (PostState.NEW, _('New')),
        (PostState.PUBLISHED, _('Published')),
        (PostState.ARCHIVED, _('Archive')),
        (PostState.REMOVED_BEFORE_PUBLISH, _('Removed before publish')),
        (PostState.REJECTED_AFTER_PUBLISH, _('Rejected after publish')),
    ], default=PostState.NEW, verbose_name=_('Post state'))

we make the index in the Meta part of the model and it has a condition argument in which you can pass the partial condition.

于 2021-06-12T09:51:29.193 回答