如何使用存储在字段值中的正则表达式执行正则表达式查找？

本文介绍了如何使用存储在字段值中的正则表达式执行正则表达式查找？的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述

给出以下模型：

from django.db import models from django.conf import settings class UserMessage(models.Model): user = models.ForeignKey(settings.AUTH_USER_MODEL) path = models.CharField(max_length=255) message = models.TextField()

并给出以下模型实例：

UserMessage.objects.create( user=request.user, path='^/dashboard/(.*)+$', message='Welcome to your dashboard!' )

我想能够针对UserMessage.path的值执行当前请求路径的查找。这意味着我需要在查询的右侧添加路径，例如：

I want to be able to perform a lookup of the current request path against the value of UserMessage.path. This means that I need to have 'path' on the right side of my query, e.g.:

SELECT * FROM user_message WHERE '/dashboard/foo/' ~ path;

但是，Django ORM的正则表达式查找产生相反的顺序，例如：

However, the Django ORM's regexp lookup produces the opposite order, e.g.:

SELECT * FROM user_message WHERE path ~ '/dashboard/foo/';

是否有一种方法可以使用ORM查找轻松地将其反转为所需的结果？还是更适合.extra（）或自定义查找表达式？

Is there a way I can easily reverse this for my desired result, using an ORM lookup? Or is this better suited for a .extra() or custom lookup expression?

推荐答案

extra（）

UserMessage.objects.extra(where=['%s ~ path'], params=[request.path])

自定义查找

models.py

from django.db.models import Lookup @models.CharField.register_lookup class NotEqual(Lookup): lookup_name = 'test' def as_postgresql(self, compiler, connection): lhs, lhs_params = self.process_lhs(compiler, connection) rhs, rhs_params = self.process_rhs(compiler, connection) params = lhs_params + rhs_params return '%s ~ %s' % (rhs, lhs), params

用法： UserMessages.objects.get（path__test = request.path）