获取 Django 编程错误：对于确实存在的列，该列不存在

Question

我对 Django 还很陌生，仍在努力解决问题。

我正在尝试创建一个表单来过滤课程并使用我的 Postgres 数据库中的值填充 HTML 下拉列表。

我的模型.py

from django.db import models
# Create your models here.
class AgeGroup(models.Model):
    agegroupid = models.AutoField(primary_key=True)
    agegrouptitle = models.CharField(max_length=50, blank=True, null=True)
    agegroupdescription = models.CharField(max_length=200, blank=True, null=True)

    class Meta:
        managed = False
        db_table = 'age_group'


class Subjects(models.Model):
    subjectid = models.AutoField(primary_key=True)
    subjecttitle = models.CharField(max_length=50, blank=True, null=True)
    subjectdescription = models.CharField(max_length=200, blank=True, null=True)

    class Meta:
        managed = False
        db_table = 'subjects'


class InstructorProfiles(models.Model):
    instructorid = models.AutoField(primary_key=True)
    instructorname = models.CharField(max_length=50, blank=True, null=True)
    instructordegrees = models.CharField(max_length=100, blank=True, null=True)
    instructorlongbio = models.CharField(max_length=1000, blank=True, null=True)
    instructorshortbio = models.CharField(max_length=500, blank=True, null=True)
    instructorphoto = models.CharField(max_length=1000, blank=True, null=True)

    class Meta:
        managed = False
        db_table = 'instructor_profiles'


class Courses(models.Model):
    courseid = models.AutoField(primary_key=True)
    coursetitle = models.CharField(max_length=100)
    # instructorid = models.SmallIntegerField(blank=True, null=True)
    coursephoto = models.CharField(max_length=1000, blank=True, null=True)
    coursethumbnailphoto = models.CharField(max_length=1000, blank=True, null=True)
    credithours = models.DecimalField(max_digits=5, decimal_places=2)
    courseoneliner = models.CharField(max_length=200)
    coursedescription = models.CharField(max_length=500)
    instructor = models.ForeignKey(InstructorProfiles, on_delete=models.CASCADE)

    class Meta:
        managed = False
        db_table = 'courses'

我的意见.py

from django_mako_plus import view_function, jscontext
from datetime import datetime, timezone
from homepage import models as hmod

from django.http import HttpResponseRedirect
from django.shortcuts import render

from django import forms
#from .forms import FilterForm

@view_function
def process_request(request, cat_id:int = None, pnum:int = 1):
    currentDate = datetime.today()
    currentYear = currentDate.year

    allcourses = hmod.Courses.objects.only("courseid", "coursetitle", "coursephoto", "coursedescription")

    form = FilterForm();

    context = {
        # sent to index.html:
        'form': form,
        'current_year': currentYear,
        'allcourses': allcourses,
    }
    return request.dmp.render('courselist.html', context)

class FilterForm(forms.Form):
    def __init__(self, *args, **kwargs):
        super(FilterForm, self).__init__(*args, **kwargs)

        ichoices = [(i.instructorid, i.instructorname)
                   for i in hmod.InstructorProfiles.objects.all()];

        print (ichoices)

        tchoices = [(t.courseid, t.credithours)
                   for t in hmod.Courses.objects.all()];

        # schoices = [(s.subjectid, s.subjecttitle)
        #            for s in hmod.Subjects.objects.all()];
        #
        # achoices = [(a.ageGroupId, a.ageGroupTitle)
        #            for a in hmod.AgeGroups.objects.all()];

        self.fields['Instructor'] = forms.ChoiceField(initial='Select Instructor', choices=ichoices)
        # self.fields['Training Hours/Credits'] = forms.ChoiceField(initial='Select Training Hours', choices=tchoices)
        # self.fields['Subject'] = forms.ChoiceField(initial='Select Subject', choices=schoices)
        # self.fields['Age Group'] = forms.ChoiceField(initial='Select Age Group', choices=achoices)

我得到的错误是我得到了错误ProgrammingError at /homepage/courselist/ column courses.instructor does not exist LINE 1: ...."courseoneliner", "courses"."coursedescription", "courses"....。这只发生在我尝试使用变量tchoices 时。

我已经仔细检查了讲师列确实存在，并且有数据。讲师列是一个外键，将课程表链接到讲师档案。我运行了makemigrations 和migrate，它告诉我没有更改或未应用的迁移。

我已经搜索了很多不同的问题来寻找类似的问题，但我一直无法找到解决方案。

提前感谢您的帮助！

Answer 1

我想that questions 可以帮助你。尝试删除所有旧迁移并创建新迁移。