Django中的多对多关系"ProgrammingError: shoe_size_run.id不存在“

Question

我通过内省现有的数据库，使用inspectdb工具创建模型。

部分ERD：

​

models.py：

class Shoe(models.Model):
    sku = models.AutoField(primary_key=True)
    style_number = models.CharField(unique=True, max_length=6)
    factory_style_number = models.CharField(unique=True, max_length=10, blank=True, null=True)
    stock_name = models.CharField(max_length=10)
    season = models.CharField(max_length=30)
    date_created = models.DateField()
    category_code = models.ForeignKey(Category, models.DO_NOTHING, db_column='category_code')
    brand_code = models.ForeignKey(Brand, models.DO_NOTHING, db_column='brand_code')
    factory_number = models.ForeignKey(Factory, models.DO_NOTHING, db_column='factory_number')
    spec_sheet = models.ForeignKey('SpecSheet', models.DO_NOTHING, blank=True, null=True)

    class Meta:
        managed = False
        db_table = 'shoe'

class ShoeSizeRun(models.Model):
    sku = models.ForeignKey(Shoe, models.DO_NOTHING, db_column='sku')
    size_run = models.ForeignKey('SizeRun', models.DO_NOTHING)

    class Meta:
        managed = False
        db_table = 'shoe_size_run'
        unique_together = (('sku', 'size_run'),)

class SizeRun(models.Model):
    size_run_id = models.AutoField(primary_key=True)
    run = models.IntegerField()
    width = models.CharField(max_length=4)
    pairs_of_five = models.IntegerField(blank=True, null=True)
    pairs_of_five_and_half = models.IntegerField(blank=True, null=True)
    pairs_of_six = models.IntegerField(blank=True, null=True)
    pairs_of_six_and_half = models.IntegerField(blank=True, null=True)
    pairs_of_seven = models.IntegerField(blank=True, null=True)
    pairs_of_seven_and_half = models.IntegerField(blank=True, null=True)
    pairs_of_eight = models.IntegerField(blank=True, null=True)
    pairs_of_eight_and_half = models.IntegerField(blank=True, null=True)
    pairs_of_nine = models.IntegerField(blank=True, null=True)
    pairs_of_nine_and_half = models.IntegerField(blank=True, null=True)
    pairs_of_ten = models.IntegerField(blank=True, null=True)
    pairs_of_ten_and_half = models.IntegerField(blank=True, null=True)
    pairs_of_eleven = models.IntegerField(blank=True, null=True)
    pairs_of_eleven_and_half = models.IntegerField(blank=True, null=True)
    pairs_of_twelve = models.IntegerField(blank=True, null=True)

    class Meta:
        managed = False
        db_table = 'size_run'`

这些是这些表的sql定义：

CREATE TABLE shoe (
  sku                  SERIAL NOT NULL, 
  style_number    varchar(6) NOT NULL UNIQUE, 
  factory_style_number varchar(10) UNIQUE, 
  stock_name      varchar(10) NOT NULL, 
  season               varchar(30) NOT NULL, 
  date_created         date NOT NULL, 
  category_code        int4 NOT NULL, 
  brand_code           int4 NOT NULL, 
  factory_number       int4 NOT NULL, 
  spec_sheet_id        int4, 
  PRIMARY KEY (sku));
CREATE TABLE shoe_size_run (
  sku         int4 NOT NULL, 
  size_run_id int4 NOT NULL, 
  PRIMARY KEY (sku, 
  size_run_id));
CREATE TABLE size_run (
  size_run_id              SERIAL NOT NULL, 
  run                      int4 NOT NULL, 
  width                    varchar(4) NOT NULL, 
  pairs_of_five            int4, 
  pairs_of_five_and_half   int4, 
  pairs_of_six             int4, 
  pairs_of_six_and_half    int4, 
  pairs_of_seven           int4, 
  pairs_of_seven_and_half  int4, 
  pairs_of_eight           int4, 
  pairs_of_eight_and_half  int4, 
  pairs_of_nine            int4, 
  pairs_of_nine_and_half   int4, 
  pairs_of_ten             int4, 
  pairs_of_ten_and_half    int4, 
  pairs_of_eleven          int4, 
  pairs_of_eleven_and_half int4, 
  pairs_of_twelve          int4, 
  PRIMARY KEY (size_run_id));
ALTER TABLE shoe_size_run ADD CONSTRAINT FKshoe_size_544815 FOREIGN KEY (sku) REFERENCES shoe (sku);
ALTER TABLE shoe_size_run ADD CONSTRAINT FKshoe_size_544404 FOREIGN KEY (size_run_id) REFERENCES size_run (size_run_id);

现在，我在Django中使用多到多个表有问题。为什么会有这个错误？

我该如何解决这个问题？

Answer 1

您的表shoe_size_run有一个复合主键(sku, size_run_id)。不幸的是，Django还不支持这一点(参见票证373)

如果要在Django中使用该表，则必须向该表添加一个列主键。最简单的列名是id，因为默认情况下，这正是Django所期望的。

查看您的图表，您还需要对您的shoe_image表执行同样的操作。

Answer 2

表为shoe_size_run，列为size_run_id。因此，您的模型字段需要是size_run_id而不是size_run。