使用Django的复合/复合主/唯一键

Question

如何使用Django使用复合（复合）主/唯一键创建模型（以及表格）？

Answer 1

Django does not support compound primary keys. You can create a single compound unique key with Meta.unique_together .

Answer 2

if you want only unique mixed fields together use belowcode:

class MyTable(models.Model):
    class Meta:
        unique_together = (('key1', 'key2'),)

    key1 = models.IntegerField()
    key2 = models.IntegerField()

But if you want unique together and one of column be primary, set primary argument for model column, similar below code:

class MyTable(models.Model):
    class Meta:
        unique_together = (('key1', 'key2'),)

    key1 = models.IntegerField(primary_key=True)
    key2 = models.IntegerField()

Answer 3

A composite key consists of more than one attribute to uniquely identify an entity occurrence. This differs from a compound key in that one or more of the attributes, which make up the key, are not simple keys in their own right.

For example, you have a database holding your CD collection. One of the entities is called tracks, which holds details of the tracks on a CD. This has a composite key of CD name, track number.