python - Django 多个 unique_together 是否在 PostgreSQL 中被错误映射？

Question

当我在我的 Django 模型中添加多个 unique_together 元组时，PostgreSQL 数据库映射出现错误(也根据 a previous SO answer on the subject )。示例如下。

这是我的迁移:

migrations.CreateModel(
    name='FinancialConcept',
    fields=[
        ('id', models.AutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
        ('taxonomy', models.CharField(max_length=128)),
        ('name', models.CharField(max_length=256)),
        ('xbrl_element', models.CharField(max_length=256)),
        ('parent', models.ForeignKey(null=True, on_delete=django.db.models.deletion.SET_NULL, to='analysis.FinancialConcept')),
    ],
),
migrations.AlterUniqueTogether(
    name='financialconcept',
    unique_together=set([('taxonomy', 'name'), ('taxonomy', 'xbrl_element'), ('parent', 'xbrl_element')]),
),
....

我预计这会创建三个 UNIQUE 索引，每对一个。但是，数据库映射最终是这样的:

    Column    |          Type          |                               Modifiers                                
--------------+------------------------+------------------------------    ------------------------------------------
 id           | integer                | not null default nextval('analysis_financialconcept_id_seq'::regclass)
 taxonomy     | character varying(128) | not null
 name         | character varying(256) | not null
 xbrl_element | character varying(256) | not null
 parent_id    | integer                | 
Indexes:
    "analysis_financialconcept_pkey" PRIMARY KEY, btree (id)
    "analysis_financialconcept_taxonomy_xbrl_element_d8b45254_uniq" UNIQUE CONSTRAINT, btree (taxonomy, xbrl_element)
    "analysis_financialconcept_parent_id_51fc8021" btree (parent_id)

即 UNIQUE 索引之一是正确的，但其他两个缺失。

知道是什么原因造成的吗？

Answer 1

你试过元组的元组吗？

unique_together = (('taxonomy', 'name'), ('taxonomy', 'xbrl_element'), ('parent', 'xbrl_element'))