Django: Make a column which is not primary key unique

Question

I have a list of numeric `codes` with corresponding mnemonic `names` and I want to have a Django model for them so the `names` are primary keys, but there is also a constraint that the values in the `code` column are unique. What I tried is the following: ``` class Constant(models.Model): name = models.CharField(max_length=70) name.primary_key = True code = models.IntegerField() description = models.CharField(max_length=100) unique_together = (("code",),) ``` I realize that `unique_together` is meant to enforce uniqueness of values in a set of columns, but I thought I would try with just one and it seemed to work, i.e. no error when doing `python manage.py syncdb`, but it doesn't really enforce the constraint I want: ``` mysql> describe constant; +-------------+--------------+------+-----+---------+-------+ | Field | Type | Null | Key | Default | Extra | +-------------+--------------+------+-----+---------+-------+ | name | varchar(70) | NO | PRI | | | | code | int(11) | NO | | | | |…

Accepted Answer

Add the unique option to your code field.

```
class Constant(models.Model):
    name = models.CharField(max_length=70, primary_key=True)
    code = models.IntegerField(unique=True)
    description = models.CharField(max_length=100)
```

Django: Make a column which is not primary key unique

Solution

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