How to get the primary key id, which is automatically generated in Django models

Question

I have a DB schema that I inherited from some legacy code. Now we intend to use Django to mirror tables in models. This means that I cannot create tables using django models. The table layout looks like this: -

mysql> desc student_profile; +-------------+-------------+------+-----+---------+----------------+ | Field | Type | Null | Key | Default | Extra | +-------------+-------------+------+-----+---------+----------------+ | id | int(11) | NO | PRI | NULL | auto_increment | | joining_on | datetime | YES | | NULL | | | brothername | varchar(45) | YES | | NULL | | +-------------+-------------+------+-----+---------+----------------+ 3 rows in set (0.01 sec) 

Now the Django model created for this circuit looks like this: -

 class StudentProfile(models.Model): id=models.IntegerField(primary_key=True) joining_on=models.DateField() brothername=models.CharField(max_length=45) class Meta: db_table="student_profile" 

When I insert a line into this, like this: -

 StudentProfile.objects.insert(brothername="Bro") 

The row is correctly inserted. But I have no way to extract the id field. It appears that since this field is not AutoField , django does not copy the identifier that MySql automatically generates. What can I do to get the id value with which the string was created? I checked ( https://code.djangoproject.com/ticket/8799#comment:1 ) and it looks by design. But I still need a way to get to id and reflect it in the StudentProfile model. What can I do?

One solution might be to override the default save() value and explicitly provide id in the save() model. But is that right? The database (this is MySql) provides a way to generate an identifier, and I should be able to use this fact to my advantage, and not support the operation of the counter by the application. Any clues?

Answer 1

You can skip the definition of the id column as a whole, i.e.:

 class StudentProfile(models.Model): # id=models.IntegerField(primary_key=True) joining_on=models.DateField() brothername=models.CharField(max_length=45) class Meta: db_table="student_profile" 

Django will create or use a default auto-increment column with the id name that matches your previous column.

If the column name is different, you can use AutoField with a different name, for example:

 my_id = models.AutoField(primary_key=True)