添加新模型后。 如何在不丢失数据的情况下进行 Django 表迁移

Question

class UserSubStatus(models.Model):
    msisdn = models.CharField(max_length=200)
    category = models.CharField(max_length=200, null=True, blank=True)
    validity = models.IntegerField(default=1,null=True,blank=True)
    sub_status = models.IntegerField(default=0)
    created_at = models.DateTimeField(auto_now_add=True)
    updated_at = models.DateTimeField(auto_now=True)

    class Meta:
        ordering = ['-created_at']
        db_table = "user_sub_status"

I add this table on my model.py file. How add this "user_sub_status" table on my database without losing any data.

Answer 1

run makemigrations and migrate as you did before. If you do not erase previous migrations files then by running makemigrations new migrations files will add to migrations folder and by migrate new tables or columns for previous tables will add to your database and there will be no problem with your stored data

Answer 2

First, you have to run makemigrations command which is responsible for creating new migrations based on the changes you have made to your models.

python manage.py makemigrations

Then you have to run a migration command which is responsible for applying and unapplying migrations that are created by the above command.

python manage.py migrate

With the help of above both command, your table "user_sub_status" will be added in your database without losing any data from your database.

Answer 3

Hello Dear

First run the following command:

python manage.py makemigrations your_app_name

than run this command:

python manage.py migrate your_app_name

NB: I hope, "user_sub_status" will be added to your database without losing data.