django south migration error relation “photo_photo” already exists

问题

I am using Django South.I am following the tutorial of http://south.readthedocs.org/en/latest/tutorial/part1.html

first of all i want to give some information about my project and the apps. I have a django app namely photo and i have two model namely Photo and UserCommission.

these are the models

class Photo(models.Model):
   name = models.CharField(max_length = 100)
   photo = models.ImageField(upload_to = 'photos', blank=False,null=True)
   approved = models.BooleanField(default = False)
   approved_time = models.DateTimeField(auto_now=True,null=True,blank=True)
   uploaded_time = models.DateTimeField()
   description = models.CharField(max_length = 500 , blank = False , null = True)

and

class UserCommission(models.Model):
        user = models.ForeignKey(User)
        created_time = models.DateTimeField('Created Time',auto_now_add=True)
        commission = models.IntegerField()
        photo_name=models.CharField(max_length=255)
        photo = models.ImageField(upload_to='commission_image')
        download = models.DateTimeField()
        photo_id = models.CharField(max_length=300)

for my first migration i have applied the following according to the tutorial,

python manage.py schemamigration photo --initial

and immediately i have apply the following command

python manage.py migrate photo

then i made a change in my Photo model and apply the following command for final migration

  python manage.py schemamigration photo --auto

and

  python manage.py migrate photo

and finally my first migration has successfully done and the edited columns are added in the Photo model!

now in another situation,i have to make change in my UserCommission model and for that i have followed the same process i have followed for my first migration.but after the last command for this second migration that is

python manage.py migrate photo

i am facing the following error

Running migrations for photo: - Migrating forwards to 0002_initial.

photo:0001_initial FATAL ERROR - The following SQL query failed: CREATE TABLE "photo_photo" ("id" serial NOT NULL PRIMARY KEY, "name" varchar(100) NOT NULL, "photo" varchar(100) NULL, "approved" boolean NOT NULL, "approved_time" timestamp with time zone NULL, "uploaded_time" timestamp with time zone NOT NULL, "description" varchar(500) NULL, "keyword" varchar(500) NULL, "image_id" varchar(300) NULL, "Certified" boolean NOT NULL, "approved_by" varchar(100) NOT NULL, "user_id" integer NOT NULL, "total_download" integer NOT NULL, "watermarked_image" varchar(100) NULL, "dpi_value" integer NOT NULL) The error was: relation "photo_photo" already exists Error in migration: photo:0001_initial DatabaseError: relation "photo_photo" already exists

DatabaseError: relation "photo_photo" already exists

and tell you what, its really bothering me.

回答1:

Sounds like that migration has already been applied and the database thinks it hasn't. You can always migrate --fake to just update the table in the database without trying to apply the migration.

In your case, it looks like you need to (at least) python manage.py migrate photo --fake 0002. You may have to do this for more than one migration depending on how many you have and what you've done.

来源：https://stackoverflow.com/questions/28735525/django-south-migration-error-relation-photo-photo-already-exists

标签

python

django

django-south