изменение уже созданной бд | Forum

15 June 2013, 18:19

slavikrusin

Posts: 19

15 June 2013, 18:19

slavikrusin

Posts: 19

вот модель по которой созданы таблицы

from django.db import models

class Posts(models.Model):
title = models.CharField(max_length = 100)
authors = models.CharField(max_length = 100, blank = True)
post = models.TextField(max_length = 1000)
data_posts = models.DateField(auto_now=True)

    class Meta:
    ordering = ('-data_posts',)

    def __unicode__(self):
    return  self.title


class BlogUser(models.Model):
name = models.CharField(max_length = 100)
email = models.EmailField()
info = models.TextField(max_length = 500)
twitter = models.URLField()
facebook = models.URLField()
vk = models.URLField()

я хочу добавить следующее поле в Posts:

    category = models.CharField(max_length = 100)

выполняю первую миграцию

python manage.py schemamigration weblog --initial
Creating migrations directory at 'D:\blog_v\weblog\migrations'...
Creating __init__.py in 'D:\blog_v\weblog\migrations'...
+ Added model weblog.Posts
+ Added model weblog.BlogUser
Created 0001_initial.py. You can now apply this migration with: ./manage.py migrate weblog

добавляю category в Posts и затем выполняю вот это

python manage.py schemamigration weblog --auto

у меня появляется вот это

? The field 'Posts.category' does not have a default specified, yet is NOT NULL.
? Since you are adding this field, you MUST specify a default
? value to use for existing rows. Would you like to:
?  1. Quit now, and add a default to the field in models.py
?  2. Specify a one-off value to use for existing columns now
? Please select a choice:

можете подсказать что мне надо здесь написать заранее спасибо

Answer | 0

15 June 2013, 18:39 NikitaKurinny Posts: 211 Location: Moscow	15 June 2013, 18:39 NikitaKurinny Posts: 211 Location: Moscow поле не может быть пустым и не заданно значение по умолчанию. добавте или null= True, или default= ''
	Answer \| 0

15 June 2013, 19:05

slavikrusin

Posts: 19

15 June 2013, 19:05

slavikrusin

Posts: 19

при выполнение команды migrate появляется вот это

D:\blog_v>.\manage.py migrate weblog
Running migrations for weblog:
- Migrating forwards to 0002_auto__add_field_posts_slug.
> weblog:0001_initial
FATAL ERROR - The following SQL query failed: CREATE TABLE "weblog_posts" ("id"
integer NOT NULL PRIMARY KEY, "title" varchar(100) NOT NULL, "authors" varchar(1
00) NOT NULL, "post" text NOT NULL, "data_posts" date NOT NULL, "category" varch
ar(100) NULL)
The error was: table "weblog_posts" already exists
! Error found during real run of migration! Aborting.

! Since you have a database that does not support running
! schema-altering statements in transactions, we have had
! to leave it in an interim state between migrations.

! You *might* be able to recover with:   = DROP TABLE "weblog_posts"; []
= DROP TABLE "weblog_bloguser"; []

! The South developers regret this has happened, and would
! like to gently persuade you to consider a slightly
! easier-to-deal-with DBMS (one that supports DDL transactions)
! NOTE: The error which caused the migration to fail is further up.
Error in migration: weblog:0001_initial
Traceback (most recent call last):
File "D:\blog_v\manage.py", line 10, in <module>
execute_from_command_line(sys.argv)
File "C:\Python27\lib\site-packages\django\core\management\__init__.py", line
443, in execute_from_command_line
utility.execute()
File "C:\Python27\lib\site-packages\django\core\management\__init__.py", line
382, in execute
self.fetch_command(subcommand).run_from_argv(self.argv)
File "C:\Python27\lib\site-packages\django\core\management\base.py", line 196,
in run_from_argv
self.execute(*args, **options.__dict__)
File "C:\Python27\lib\site-packages\django\core\management\base.py", line 232,
in execute
output = self.handle(*args, **options)
File "C:\Python27\lib\site-packages\south-0.8.1-py2.7.egg\south\management\com
mands\migrate.py", line 111, in handle
ignore_ghosts = ignore_ghosts,
File "C:\Python27\lib\site-packages\south-0.8.1-py2.7.egg\south\migration\__init__.py", 
line         220, in migrate_app
success = migrator.migrate_many(target, workplan, database)
File "C:\Python27\lib\site-packages\south-0.8.1-py2.7.egg\south\migration\
migrators.py",   line 232, in migrate_many
result = migrator.__class__.migrate_many(migrator, target, migrations, database)
File "C:\Python27\lib\site-packages\south-0.8.1-py2.7.egg\south\migration\
migrators.py", line 307, in migrate_many
result = self.migrate(migration, database)
File "C:\Python27\lib\site-packages\south-0.8.1-py2.7.egg\south\migration\
migrators.py", line 132, in migrate
result = self.run(migration, database)
File "C:\Python27\lib\site-packages\south-0.8.1-py2.7.egg\south\migration\
migrators.py", line 116, in run
return self.run_migration(migration, database)
File "C:\Python27\lib\site-packages\south-0.8.1-py2.7.egg\south\migration\
migrators.py", line 86, in run_migration
migration_function()
File "C:\Python27\lib\site-packages\south-0.8.1-py2.7.egg\south\migration\
migrators.py", line 62, in <lambda>
return (lambda: direction(orm))
File "D:\blog_v\weblog\migrations\0001_initial.py", line 18, in forwards
('category', self.gf('django.db.models.fields.CharField')(max_length=100, null=True)),
File "C:\Python27\lib\site-packages\south-0.8.1-py2.7.egg\south\db\generic.py"
, line 47, in _cache_clear
return func(self, table, *args, **opts)
File "C:\Python27\lib\site-packages\south-0.8.1-py2.7.egg\south\db\generic.py"
, line 361, in create_table
"columns": ', '.join([col for col in columns if col]),
File "C:\Python27\lib\site-packages\south-0.8.1-py2.7.egg\south\db\generic.py"
, line 282, in execute
cursor.execute(sql, params)
File "C:\Python27\lib\site-packages\django\db\backends\util.py", line 40, in execute
return self.cursor.execute(sql, params)
File "C:\Python27\lib\site-packages\django\db\backends\sqlite3\base.py", line
344, in execute
return Database.Cursor.execute(self, query, params)
django.db.utils.DatabaseError: table "weblog_posts" already exists

Answer | 0

15 June 2013, 19:13 NikitaKurinny Posts: 211 Location: Moscow	15 June 2013, 19:13 NikitaKurinny Posts: 211 Location: Moscow DatabaseError: table "weblog_posts" already exists. таблица уже создана. выполните либо фейковую миграцию, либо создайте бд заново
	Answer \| 0

15 June 2013, 19:43 slavikrusin Posts: 19	15 June 2013, 19:43 slavikrusin Posts: 19 все заработало, хотя я и не понял как
	Answer \| 0

18 June 2013, 17:25 Andrew_Lvov Posts: 102	18 June 2013, 17:25 Andrew_Lvov Posts: 102 А как сделать фейковую миграцию ?
	Answer \| 0

18 June 2013, 18:18 RaD Posts: 2813 Location: Снегири, МО	18 June 2013, 18:18 RaD Posts: 2813 Location: Снегири, МО Прочитать доку `south` на предмет аргумента `--fake`. Если ничего не помогает, прочтите документацию, наконец!
	Answer \| 0

18 June 2013, 18:46 alerion Posts: 5750 Location: Львов	18 June 2013, 18:46 alerion Posts: 5750 Location: Львов `--fake` это типа зафейкать ее. Вам такое нужно или типа "ненастоящую" миграцию? Фиксю баги по трейсбеку.
	Answer \| 0

19 June 2013, 0:04 Andrew_Lvov Posts: 102	19 June 2013, 0:04 Andrew_Lvov Posts: 102 У меня была ситуация, когда не мог сделать миграцию из-за table already exists - как у автора. Я так понимаю, это можно исправить с помощью ненастоящей миграции ?
	Answer \| 0

19 June 2013, 12:02 alerion Posts: 5750 Location: Львов	19 June 2013, 12:02 alerion Posts: 5750 Location: Львов Делаете --fake при миграции и она будет записана как выполненная. Главное что бы там не было еще каких-то изменений, которых нет в БД. Фиксю баги по трейсбеку.
	Answer \| 0