mysql - Django South - db.alter 函数删除 null=true Blank=true 失败，mysql 失败

Question

通过删除这两个值将日期字段从 null=True 和 Blank=True 更改为 required 时，使用 db.alter 命令时遇到问题。

当以下行被注释掉时，迁移运行不会出现问题。

    db.alter_column('milestones_milestone', 'date', self.gf('django.db.models.fields.DateField')(default='2011-01-01'))

这应该更改列描述:

'milestones.milestone': {
  'date': ('django.db.models.fields.DateField', [], {'null': 'True', 'blank': 'True'}),
},

至

'milestones.milestone': {
  'date': ('django.db.models.fields.DateField', [], {default:'2011-01-01'}),
},

当迁移中保留上述行时，我得到的错误:

 - Migrating forwards to 0002_auto__add_field_milestone_type__chg_field_milestone_date__add_field_mi.
 > milestones:0002_auto__add_field_milestone_type__chg_field_milestone_date__add_field_mi
 ! 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:   = ALTER TABLE `milestones_milestone` DROP COLUMN `type` CASCADE; []
   = ALTER TABLE `milestones_milestonetemplate` DROP COLUMN `type` CASCADE; []

 ! The South developers regret this has happened, and would
 ! like to gently persuade you to consider a slightly
 ! easier-to-deal-with DBMS.
 ! NOTE: The error which caused the migration to fail is further up.
Traceback (most recent call last):
  File "manage.py", line 11, in <module>
    execute_manager(global_settings)
  File "C:\Python26\lib\site-packages\django\core\management\__init__.py", line 438, in execute_manager
    utility.execute()
  File "C:\Python26\lib\site-packages\django\core\management\__init__.py", line 379, in execute
    self.fetch_command(subcommand).run_from_argv(self.argv)
  File "C:\Python26\lib\site-packages\django\core\management\base.py", line 191, in run_from_argv
    self.execute(*args, **options.__dict__)
  File "C:\Python26\lib\site-packages\django\core\management\base.py", line 218, in execute
    output = self.handle(*args, **options)
  File "C:\SQE_Dashboard\SQE Dashboard-mimercha\SQE Dashboard\dashboard\lib\south\management\commands\migrate.py", line 109, in ha
ndle
    ignore_ghosts = ignore_ghosts,
  File "C:\SQE_Dashboard\SQE Dashboard-mimercha\SQE Dashboard\dashboard\lib\south\migration\__init__.py", line 202, in migrate_app

    success = migrator.migrate_many(target, workplan, database)
  File "C:\SQE_Dashboard\SQE Dashboard-mimercha\SQE Dashboard\dashboard\lib\south\migration\migrators.py", line 292, in migrate_ma
ny
    result = self.migrate(migration, database)
  File "C:\SQE_Dashboard\SQE Dashboard-mimercha\SQE Dashboard\dashboard\lib\south\migration\migrators.py", line 125, in migrate
    result = self.run(migration)
  File "C:\SQE_Dashboard\SQE Dashboard-mimercha\SQE Dashboard\dashboard\lib\south\migration\migrators.py", line 99, in run
    return self.run_migration(migration)
  File "C:\SQE_Dashboard\SQE Dashboard-mimercha\SQE Dashboard\dashboard\lib\south\migration\migrators.py", line 81, in run_migrati
on
    migration_function()
  File "C:\SQE_Dashboard\SQE Dashboard-mimercha\SQE Dashboard\dashboard\lib\south\migration\migrators.py", line 57, in <lambda>
    return (lambda: direction(orm))
  File "C:\SQE_Dashboard\SQE Dashboard-mimercha\SQE Dashboard\dashboard\milestones\migrations\0002_auto__add_field_milestone_type_
_chg_field_milestone_date__add_field_mi.py", line 15, in forwards
    db.alter_column('milestones_milestone', 'date', self.gf('django.db.models.fields.DateField')(default='2011-01-01'))
  File "C:\SQE_Dashboard\SQE Dashboard-mimercha\SQE Dashboard\dashboard\lib\south\db\generic.py", line 373, in alter_column
    self.execute("ALTER TABLE %s %s;" % (self.quote_name(table_name), sql), values)
  File "C:\SQE_Dashboard\SQE Dashboard-mimercha\SQE Dashboard\dashboard\lib\south\db\generic.py", line 137, in execute
    cursor.execute(sql, params)
  File "C:\Python26\lib\site-packages\django\db\backends\util.py", line 15, in execute
    return self.cursor.execute(sql, params)
  File "C:\Python26\lib\site-packages\django\db\backends\mysql\base.py", line 86, in execute
    return self.cursor.execute(query, args)
  File "C:\Python26\lib\site-packages\MySQLdb\cursors.py", line 173, in execute
    self.errorhandler(self, exc, value)
  File "C:\Python26\lib\site-packages\MySQLdb\connections.py", line 36, in defaulterrorhandler
    raise errorclass, errorvalue
django.db.utils.DatabaseError: (1265, "Data truncated for column 'date' at row 512")

我正在使用:

South 0.71 注意:我尝试升级到 0.73，发现 0.73 给了我同样的错误，并且在加载较旧的装置时破坏了我的脚本。

Django 1.2.1

Python 库:MySQLDdb DB API v2.0 兼容，修订版 603

mysql 版本 14.14 Distrib 5.1.51，适用于 Win32 (ia32)

InnoDB存储引擎

Answer 1

我刚刚遇到了同样的错误。就我而言，我不小心将列的默认值设置为datetime.now，这导致了数据截断。

我建议您从模型中删除默认值，设置 auto_now_add=True 并重新生成迁移文件。