Question

我在三个Django模型之间有以下关系：

  class TestCase(models.Model):
       '''
       Define the testcase model. A testcase is a python Class
       which contains a set of tests
       '''
       name = models.BinaryField(blank=False)
       filename = models.BinaryField(blank=True)
       run_flag = models.IntegerField(default=0)
       run_as_root = models.BooleanField(default=0)
       num_tests = models.IntegerField(default=0)
       testsuite = models.ForeignKey(TestSuite)

       def __str__(self):
           return self.name

请忽略TestSuite：这对此问题并不重要。每个TestCase都是您可能想象的：TestCase（类）。因此，每次执行TestCase时，它都会有TestExecution和Result：

  class Result(models.Model):
       '''
       Define the result of a testcase. It may be 'PASS', 'FAIL',
       'SKIPPED' or 'ABORTED'
       '''
       FAIL = 0
       PASS = 1
       ABORTED = 2
       SKIPPED = 3

       Status = (
           (PASS, 'PASS'),
           (FAIL, 'FAIL'),
           (SKIPPED, 'SKIPPED'),
           (ABORTED, 'ABORTED'),
       )

       status = models.IntegerField(choices=Status, default=FAIL)

       testcase = models.ForeignKey(TestCase)


   class TestExecution(models.Model):

       name = models.BinaryField(blank=False)
       num_testsuites = models.IntegerField(default=0)
       time = models.FloatField()
       date = models.DateTimeField(default=django.utils.timezone.now)

      result = models.OneToOneField(Result)

      def __str__(self):
          return self.name + " : " + self.date + " : " + self.time

可以说，TestCase hasMany Result但Result和TestExecution之间的关系为OneToOne。我的模型架构遇到了一些问题。我知道一个简单的解决方案是merge表Result和TestExecution：

    python manage.py migrate
Operations to perform:
  Synchronize unmigrated apps: staticfiles, messages
  Apply all migrations: admin, autotester, contenttypes, auth, sessions
Synchronizing apps without migrations:
  Creating tables...
    Running deferred SQL...
  Installing custom SQL...
Running migrations:
  Rendering model states... DONE
  Applying autotester.0005_auto_20150519_1831...Traceback (most recent call last):
  File "manage.py", line 10, in <module>
    execute_from_command_line(sys.argv)
  File "/usr/local/lib/python2.7/dist-packages/django/core/management/__init__.py", line 338, in execute_from_command_line
    utility.execute()
  File "/usr/local/lib/python2.7/dist-packages/django/core/management/__init__.py", line 330, in execute
    self.fetch_command(subcommand).run_from_argv(self.argv)
  File "/usr/local/lib/python2.7/dist-packages/django/core/management/base.py", line 390, in run_from_argv
    self.execute(*args, **cmd_options)
  File "/usr/local/lib/python2.7/dist-packages/django/core/management/base.py", line 441, in execute
    output = self.handle(*args, **options)
  File "/usr/local/lib/python2.7/dist-packages/django/core/management/commands/migrate.py", line 221, in handle
    executor.migrate(targets, plan, fake=fake, fake_initial=fake_initial)
  File "/usr/local/lib/python2.7/dist-packages/django/db/migrations/executor.py", line 110, in migrate
    self.apply_migration(states[migration], migration, fake=fake, fake_initial=fake_initial)
  File "/usr/local/lib/python2.7/dist-packages/django/db/migrations/executor.py", line 147, in apply_migration
    state = migration.apply(state, schema_editor)
  File "/usr/local/lib/python2.7/dist-packages/django/db/migrations/migration.py", line 115, in apply
    operation.database_forwards(self.app_label, schema_editor, old_state, project_state)
  File "/usr/local/lib/python2.7/dist-packages/django/db/migrations/operations/fields.py", line 62, in database_forwards
    field,
  File "/usr/local/lib/python2.7/dist-packages/django/db/backends/mysql/schema.py", line 43, in add_field
    super(DatabaseSchemaEditor, self).add_field(model, field)
  File "/usr/local/lib/python2.7/dist-packages/django/db/backends/base/schema.py", line 403, in add_field
    self.execute(sql, params)
  File "/usr/local/lib/python2.7/dist-packages/django/db/backends/base/schema.py", line 111, in execute
    cursor.execute(sql, params)
  File "/usr/local/lib/python2.7/dist-packages/django/db/backends/utils.py", line 79, in execute
    return super(CursorDebugWrapper, self).execute(sql, params)
  File "/usr/local/lib/python2.7/dist-packages/django/db/backends/utils.py", line 64, in execute
    return self.cursor.execute(sql, params)
  File "/usr/local/lib/python2.7/dist-packages/django/db/utils.py", line 97, in __exit__
    six.reraise(dj_exc_type, dj_exc_value, traceback)
  File "/usr/local/lib/python2.7/dist-packages/django/db/backends/utils.py", line 64, in execute
    return self.cursor.execute(sql, params)
  File "/usr/local/lib/python2.7/dist-packages/django/db/backends/mysql/base.py", line 124, in execute
    return self.cursor.execute(query, args)
  File "/usr/local/lib/python2.7/dist-packages/MySQLdb/cursors.py", line 205, in execute
    self.errorhandler(self, exc, value)
  File "/usr/local/lib/python2.7/dist-packages/MySQLdb/connections.py", line 36, in defaulterrorhandler
    raise errorclass, errorvalue
django.db.utils.IntegrityError: (1062, "Duplicate entry '0' for key 'result_id'")

关于模型架构，最合适的方法是什么？

根据请求添加autotester/migrations/0005_auto_20150519_1831.py：

＃ - - 编码：utf-8 - - 来自 future 导入unicode_literals

来自django.db导入模型，迁移

类迁移（migrations.Migration）：

    dependencies = [
       ('autotester', '0004_auto_20150519_1744'),
   ]

   operations = [
       migrations.RemoveField(
           model_name='testexecution',
           name='framework',
       ),
       migrations.AddField(
           model_name='testexecution',
           name='result',
           field=models.OneToOneField(default=None, to='autotester.Result'),
           preserve_default=False,
       ),
   ]

Answer 1

routes.IgnoreRoute("{resource}.axd/{*pathInfo}"); routes.MapMvcAttributeRoutes(); AreaRegistration.RegisterAllAreas(); routes.MapRoute( "Default", // Route name "{controller}/{action}/{id}", // URL with parameters new { controller = "Home", action = "Index", id = "" } // Parameter defaults );与OneToOneField ForeignKey类似。

您的问题伴随着这种独特的约束，因为如果您的数据库不为空，则无法添加具有唯一约束的字段。你要做的是：

添加没有唯一约束的字段= unique=True
填写此字段，了解即将出现的唯一约束
将ForeignKey更改为ForeignKey

以下是详细步骤：

第一步：

删除OneToOneField文件，并在autotester/migrations/0005_auto_20150519_1831.py模型中使用result更改result = models.ForeignKey(Result, null=True, blank=True)字段并执行迁移：

TestExecution

第二步：

对于您拥有的每个./manage.py makemigrations autotester ./manage.py migrate autotester，创建一个Result（用适当的数据替换FOO）：

TestExecution

第三步

使用results = Result.objects.all() for result in results: tst = TestExecution() tst.name = FOO tst. num_testsuites = FOO tst.time = FOO tst.result_id = result.id tst.save()更改结果字段，然后执行迁移：

result = models.OneToOneField(Result)

你应该好好去。

定义多个模型之间的关系 - Django

1 个答案: