将announcement 加入 setings.py 里面的 INSTALLED_APPS，并且创建announcement这张表

announcement/migrations/0001_initial.py

@@ -0,0 +1,29 @@
+# -*- coding: utf-8 -*-
+from __future__ import unicode_literals
+
+from django.db import models, migrations
+from django.conf import settings
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        migrations.swappable_dependency(settings.AUTH_USER_MODEL),
+    ]
+
+    operations = [
+        migrations.CreateModel(
+            name='Announcement',
+            fields=[
+                ('id', models.AutoField(verbose_name='ID', serialize=False, auto_created=True, primary_key=True)),
+                ('title', models.CharField(max_length=50)),
+                ('description', models.TextField()),
+                ('create_time', models.DateTimeField(auto_now_add=True)),
+                ('visible', models.BooleanField(default=True)),
+                ('created_by', models.ForeignKey(to=settings.AUTH_USER_MODEL)),
+            ],
+            options={
+                'db_table': 'announcement',
+            },
+        ),
+    ]

oj/settings.py

@@ -47,6 +47,7 @@ INSTALLED_APPS = (
     'django.contrib.staticfiles',
 
     'account',
+    'announcement',
     'utils',
 
     'rest_framework',