创建新工程 添加了一些通用代码和数据库模型

problem/models.py

@@ -0,0 +1,19 @@
+# coding=utf-8
+from django.db import models
+
+from account.models import User
+
+
+class AbstractProblem(models.Model):
+
+    class Meta:
+        abstract = True
+
+
+class Problem(AbstractProblem):
+    pass
+
+
+class Solution(models.Model):
+    user = models.ForeignKey(User)
+    problem = models.ForeignKey(Problem)