support display id

contest/migrations/0002_auto_20170209_0845.py

@@ -0,0 +1,29 @@
+# -*- coding: utf-8 -*-
+# Generated by Django 1.9.12 on 2017-02-09 08:45
+from __future__ import unicode_literals
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('contest', '0001_initial'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='contestproblem',
+            name='_id',
+            field=models.CharField(db_index=True, default='1', max_length=24),
+            preserve_default=False,
+        ),
+        migrations.RemoveField(
+            model_name='contestproblem',
+            name='sort_index',
+        ),
+        migrations.AlterUniqueTogether(
+            name='contestproblem',
+            unique_together=set([('_id', 'contest')]),
+        ),
+    ]

contest/models.py

@@ -62,14 +62,14 @@ class Contest(models.Model):
 
 
 class ContestProblem(AbstractProblem):
+    _id = models.CharField(max_length=24, db_index=True)
     contest = models.ForeignKey(Contest)
-    # 比如A B 或者1 2 或者 a b 将按照这个排序
-    sort_index = models.CharField(max_length=30)
     # 是否已经公开了题目，防止重复公开
     is_public = models.BooleanField(default=False)
 
     class Meta:
         db_table = "contest_problem"
+        unique_together = (("_id", "contest"), )
 
 
 class ContestRank(models.Model):