Add unique together for model

chat_box/migrations/0010_auto_20221028_0300.py

@@ -0,0 +1,18 @@
+# Generated by Django 2.2.25 on 2022-10-27 20:00
+
+from django.db import migrations
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('judge', '0135_auto_20221028_0300'),
+        ('chat_box', '0009_auto_20220618_1452'),
+    ]
+
+    operations = [
+        migrations.AlterUniqueTogether(
+            name='userroom',
+            unique_together={('user', 'room')},
+        ),
+    ]

chat_box/models.py

@@ -55,6 +55,8 @@ class UserRoom(models.Model):
     )
     last_seen = models.DateTimeField(verbose_name=_("last seen"), auto_now_add=True)
 
+    class Meta:
+        unique_together = ("user", "room")
 
 class Ignore(models.Model):
     user = models.OneToOneField(