From e685a35d19861f8ae4f11d23a72008f36c5ec5e6 Mon Sep 17 00:00:00 2001
From: Midgard <midgard@zeus.ugent.be>
Date: Wed, 22 Jul 2020 16:16:33 +0200
Subject: [PATCH] Only one registration for you

---
 events/models.py | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/events/models.py b/events/models.py
index 754ebd8..dabbbfc 100644
--- a/events/models.py
+++ b/events/models.py
@@ -46,6 +46,15 @@ class EventRegistration(models.Model):
     user = models.ForeignKey(CustomUser, on_delete=models.CASCADE)
     state = models.CharField(max_length=1, choices=REGISTRATION_STATE.items())
 
+
+    class Meta:
+        constraints = [
+            models.UniqueConstraint(
+                fields=["event", "user"], name="user can only register once per event"
+            )
+        ]
+
+
     def __str__(self):
         return f"Reservation[{self.user.username}:{self.event.date}:{self.state}]"