--- a/server/ammico/models.py	Fri Apr 03 15:02:19 2015 +0200
+++ b/server/ammico/models.py	Fri Apr 03 15:03:04 2015 +0200
@@ -8,7 +8,7 @@
 
 class Book(models.Model):
     user = models.ForeignKey(AmmicoUser, related_name = "books")
-    idArticle = models.CharField(max_length=512, unique=True)
+    idArticle = models.CharField(max_length=512, unique=True, null=True)
     title = models.CharField(max_length=512, blank=True)
     description = models.CharField(max_length=512, blank=True, null=True)
     image = models.URLField(max_length=2048, blank=True)