Fix reference empty guid

GerbilManagerWebAPI/Dtos/CreateGerbilDto.cs

@@ -4,8 +4,8 @@ namespace GerbilManagerWebAPI.Dtos
     {
         public required string Name { get; init; }
         public required GenderDto Gender { get; init; }
-        public Guid? Litter { get; init; }
+        public Guid Litter { get; init; }
-        public Guid? Breeder { get; init; }
+        public Guid Breeder { get; init; }
     }
     
 }

GerbilManagerWebAPI/Dtos/CreateLitterDto.cs

@@ -5,7 +5,7 @@ namespace GerbilManagerWebAPI.Dtos
         public required string Name { get; init; }
         public required DateTime Date { get; init; }
         public int? Strength { get; init; }
-        public Guid? Father { get; init; }
+        public Guid Father { get; init; }
-        public Guid? Mother { get; init; }
+        public Guid Mother { get; init; }
     }
 }

README.md

@@ -9,4 +9,8 @@ docker compose up
 ## Create the initial database
 dotnet ef database update
 ## Create an migration script
-dotnet ef migrations add <name>
+dotnet ef migrations add <name>
+
+
+TODO:
+Backup docker volume database