4 files changed, 10 insertions, 5 deletions
diff --git a/src/DevHive.Data/Models/Language.cs b/src/DevHive.Data/Models/Language.cs
index 2983107..f2b2786 100644
--- a/src/DevHive.Data/Models/Language.cs
+++ b/src/DevHive.Data/Models/Language.cs
@@ -1,4 +1,5 @@
 using System;
+using System.Collections.Generic;
 using DevHive.Data.Interfaces.Models;
 
 namespace DevHive.Data.Models
@@ -7,5 +8,6 @@ namespace DevHive.Data.Models
 	{
 		public Guid Id { get; set; }
 		public string Name { get; set; }
+		public HashSet<User> Users { get; set; }
 	}
 }
diff --git a/src/DevHive.Data/Models/Role.cs b/src/DevHive.Data/Models/Role.cs
index e63f007..e0855aa 100644
--- a/src/DevHive.Data/Models/Role.cs
+++ b/src/DevHive.Data/Models/Role.cs
@@ -12,6 +12,6 @@ namespace DevHive.Data.Models
 		public const string DefaultRole = "User";
 		public const string AdminRole = "Admin";
 
-		public List<User> Users { get; set; }
+		public HashSet<User> Users { get; set; }
 	}
 }
diff --git a/src/DevHive.Data/Models/Technology.cs b/src/DevHive.Data/Models/Technology.cs
index 36cec32..a0728d5 100644
--- a/src/DevHive.Data/Models/Technology.cs
+++ b/src/DevHive.Data/Models/Technology.cs
@@ -1,4 +1,5 @@
 using System;
+using System.Collections.Generic;
 using DevHive.Data.Interfaces.Models;
 
 namespace DevHive.Data.Models
@@ -7,5 +8,6 @@ namespace DevHive.Data.Models
 	{
 		public Guid Id { get; set; }
 		public string Name { get; set; }
+		public HashSet<User> Users { get; set; }
 	}
 }
diff --git a/src/DevHive.Data/Models/User.cs b/src/DevHive.Data/Models/User.cs
index 64e138f..2ac7adf 100644
--- a/src/DevHive.Data/Models/User.cs
+++ b/src/DevHive.Data/Models/User.cs
@@ -18,15 +18,16 @@ namespace DevHive.Data.Models
 		/// <summary>
 		/// Languages that the user uses or is familiar with
 		/// </summary>
-		public IList<Language> Languages { get; set; }
+		// [Unique]
+		public HashSet<Language> Languages { get; set; }
 
 		/// <summary>
 		/// Technologies that the user uses or is familiar with
 		/// </summary>
-		public IList<Technology> Technologies { get; set; }
+		public HashSet<Technology> Technologies { get; set; } = new HashSet<Technology>();
 
-		public IList<Role> Roles { get; set; } = new List<Role>();
+		public HashSet<Role> Roles { get; set; } = new HashSet<Role>();
 
-		public IList<User> Friends { get; set; } = new List<User>();
+		public HashSet<User> Friends { get; set; } = new HashSet<User>();
 	}
 }