diff --git a/.gitignore b/.gitignore
index 1b1a367..ee01dda 100644
--- a/.gitignore
+++ b/.gitignore
@@ -136,3 +136,6 @@ gradle-app.setting
 
 # # Work around https://youtrack.jetbrains.com/issue/IDEA-116898
 # gradle/wrapper/gradle-wrapper.properties
+
+# IntelliJ
+*.iml
\ No newline at end of file
diff --git a/backend.iml b/backend.iml
deleted file mode 100644
index 1eae0df..0000000
--- a/backend.iml
+++ /dev/null
@@ -1,12 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<module version="4">
-  <component name="NewModuleRootManager" inherit-compiler-output="true">
-    <exclude-output />
-    <content url="file://$MODULE_DIR$">
-      <excludeFolder url="file://$MODULE_DIR$/.gradle" />
-      <excludeFolder url="file://$MODULE_DIR$/build" />
-    </content>
-    <orderEntry type="inheritedJdk" />
-    <orderEntry type="sourceFolder" forTests="false" />
-  </component>
-</module>
\ No newline at end of file
diff --git a/src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/models/Device.java b/src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/models/Device.java
index 7aa65e8..e8a621b 100644
--- a/src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/models/Device.java
+++ b/src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/models/Device.java
@@ -30,7 +30,7 @@ public abstract class Device {
      * The room this device belongs in, as a foreign key id. To use when updating and inserting from
      * a REST call.
      */
-    @Column(name = "room_id", nullable = false)
+    @Column(name = "room_id", nullable = false, unique = true)
     @NotNull
     private Long roomId;
 
diff --git a/src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/models/Room.java b/src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/models/Room.java
index c5b196a..e54b462 100644
--- a/src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/models/Room.java
+++ b/src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/models/Room.java
@@ -111,7 +111,7 @@ public class Room {
 
     @Id
     @GeneratedValue(strategy = GenerationType.AUTO)
-    @Column(name = "id", updatable = false, nullable = false)
+    @Column(name = "id", updatable = false, nullable = false, unique = true)
     @ApiModelProperty(hidden = true)
     private Long id;
 
@@ -133,7 +133,7 @@ public class Room {
      * inserting from a REST call.
      */
     @NotNull
-    @Column(name = "user_id", nullable = false)
+    @Column(name = "user_id", nullable = false, unique = true)
     private Long userId;
 
     /** The user given name of this room (e.g. 'Master bedroom') */
diff --git a/src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/models/User.java b/src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/models/User.java
index ba86712..f1b88ca 100644
--- a/src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/models/User.java
+++ b/src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/models/User.java
@@ -9,7 +9,7 @@ public class User {
 
     @Id
     @GeneratedValue(strategy = GenerationType.AUTO)
-    @Column(name = "id", updatable = false, nullable = false)
+    @Column(name = "id", updatable = false, nullable = false, unique = true)
     @ApiModelProperty(hidden = true)
     private Long id;
 
@@ -17,8 +17,8 @@ public class User {
     @Column(nullable = false)
     private String name;
 
-    /** The full name of the user */
-    @Column(nullable = false)
+    /** The full username of the user */
+    @Column(nullable = false, unique = true)
     private String username;
 
     /** A properly salted way to store the password */