diff --git a/src/main/java/de/anxietyprime/swajodel/JodelPost.java b/src/main/java/de/anxietyprime/swajodel/JodelPost.java
index 78a0c55..5ab98b5 100644
--- a/src/main/java/de/anxietyprime/swajodel/JodelPost.java
+++ b/src/main/java/de/anxietyprime/swajodel/JodelPost.java
@@ -83,7 +83,7 @@ public class JodelPost {
         this.content = rs.getString("content");
         this.date = rs.getTimestamp("postdate");
         this.location = new Location(rs.getFloat("longitude"), rs.getFloat("latitude"));
-        this.reaction = Optional.of(rs.getBoolean("reaction"));
+        this.reaction = rs.getString("reaction") == null ? Optional.empty() : Optional.of(rs.getBoolean("reaction"));
         this.reactions = new Reactions(rs.getLong("positive"), rs.getLong("negative"));
         this.parent = Optional.of(rs.getLong("parent"));
     }
@@ -99,7 +99,7 @@ public class JodelPost {
 		     @JsonProperty("date") Timestamp date,
 		     @JsonProperty("location") Location location,
              @JsonProperty("parent") Optional<Long> parent) {
-	this.authorID = User.getUserID(); // TODO: getter from Keycloak
+	this.authorID = User.getID(); // TODO: getter from Keycloak
 	this.title = title;
 	this.content = content;
 	this.date = date;
diff --git a/src/main/java/de/anxietyprime/swajodel/Routes.java b/src/main/java/de/anxietyprime/swajodel/Routes.java
index 0e21782..9d10f5a 100644
--- a/src/main/java/de/anxietyprime/swajodel/Routes.java
+++ b/src/main/java/de/anxietyprime/swajodel/Routes.java
@@ -19,7 +19,7 @@ public class Routes {
         Vector<JodelPost> posts = new Vector<>();
 
         // get UserID
-        Long userID = User.getUserID();
+        Long userID = User.getID();
 
         // DB connection and statement
         Connection c;
@@ -135,7 +135,7 @@ public class Routes {
         Optional<JodelPost> root_post = Optional.empty();
 
         // get UserID
-        Long userID = User.getUserID();
+        Long userID = User.getID();
 
         // DB connection and statement
         Connection c;
@@ -316,6 +316,65 @@ public class Routes {
         return post;
     }
 
+    @PatchMapping("/post/{id}")
+    public void reactToPost(@PathVariable long id, @RequestBody Optional<Boolean> reaction) {
+        long userID = User.getID();
+
+        // DB connection and statement
+        Connection c;
+        PreparedStatement stmt;
+
+        // try to get data from db
+        try {
+            // check for the driver
+            Class.forName("org.postgresql.Driver");
+            // get the connection with credentials from env variables
+            c = DriverManager
+                    .getConnection("jdbc:postgresql://"+
+                                    System.getenv("POSTGRES_IP")+"/"+System.getenv("POSTGRES_DB"),
+                            System.getenv("POSTGRES_USER"), System.getenv("POSTGRES_PASSWORD"));
+            // disable auto commits
+            c.setAutoCommit(false);
+
+            // create a new statement
+            stmt = c.prepareStatement("UPDATE Reactions SET positive = (?) WHERE post = (?) AND userid = (?) RETURNING id, positive");
+
+            stmt.setObject(1, reaction.orElse(null));
+            stmt.setObject(2, id);
+            stmt.setObject(3, userID);
+
+            // insert post and get its id
+            ResultSet rs = stmt.executeQuery();
+
+            // check if there is a parent
+            if (!rs.next()) {
+                // create a new statement
+                stmt = c.prepareStatement("INSERT INTO Reactions(userid, post, positive) VALUES ((?), (?), (?))");
+
+                // fill statement
+                stmt.setObject(1, userID);
+                stmt.setObject(2, id);
+                stmt.setObject(3, reaction.orElse(null));
+
+                // execute statement
+                stmt.execute();
+            }
+
+            // commit the changes
+            c.commit();
+
+            // close all connections to db
+            stmt.close();
+            c.close();
+        }
+
+        // else log the error
+        catch ( Exception e ) {
+            System.err.println( e.getClass().getName()+": "+ e.getMessage() );
+            throw new ResponseStatusException(HttpStatus.SERVICE_UNAVAILABLE, "Database is offline");
+        }
+    }
+
     @DeleteMapping("/post/{id}")
     public void deletePost(@PathVariable long id) {
         // DB connection and statement
@@ -338,7 +397,7 @@ public class Routes {
             stmt = c.prepareStatement("UPDATE Posts SET deleted = now() WHERE id = ? AND author = (?) AND deleted IS NULL");
 
             stmt.setObject(1, id);
-            stmt.setObject(2, User.getUserID());
+            stmt.setObject(2, User.getID());
 
             // insert delete time
             stmt.execute();
diff --git a/src/main/java/de/anxietyprime/swajodel/User.java b/src/main/java/de/anxietyprime/swajodel/User.java
index ea33422..f9fd9b3 100644
--- a/src/main/java/de/anxietyprime/swajodel/User.java
+++ b/src/main/java/de/anxietyprime/swajodel/User.java
@@ -14,9 +14,9 @@ public class User {
         return SecurityContextHolder.getContext().getAuthentication().getName();
     }
 
-    static public Long getUserID () {
+    static public Long getID() {
         String uuid = SecurityContextHolder.getContext().getAuthentication().getName();
-        Long id = -1L;
+        long id;
 
         // DB connection and statement
         Connection c;