register done

app/controller/user/UserDb.php

@@ -84,5 +84,34 @@
             }
             return null;
         }
+
+        function isEmailExist($email){
+            $sql = 'SELECT 1 from user WHERE email=?';
+            $stmt = $this->conn->prepare($sql);
+
+            if ($stmt->execute([$email])){
+                if (count($stmt->fetchAll()) == 0) {
+                    return false;
+                } else {
+                    return true;
+                }
+            } 
+
+            return false;
+        }
+
+        function isUsernameExist($username){
+            $sql = 'SELECT 1 from user WHERE username=?';
+            $stmt = $this->conn->prepare($sql);
+
+            if ($stmt->execute([$username])){
+                if (count($stmt->fetchAll()) == 0) {
+                    return false;
+                } else {
+                    return true;
+                }
+            }
+            return false;
+        }
     }
 ?>
\ No newline at end of file