diff --git a/src/main/java/database/DatabaseHelper.java b/src/main/java/database/DatabaseHelper.java
index 7ae4616..61120c2 100644
--- a/src/main/java/database/DatabaseHelper.java
+++ b/src/main/java/database/DatabaseHelper.java
@@ -10,6 +10,7 @@ public class DatabaseHelper {
     private static final String DATABASE_PWD = "vHEQszGXcJ6;/)}z!V";
     private final static String DATABASE_URL = "jdbc:postgresql://37.187.101.44:5432/"+DATABASE_NAME;
 
+
     public ConnectionSource setupDatabaseConnection(){
         try{
             return new JdbcConnectionSource(DATABASE_URL, DATABASE_USER, DATABASE_PWD);
diff --git a/src/main/java/database/Wallet/WalletDao.java b/src/main/java/database/Wallet/WalletDao.java
index c4cd4b8..c433aa3 100644
--- a/src/main/java/database/Wallet/WalletDao.java
+++ b/src/main/java/database/Wallet/WalletDao.java
@@ -16,23 +16,26 @@ import java.util.List;
 public class WalletDao {
     private DatabaseHelper dbh = new DatabaseHelper();
     private Dao<Wallet, String> walletDao;
-
-    private Dao createWalletDaoConnection(){
+    private boolean sessionOpen = false;
+    private void createWalletDaoConnection(){
         try {
-            return DaoManager.createDao(dbh.setupDatabaseConnection(),Wallet.class);
+            if(!sessionOpen){
+                walletDao = DaoManager.createDao(dbh.setupDatabaseConnection(),Wallet.class);
+                sessionOpen=true;
+            }
+
         }catch (Exception e){
-            System.out.println(e.getMessage());
-            return null;
+            e.printStackTrace();
         }
     }
 
     public void addWallet(Wallet wallet)throws Exception {
-        walletDao = createWalletDaoConnection();
+        createWalletDaoConnection();
         walletDao.create(wallet);
     }
 
     public Wallet getWallet(String walletHash) throws Exception {
-        walletDao = createWalletDaoConnection();
+        createWalletDaoConnection();
         QueryBuilder<Wallet, String> queryBuilder = walletDao.queryBuilder();
         queryBuilder.where().eq("wallet_hash",walletHash).and().eq("is_active",true);
         PreparedQuery<Wallet> preparedQuery = queryBuilder.prepare();
@@ -40,8 +43,7 @@ public class WalletDao {
     }
 
     public void updateWalletBalance(String walletHash, double newBalance) throws Exception {
-
-        walletDao = createWalletDaoConnection();
+        createWalletDaoConnection();
         UpdateBuilder<Wallet, String> updateBuilder = walletDao.updateBuilder();
         long now = Instant.now().toEpochMilli();
         updateBuilder.updateColumnValue("balance",newBalance);
@@ -51,7 +53,7 @@ public class WalletDao {
     }
 
     public List<Wallet> getUserWallet(String userHash) throws Exception {
-        walletDao = createWalletDaoConnection();
+        createWalletDaoConnection();
         QueryBuilder<Wallet, String> queryBuilder = walletDao.queryBuilder();
         queryBuilder.where().eq("user_hash",userHash).and().eq("is_active",true);
         PreparedQuery<Wallet> preparedQuery = queryBuilder.prepare();
@@ -59,7 +61,7 @@ public class WalletDao {
     }
 
     public List<Wallet> getUserOldWallets(String userHash) throws Exception{
-        walletDao = createWalletDaoConnection();
+        createWalletDaoConnection();
         QueryBuilder<Wallet, String> queryBuilder = walletDao.queryBuilder();
         queryBuilder.where().eq("user_hash",userHash).and().eq("is_active",false);
         PreparedQuery<Wallet> preparedQuery = queryBuilder.prepare();
@@ -67,7 +69,7 @@ public class WalletDao {
     }
 
     public void transferWallet(String walletHash, String newUserHash) throws Exception{
-        walletDao = createWalletDaoConnection();
+        createWalletDaoConnection();
         UpdateBuilder<Wallet, String> updateBuilder = walletDao.updateBuilder();
         updateBuilder.updateColumnValue("user_hash",newUserHash);
         long now = Instant.now().toEpochMilli();
@@ -77,7 +79,7 @@ public class WalletDao {
     }
 
     public void deleteWallet(String walletHash, String userHash) throws Exception{
-        walletDao = createWalletDaoConnection();
+        createWalletDaoConnection();
         UpdateBuilder<Wallet, String> updateBuilder = walletDao.updateBuilder();
         updateBuilder.updateColumnValue("is_active",false);
         long now = Instant.now().toEpochMilli();
diff --git a/src/main/java/database/session/SessionDao.java b/src/main/java/database/session/SessionDao.java
index e415d0d..8473c39 100644
--- a/src/main/java/database/session/SessionDao.java
+++ b/src/main/java/database/session/SessionDao.java
@@ -9,24 +9,27 @@ import java.time.Instant;
 public class SessionDao {
     private DatabaseHelper dbh = new DatabaseHelper();
     private Dao<Session, String> sessionDao;
-
-    private Dao createSessionDaoConnection(){
+    private boolean sessionOpen = false;
+    private void createSessionDaoConnection(){
         try {
-            return DaoManager.createDao(dbh.setupDatabaseConnection(),Session.class);
+            if(!sessionOpen){
+                sessionDao = DaoManager.createDao(dbh.setupDatabaseConnection(),Session.class);
+                sessionOpen=true;
+            }
+
         }catch (Exception e){
-            System.out.println(e.getMessage());
-            return null;
+            e.printStackTrace();
         }
     }
 
     public int setStartSession(Session session) throws Exception {
-        sessionDao = createSessionDaoConnection();
+        createSessionDaoConnection();
         sessionDao.create(session);
         return session.getSession_id();
     }
 
     public void setEndSession(int session_id) throws Exception {
-        sessionDao = createSessionDaoConnection();
+        createSessionDaoConnection();
         UpdateBuilder<Session,String> updateBuilder = sessionDao.updateBuilder();
         long now = Instant.now().toEpochMilli();
         updateBuilder.updateColumnValue("end_session",now);
diff --git a/src/main/java/database/transaction/TransactionDao.java b/src/main/java/database/transaction/TransactionDao.java
index 42cf198..c55d65e 100644
--- a/src/main/java/database/transaction/TransactionDao.java
+++ b/src/main/java/database/transaction/TransactionDao.java
@@ -11,33 +11,25 @@ import java.util.List;
 public class TransactionDao {
     private DatabaseHelper dbh = new DatabaseHelper();
     private Dao<Transaction, String> transactionDao;
-
-    private Dao createTransactionDaoConnection(){
+    private boolean sessionOpen = false;
+    private void createTransactionDaoConnection(){
         try {
-            return DaoManager.createDao(dbh.setupDatabaseConnection(),Transaction.class);
+            if(!sessionOpen){
+                transactionDao = DaoManager.createDao(dbh.setupDatabaseConnection(),Transaction.class);
+                sessionOpen=true;
+            }
         }catch (Exception e){
-            System.out.println(e.getMessage());
-            return null;
+            e.printStackTrace();
         }
     }
 
     public void addTransaction(Transaction transaction)throws Exception{
-        transactionDao = createTransactionDaoConnection();
+        createTransactionDaoConnection();
         transactionDao.create(transaction);
     }
 
     public List<Transaction> getWalletTransactions(String wallet_hash)throws Exception{
-        transactionDao = createTransactionDaoConnection();
-        QueryBuilder<Transaction, String> queryBuilder = transactionDao.queryBuilder();
-        queryBuilder.where().eq("transaction_from",wallet_hash).or().eq("transaction_to",wallet_hash);
-        queryBuilder.orderBy("transaction_date",false);
-        PreparedQuery<Transaction> preparedQuery = queryBuilder.prepare();
-        return transactionDao.query(preparedQuery);
-    }
-
-    /*
-    public List<Transaction> getTenLastUserTransactions(String wallet_hash)throws Exception{
-        transactionDao = createTransactionDaoConnection();
+        createTransactionDaoConnection();
         QueryBuilder<Transaction, String> queryBuilder = transactionDao.queryBuilder();
         queryBuilder.where().eq("transaction_from",wallet_hash).or().eq("transaction_to",wallet_hash);
         queryBuilder.limit(new Long(10));
@@ -45,10 +37,9 @@ public class TransactionDao {
         PreparedQuery<Transaction> preparedQuery = queryBuilder.prepare();
         return transactionDao.query(preparedQuery);
     }
-    */
 
     public Transaction getTransaction(String wallet_hash, String transaction_hash)throws Exception{
-        transactionDao = createTransactionDaoConnection();
+        createTransactionDaoConnection();
         QueryBuilder<Transaction, String> queryBuilder = transactionDao.queryBuilder();
         queryBuilder.where().eq("transaction_to",wallet_hash).or().eq("transaction_from",wallet_hash).and().eq("transaction_hash",transaction_hash);
         PreparedQuery<Transaction> preparedQuery = queryBuilder.prepare();
@@ -56,7 +47,7 @@ public class TransactionDao {
     }
 
     public List<Transaction> getUserSentTransaction(String wallet_hash)throws Exception{
-        transactionDao = createTransactionDaoConnection();
+        createTransactionDaoConnection();
         QueryBuilder<Transaction, String> queryBuilder = transactionDao.queryBuilder();
         queryBuilder.where().eq("transaction_from",wallet_hash);
         queryBuilder.orderBy("transaction_date",false);
@@ -65,7 +56,7 @@ public class TransactionDao {
     }
 
     public List<Transaction> getUserReceivedTransaction(String wallet_hash)throws Exception{
-        transactionDao = createTransactionDaoConnection();
+        createTransactionDaoConnection();
         QueryBuilder<Transaction, String> queryBuilder = transactionDao.queryBuilder();
         queryBuilder.where().eq("transaction_to",wallet_hash);
         queryBuilder.orderBy("transaction_date",false);
@@ -73,5 +64,4 @@ public class TransactionDao {
         return transactionDao.query(preparedQuery);
     }
 
-
 }
diff --git a/src/main/java/database/user/UserDao.java b/src/main/java/database/user/UserDao.java
index 0fd7d77..8369d91 100644
--- a/src/main/java/database/user/UserDao.java
+++ b/src/main/java/database/user/UserDao.java
@@ -12,24 +12,26 @@ import java.time.Instant;
 //Class to communicate with database with ORMLite
 public class UserDao {
     private DatabaseHelper dbh = new DatabaseHelper();
-    private Dao createUserDaoConnection(){
+    private boolean sessionOpen = false;
+    private Dao<User, String> userDao ;
+    private void createUserDaoConnection(){
         try {
-            return DaoManager.createDao(dbh.setupDatabaseConnection(),User.class);
+            if(!sessionOpen){
+                userDao = DaoManager.createDao(dbh.setupDatabaseConnection(),User.class);
+                sessionOpen = true;
+            }
         }catch (Exception e){
-            System.out.println(e.getMessage());
-            return null;
+            e.printStackTrace();
         }
     }
 
     public void addUser(User user)throws Exception {
-        Dao<User, String> userDao;
-        userDao = createUserDaoConnection();
+        createUserDaoConnection();
         userDao.create(user);
     }
 
     public boolean checkApprovedUser(String email) throws Exception {
-        Dao<User, String> userDao;
-        userDao = createUserDaoConnection();
+        createUserDaoConnection();
         QueryBuilder<User, String> queryBuilder = userDao.queryBuilder();
         queryBuilder.where().eq("email",email);
         PreparedQuery<User> preparedQuery = queryBuilder.prepare();
@@ -38,8 +40,7 @@ public class UserDao {
     }
 
     public boolean checkVerifiedUser(String email) throws Exception {
-        Dao<User, String> userDao;
-        userDao = createUserDaoConnection();
+        createUserDaoConnection();
         QueryBuilder<User, String> queryBuilder = userDao.queryBuilder();
         queryBuilder.where().eq("email",email);
         PreparedQuery<User> preparedQuery = queryBuilder.prepare();
@@ -48,8 +49,7 @@ public class UserDao {
     }
 
     public boolean updateUserPassword(String email, String password) throws Exception {
-        Dao<User, String> userDao;
-        userDao = createUserDaoConnection();
+        createUserDaoConnection();
         UpdateBuilder<User, String> updateBuilder = userDao.updateBuilder();
         updateBuilder.updateColumnValue("password",password);
         long now = Instant.now().toEpochMilli();
@@ -65,16 +65,14 @@ public class UserDao {
     }
 
     public void deleteUser(String email) throws Exception {
-        Dao<User, String> userDao;
-        userDao = createUserDaoConnection();
+        createUserDaoConnection();
         DeleteBuilder<User, String> deleteBuilder = userDao.deleteBuilder();
         deleteBuilder.where().eq("email",email);
         deleteBuilder.delete();
     }
 
     public boolean verifyUserExist(String email) throws Exception {
-        Dao<User, String> userDao;
-        userDao = createUserDaoConnection();
+        createUserDaoConnection();
         QueryBuilder<User, String> queryBuilder = userDao.queryBuilder();
         queryBuilder.where().eq("email",email);
         PreparedQuery<User> preparedQuery = queryBuilder.prepare();
@@ -88,6 +86,7 @@ public class UserDao {
     }
 
     public boolean checkUserPassword(String email, String password) throws Exception {
+        createUserDaoConnection();
         User user = getUserWithEmail(email);
         if(password.equals(user.getPassword())){
             return true;
@@ -97,11 +96,10 @@ public class UserDao {
     }
 
     public User getUserWithEmail(String email) throws Exception {
-        Dao<User, String> userDao;
+        createUserDaoConnection();
         if(!verifyUserExist(email)){
             return null;
         }else{
-            userDao = createUserDaoConnection();
             QueryBuilder<User, String> queryBuilder = userDao.queryBuilder();
             queryBuilder.where().eq("email",email);
             PreparedQuery<User> preparedQuery = queryBuilder.prepare();
@@ -110,8 +108,7 @@ public class UserDao {
     }
 
     public User getUserWithPhone(String phone) throws Exception {
-        Dao<User, String> userDao;
-        userDao = createUserDaoConnection();
+        createUserDaoConnection();
         QueryBuilder<User, String> queryBuilder = userDao.queryBuilder();
         queryBuilder.where().eq("phone",phone);
         PreparedQuery<User> preparedQuery = queryBuilder.prepare();
@@ -119,8 +116,7 @@ public class UserDao {
     }
 
     public User getUserWithMailAndPhone(String email, String phone) throws Exception {
-        Dao<User, String> userDao;
-        userDao = createUserDaoConnection();
+        createUserDaoConnection();
         QueryBuilder<User, String> queryBuilder = userDao.queryBuilder();
         queryBuilder.where().eq("email",email).and().eq("phone",phone);
         PreparedQuery<User> preparedQuery = queryBuilder.prepare();
@@ -128,8 +124,7 @@ public class UserDao {
     }
 
     public User getUserWithHash(String userHash) throws Exception {
-        Dao<User, String> userDao;
-        userDao = createUserDaoConnection();
+        createUserDaoConnection();
         QueryBuilder<User,String> queryBuilder = userDao.queryBuilder();
         queryBuilder.where().eq("user_hash",userHash);
         PreparedQuery<User> preparedQuery = queryBuilder.prepare();
@@ -137,8 +132,7 @@ public class UserDao {
     }
 
     public int getUserIdWithHashAndEmail(String userHash, String userEmail) throws Exception {
-        Dao<User, String> userDao;
-        userDao = createUserDaoConnection();
+        createUserDaoConnection();
         QueryBuilder<User,String> queryBuilder = userDao.queryBuilder();
         queryBuilder.where().eq("user_hash",userHash).and().eq("email",userEmail);
         PreparedQuery<User> preparedQuery = queryBuilder.prepare();
@@ -147,8 +141,7 @@ public class UserDao {
     }
 
     public void approveUser (String email) throws Exception {
-        Dao<User, String> userDao;
-        userDao = createUserDaoConnection();
+        createUserDaoConnection();
         UpdateBuilder<User, String> updateBuilder = userDao.updateBuilder();
         updateBuilder.updateColumnValue("approved",true);
         long now = Instant.now().toEpochMilli();
@@ -158,8 +151,7 @@ public class UserDao {
     }
 
     public void verifyUser (String email) throws Exception{
-        Dao<User, String> userDao;
-        userDao = createUserDaoConnection();
+        createUserDaoConnection();
         UpdateBuilder<User, String> updateBuilder = userDao.updateBuilder();
         updateBuilder.updateColumnValue("verified",true);
         long now = Instant.now().toEpochMilli();