diff --git a/example/example copy.db b/example/example copy.db
deleted file mode 100644
index 15a87b0..0000000
Binary files a/example/example copy.db and /dev/null differ
diff --git a/lib/sql3.hpp b/lib/sql3.hpp
index 37762d4..738dc34 100644
--- a/lib/sql3.hpp
+++ b/lib/sql3.hpp
@@ -10,6 +10,7 @@
 #include <map>
 // #include <algorithm>
 #include <iostream>
+#include <mutex>
 
 using namespace std;
 
@@ -24,15 +25,13 @@ class sql3 {
     bool keepOpen;
     string Answer;
     map<string, vector<string>> parsed;
+    mutex io;
     
     sql3(const string path, bool _keepOpen = false);
     bool open();
     bool close();
-    bool run(const string sql_command);
-    string answer();
     void mapit();
 
-    string ask(const string sql_command);
     map<string, vector<string>> query(const string sql_command);
     
     ~sql3();
diff --git a/src/sql3.cpp b/src/sql3.cpp
index d1dd704..04f09ff 100644
--- a/src/sql3.cpp
+++ b/src/sql3.cpp
@@ -23,10 +23,11 @@ bool sql3::close() {
    return operationStatus != SQLITE_OK;
 }
 
-bool sql3::run(const string sql_command) {
-
+map<string, vector<string>> sql3::query(const string sql_command) {
+   io.lock();
    if (!keepOpen) {
       if (open()) {
+         io.unlock();
          throw string("[ERROR] Unable to open database ");
       }
    }
@@ -37,7 +38,6 @@ bool sql3::run(const string sql_command) {
    exec_stuts = sqlite3_exec(db, sql_command.c_str(), callback, NULL, &messaggeError);
 
    if (exec_stuts != SQLITE_OK) {
-      // printf("[ERROR] Ne mogu čitati bazu podataka!");
       sqlite3_free(messaggeError);
       r = false;
    }
@@ -48,40 +48,25 @@ bool sql3::run(const string sql_command) {
 
    if (!keepOpen) {
       if(close()) {
+         io.unlock();
          throw string("[ERROR] Unable to close database ");
       }
    }
 
-   return r;
-}
-
-string sql3::answer() {
-   string _Answer = Answer;
-   Answer.clear();
-   return _Answer;
-}
+   map<string, vector<string>> _parsed;
 
-string sql3::ask(const string sql_command) {
-   if (!run(sql_command)) {
+   if (!r) {
+      io.unlock();
       throw string("[ERROR] Unable to read database ");
-      //return {};
    }
-   else {
-      return answer();
-   }
-}
 
-map<string, vector<string>> sql3::query(const string sql_command) {
-   if (!run(sql_command)) {
-      throw string("[ERROR] Unable to read database ");
-      //return {};
-   }
    else {
       mapit();
-      map<string, vector<string>> _parsed = parsed;
+      _parsed = parsed;
       parsed.clear();
-      return _parsed;
    }
+   io.unlock();
+   return _parsed;
 }
 
 void sql3::mapit() {
diff --git a/test/test.cpp b/test/test.cpp
index 85c864a..b97e378 100644
--- a/test/test.cpp
+++ b/test/test.cpp
@@ -5,21 +5,27 @@
 using namespace std;
 
 int main() {
+    try {
 
-    sql3 mydb("../example/example.db", false);
+    sql3 mydb("../example/example_copy.db", false);
 
     // cout << mydb.ask("Select * from Tab1");
     // cout << mydb.ask("INSERT INTO Tab1 VALUES(3,'Pakora', 'marijanab@bitelex.ml');");
 
-    // auto res = mydb.query("Select * from Tab1");
-    auto res = mydb.query("INSERT INTO Tab1 VALUES(4,'Mare', 'marijanab@bitelex.co');");
+    auto res = mydb.query("Select * from Tab1");
+    // cout << endl <<  res["NAME"][1];
 
-    // for (auto i : res) 
-    //     for (auto j: i.second)
-    //         cout << i.first << " : " << j << endl;
-    
+    // cout << endl <<  res["MAIL"][1];
 
-    // cout << endl <<  res["NAME"][1];
+    for (auto i : res) {
+        for (auto j: i.second) {
+            cout << i.first << " : " << j << endl; 
+        }
+    }
+
+    } catch (const string err) {
+        cout << err << endl;
+    }
 
     return 0;
 }
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