问无法使用arduino连接到数据库服务器以发送某些数据

EN

if (conn.connect(server_addr, 3306, user, password)) 
    { Serial.println("Connecting to database server...");
      delay(1000);     
      // Initiate the query class instance
      MySQL_Cursor *cur_mem = new MySQL_Cursor(&conn);    
      dtostrf(voltage, 6, 2, voltageNew);
      dtostrf(current, 6, 4, currentNew);     
      sprintf(querymessuremnt, INSERT_measurements,voltageNew, currentNew);

      // Execute the query 
      cur_mem->execute(querybuffer);
      delete cur_mem;
      Serial.println("Data recorded.");
    }
    else   
    Serial.println("Connection to DB failed.");
    conn.close(); 
}