diff --git a/concordia-server/CMakeLists.txt b/concordia-server/CMakeLists.txt
index 6abcb01..548e426 100644
--- a/concordia-server/CMakeLists.txt
+++ b/concordia-server/CMakeLists.txt
@@ -6,6 +6,10 @@ add_executable(concordia_server_process
                   json_generator.cpp
                   unit_dao.cpp
                   db_connection.cpp
+                  query_param.cpp
+                  string_param.cpp
+                  int_param.cpp
+                  logger.cpp
               )
 target_link_libraries(concordia_server_process fcgi fcgi++ pq concordia config++ log4cpp ${Boost_LIBRARIES} divsufsort utf8case)
 
diff --git a/concordia-server/concordia_server.cpp b/concordia-server/concordia_server.cpp
index 4d5f1ac..e7da983 100644
--- a/concordia-server/concordia_server.cpp
+++ b/concordia-server/concordia_server.cpp
@@ -31,7 +31,6 @@ std::string ConcordiaServer::handleRequest(std::string & requestString) {
     rapidjson::Writer<rapidjson::StringBuffer> jsonWriter(outputJson);
 
     std::stringstream outputString;
-
     try {
         outputString << "Content-type: application/json\r\n\r\n";
         rapidjson::Document d;
diff --git a/concordia-server/db_connection.cpp b/concordia-server/db_connection.cpp
index f4bd8c3..5ffaba3 100644
--- a/concordia-server/db_connection.cpp
+++ b/concordia-server/db_connection.cpp
@@ -1,6 +1,11 @@
 #include "db_connection.hpp"
 
+#include <boost/foreach.hpp>
+#include <sstream>
+
+
 #include "config.hpp"
+#include "logger.hpp"
 
 DBconnection::DBconnection() throw(ConcordiaException) {
     std::string connectionInfo = "dbname="DB_NAME" user="DB_USER;
@@ -53,9 +58,12 @@ PGresult * DBconnection::execute(std::string query) throw(ConcordiaException) {
     if (_connection != NULL) {
         PGresult * result = PQexec(_connection, query.c_str());
         if (PQresultStatus(result) != PGRES_COMMAND_OK) {
+            std::stringstream ss;
+            ss << "query execution failed with message: ";
+            ss << PQresultErrorMessage(result) << std::endl;
             PQclear(result);
             close();
-            throw ConcordiaException("ending transaction failed");
+            throw ConcordiaException(ss.str());
         } else {
             return result;
         }
@@ -65,7 +73,42 @@ PGresult * DBconnection::execute(std::string query) throw(ConcordiaException) {
 }
 
 PGresult * DBconnection::execute(std::string query,
-                                 std::vector<std::string> params) throw(ConcordiaException) {
+                                 std::vector<QueryParam*> params) throw(ConcordiaException) {
+    if (_connection != NULL) {
+        const char * paramValues[params.size()];
+        int paramLengths[params.size()];
+        int paramFormats[params.size()];
+        int index = 0;
+        BOOST_FOREACH (QueryParam * param, params) {
+            paramValues[index] = param->getValue();
+            paramLengths[index] = param->getLength();
+            paramFormats[index] = param->isBinary();
+            index++;
+        }
+        
+        
+        PGresult * result = PQexecParams(_connection,
+                                         query.c_str(),
+                                         params.size(),
+                                         NULL,
+                                         paramValues,
+                                         paramLengths,
+                                         paramFormats,
+                                         0
+                            );
+        if (PQresultStatus(result) != PGRES_COMMAND_OK) {
+            std::stringstream ss;
+            ss << "parametrized query execution failed with message: ";
+            ss << PQresultErrorMessage(result) << std::endl;
+            PQclear(result);
+            close();
+            throw ConcordiaException(ss.str());
+        } else {
+            return result;
+        }
+    } else {
+        throw ConcordiaException("requested query execution but the database connection is not ready");
+    }
 }
 
 
diff --git a/concordia-server/db_connection.hpp b/concordia-server/db_connection.hpp
index cf8e7d9..2c04183 100644
--- a/concordia-server/db_connection.hpp
+++ b/concordia-server/db_connection.hpp
@@ -7,6 +7,8 @@
 
 #include <concordia/concordia_exception.hpp>
 
+#include "query_param.hpp"
+
 class DBconnection {
 public:
     /*! Constructor.
@@ -23,7 +25,7 @@ public:
     PGresult * execute(std::string query) throw(ConcordiaException);
 
     PGresult * execute(std::string query,
-                       std::vector<std::string> params) throw(ConcordiaException);
+                       std::vector<QueryParam*> params) throw(ConcordiaException);
 private:
     void close();
     
diff --git a/concordia-server/index_controller.cpp b/concordia-server/index_controller.cpp
index 393dd6c..0506a05 100644
--- a/concordia-server/index_controller.cpp
+++ b/concordia-server/index_controller.cpp
@@ -1,6 +1,5 @@
 #include "index_controller.hpp"
 
-#include <concordia/common/config.hpp>
 #include "json_generator.hpp"
 
 IndexController::IndexController(boost::shared_ptr<Concordia> concordia)
@@ -20,7 +19,7 @@ void IndexController::addSentence(
 
     try {
         boost::shared_ptr<TokenizedSentence> tokenizedSentence = _concordia->tokenize(sourceSentence);
-        SUFFIX_MARKER_TYPE sentenceId = _unitDAO.addSentence(tokenizedSentence, targetSentence, tmId);     
+        int sentenceId = _unitDAO.addSentence(tokenizedSentence, targetSentence, tmId);     
         _concordia->addTokenizedExample(tokenizedSentence, sentenceId);
         _concordia->refreshSAfromRAM();
 
diff --git a/concordia-server/int_param.cpp b/concordia-server/int_param.cpp
new file mode 100644
index 0000000..6d2dfb1
--- /dev/null
+++ b/concordia-server/int_param.cpp
@@ -0,0 +1,23 @@
+#include "int_param.hpp"
+
+#include <netinet/in.h>
+#include <arpa/inet.h>
+
+IntParam::IntParam(int value) {
+    _value = htonl((unsigned long int) value);
+}
+
+IntParam::~IntParam() {
+}
+
+const char * IntParam::getValue() {
+    return (const char *) &_value;
+}
+    
+const int IntParam::getLength() {
+    return sizeof(_value);
+}
+
+const int IntParam::isBinary() {
+    return 1;
+}
diff --git a/concordia-server/int_param.hpp b/concordia-server/int_param.hpp
new file mode 100644
index 0000000..aae6949
--- /dev/null
+++ b/concordia-server/int_param.hpp
@@ -0,0 +1,24 @@
+#ifndef INT_PARAM_HDR
+#define INT_PARAM_HDR
+
+#include "query_param.hpp"
+
+class IntParam : public QueryParam {
+public:
+    /*! Constructor.
+    */
+    IntParam(int value);
+    /*! Destructor.
+    */
+    virtual ~IntParam();
+    
+    const char * getValue();
+    
+    const int getLength();
+    
+    const int isBinary();
+private:
+    unsigned int _value;
+};
+
+#endif
diff --git a/concordia-server/logger.cpp b/concordia-server/logger.cpp
new file mode 100644
index 0000000..77a0a48
--- /dev/null
+++ b/concordia-server/logger.cpp
@@ -0,0 +1,31 @@
+#include "logger.hpp"
+
+#include "log4cpp/Category.hh"
+#include "log4cpp/Appender.hh"
+#include "log4cpp/FileAppender.hh"
+#include "log4cpp/BasicLayout.hh"
+#include "log4cpp/Priority.hh"
+
+Logger::Logger() {
+}
+
+Logger::~Logger() {
+}
+
+int Logger::initialized = 0;
+
+void Logger::log(std::string message) {
+    log4cpp::Category & root = log4cpp::Category::getRoot();
+    if (initialized == 0) {
+        log4cpp::Appender *appender = new log4cpp::FileAppender("default", "/tmp/concordia-server.log");
+	    appender->setLayout(new log4cpp::BasicLayout());
+
+	    root.setPriority(log4cpp::Priority::INFO);
+	    root.addAppender(appender);
+	    
+	    initialized = 1;
+	}
+	root.info(message);
+}
+
+
diff --git a/concordia-server/logger.hpp b/concordia-server/logger.hpp
new file mode 100644
index 0000000..9653c19
--- /dev/null
+++ b/concordia-server/logger.hpp
@@ -0,0 +1,21 @@
+#ifndef LOGGER_HDR
+#define LOGGER_HDR
+
+#include <string>
+#include <sstream>
+
+class Logger {
+public:
+    /*! Constructor.
+    */
+    Logger();
+    /*! Destructor.
+    */
+    virtual ~Logger();
+    
+    static void log(std::string message);
+private:
+    static int initialized;
+};
+
+#endif
diff --git a/concordia-server/query_param.cpp b/concordia-server/query_param.cpp
index f4bd8c3..df34889 100644
--- a/concordia-server/query_param.cpp
+++ b/concordia-server/query_param.cpp
@@ -1,71 +1,16 @@
-#include "db_connection.hpp"
+#include "query_param.hpp"
 
-#include "config.hpp"
+QueryParam::QueryParam() {
+}
 
-DBconnection::DBconnection() throw(ConcordiaException) {
-    std::string connectionInfo = "dbname="DB_NAME" user="DB_USER;
-    _connection = PQconnectdb(connectionInfo.c_str());
-    if (PQstatus(_connection) != CONNECTION_OK) {
-        close();
-        throw ConcordiaException("Could not establish connection with the database");
-    }
+QueryParam::~QueryParam() {
+}
+
+const char * QueryParam::getValue() {
+}
     
+const int QueryParam::getLength() {
 }
 
-DBconnection::~DBconnection() {
-    close();
+const int QueryParam::isBinary() {
 }
-
-void DBconnection::close() {
-    if (_connection != NULL) {
-        PQfinish(_connection);
-        _connection = NULL;
-    }
-}
-
-void DBconnection::startTransaction() throw(ConcordiaException) {
-    if (_connection != NULL) {
-        PGresult * result = PQexec(_connection, "BEGIN");
-        if (PQresultStatus(result) != PGRES_COMMAND_OK) {
-            PQclear(result);
-            close();
-            throw ConcordiaException("starting transaction failed");
-        }
-    } else {
-        throw ConcordiaException("requested start transaction but the database connection is not ready");
-    }
-}
-
-void DBconnection::endTransaction() throw(ConcordiaException) {
-    if (_connection != NULL) {
-        PGresult * result = PQexec(_connection, "END");
-        if (PQresultStatus(result) != PGRES_COMMAND_OK) {
-            PQclear(result);
-            close();
-            throw ConcordiaException("ending transaction failed");
-        }
-    } else {
-        throw ConcordiaException("requested end transaction but the database connection is not ready");
-    }
-}
-
-PGresult * DBconnection::execute(std::string query) throw(ConcordiaException) {
-    if (_connection != NULL) {
-        PGresult * result = PQexec(_connection, query.c_str());
-        if (PQresultStatus(result) != PGRES_COMMAND_OK) {
-            PQclear(result);
-            close();
-            throw ConcordiaException("ending transaction failed");
-        } else {
-            return result;
-        }
-    } else {
-        throw ConcordiaException("requested query execution but the database connection is not ready");
-    }
-}
-
-PGresult * DBconnection::execute(std::string query,
-                                 std::vector<std::string> params) throw(ConcordiaException) {
-}
-
-
diff --git a/concordia-server/query_param.hpp b/concordia-server/query_param.hpp
index 7972635..2afd1f8 100644
--- a/concordia-server/query_param.hpp
+++ b/concordia-server/query_param.hpp
@@ -5,11 +5,16 @@ class QueryParam {
 public:
     /*! Constructor.
     */
-    QueryParam() throw(ConcordiaException);
+    QueryParam();
     /*! Destructor.
     */
     virtual ~QueryParam();
     
+    virtual const char * getValue();
+    
+    virtual const int getLength();
+    
+    virtual const int isBinary();
 private:
 
 };
diff --git a/concordia-server/string_param.cpp b/concordia-server/string_param.cpp
new file mode 100644
index 0000000..c5469c7
--- /dev/null
+++ b/concordia-server/string_param.cpp
@@ -0,0 +1,19 @@
+#include "string_param.hpp"
+
+StringParam::StringParam(std::string value) : _value(value) {
+}
+
+StringParam::~StringParam() {
+}
+
+const char * StringParam::getValue() {
+    return _value.c_str();
+}
+    
+const int StringParam::getLength() {
+    return _value.size();
+}
+
+const int StringParam::isBinary() {
+    return 0;
+}
diff --git a/concordia-server/string_param.hpp b/concordia-server/string_param.hpp
new file mode 100644
index 0000000..c58c913
--- /dev/null
+++ b/concordia-server/string_param.hpp
@@ -0,0 +1,26 @@
+#ifndef STRING_PARAM_HDR
+#define STRING_PARAM_HDR
+
+#include "query_param.hpp"
+
+#include <string>
+
+class StringParam : public QueryParam {
+public:
+    /*! Constructor.
+    */
+    StringParam(std::string value);
+    /*! Destructor.
+    */
+    virtual ~StringParam();
+    
+    const char * getValue();
+    
+    const int getLength();
+    
+    const int isBinary();
+private:
+    std::string _value;
+};
+
+#endif
diff --git a/concordia-server/unit_dao.cpp b/concordia-server/unit_dao.cpp
index 9a0bcc6..453115d 100644
--- a/concordia-server/unit_dao.cpp
+++ b/concordia-server/unit_dao.cpp
@@ -1,6 +1,13 @@
 #include "unit_dao.hpp"
 
 #include "db_connection.hpp"
+#include "query_param.hpp"
+#include "string_param.hpp"
+#include "int_param.hpp"
+#include "logger.hpp"
+
+#include <vector>
+#include <boost/foreach.hpp>
 
 UnitDAO::UnitDAO() {
 }
@@ -8,15 +15,28 @@ UnitDAO::UnitDAO() {
 UnitDAO::~UnitDAO() {
 }
 
-SUFFIX_MARKER_TYPE UnitDAO::addSentence(
+int UnitDAO::addSentence(
      boost::shared_ptr<TokenizedSentence> sourceSentence,
      std::string & targetSentence,
      int tmId) {
-
+    
     DBconnection connection;
     connection.startTransaction();
-    connection.execute("INSERT INTO unit(source_segment) values('just testing')");
+    std::string query = "INSERT INTO unit(source_segment, target_segment, tm_id) values($1::text,$2::text,$3::integer)";
+    std::vector<QueryParam*> params;
+    params.push_back(new StringParam(sourceSentence->getSentence()));
+    params.push_back(new StringParam(targetSentence));
+    params.push_back(new IntParam(tmId));
+    
+    connection.execute(query, params);
     connection.endTransaction();
+    
+    BOOST_FOREACH (QueryParam * param, params) {
+        delete param;
+    }
+
+    //todo return new unit id
+    return 0;
      
 }
 
diff --git a/concordia-server/unit_dao.hpp b/concordia-server/unit_dao.hpp
index f3aa37f..97fa334 100644
--- a/concordia-server/unit_dao.hpp
+++ b/concordia-server/unit_dao.hpp
@@ -4,7 +4,6 @@
 #include <string>
 
 #include <concordia/tokenized_sentence.hpp>
-#include <concordia/common/config.hpp>
 #include <boost/shared_ptr.hpp>
 
 class UnitDAO {
@@ -16,7 +15,7 @@ public:
     */
     virtual ~UnitDAO();
 
-    SUFFIX_MARKER_TYPE addSentence(
+    int addSentence(
              boost::shared_ptr<TokenizedSentence> sourceSentence,
              std::string & targetSentence,
              int tmId);
diff --git a/tests/testCurl.sh b/tests/testCurl.sh
index 882fb40..c7b1750 100755
--- a/tests/testCurl.sh
+++ b/tests/testCurl.sh
@@ -1,5 +1,7 @@
 #!/bin/sh
 
-curl -H "Content-Type: application/json" -X POST -d '{"operation":"addSentence", "sentence":"zupełnie nowe zdanie"}' http://localhost
+curl -H "Content-Type: application/json" -X POST -d '{"operation":"addSentence", "sourceSentence":"zupełnie nowe zdanie", "targetSentence":"zażółć gęślą jaźńZAŻÓŁĆ GĘŚLĄ JAŹŃ", "tmId":1234782314}' http://localhost
+
+
 #curl -H "Content-Type: application/json" -X POST -d '{"operation":"simpleSearch", "sentence":"zupełnie nowe"}' http://localhost