diff --git a/db_bridge/postgresql_db.cpp b/db_bridge/postgresql_db.cpp
--- a/db_bridge/postgresql_db.cpp
+++ b/db_bridge/postgresql_db.cpp
@@ -4,6 +4,7 @@
  */
 
 #include <postgresql_db.h>
+#include <exception>
 
 PostgreSQL_DB::PostgreSQL_DB (std::string srv, std::string usr, std::string pwd, std::string db)
 {
@@ -43,7 +44,8 @@
     Abstract_DB::DB_ROW vec;
     Abstract_DB::DB_RESULT rows;
     PGresult *res;
-    int i, j, nFields;
+    int i, j;
+    int nFields, nRows;
 
     /*
      * send SQL query
@@ -51,13 +53,14 @@
     res = PQexec (conn, sql_string.c_str ());
 
     nFields = PQnfields (res);
+    nRows = PQntuples (res);
 
-    std::cout << "Die Abfrage ergab " << nFields << " Zeilen." << std::endl;
+    std::cout << "Die Abfrage hat " << nFields << " Spalte(n) und " << nRows << " Reihe(n)." << std::endl;
 
     /*
      * push everything into a vector< vector<string> >
      */
-    for (i = 0; i < PQntuples (res); i++) {
+    for (i = 0; i < nRows; i++) {
         for (j = 0; j < nFields; j++) {
             vec.push_back (PQgetvalue (res, i, j));
         }