C ++ pqxx工作事务崩溃

Question

I'm working with the c++ PostgreSQL libpqxx library and I'm not sure why I can't open a transaction/nontransaction object.

My code is currently as follows

#include <iostream>
#include <pqxx/pqxx>

using namespace std;
using namespace pqxx;

int main() {

   // define variables
   string params;
   connection* pgsql;
   string sql;

   // db connection parameters
   params = "dbname=dummy user=postgres password=postgres hostaddr=10.10.0.2 port=5431";

   try {
      // make connection
      pgsql = new connection(params);
   } catch(const exception &log) {
      // connection failed
      cerr << log.what() << endl;
   }

   // prepare sql
   sql = " select * from categories where cat_idno = $1 ";
   pgsql->prepare("categories", sql)("integer");

   // execute transaction
   // this bit doesn't work
   work tr(pgsql);
   result row = tr.prepared("categories")(1).exec();
   tr.commit();

   // disconnect
   pgsql->disconnect();

}

It's making the connection to the database just fine and preparing my sql fine as well but it is failing to compile (I'm compiling on CentOS 5 btw)

g++ -o ./pgsqltest ./pgsqltest02.cpp -lpqxx

gives me the following errors

./pgsqltest02.cpp: In function ‘int main()’:
./pgsqltest02.cpp:24: error: no matching function for call to ‘pqxx::transaction<read_committed, read_write>::transaction(pqxx::connection*&)’
/usr/include/pqxx/transaction.hxx:102: note: candidates are: pqxx::transaction<ISOLATIONLEVEL, READWRITE>::transaction(pqxx::connection_base&) [with pqxx::isolation_level ISOLATIONLEVEL = read_committed, pqxx::readwrite_policy READWRITE = read_write]
/usr/include/pqxx/transaction.hxx:97: note: pqxx::transaction<ISOLATIONLEVEL, READWRITE>::transaction(pqxx::connection_base&, const std::string&) [with pqxx::isolation_level ISOLATIONLEVEL = read_committed, pqxx::readwrite_policy READWRITE = read_write]
/usr/include/pqxx/transaction.hxx:87: note: pqxx::transaction<read_committed, read_write>::transaction(const pqxx::transaction<read_committed, read_write>&)

I'm not sure why this would be, maybe I'm missing something very obvious

Answer 1

The error had to do with the compile command, it needed additional arguments that point to the libpqxx headers and binaries. The correct compile command was

g++ -o ./pgsqltest ./pgsqltest02.cpp -I /opt/libpqxx/include -L /opt/libpqxx/lib -lpq -lpqxx