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/*
* testlibpq2.cc
* Test the C++ version of LIBPQ, the POSTGRES frontend library.
*
* queries the template1 database for a list of database names using transaction block
*
*/
#include <iostream.h>
#include <iomanip.h>
#include <libpq++.h>
int main()
{
// Begin, by establishing a connection to the backend.
// When no parameters are given then the system will
// try to use reasonable defaults by looking up environment variables
// or, failing that, using hardwired constants
const char* dbName = "template1";
PgTransaction data(dbName);
// check to see that the backend connection was successfully made
if ( data.ConnectionBad() ) {
cerr << "Connection to database '" << dbName << "' failed." << endl
<< "Error returned: " << data.ErrorMessage() << endl;
exit(1);
}
// submit command to the backend
if ( !data.ExecCommandOk("DECLARE myportal CURSOR FOR select * from pg_database") ) {
cerr << "DECLARE CURSOR command failed" << endl;
exit(1);
}
// fetch instances from the pg_database, the system catalog of databases
if ( !data.ExecTuplesOk("FETCH ALL in myportal") ) {
cerr << "FETCH ALL command didn't return tuples properly" << endl;
exit(1);
}
// first, print out the attribute names
int nFields = data.Fields();
for (int i=0; i < nFields; i++)
cout << setiosflags(ios::right) << setw(15) << data.FieldName(i);
cout << endl << endl;
// next, print out the instances
for (int i=0; i < data.Tuples(); i++) {
for (int j=0; j < nFields; j++)
cout << setiosflags(ios::right) << setw(15) << data.GetValue(i,j);
cout << endl;
}
// close the portal
data.Exec("CLOSE myportal");
}
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