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/*
* testlibpq3.cc
* Test the C++ version of LIBPQ, the POSTGRES frontend library.
*
* queries the template1 database for a list of database names using transaction block
* and cursor interface.
*
*/
#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.
// Create a cursor database query object.
// All queries using cursor will be performed through this object.
const char* dbName = "template1";
PgCursor cData(dbName, "myportal");
// check to see that the backend connection was successfully made
if ( cData.ConnectionBad() ) {
cerr << "Connection to database '" << dbName << "' failed." << endl
<< "Error returned: " << cData.ErrorMessage() << endl;
exit(1);
}
// submit command to the backend
if ( !cData.Declare("select * from pg_database") ) {
cerr << "DECLARE CURSOR command failed" << endl;
exit(1);
}
// fetch instances from the pg_cDatabase, the system catalog of cDatabases
if ( !cData.Fetch() ) {
cerr << "FETCH ALL command didn't return tuples properly" << endl;
exit(1);
}
// first, print out the attribute names
int nFields = cData.Fields();
for (int i=0; i < nFields; i++)
cout << setiosflags(ios::right) << setw(15) << cData.FieldName(i);
cout << endl << endl;
// next, print out the instances
for (int i=0; i < cData.Tuples(); i++) {
for (int j=0; j < nFields; j++)
cout << setiosflags(ios::right) << setw(15) << cData.GetValue(i,j);
cout << endl;
}
}
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