mirror of
https://github.com/postgres/postgres.git
synced 2025-05-21 00:02:53 -04:00
58 lines
1.7 KiB
C++
58 lines
1.7 KiB
C++
/*
|
|
* 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 = "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");
|
|
return 0;
|
|
}
|