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/*
* testlibpq.cc
* Test the C++ version of LIBPQ, the POSTGRES frontend library.
*
* queries the template1 database for a list of database names
*
*/
#include <stdio.h>
#include "libpq++.H"
main()
{
char* dbName;
int nFields;
int i,j;
/* begin, by creating the parameter environtment for a backend
connection. 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 */
PGenv env;
PGdatabase* data;
/* Select a database */
dbName = "template1";
/* make a connection to the database */
data = new PGdatabase(&env, dbName);
/* check to see that the backend connection was successfully made */
if (data->status() == CONNECTION_BAD) {
fprintf(stderr,"Connection to database '%s' failed.\n", dbName);
fprintf(stderr,"%s",data->errormessage());
delete data;
exit(1);
}
/* start a transaction block */
if(data->exec("BEGIN") != PGRES_COMMAND_OK) {
fprintf(stderr,"BEGIN command failed\n");
delete data;
exit(1);
}
/* fetch instances from the pg_database, the system catalog of databases*/
if (data->exec("DECLARE myportal CURSOR FOR select * from pg_database")
!= PGRES_COMMAND_OK) {
fprintf(stderr,"DECLARE CURSOR command failed\n");
delete data;
exit(1);
}
if(data->exec("FETCH ALL in myportal") != PGRES_TUPLES_OK) {
fprintf(stderr,"FETCH ALL command didn't return tuples properly\n");
delete data;
exit(1);
}
/* first, print out the attribute names */
nFields = data->nfields();
for (i=0; i < nFields; i++) {
printf("%-15s",data->fieldname(i));
}
printf("\n\n");
/* next, print out the instances */
for (i=0; i < data->ntuples(); i++) {
for (j=0 ; j < nFields; j++) {
printf("%-15s", data->getvalue(i,j));
}
printf("\n");
}
/* close the portal */
data->exec("CLOSE myportal");
/* end the transaction */
data->exec("END");
/* close the connection to the database and cleanup */
delete data;
}
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