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