TPgSQLResult.cxx

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// @(#)root/pgsql:$Id$
// Author: g.p.ciceri <gp.ciceri@acm.org> 01/06/2001
 
/*************************************************************************
 * Copyright (C) 1995-2001, Rene Brun and Fons Rademakers.               *
 * All rights reserved.                                                  *
 *                                                                       *
 * For the licensing terms see $ROOTSYS/LICENSE.                         *
 * For the list of contributors see $ROOTSYS/README/CREDITS.             *
 *************************************************************************/
 
#include "TPgSQLResult.h"
#include "TPgSQLRow.h"
 
#include <libpq-fe.h>
 
ClassImp(TPgSQLResult);
 
////////////////////////////////////////////////////////////////////////////////
/// PgSQL query result.
 
TPgSQLResult::TPgSQLResult(PGresult *result)
{
   fResult     = (PGresult *) result;
   fRowCount   = fResult ? PQntuples(fResult) : 0;
   fCurrentRow = 0;
}
 
////////////////////////////////////////////////////////////////////////////////
/// Cleanup PgSQL query result.
 
TPgSQLResult::~TPgSQLResult()
{
   if (fResult)
      Close();
}
 
////////////////////////////////////////////////////////////////////////////////
/// Close query result.
 
void TPgSQLResult::Close(Option_t *)
{
   if (!fResult)
      return;
 
   PQclear(fResult);
   fResult     = nullptr;
   fRowCount   = 0;
   fCurrentRow = 0;
}
 
////////////////////////////////////////////////////////////////////////////////
/// Check if result set is open and field index within range.
 
Bool_t TPgSQLResult::IsValid(Int_t field)
{
   if (!fResult) {
      Error("IsValid", "result set closed");
      return kFALSE;
   }
   if (field < 0 || field >= GetFieldCount()) {
      Error("IsValid", "field index out of bounds");
      return kFALSE;
   }
   return kTRUE;
}
 
////////////////////////////////////////////////////////////////////////////////
/// Get number of fields in result.
 
Int_t TPgSQLResult::GetFieldCount()
{
   if (!fResult) {
      Error("GetFieldCount", "result set closed");
      return 0;
   }
   return PQnfields(fResult);
}
 
////////////////////////////////////////////////////////////////////////////////
/// Get name of specified field.
 
const char *TPgSQLResult::GetFieldName(Int_t field)
{
   if (!fResult) {
      Error("GetFieldName", "result set closed");
      return nullptr;
   }
   return PQfname(fResult, field);
}
 
////////////////////////////////////////////////////////////////////////////////
/// Get next query result row. The returned object must be
/// deleted by the user.
 
TSQLRow *TPgSQLResult::Next()
{
   if (!fResult) {
      Error("Next", "result set closed");
      return nullptr;
   }
   ULong_t row = fCurrentRow++;
   if ((Int_t) row >= fRowCount)
      return nullptr;
 
   return new TPgSQLRow(fResult, row);
}