connectionpool.cpp

ODBC的动态的数据库连接,可以参考使用.

#include "stdafx.h"
#include "StrDefines.h"
#include "ConnectionPool.h"

CConnectionPool::CConnectionPool()
{
}

CConnectionPool::~CConnectionPool()
{
	for(int n = 0 ; n < m_pConnections.GetSize(); n++)
	{
		if(m_pConnections[n]->m_DataBase.IsOpen())
			m_pConnections[n]->m_DataBase.Close();
		delete m_pConnections[n];
	}//for(int n = 0 ; n < m_pConnections.GetSize(); n++)		
	m_pConnections.RemoveAll();
}//CConnectionPool::~CConnectionPool()

// Function : AddConnection
// Purpose  : Keeps a connection in the internal structur until the whole structure is destroyed
// Param    : DBCon a connection that is allready initialized to a database
// Return   : 
void CConnectionPool::AddConnection(CDBConnection *DBCon)
{
	m_pConnections.Add(DBCon);
}//void CConnectionPool::AddConnection(CDBConnection *DBCon)

// Function : AddConnection
// Purpose  : Creates a new connection and adds it to the internal structure
// Param    : DSN, user name, user password, if the database logon dialog should be run
// Return   : TRUE if connection is established, otherwise FALSE
BOOL CConnectionPool::AddConnection(CString DSN,CString sUser,CString sPassword,BOOL UseLogonDlg)
{
	CDBConnection *pDBCon = new CDBConnection();
	if(pDBCon->ConnectToDataBase(DSN,sUser,sPassword,UseLogonDlg))
		AddConnection(pDBCon);
	else
		return FALSE;
	
	return TRUE;
}//BOOL CConnectionPool::AddConnection(CString DSN,CString sUser,CString sPassword,BOOL UseLogonDlg)

// Function : GetConnection
// Purpose  : Finds and returns a connection to a database
// Param    : The DSN that specifies the database connection 
// Return   : A connection class
CDBConnection* CConnectionPool::GetConnection(CString sDSN)
{
	BOOL Found = FALSE;
	int i = 0;
	if (m_pConnections.GetSize() < 1)
		return NULL;

	while(!Found)
	{
		CDBConnection* pCon = m_pConnections.GetAt(i);
		if(pCon->m_sConnectedDSN.CompareNoCase(sDSN) == 0)
			return pCon;
		else
			if(i >= m_pConnections.GetSize() -1 )
				return NULL;
		i++;
	}//while(!Found)

	return NULL;
}//CDBConnection* CConnectionPool::GetConnection(CString sDSN)

// Function : GetConnection
// Purpose  : Finds and returns a connection to a database
// Param    : The index of the requested database connection 
// Return   : A connection class
CDBConnection* CConnectionPool::GetConnection(int index)
{
	ASSERT(index < m_pConnections.GetSize());
	return m_pConnections.GetAt(index);
}//CDBConnection* CConnectionPool::GetConnection(int index)

// Function : GetNumConnections
// Purpose  : Retrives number of database connections held in the structure
// Param    : none
// Return   : number of DB connections
int CConnectionPool::GetNumConnections()
{
	return m_pConnections.GetSize();
}//int CConnectionPool::GetNumConnections()