sql.cpp

数据库的简单连接实例

#include "afx.h"
#include "afxwin.h"
#import "c:\program files\common files\system\ado\msado15.dll" no_namespace rename("EOF","adoEOF") rename("BOF","adoBOF")


#include "stdio.h"
#include "comutil.h"

#pragma comment(lib,"comsupp.lib")

//数据库操作步骤：1。初始化OLEDB-》2。连接数据库-》3。执行SQL语句（数据从数据库取到了记录集对像中）
                //-》4。你对数据的使用->5。关闭记录集，关闭连接，卸载OLEDB;
void main()
{    CoInitialize(NULL);  //初始化OLEDB
	 _ConnectionPtr m_pConnection;//定义连接
	 _RecordsetPtr m_pRecordset;//定义记录集
	 

	m_pConnection.CreateInstance("ADODB.Connection");//创建连接对像

	_bstr_t strConnect ="Provider=SQLOLEDB;Server=WKLOVERONG;Database=cap;uid=WK509;pwd=;";//连接字符串
      
	m_pConnection->Open(strConnect,"","",adModeUnknown);//连接数据库
	printf("连接成功！\n");
		
	
	_bstr_t vSQL;
	vSQL="select * from agents";//SQL语句；
		
	m_pRecordset.CreateInstance(__uuidof(Recordset));//创建记录集对像
	
	m_pRecordset->Open(vSQL,m_pConnection.GetInterfacePtr(),adOpenDynamic,adLockOptimistic,adCmdText);//打开记录集
		
	
	//把记录集里的记录输出
	CString aid,aname,city;int percents;
			
	while(!m_pRecordset->adoEOF)
		{
			aid=(LPCTSTR)(_bstr_t)m_pRecordset->GetCollect("aid");
			aname=(LPCTSTR)(_bstr_t)m_pRecordset->GetCollect("aname");
			city=(LPCTSTR)(_bstr_t)m_pRecordset->GetCollect("city");
		    percents=atoi((LPCTSTR)(_bstr_t)m_pRecordset->GetCollect("percents"));

		printf("%s  %s  %s  %d\n",aid,aname,city,percents);
		m_pRecordset->MoveNext();
		}
	//关闭记录集	
	m_pRecordset->Close();
	//关闭连接
	m_pConnection->Close();
      
//关闭OLDB
::CoUninitialize();
}