数据库的编程(ADO)

一. 数据库的编程(ADO)

1. 要用ADO连接数据的头文件中加入 #import "c:/Program Files/Common Files/System/ado/msado15.dll" no_namespace rename("EOF","adoEOF") rename("BOF","adoBOF")

2. // 初始化OLE/COM库环境 _ConnectionPtr m_pConnection;
::CoInitialize(NULL);
char buf[256],server[256],datebase[256],uid[256],pwd[256];char str[255];
GetCurrentDirectory(255,str);//获得当前目录
strcat(str,"//dbinfo.ini");int len0=GetPrivateProfileString("dbinfo","Provider","No Text",buf,256,str);//读取配置文件中的数据库连接信息
int len1=GetPrivateProfileString("dbinfo","server","No Text",server,256,str);
int len2=GetPrivateProfileString("dbinfo","Database","No Text",datebase,256,str);
int len3=GetPrivateProfileString("dbinfo","uid","No Text",uid,256,str);
int len4=GetPrivateProfileString("dbinfo","pwd","No Text",pwd,256,str); try
{
// 创建Connection对象
m_pConnection.CreateInstance("ADODB.Connection");
// 设置连接字符串，必须是BSTR型或者_bstr_t类型
_bstr_t strConnect = "Provider=";
strConnect =strConnect+buf;
strConnect =strConnect+";Server=";
strConnect =strConnect+server;
strConnect =strConnect+";Database=";
strConnect =strConnect+datebase;
strConnect =strConnect+";uid=";
strConnect =strConnect+uid;
strConnect =strConnect+";pwd=";
strConnect =strConnect+pwd; m_pConnection->Open(strConnect,"","",adModeUnknown);//连接到指定的数据库
}
// 捕捉异常
catch(_com_error e)
{
// 显示错误信息
AfxMessageBox(e.Description());
}

3. 执行无返回值（记录集）的SQL语句，Insert Update等无返回值的语句
// Connection对象的Execute方法:(_bstr_t CommandText,
// VARIANT * RecordsAffected, long Options )
// 其中CommandText是命令字串，通常是SQL命令。
// 参数RecordsAffected是操作完成后所影响的行数,
// 参数Options表示CommandText的类型：adCmdText-文本命令；adCmdTable-表名
// adCmdProc-存储过程；adCmdUnknown-未知
m_pConnection->Execute(bstrSQL,NULL,adCmdText);

4. 执行有返回值（记录集）的SQL语句
_RecordsetPtr m_pRecordset;
// 创建记录集对象
m_pRecordset.CreateInstance(__uuidof(Recordset));
// 返回表中的记录
m_pRecordset->Open(bstrSQL,m_pConnection.GetInterfacePtr(),adOpenDynamic,adLockOptimistic,adCmdText);
CListCtrl m_list1;//记录显示在CListCtrl中
if(!m_pRecordset->adoEOF) //如果记录不为空
{
while(!m_pRecordset->adoEOF)
{
m_list1.InsertItem(i,(LPCTSTR)(_bstr_t)m_pRecordset->GetCollect("ID"));
m_list1.SetItemText(i,1,(LPCTSTR)(_bstr_t)m_pRecordset->GetCollect("tintCallType"));
m_list1.SetItemText(i,2,(LPCTSTR)(_bstr_t)m_pRecordset->GetCollect("tintHangUp"));

_variant_t vMaxid(m_pRecordset->GetCollect("strCallingNmb"));
if(vMaxid.vt==VT_NULL)
vMaxid="";
m_list1.SetItemText(i,3,(LPCTSTR)(_bstr_t)vMaxid);

_variant_t vMaxid0(m_pRecordset->GetCollect("strCalledNmb"));
if(vMaxid0.vt==VT_NULL)
vMaxid0="";
m_list1.SetItemText(i,4,(LPCTSTR)(_bstr_t)vMaxid0);

_variant_t vMaxid1(m_pRecordset->GetCollect("strOriginNmb"));
if(vMaxid1.vt==VT_NULL) //此字段在数据库中为NULL值
vMaxid1=""; i++;//CListCtrl中的第i行显示此记录
m_pRecordset->MoveNext();//下一条记录

}
}
m_pRecordset->Close();//记录集读取完毕，关闭记录集

5. 执行带参数无返回值(一个或者多个记录集)的存储过程
_CommandPtr m_pnewCommand;
m_pnewCommand.CreateInstance("ADODB.Command");
m_pnewCommand->ActiveConnection=m_pConnection;
m_pnewCommand->CommandType=adCmdStoredProc;
m_pnewCommand->CommandText=_bstr_t("proc_deleteSMCBQueue");
unsigned char newflag = 1;
_ParameterPtr Pnewflag,PnewrecordID;
Pnewflag.CreateInstance(__uuidof(Parameter));
PnewrecordID.CreateInstance(__uuidof(Parameter));

CString newst="";
newst.Format("%d",recordID);
Pnewflag=m_pnewCommand->CreateParameter(_bstr_t("flag"),adTinyInt,adParamInput,1,(_variant_t)newflag);
m_pnewCommand->Parameters->Append(Pnewflag);
PnewrecordID=m_pnewCommand->CreateParameter(_bstr_t("recordID"),adInteger,adParamInput,4,(_variant_t)(_bstr_t)newst);
m_pnewCommand->Parameters->Append(PnewrecordID);

try
{
m_pnewCommand->Execute(NULL,NULL,adCmdStoredProc);
}
catch(...)
{
}

6. 执行有参数有返回记录集的存储过程(其实就是执行有返回值（记录集）的SQL语句)
CString sqlrecord ="exec proc_getSMCBQueue 1";
try
{
m_pRecordset = m_pConnection->Execute((_bstr_t)sqlrecord,NULL,adCmdText);
}
catch(...)
{
}
今天就记一下VC关于数据库的编程吧，下次再记VC关于网络的编程吧！
只是真正的用_CommandPtr m_pnewCommand执行存储过程返回一个或者多个记录集，再分别对各记录集进行操作还没有实现啊！