sql查询语句中使用vc定义的变量

Question

SELECT stu_num,stu_name,stu_style,stu_system,stu_class FROM student WHERE stu_num='+i+'";请问在sql查询语句中使用vc定义的变量是    '+变量+'  的形式么？
在运行后报错：在将varchar值'+i+'转换成数据类型int时失败、我定义的i是下面这样的： int i;
i=GetDlgItemInt(IDC_chaxun);
有没人帮我看看，指导指导，谢谢拉！

Answer 1

CString strSql;
strSql.Format("SELECT stu_num,stu_name,stu_style,stu_system,stu_class FROM student WHERE stu_num='%d'",i);

Answer 2

int i;
i=GetDlgItemInt(IDC_chaxun);
CString str;
str.Format("%d",i);
CString strSql = "SELECT stu_num,stu_name,stu_style,stu_system,stu_class FROM student WHERE stu_num='"+str+"'";

Answer 3

我这段代码要实现已i为条件查询数据库，怎么弄呢
int i;
i=GetDlgItemInt(IDC_chaxun);
try
{
m_pRecordset.CreateInstance("ADODB.Recordset"); 
CString strSql;
_bstr_t strCmd="SELECT stu_num,stu_name,stu_style,stu_system,stu_class FROM student WHERE stu_num=i";

  m_pRecordset=m_pConnection->Execute(strCmd,&RecordsAffected,adCmdText);
    }
catch(_com_error &e)
{
AfxMessageBox(e.Description());
}

        _variant_t vstu_num,vstu_name,vstu_style,vstu_system,vstu_class;


try
{

vstu_num=m_pRecordset->GetCollect(_variant_t((long)0));
    vstu_name=m_pRecordset->GetCollect("stu_name");
vstu_style=m_pRecordset->GetCollect("stu_style");
vstu_system=m_pRecordset->GetCollect("stu_system");
vstu_class=m_pRecordset->GetCollect("stu_class");


m_num=(long)(LPCTSTR)(_bstr_t)vstu_num;
m_name=(LPCTSTR)(_bstr_t)vstu_name;
m_style=(LPCTSTR)(_bstr_t)vstu_style;
m_system=(LPCTSTR)(_bstr_t)vstu_system;
m_class=(LPCTSTR)(_bstr_t)vstu_class; UpdateData(FALSE);
   
}
catch(_com_error &e)
{
AfxMessageBox(e.Description());
} m_pRecordset->Close();
m_pRecordset=NULL;
m_pConnection->Close();
m_pConnection=NULL;
}