c#,SQL验证登录
//查询语句
string sqlstr = null;
//链接数据库语句,计算机用户链接
string constr = "server=MSI\\SQLEXPRESS01;database=db_RC;integrated security=SSPI";
if (manager.Checked)
{
sqlstr = "select mno,pawd from dbo.manager where mno=@nametxt";
}
else
{
sqlstr = "select uname,pawd from dbo.user where uname=@nametxt";
}
SqlConnection myconn = new SqlConnection(constr);
myconn.Open();
SqlCommand mycom = new SqlCommand(sqlstr, myconn);
mycom.Parameters.Add("@nametxt", SqlDbType.VarChar, 30).Value = nametext.Text;
SqlDataReader sqlDR = mycom.ExecuteReader();
if (!sqlDR.Read())
{
MessageBox.Show("用户名错误,请重新输入!", "ERROR");
nametext.Text = "";
pawdtext.Text = "";
nametext.Focus();
}
else
{
if (sqlDR["pawd"].ToString().Trim() == pawdtext.Text.Trim())
MessageBox.Show("登陆成功!");
this.Hide();
if (manager.Checked)
{
Mindex mindex = new Mindex
{
name = nametext.Text
};
mindex.Show();
}
else
{
uindex uindex = new uindex
{
name = nametext.Text
};
uindex.Show();
}
myconn.Close();
}
先判断管理员还是用户登录,然后给sqlstr赋值。但是读取数据库返回值时候,只有管理员可以成功,而用户的sqlDR为空,请问怎么处理