/// <summary>
/// 统计学生人数
/// </summary>
public void Query_two()
{
string sql = "Select COUNT(StudentName) from Student";
try
{
var iRed = DBOperation.ExecuteScalar(sql);
if (iRed > 0)
{
Console.WriteLine("学生人数为：{0}名", iRed);
}
else
{
Console.WriteLine("获取失败！");
}
}
catch (Exception ex)
{
Console.WriteLine("出现异常：{0}", ex.Message);
}
}
/// <summary>
/// 新增年级
/// </summary>
public void New_one()
{
Console.WriteLine("请输入待插入的年级名称：");
string Grade_Name = Console.ReadLine();
string sql = string.Format("Insert Grade Values('{0}')", Grade_Name);
try
{
var New = DBOperation.ExecuteNonQuery(sql);
if (New > 0)
{
Console.WriteLine("插入成功！");
}
else
{
Console.WriteLine("插入失败！");
}
}
catch (Exception ex)
{
Console.WriteLine("出现异常：{0}", ex.Message);
}
}
int count; //输入次数
/// <summary>
/// 判断用户密码是否有误
/// </summary>
public void Query_one()
{
do
{
//登陆账号
Console.WriteLine("请输入用户名：");
name = Console.ReadLine();
Console.WriteLine("请输入密码：");
string pwo = Console.ReadLine();
string sql = string.Format("Select StudentName,LoginPwe from Student Where StudentName='{0}' and LoginPwe='{1}'", name, pwo);
try
{
var reader = DBOperation.ExecuteReader(sql);
if (reader.HasRows != true)
{
Console.WriteLine("\n登陆失败！用户名或密码有误！");
count++;
}
else
{
Console.WriteLine("登陆成功！欢迎：{0}\n\n欢迎使用学生管理系统", name);
reader.Close();
Choose_one();
}
}
catch (Exception ex)
{
Console.WriteLine("出现异常：{0}", ex.Message);
}
finally
{
DBOperation.CloseConnection();
//Console.WriteLine("数据库关闭成功！");
}
} while (count < 3);
Console.WriteLine("\n您输入三次有误，本次退出！");
}