SQL第十七章项目案例:QQ用户信息管理系统

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Data.SqlClient;
using System.Data;

namespace ConsoleApplication1
{
class DBHandle
{
private const string strConn = "Data Source=.;Initial Catalog=QQDB;User ID=admin;Password=bdqn";

//得到用户列表
public SqlDataReader GetUserList()
{
try
{
SqlConnection conn = new SqlConnection(strConn);
conn.Open();
StringBuilder sb = new StringBuilder();
sb.AppendLine(" SELECT");
sb.AppendLine("           a.[UserId]");
sb.AppendLine("          ,a.[UserName]");
sb.AppendLine("          ,b.[LevelName]");
sb.AppendLine("          ,a.[Email]");
sb.AppendLine("          ,a.[OnLineDay]");
sb.AppendLine(" FROM");
sb.AppendLine("             [UserInfo] a, [Level] b ");
sb.AppendLine(" WHERE");
sb.AppendLine("           a.[LevelId] = b.[LevelId]");
SqlCommand comm = new SqlCommand(sb.ToString(), conn);
return comm.ExecuteReader(CommandBehavior.CloseConnection);

}
catch (Exception e)
{
Console.WriteLine(e.Message);
return null;

}
}
//显示用户信息
public void ShowUserInfo()
{
StringBuilder sb = new StringBuilder();
SqlDataReader reader = GetUserList();
if (reader == null)
{
Console.WriteLine("出现异常");
return;
}
Console.WriteLine("-----------------------------------------------------");
Console.WriteLine("编号\t\t昵称\t\t等级\t\t邮箱\t\t在线天数");
while (reader.Read())
{
sb.AppendFormat("{0}\t{1}\t{2}\t{3}\t{4}", reader["UserId"], reader["UserName"], reader["LevelName"], reader["Email"], reader["OnLineDay"]);
Console.WriteLine(sb.ToString());
sb.Length = 0;
}
Console.WriteLine("-----------------------------------------------------");
reader.Close();
}

//更改在线天数
public int UpdateOnlineDay(int userId, double newOnlineDay)
{
try
{
SqlConnection conn = new SqlConnection(strConn);
conn.Open();

StringBuilder sb = new StringBuilder();
sb.AppendLine("UPDATE");
sb.AppendLine("           [UserInfo]");
sb.AppendLine("  SET");
sb.AppendLine("          OnLineDay=" + newOnlineDay);
sb.AppendLine(" WHERE");
sb.AppendLine("          UserId="+userId);

SqlCommand comm = new SqlCommand(sb.ToString(), conn);
// Console.WriteLine(sb.ToString());
return comm.ExecuteNonQuery();
}
catch (Exception e)
{
Console.WriteLine(e.Message);
return -1;
}
}

//插入用户信息
public object InsertUserInfo(string userName, string userPwd, string email)
{
SqlConnection conn = new SqlConnection(strConn);
try
{
conn.Open();

StringBuilder sb = new StringBuilder();

sb.AppendLine(" INSERT INTO");
sb.AppendLine("          [UserInfo]");
sb.AppendLine(" VALUES");
sb.AppendLine("          ('" + userName + "','" + userPwd + "',1,'" + email + "',0);");

sb.AppendLine(" SELECT @@Identity;");

SqlCommand comm = new SqlCommand(sb.ToString(), conn);
return comm.ExecuteScalar();

}
catch (Exception e)
{
Console.WriteLine(e.Message);
return -1;
}
}

//获取账户Id和在线天数
public SqlDataReader GetUserIdAndOnlineDay()
{
try
{
SqlConnection conn = new SqlConnection(strConn);
conn.Open();

StringBuilder sb = new StringBuilder();
sb.AppendLine(" SELECT");
sb.AppendLine("           UserId");
sb.AppendLine("          ,OnLineDay");
sb.AppendLine(" FROM");
sb.AppendLine("           UserInfo ");
SqlCommand comm = new SqlCommand(sb.ToString(), conn);
return comm.ExecuteReader(CommandBehavior.CloseConnection);
}
catch (Exception e)
{
Console.WriteLine(e.Message);
return null;
}
}
//更改指定用户QQ等级
public int UpdateUserLevel(int userId, int iLevel)
{
try
{
SqlConnection conn = new SqlConnection(strConn);
conn.Open();

StringBuilder sb = new StringBuilder();
sb.AppendLine(" UPDATE");
sb.AppendLine("          from [UserInfo]");
sb.AppendLine(" SET");
sb.AppendLine("           [LevelId]=" + iLevel);
sb.AppendLine(" WHERE");
sb.AppendLine("           [UserId]=" + userId);
SqlCommand comm = new SqlCommand(sb.ToString(), conn);
return comm.ExecuteNonQuery();
}
catch (Exception)
{
return -1;
}
}

//根据用户编号查找指定用户信息
public SqlDataReader GetUserByID(int UserID)
{
try
{
SqlConnection conn = new SqlConnection(strConn);
conn.Open();

StringBuilder sb = new StringBuilder();
sb.AppendLine(" SELECT");
sb.AppendLine("           a.[UserId]");
sb.AppendLine("          ,a.[UserName]");
sb.AppendLine("          ,b.[LevelName]");
sb.AppendLine("          ,a.[Email]");
sb.AppendLine("          ,a.[OnLineDay]");
sb.AppendLine("FROM");
sb.AppendLine("             [UserInfo] as a, [Level] as b");
sb.AppendLine(" WHERE");
sb.AppendLine("           a.[UserId] = " + UserID);
sb.AppendLine(" AND");
sb.AppendLine("           a.[LevelId] = b.[LevelId]");
SqlCommand comm = new SqlCommand(sb.ToString(), conn);
return comm.ExecuteReader(CommandBehavior.CloseConnection);
}
catch (Exception e)
{
Console.WriteLine(e.Message);
return null;
}
}

//删除用户
public int DeleteUserInfo(int strUserId)
{
try
{
SqlConnection conn = new SqlConnection(strConn);
conn.Open();

StringBuilder sb = new StringBuilder();

sb.AppendLine("DELETE");
sb.AppendLine("           [UserInfo]");
sb.AppendLine("  WHERE");
sb.AppendLine("          [UserId]=" + strUserId);
SqlCommand comm = new SqlCommand(sb.ToString(), conn);
return comm.ExecuteNonQuery();
}
catch (Exception e)
{
Console.WriteLine(e.Message);
return -1;
}
}
}
}

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Data.SqlClient;
using System.Data;

namespace ConsoleApplication1
{
class UserManager
{
private const  string strConn = "Data Source=.;Initial Catalog=QQDB;User ID=admin;Password=bdqn";
DBHandle db = new DBHandle();

//登录
public void login()
{
int count = 0;
do
{
count++;
string strUserName = string.Empty;
string strPwd = string.Empty;
Console.WriteLine("请输入用户名:");
strUserName = Console.ReadLine();
Console.WriteLine("请输入密码:");
strPwd = Console.ReadLine();

4000
if (strUserName.Equals(string.Empty) || strPwd.Equals(string.Empty))
{
Console.WriteLine("输入错误，请重新输入！\n");
continue;
}
else
{
string strMsg = string.Empty;

bool bRet = CheckAdminInfo(strUserName, strPwd, ref strMsg);
if (bRet)
{
Console.WriteLine("登录成功！");
ShowMenu();
break;
}
else
{
Console.WriteLine("登录失败：" + strMsg + "\n");
continue;
}
}
} while (count < 3);
if (count == 3)
{
Console.WriteLine("\n连续三次登录失败，退出本系统！\n");
}
}

//检查用户信息是否存在
public bool CheckAdminInfo(string strUserName,string  strPwd,ref string strMsg )
{
try
{
SqlConnection conn = new SqlConnection(strConn);
conn.Open();
StringBuilder sb = new StringBuilder();
sb.AppendLine("SELECT");
sb.AppendLine("      [LoginId]");
sb.AppendLine("      ,[LoginPwd]");
sb.AppendLine("FROM");
sb.AppendLine("      Admin");
SqlCommand comm = new SqlCommand(sb.ToString(), conn);

SqlDataReader reader = comm.ExecuteReader();
while (reader.Read())
{
strUserName = (string)reader["LoginId"];
strPwd = (string)reader["LoginPwd"];
}

reader.Close();
return true;
}
catch (Exception e)
{
Console.WriteLine(e.Message);
return false;
}

}

//是否退出
private bool IsExit()
{
Console.WriteLine("是否退出？（Y/N）");
string strRet = Console.ReadLine();
strRet = strRet.Trim().ToUpper();
if (strRet.Equals("Y"))
{
return true;
}
else
{
return false;
}
}

//显示菜单
private void ShowMenu()
{
string option = "";
do
{
Console.WriteLine("");
Console.WriteLine("=======欢迎登录QQ用户信息管理系统======");
Console.WriteLine("----------------请选择菜单项----------");
Console.WriteLine("1、显示用户清单");
Console.WriteLine("2、更新在线天数");
Console.WriteLine("3、添加用户新记录");
Console.WriteLine("4、更新用户等级");
Console.WriteLine("5、删除用户记录");
Console.WriteLine("0、退出");
Console.WriteLine("=======================================");
option = Console.ReadLine();
switch (option)
{
case "1"://显示用户信息
db.ShowUserInfo();
continue;
case "2"://更新在线天数
UpdateOnlineDay();
continue;
case "3"://添加用户
InsertUserInfo();
continue;
case "4"://更新用户等级
UpdateUserLevel();
continue;
case "5"://删除用户
DeleteUserInfo();
continue;
case "0":

break;//退出

default:
continue;
}

break;
} while (true);

}

//更改在线天数
public void UpdateOnlineDay()
{
try
{
Console.WriteLine("请输入用户编号：");
string strUserId = Console.ReadLine();
int iUserId = Convert.ToInt32(strUserId);
Console.WriteLine("请输入新的在线天数");
string strNewOnlineDay = Console.ReadLine();
double iNewOnlineDay = Convert.ToDouble(strNewOnlineDay);
int iRet = db.UpdateOnlineDay(iUserId, iNewOnlineDay);
if (iRet == -1)
Console.WriteLine("发生异常");
else if (iRet == 0)
{
Console.WriteLine("用户记录不存在");
}
else
{
Console.WriteLine("修改成功！");
}
}
catch (Exception e)
{
Console.WriteLine(e.Message);
}
}

//插入用户信息
private void InsertUserInfo()
{
Console.WriteLine("请输入用户昵称：");
string strUserName = Console.ReadLine();
Console.WriteLine("请输入用户密码：");
string strUserPwd = Console.ReadLine();
Console.WriteLine("请输入用户邮箱地址：");
string strUserEmail = Console.ReadLine();

int iRet = Convert.ToInt32(db.InsertUserInfo(strUserName, strUserPwd, strUserEmail));
if (iRet == -1)
{
Console.WriteLine("存在异常");
}
else if (iRet == 0)
{
Console.WriteLine("用户记录不存在");
}
else
{
Console.WriteLine("插入成功！用户编号是：" + iRet);
}
}

//根据天数确认等级
private int JudgeLevelByOnLineDay(double iOnlineDay)
{
const int LEVEL1 = 5;
const int LEVEL2 = 32;
const int LEVEL3 = 320;

int iNewLevel = 0;

if (iOnlineDay >= LEVEL1 && iOnlineDay < LEVEL2)
{
iNewLevel = 2;
}
else if (iOnlineDay >= LEVEL2 && iOnlineDay < LEVEL3)
{
iNewLevel = 3;
}
else if (iOnlineDay >= LEVEL3)
{
iNewLevel = 4;
}
else
{
iNewLevel = 1;
}
return iNewLevel;
}

//用户等级更新
private void UpdateUserLevel()
{

SqlDataReader reader = db.GetUserIdAndOnlineDay();
if (reader == null)
{
Console.WriteLine("存在异常");
return;
}

int iUserId = 0;
double iLineDay = 0;
int iLevelId = 0;
int count = 0;

while (reader.Read())
{
iUserId = Convert.ToInt32(reader["UserId"]);
iLineDay = Convert.ToDouble(reader["OnLineDay"]);
iLevelId = JudgeLevelByOnLineDay(iLineDay);
db.UpdateUserLevel(iUserId, iLevelId);
count++;
}
Console.WriteLine("本次共更新用户记录数："+ count);
Console.WriteLine("更新成功！");

}

//显示个人用户信息
private void DisplayUserInfo(SqlDataReader reader)
{
Console.WriteLine("--------------------------------------------------------------------------------");
Console.WriteLine("编号\t昵称\t\t等级\t\t邮箱\t\t在线天数");
Console.WriteLine("--------------------------------------------------------------------------------");
while (reader.Read())
{
Console.Write(reader["UserId"] + "\t");
Console.Write(reader["UserName"] + "\t");
Console.Write(reader["LevelName"] + "\t\t");
Console.Write(reader["Email"] + "\t");
Console.WriteLine(reader["OnLineDay"]);
}
Console.WriteLine("--------------------------------------------------------------------------------");

}

//删除指定用户信息
public void DeleteUserInfo()
{
try
{

Console.WriteLine("请输入删除的用户编号：");
string strUserId = Console.ReadLine();
int iUserId = Convert.ToInt32(strUserId);

Console.WriteLine("将要删除的用户信息是：");
SqlDataReader reader = db.GetUserByID(iUserId);

if (reader == null)
{
Console.WriteLine("发生异常");
return;
}
DisplayUserInfo(reader);
Console.WriteLine("要删除该用户记录吗？（Y/N）");
if (Console.ReadLine().Trim().ToUpper() != "Y")
{
Console.WriteLine("退出删除操作！");
return;
}

int iRet = db.DeleteUserInfo(iUserId);
if (iRet == -1)
{
Console.WriteLine("发生异常");
}
else
{
Console.WriteLine("删除成功！");
}
}
catch (Exception ex)
{
Console.WriteLine("删除失败：" + ex.Message);
}
}

}
}

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Data.SqlClient;

namespace ConsoleApplication1
{
class Program
{

static void Main(string[] args)
{
UserManager u = new UserManager();
u.login();
Console.ReadLine();
}
}
}