用MVC写的查询，添加，删除，修改，登录。

一.SQL数据库代码

CREATE DATABASE MVCLession31
GO
USE MVCLession31
GO
CREATE TABLE Dept (DeptId int IDENTITY(1,1) PRIMARY KEY NOT NULL,DeptName varchar(50)  NOT NULL
);
GO
insert into Dept values('销售部'),('开发部'),('研发部')
CREATE TABLE Employee (EmpId int IDENTITY(1,1) PRIMARY KEY NOT NULL,DeptId int references Dept(DeptId)  NOT NULL,EmpName varchar(50)  NOT NULL,EmpPhone varchar(50)  NOT NULL,EmpArea varchar(50)  NOT NULL,EmpSalary decimal(18,2)  NOT NULL
);
GO
insert into Employee values(1,'李四','15914541452','北京',12345),(2,'王麻子','15154541452','北京',22345),(3,'张三','15414541452','北京',52345)
go
CREATE TABLE UserInfo
(
UserId int IDENTITY(1,1) PRIMARY KEY NOT NULL,
UserName varchar(50)  NOT NULL,
Password varchar(50)  NOT NULL
)
go
insert into UserInfo values('123','123456'),('admin','1234567'),('admin2','11234567')

二.查询

1.查询页面

<body><center><h1>员工查询</h1><a href="AddEmpFrom">添加员工</a></center><div><table align="center" border="1" cellspacing="0" width="700"><tr><th>员工编号</th><th>部门名称</th><th>员工姓名</th><th>员工电话</th><th>所在地区</th><th>员工薪资</th><th colspan="2">操作</th></tr>@foreach (var item in ViewBag.info){<tr><td>@item.EmpId</td><td>@item.DeptName</td><td>@item.EmpName</td><td>@item.EmpPhone</td><td>@item.EmpArea</td><td>@item.EmpSalary</td><td><a href="DeleteEmp?EmpId=@item.EmpId" onclick="return confirm('确定删除吗?') ">删除</a></td><td><a href="ExcistEmpFrom?EmpId=@item.EmpId">编辑</a></td></tr>}</table></div>
</body>

2.EmployeeViewFrom类

public class EmployeeViewFrom{public int EmpId { get; set; }public string DeptName { get; set; }public string EmpName { get; set; }public string EmpPhone { get; set; }public string EmpArea { get; set; }public Nullable<decimal> EmpSalary { get; set; }}

3.Home控制器中的Index方法

public ActionResult Index(){//ViewBag.info = db.Employee;ViewBag.info = from e in db.Employeejoin d in db.Dept on e.DeptId equals d.DeptIdselect new EmployeeViewFrom{EmpId =e.EmpId,EmpName =e.EmpName,EmpPhone =e.EmpPhone,EmpArea =e.EmpArea,EmpSalary =e.EmpSalary,DeptName =d.DeptName};return View();}

4.运行结果

三.添加

1.添加页面

<body><center><h1>添加员工</h1></center><div><form action="AddEmp" method="post"><table align="center" cellspacing="0" border="1" width="500"><tr><th>所属部门:</th><td><select name="DeptId"><option value="0">--请选择--</option>@foreach (var imte in ViewBag.info){<option value="@imte.DeptId">@imte.DeptName</option>}</select></td></tr><tr><th>员工姓名:</th><td><input type="text" name="EmpName" value="" /></td></tr><tr><th>员工电话:</th><td><input type="text" name="EmpPhone" value="" /></td></tr><tr><th>所在地区:</th><td><input type="text" name="EmpArea" value="" /></td></tr><tr><th>员工薪资:</th><td><input type="text" name="EmpSalary" value="" /></td></tr><tr><td colspan="2" align="center"><input type="submit" name="name" value="添加员工" /></td></tr></table></form></div>
</body>

2.Home控制器中的AddEmp方法与AddEmpFrom方法

//添加员工页面显示public ActionResult AddEmpFrom(){ViewBag.info = db.Dept;return View();}//添加员工public ActionResult AddEmp(){Employee emp = new Employee(){DeptId = int.Parse(Request["DeptId"]),EmpName = Request["EmpName"],EmpPhone = Request["EmpPhone"],EmpArea = Request["EmpArea"],EmpSalary =decimal.Parse(Request["EmpSalary"])};db.Employee.Add(emp);int i = db.SaveChanges();if (i>0){return Content("<script>alert('添加成功');window.location.href='Index';</script>");}else{return Content("<script>alert('添加失败');window.location.href='AddEmpFrom';</script>");}}

3.运行结果

三.删除

1.Home控制器中的DeleteEmp方法

//删除员工
//简单写法以注释public ActionResult DeleteEmp(){int empid = int.Parse(Request["EmpId"]);//var emp = db.Employee.Find(empid);//db.Employee.Remove(emp);//int i = db.SaveChanges();string sql = "delete from Employee where EmpId = @EmpId";SqlParameter parameter = new SqlParameter("@EmpId", empid);int i = db.Database.ExecuteSqlCommand(sql, parameter);if (i > 0){return Content("<script>alert('删除成功');window.location.href='Index';</script>");}else{return Content("<script>alert('删除失败');window.location.href='Index';</script>");}}

2.运行结果

四.修改

1.修改页面

<body><center><h1>编辑员工</h1></center><div><form action="ExcistEmp" method="post"><input type="hidden" name="EmpId" value="@ViewBag.empinfo.EmpId" /><table align="center" cellspacing="0" border="1" width="500"><tr><th>所属部门:</th><td><select name="DeptId"><option value="0">--请选择--</option>@foreach (var item in ViewBag.info){<option value="@item.DeptId">@item.DeptName</option>}</select></td></tr><tr><th>员工姓名:</th><td><input type="text" name="EmpName" value="@ViewBag.empinfo.EmpName" /></td></tr><tr><th>员工电话:</th><td><input type="text" name="EmpPhone" value="@ViewBag.empinfo.EmpPhone" /></td></tr><tr><th>所在地区:</th><td><input type="text" name="EmpArea" value="@ViewBag.empinfo.EmpArea" /></td></tr><tr><th>员工薪资:</th><td><input type="text" name="EmpSalary" value="@ViewBag.empinfo.EmpSalary" /></td></tr><tr><td colspan="2" align="center"><input type="submit" name="name" value="修改员工" /></td></tr></table></form></div>
</body>

2.Home控制器中的ExcistEmpFrom方法和ExcistEmp

//编辑员工页面显示public ActionResult ExcistEmpFrom(){int empid = int.Parse(Request["EmpId"]);ViewBag.empinfo = db.Employee.Find(empid);ViewBag.info = db.Dept;return View();}
//编辑员工public ActionResult ExcistEmp(){int empid = int.Parse(Request["EmpId"]);var emp = db.Employee.Find(empid);emp.DeptId = int.Parse(Request["DeptId"]);emp.EmpName = Request["EmpName"];emp.EmpPhone = Request["EmpPhone"];emp.EmpArea = Request["EmpArea"];emp.EmpSalary = decimal.Parse(Request["EmpSalary"]);int i = db.SaveChanges(); if (i > 0){return Content("<script>alert('编辑成功');window.location.href='Index';</script>");}else{return Content("<script>alert('编辑失败');window.location.href='Index';</script>");}}

3.运行结果

五.登录

1.先在配置文件Web.config找到

<system.web>

</system.web>在里面写

</authentication>。配图如下：

2.在Controllers文件夹里建AccountController控制器

3.在所建项目中添加文件夹Filter,在文件夹Filter添加类MyExceptionFilter.cs里面后继承 HandleErrorAttribute类，重写HandleErrorAttribute类里的OnException方法

代码如下：

//引用using System.Web.Mvc;命名空间
//MyExceptionFilter类继承HandleErrorAttribute类
//重写HandleErrorAttribute类里的OnException方法public class MyExceptionFilter : HandleErrorAttribute{public override void OnException(ExceptionContext filterContext){filterContext.Result = new RedirectResult("~/Account/LogOut");filterContext.ExceptionHandled = true;return;}}

4.HomeController控制器控制器下的Index页面是整个项目的首页，不需要登录就可以查看

代码如下：

<body><div>首页@Html.ActionLink("登录", "LogOn", "Account")@Html.ActionLink("员工查询", "Index", "Account")@Html.ActionLink("退出", "LogOut", "Account")</div>
</body>

页面效果图

5.在AccountController控制器里面添加LogOn，LogOut页面。AccountController控制器里面Index页面是登录之后才能看到的页面。三个页面代码如下：

（1）LogOn页面里需要引用语法@model (项目名称).Models.(数据库里的表名)

例：@model MVC登录.Models.UserInfo

@model MVC登录.Models.UserInfo
<body><div style="text-align:center">@using (Html.BeginForm()){<table width="500" cellspacing="0" border="1" align="center"><tr><td colspan="3" align="center">用户登录</td></tr><tr><td>用户名：</td><td>@Html.TextBoxFor(u => u.UserName)</td><td style="color:red">@Html.ValidationMessageFor(u => u.UserName)</td></tr><tr><td>密码：</td><td>@Html.PasswordFor(u => u.Password)</td><td style="color:red">@Html.ValidationMessageFor(u => u.Password)</td></tr><tr><td colspan="3" align="center"><input type="submit" value="登录" /></td></tr><tr><td colspan="3" style="color:red">@Html.ValidationSummary(true)</td></tr></table>}</div>
</body>

页面效果图

（2）LogOut页面

<body><div>@Html.ActionLink("首页", "Index", "Home")<div><img src="~/Img/2022-05-20_113017.png" width="100%" /></div></div>
</body>

（3.Index页面

<div> 用户设置@Html.ActionLink("主页","Index","Home")</div>

6.在Models数据模型Model1.edmx下的Model1.tt里面找UserInfo.cs类，给属性添加验证

代码如下：

    using System.ComponentModel.DataAnnotations;public partial class UserInfo{public int UserId { get; set; }[Required(ErrorMessage = "用户名不能为空")]public string UserName { get; set; }[Required(ErrorMessage = "密码不能为空")][DataType(DataType.Password)]public string Password { get; set; }}

7.在AccountController控制器里面添加LogOn，LogOut，Index方法

三个方法代码如下：

 public class AccountController : Controller{// GET: AccountMVCLession31Entities db = new MVCLession31Entities();//登录之后才能看到的页面[Authorize]public ActionResult Index(){//ViewBag.info = db.Employee;ViewBag.info = from e in db.Employeejoin  d in db.Dept on e.DeptId equals d.DeptIdselect new EmpViewForm{EmpId = e.EmpId,DeptName = d.DeptName,EmpName = e.EmpName,EmpPhone =e.EmpPhone,EmpArea = e.EmpArea,EmpSalary =e.EmpSalary};return View();}//登录页面public ActionResult LogOn(){return View();}//在post表单请求下执行的登录方法[HttpPost]public ActionResult LogOn(UserInfo u){if (ModelState.IsValid && ValidateUser(u.UserName, u.Password)){//添加票证FormsAuthentication.SetAuthCookie(u.UserName, false);return RedirectToAction("Index");}ModelState.AddModelError("", "账号或者密码错误");return View();}//与数据库连接的方法private bool ValidateUser(string name, string pwd){using (MVCLession31Entities db = new MVCLession31Entities()){var u = (from p in db.UserInfo where p.UserName == name && p.Password == pwd select p).FirstOrDefault();if (u == null){return false;}else{return true;}}}[MyExceptionFilter]//退出页面public ActionResult LogOut(){FormsAuthentication.SignOut();return View();}

8.运行视频

运行结果