ORM概述：
ORM全稱是“物件 - 關係對映” 。
ORM是將關聯式資料庫中的資料用物件的形式表現出來，並通過物件導向的方式將這些物件組織起來，實現系統業務邏輯的過程。
Entity Framework（簡稱EF）：
ASP.NET MVC應用程式推薦使用的ORM框架；
支援多種資料庫；
對映引擎支援儲存過程；
提供Visual Studio整合工具，執行視覺化操作；
一、資料準備
本教程使用具體例項進行演示EF的基本使用，需要用資料庫以及一些工具類。
資料表結構指令碼：
create table Dept --部門資訊
(
DeptId int primary key identity(1,1),
DeptName varchar(50) not null
)
create table Employee --員工資訊
(
EmpId int primary key identity(1,1),
DeptId int not null,
EmpName varchar(50) not null,
EmpPhone varchar(50) not null,
EmpArea varchar(50) not null,
EmpSalary decimal(18,2) not null
)
insert into Dept(DeptName) values('開發部')
insert into Dept(DeptName) values('測試部')
insert into Dept(DeptName) values('實施部')
insert into Employee(DeptId,EmpName,EmpPhone,EmpArea,EmpSalary)
values(1,'劉德華','13887855552','武漢',6500)
insert into Employee(DeptId,EmpName,EmpPhone,EmpArea,EmpSalary)
values(2,'張學友','13556528634','深圳',6500)
insert into Employee(DeptId,EmpName,EmpPhone,EmpArea,EmpSalary)
values(3,'劉亦菲','13448494546','廣州',6500)
insert into Employee(DeptId,EmpName,EmpPhone,EmpArea,EmpSalary)
values(1,'周杰倫','13888666855','北京',6500)
insert into Employee(DeptId,EmpName,EmpPhone,EmpArea,EmpSalary)
values(2,'許巍','13868654219','上海',6500)
insert into Employee(DeptId,EmpName,EmpPhone,EmpArea,EmpSalary)
values(3,'孫燕姿','13895133572','成都',6500)
insert into Employee(DeptId,EmpName,EmpPhone,EmpArea,EmpSalary)
values(1,'朴樹','13458788896','武漢',6500)
insert into Employee(DeptId,EmpName,EmpPhone,EmpArea,EmpSalary)
values(2,'周潤發','13554588745','南京',6500)
insert into Employee(DeptId,EmpName,EmpPhone,EmpArea,EmpSalary)
values(3,'李連杰','13998759654','上海',6500)
select * from Dept;
select * from Employee;
匿名類集合轉動態屬性：
public class MyDynamic
{
public static List<ExpandoObject> ToExpandoList(object query)
{
List<ExpandoObject> listExpando = new List<ExpandoObject>();
foreach (var entity in (IEnumerable)query)
{
Type type = entity.GetType();
dynamic dyEntity = new ExpandoObject();
IDictionary<string, object> dict = new Dictionary<string, object>();
dict = dyEntity as ExpandoObject;
PropertyInfo[] arrProperty = type.GetProperties();
foreach (PropertyInfo prop in arrProperty)
{
string a = prop.Name;
string b = prop.GetValue(entity, null).ToString();
dict.Add(prop.Name, prop.GetValue(entity, null));
}
listExpando.Add(dict as dynamic);
}
return listExpando;
}
}
二、EF實現增刪改查
在控制器中建立資料庫操作類物件：
DBTESTEntities db = new DBTESTEntities();
（1）實現資料列表
Action:
public ActionResult Index()
{
var listView = from emp in db.Employee
join dept in db.Dept on emp.DeptId equals dept.DeptId
select new
{
EmpId = emp.EmpId,
DeptId = emp.DeptId,
DeptName = dept.DeptName,
EmpName = emp.EmpName,
EmpPhone = emp.EmpPhone,
EmpArea = emp.EmpArea,
EmpSalary = emp.EmpSalary
};
ViewBag.listView = MyDynamic.ToExpandoList(listView);
return View();
}
View:
<html>
<head>
<meta name="viewport" content="width=device-width" />
<title>Index</title>
<style type="text/css">
div, table, tr, td {
margin: 0px;
padding: 0px;
}
.myTable {
width: 800px;
margin: 20px;
border-collapse: collapse;
}
.myTable td,.myTable th {
height: 30px;
line-height: 30px;
padding: 6px;
}
</style>
</head>
<body>
<div>
<h1>查詢員工資訊</h1>
<a href="AddForm">新增員工</a> <br /><br />
<table width="1000" border="1" class="myTable">
<tr>
<th>員工編號</th>
<th>部門名稱</th>
<th>員工姓名</th>
<th>員工電話</th>
<th>所在地區</th>
<th>員工工資</th>
<th>操作</th>
</tr>
@foreach (var item in ViewBag.listView)
{
<tr>
<td>@item.EmpId</td>
<td>@item.DeptName</td>
<td>@item.EmpName</td>
<td>@item.EmpPhone</td>
<td>@item.EmpArea</td>
<td>@item.EmpSalary.ToString("F2")</td>
<td>
<a href="UpdateForm?EmpId=@item.EmpId">編輯</a> |
<a href="Delete?EmpId=@item.EmpId" onclick="return confirm('確定刪除嗎');">刪除</a>
</td>
</tr>
}
</table>
</div>
</body>
</html>
（2）實現資料新增
新增頁面Action:
public ActionResult AddForm()
{
//查詢所有部門
ViewBag.listDept = db.Dept.ToList();
return View();
}
新增頁面檢視：
<html>
<head>
<meta name="viewport" content="width=device-width" />
<title>AddForm</title>
<style type="text/css">
div, table, tr, td {
margin: 0px;
padding: 0px;
}
.myTable {
width: 800px;
margin: 20px auto;
border-collapse: collapse;
}
.myTable td {
height: 30px;
line-height: 30px;
padding: 6px;
}
</style>
</head>
<body>
<form method="post" action="~/Home/Add">
<div style="text-align:center;">
<table width="800" class="myTable" border="1">
<tr>
<td colspan="2" align="center" style="font-weight:bold;">員工新增</td>
</tr>
<tr>
<td width="200" align="right">所屬部門：</td>
<td width="600" align="left">
<select name="DeptId" id="DeptId">
<option value="0">--請選擇--</option>
@foreach (var item in ViewBag.listDept)
{
<option value="@item.DeptId">@item.DeptName</option>
}
</select>
</td>
</tr>
<tr>
<td width="200" align="right">員工姓名：</td>
<td width="600" align="left"><input type="text" name="txtRealName" /></td>
</tr>
<tr>
<td width="200" align="right">員工電話：</td>
<td width="600" align="left"><input type="text" name="txtPhone" /></td>
</tr>
<tr>
<td width="200" align="right">所在城市：</td>
<td width="600" align="left"><input type="text" name="txtArea" /></td>
</tr>
<tr>
<td width="200" align="right">月薪：</td>
<td width="600" align="left"><input type="text" name="txtSalary" /></td>
</tr>
<tr>
<td width="200" align="right"></td>
<td width="600" align="left">
<input type="submit" value="新增" />
<a href="Index">返回首頁</a>
</td>
</tr>
</table>
</div>
</form>
</body>
</html>
處理新增提交請求的Action：
public ActionResult Add()
{
//執行新增操作
//Employee emp = new Employee();
//emp.DeptId = int.Parse(Request["DeptId"]);
//emp.EmpName = Request["txtRealName"];
//emp.EmpPhone = Request["txtPhone"];
//emp.EmpArea = Request["txtArea"];
//emp.EmpSalary = decimal.Parse(Request["txtSalary"]);
//db.Employee.Add(emp);
//db.SaveChanges();
//EF框架執行sql語句
string sql = "insert into Employee(DeptId,EmpName,EmpPhone,EmpArea,EmpSalary) values(@DeptId,@EmpName,@EmpPhone,@EmpArea,@EmpSalary)";
SqlParameter DeptId = new SqlParameter("@DeptId", int.Parse(Request["DeptId"]));
SqlParameter EmpName = new SqlParameter("@EmpName", Request["txtRealName"]);
SqlParameter EmpPhone = new SqlParameter("@EmpPhone", Request["txtPhone"]);
SqlParameter EmpArea = new SqlParameter("@EmpArea", Request["txtArea"]);
SqlParameter EmpSalary = new SqlParameter("@EmpSalary", decimal.Parse(Request["txtSalary"]));
int rowCount = db.Database.ExecuteSqlCommand(sql,DeptId, EmpName, EmpPhone, EmpArea, EmpSalary);
return Content("<script >alert('新增成功！');window.location.href='AddForm';</script >", "text/html");
}
（3）實現資料編輯修改
編輯頁面Action:
public ActionResult UpdateForm()
{
//查詢所有部門
ViewBag.listDept = db.Dept.ToList();
//查詢員工詳情
ViewBag.emp = db.Employee.Find(int.Parse(Request["EmpId"]));
return View();
}
編輯頁面檢視：
<html>
<head>
<meta name="viewport" content="width=device-width" />
<title>UpdateForm</title>
<style type="text/css">
div, table, tr, td {
margin: 0px;
padding: 0px;
}
.myTable {
width: 800px;
margin: 20px auto;
border-collapse: collapse;
}
.myTable td {
height: 30px;
line-height: 30px;
padding: 6px;
}
</style>
</head>
<body>
<form method="post" action="~/Home/Update">
<div style="text-align:center;">
<input type="hidden" name="hdEmpId" value="@ViewBag.emp.EmpId" />
<table width="800" class="myTable" border="1">
<tr>
<td colspan="2" align="center" style="font-weight:bold;">員工修改</td>
</tr>
<tr>
<td width="200" align="right">所屬部門：</td>
<td width="600" align="left">
<select name="DeptId" id="DeptId">
<option value="0">--請選擇--</option>
@foreach (var item in ViewBag.listDept)
{
<option value="@item.DeptId" @(item.DeptId == ViewBag.emp.DeptId ? "selected" : "")>@item.DeptName</option>
}
</select>
</td>
</tr>
<tr>
<td width="200" align="right">員工姓名：</td>
<td width="600" align="left"><input type="text" name="txtRealName" value="@ViewBag.emp.EmpName" /></td>
</tr>
<tr>
<td width="200" align="right">員工電話：</td>
<td width="600" align="left"><input type="text" name="txtPhone" value="@ViewBag.emp.EmpPhone" /></td>
</tr>
<tr>
<td width="200" align="right">所在城市：</td>
<td width="600" align="left"><input type="text" name="txtArea" value="@ViewBag.emp.EmpArea" /></td>
</tr>
<tr>
<td width="200" align="right">月薪：</td>
<td width="600" align="left"><input type="text" name="txtSalary" value="@ViewBag.emp.EmpSalary" /></td>
</tr>
<tr>
<td width="200" align="right"></td>
<td width="600" align="left">
<input type="submit" value="修改" />
<a href="Index">返回首頁</a>
</td>
</tr>
</table>
</div>
</form>
</body>
</html>
處理修改請求的Action:
public ActionResult Update()
{
//EF框架執行修改操作
//int empId = int.Parse(Request["hdEmpId"]);
//Employee emp = db.Employee.Find(empId);
//emp.DeptId = int.Parse(Request["DeptId"]);
//emp.EmpName = Request["txtRealName"];
//emp.EmpPhone = Request["txtPhone"];
//emp.EmpArea = Request["txtArea"];
//emp.EmpSalary = decimal.Parse(Request["txtSalary"]);
//db.SaveChanges();
//EF框架執行sql語句
int empId = int.Parse(Request["hdEmpId"]);
string sql = "update Employee set DeptId=@DeptId,EmpName=@EmpName,EmpPhone=@EmpPhone,EmpArea=@EmpArea,EmpSalary=@EmpSalary where EmpId=@EmpId";
SqlParameter DeptId = new SqlParameter("@DeptId", int.Parse(Request["DeptId"]));
SqlParameter EmpName = new SqlParameter("@EmpName", Request["txtRealName"]);
SqlParameter EmpPhone = new SqlParameter("@EmpPhone", Request["txtPhone"]);
SqlParameter EmpArea = new SqlParameter("@EmpArea", Request["txtArea"]);
SqlParameter EmpSalary = new SqlParameter("@EmpSalary", decimal.Parse(Request["txtSalary"]));
SqlParameter EmpId = new SqlParameter("@EmpId", empId);
int rowCount = db.Database.ExecuteSqlCommand(sql,DeptId, EmpName, EmpPhone, EmpArea, EmpSalary, EmpId);
return Content("<script >alert('修改成功！');window.location.href='UpdateForm?EmpId="+ empId + "';</script >", "text/html");
}
（4）實現資料的刪除
處理刪除請求的Action:
public ActionResult Delete()
{
//EF框架執行刪除操作
//int empId = int.Parse(Request["EmpId"]);
//Employee emp = db.Employee.Find(empId);
//db.Employee.Remove(emp);
//db.SaveChanges();
//EF框架執行SQL語句
int empId = int.Parse(Request["EmpId"]);
string sql = "delete from Employee where EmpId = @EmpId";
SqlParameter EmpId = new SqlParameter("@EmpId", empId);
int rowCount = db.Database.ExecuteSqlCommand(sql,EmpId);
return Content("<script >alert('刪除成功！');window.location.href='Index';</script >", "text/html");
}
三、組合條件搜尋+分頁
搜尋頁面Action:
public ActionResult SearchForm()
{
var listView = from emp in db.Employee
join dept in db.Dept on emp.DeptId equals dept.DeptId
select new
{
EmpId = emp.EmpId,
DeptId = emp.DeptId,
DeptName = dept.DeptName,
EmpName = emp.EmpName,
EmpPhone = emp.EmpPhone,
EmpArea = emp.EmpArea,
EmpSalary = emp.EmpSalary
};
//新增查詢條件
if (!string.IsNullOrEmpty(Request["ddlDept"]))
{
//linq to entity,不能在lambda裡面進行int.parse,或者其它的顯示隱式的轉換,所以將型別轉換寫在外面 或者下述方案也可以解決
//此處如果進行型別轉換例如ToString(),int.Parse()會報錯,可以上面的listView轉換為LinqToObject,即db.Employee和db.Dept都呼叫AsEnumerable。
int deptId = int.Parse(Request["ddlDept"]);
listView = listView.Where(p => p.DeptId == deptId);
}
if (!string.IsNullOrEmpty(Request["txtRealName"]))
{
//linq to entity,不能在lambda裡面進行int.parse,或者其它的顯示隱式的轉換
string realName = Request["txtRealName"].ToString();
listView = listView.Where(p => p.EmpName.Contains(realName));
}
//處理分頁
int pageSize = 5; //頁碼大小
int pageIndex = 1; //當前頁碼
if (!string.IsNullOrEmpty(Request["page"]))
pageIndex = int.Parse(Request["page"]);
int recordCount = listView.Count(); //總記錄條數量
//總共頁數
int pageCount = recordCount % pageSize == 0 ? recordCount / pageSize : recordCount / pageSize + 1;
if (pageIndex > pageCount) pageIndex = pageCount;
if (pageIndex < 1) pageIndex = 1;
listView = listView.OrderBy(p => p.EmpId).Skip(pageSize * (pageIndex - 1)).Take(pageSize);
ViewBag.listView = MyDynamic.ToExpandoList(listView);
//查詢所有部門
ViewBag.listDept = db.Dept.ToList();
//記錄頁碼大小，當前頁和總頁數
ViewBag.pageSize = pageSize;
ViewBag.pageIndex = pageIndex;
ViewBag.pageCount = pageCount;
return View();
}
搜尋頁面檢視：
<html>
<head>
<meta name="viewport" content="width=device-width" />
<title>多條件組合搜尋+分頁</title>
</head>
<body>
<h1>查詢員工資訊</h1>
<form action="SearchForm" method="post">
<div style="height:30px; line-height:30px;">
所屬部門:
<select name="ddlDept" id="ddlDept">
<option value="">--請選擇--</option>
@foreach (var item in ViewBag.listDept)
{
int deptId = 0;
if (!string.IsNullOrEmpty(Request["ddlDept"]))
{
deptId = int.Parse(Request["ddlDept"]);
}
<option value="@item.DeptId" @(item.DeptId == deptId ? "selected" : "")>@item.DeptName</option>
}
</select>
員工姓名:
<input type="text" name="txtRealName" id="txtRealName" value="@Request["txtRealName"]" />
<input type="submit" value="搜尋" />
</div>
</form>
<div>
<table width="1000" border="1" class="myTable">
<tr>
<th>員工編號</th>
<th>部門名稱</th>
<th>員工姓名</th>
<th>員工電話</th>
<th>所在地區</th>
<th>員工工資</th>
</tr>
@foreach (var item in ViewBag.listView)
{
<tr>
<td>@item.EmpId</td>
<td>@item.DeptName</td>
<td>@item.EmpName</td>
<td>@item.EmpPhone</td>
<td>@item.EmpArea</td>
<td>@item.EmpSalary.ToString("F2")</td>
</tr>
}
</table>
</div>
@{string urlParama = "ddlDept=" + Request["ddlDept"] + "&txtRealName=" + Request["txtRealName"];}
<form action="SearchForm?@urlParama" method="post">
<div style="height:30px; line-height:30px;">
<a href="SearchForm?page=1&@urlParama">首頁</a>
<a href="SearchForm?page=@(ViewBag.pageIndex-1)&@urlParama">上一頁</a>
<a href="SearchForm?page=@(ViewBag.pageIndex+1)&@urlParama">下一頁</a>
<a href="SearchForm?page=@ViewBag.pageCount&@urlParama">末頁</a>
轉到:<input name="page" type="text" style="width:30px;" value="@ViewBag.pageIndex" />頁
<input type="submit" value="GO" />
當前第<span style="color:orangered;">@ViewBag.pageIndex</span>頁
共<span style="color:orangered;">@ViewBag.pageCount</span>頁
</div>
</form>
</body>
</html>
四、JPager外掛實現分頁
本案例同樣實現組合條件+分頁的功能，只是分頁功能使用Jpager來實現，JPager外掛可以在Nuget中進行安裝。
安裝完成後引入名稱空間：
using JPager.Net;
Action：
public ActionResult Index(PagerInBase param)
{
param.PageSize = 3;
var list = from emp in db.Employee
join dept in db.Dept on emp.DeptId equals dept.DeptId
select new EmpAndDept
{
EmpId = emp.EmpId,
DeptId = emp.DeptId,
DeptName = dept.DeptName,
EmpName = emp.EmpName,
EmpPhone = emp.EmpPhone,
EmpArea = emp.EmpArea,
EmpSalary = emp.EmpSalary
};
if (!string.IsNullOrEmpty(Request["DeptId"]))
{
int deptId = int.Parse(Request["DeptId"]);
list = list.Where(p => p.DeptId == deptId);
}
if (!string.IsNullOrEmpty(Request["EmpName"]))
{
string EmpName = Request["EmpName"].ToString();
list = list.Where(p => p.EmpName.Contains(EmpName));
}
var data = list.OrderBy(p=>p.EmpId).Skip(param.Skip).Take(param.PageSize);
var count = list.Count();
var res = new PagerResult<EmpAndDept>
{
Code = 0,
DataList = data,
Total = count,
PageSize = param.PageSize,
PageIndex = param.PageIndex,
RequestUrl = param.RequetUrl
};
ViewBag.ListDept = db.Dept;
ViewBag.res = res;
return View();
}
View:
<html>
<head>
<meta name="viewport" content="width=device-width" />
<title>Index</title>
<style type="text/css">
</style>
</head>
<body>
<h1>查詢員工資訊</h1>
<a href="AddForm">新增員工</a> <br /><br />
<form method="get" action="Index">
<p>
部門:
<select name="DeptId">
<option value="">--請選擇--</option>
@foreach (var item in ViewBag.ListDept)
{
int deptId = 0;
if (!string.IsNullOrEmpty(Request["DeptId"]))
{
deptId = int.Parse(Request["DeptId"]);
}
<option value="@item.DeptId" @(item.DeptId == deptId ? "selected" : "")>@item.DeptName</option>
}
</select>
姓名:
<input type="text" name="EmpName" value="@Request["EmpName"]" />
<input type="submit" value="搜 索" />
</p>
</form>
<table width="1000" border="1" class="myTable">
<tr>
<th>員工編號</th>
<th>部門名稱</th>
<th>員工姓名</th>
<th>員工電話</th>
<th>所在地區</th>
<th>員工工資</th>
<th>操作</th>
</tr>
@foreach (var item in ViewBag.res.DataList)
{
<tr>
<td>@item.EmpId</td>
<td>@item.DeptName</td>
<td>@item.EmpName</td>
<td>@item.EmpPhone</td>
<td>@item.EmpArea</td>
<td>@item.EmpSalary.ToString("F2")</td>
<td>
<a href="UpdateForm?EmpId=@item.EmpId">編輯</a> |
<a href="Delete?EmpId=@item.EmpId" onclick="return confirm('確定刪除嗎');">刪除</a>
</td>
</tr>
}
</table>
<div id="mypage">
@Html.Raw(ViewBag.res.PagerHtml()) 共 @ViewBag.res.Total 條
</div>
</body>
</html>
五、PagedList外掛實現分頁
本案例同樣實現組合條件+分頁的功能，只是分頁功能使用PagedList.MVC來實現，PagedList.MVC外掛可以在Nuget中進行安裝。
安裝完成後引入名稱空間：
using PagedList;
Action：
public ActionResult Index(int page = 1)
{
var query = from emp in db.Employee
join dept in db.Dept on emp.DeptId equals dept.DeptId
select new EmpAndDept
{
EmpId = emp.EmpId,
DeptId = emp.DeptId,
EmpName = emp.EmpName,
EmpPhone = emp.EmpPhone,
EmpArea = emp.EmpArea,
EmpSalary = emp.EmpSalary,
DeptName = dept.DeptName
};
//新增查詢條件
if (!string.IsNullOrEmpty(Request["DeptId"]))
{
//linq to entity,不能在lambda裡面進行int.parse,或者其它的顯示隱式的轉換,所以將型別轉換寫在外面 或者下述方案也可以解決
//此處如果進行型別轉換例如ToString(),int.Parse()會報錯,可以上面的listView轉換為LinqToObject,即db.Employee和db.Dept都呼叫AsEnumerable。
int deptId = int.Parse(Request["DeptId"]);
query = query.Where(p => p.DeptId == deptId);
}
if (!string.IsNullOrEmpty(Request["EmpName"]))
{
//linq to entity,不能在lambda裡面進行int.parse,或者其它的顯示隱式的轉換
string realName = Request["EmpName"].ToString();
query = query.Where(p => p.EmpName.Contains(realName));
}
int pagesize = 2;
var data = query.OrderByDescending(p => p.EmpId).ToPagedList(page, pagesize);
ViewBag.ListDept = db.Dept;
ViewBag.DataList = data;
return View();
}
View：
@using PagedList;
@using PagedList.Mvc;
<!DOCTYPE html>
<html>
<head>
<meta name="viewport" content="width=device-width" />
<title>Index</title>
</head>
<body>
<h1>查詢員工資訊</h1>
<a href="AddForm">新增員工</a> <br /><br />
<form method="get">
<p>
部門:
<select name="DeptId">
<option value="">--請選擇--</option>
@foreach (var item in ViewBag.ListDept)
{
int deptId = 0;
if (!string.IsNullOrEmpty(Request["DeptId"]))
{
deptId = int.Parse(Request["DeptId"]);
}
<option value="@item.DeptId" @(item.DeptId == deptId ? "selected" : "")>@item.DeptName</option>
}
</select>
姓名:
<input type="text" name="EmpName" value="@Request["EmpName"]" />
<input type="submit" value="搜 索" />
</p>
</form>
<table width="1000" border="1" class="myTable">
<tr>
<th>員工編號</th>
<th>部門名稱</th>
<th>員工姓名</th>
<th>員工電話</th>
<th>所在地區</th>
<th>員工工資</th>
<th>操作</th>
</tr>
@foreach (var item in ViewBag.DataList)
{
<tr>
<td>@item.EmpId</td>
<td>@item.DeptName</td>
<td>@item.EmpName</td>
<td>@item.EmpPhone</td>
<td>@item.EmpArea</td>
<td>@item.EmpSalary.ToString("F2")</td>
<td>
<a href="UpdateForm?EmpId=@item.EmpId">編輯</a> |
<a href="Delete?EmpId=@item.EmpId" onclick="return confirm('確定刪除嗎');">刪除</a>
</td>
</tr>
}
</table>
<div>
@Html.PagedListPager((IPagedList)ViewBag.DataList, page => Url.Action("Index", new { page, DeptId=Request["DeptId"], EmpName=Request["EmpName"] }))
</div>
</body>
</html>
六、EF中執行SQL查詢
在EF中執行非查詢操作，在前面的例子程式碼中已經出現過，此處不做描述，此處主要描述在EF中做SQL查詢操作。
Action:
public ActionResult SqlQueryForm()
{
DBTESTEntities db = new DBTESTEntities();
var count = db.Database.SqlQuery<int>("select count(*) from Employee");
ViewBag.count = count.FirstOrDefault();
var query1 = db.Database.SqlQuery<Employee>("select * from Employee");
ViewBag.listView1 = query1;
//如果查詢的結果找不到對應的實體，需要單獨定義一個類，返回的資料必須數量和名字都與此類屬性相同
//如果查詢出的資料需要修改，有如下2種方案
//方案一:
//Employee emp = db.Employee.SqlQuery("select * from Employee where EmpId = 1").FirstOrDefault();
//emp.EmpSalary += 100;
//db.SaveChanges();
//方案二:
//Employee emp = db.Database.SqlQuery<Employee>("select * from Employee where EmpId = 1").FirstOrDefault();
//emp.EmpSalary += 100;
//db.Entry<Employee>(emp).State = System.Data.Entity.EntityState.Modified;
//db.SaveChanges();
return View();
}
View:
<div>
<h2>使用EF中SQL語句進行查詢員工資料,員工數量:@ViewBag.count</h2>
<table width="1000" border="1" class="myTable">
<tr>
<th>員工編號</th>
<th>部門編號</th>
<th>員工姓名</th>
<th>員工電話</th>
<th>所在地區</th>
<th>員工工資</th>
</tr>
@foreach (var item in ViewBag.listView1)
{
<tr>
<td>@item.EmpId</td>
<td>@item.DeptId</td>
<td>@item.EmpName</td>
<td>@item.EmpPhone</td>
<td>@item.EmpArea</td>
<td>@item.EmpSalary.ToString("F2")</td>
</tr>
}
</table>
</div>