是否可以在实体框架（代码优先）的种子方法中添加两个表的数据？
Posted
技术标签:
【中文标题】是否可以在实体框架（代码优先）的种子方法中添加两个表的数据？【英文标题】：Is it possible to add two table's data in Seed method in Entity Framework(Code-first)? 【发布时间】：2015-02-24 03:59:04 【问题描述】：在我的 DataLayer 中，我有这个“种子”方法：
protected override void Seed(Context context)
User u1 = new User()
UserName = "dayan",
Password = "dayan",
Role = "Admin"
;
User u2 = new User()
UserName = "neranjan",
Password = "neranjan",
Role = "employee"
;
context.Users.Add(u1);
context.Users.Add(u2);
base.Seed(context);
这是我的用户表的样子：
所以现在我需要像这样在这个种子方法中添加更多的表数据：
Examination e = new Examination()
Description = "fromda console",
CutOffMark = 1000,
QuestionID = new List<Question>()
new Question()
QuestionDes = "Question",
Answer1 = "11",
Answer2 = "22",
Answer3 = "33",
Answer4 = "44",
Correct = 1
;
我需要这种方法的目的是因为我使用的是代码优先实体框架 我需要确保当我删除数据库并再次创建数据库时，这些行应该写入这些表中。
你能告诉我如何解决这个问题吗... 谢谢！！
【问题讨论】：
你为什么不能把它也放在你的种子方法中？ 【参考方案1】：这就是我解决它的方法......
public class ContextSeeder : DropCreateDatabaseIfModelChanges<Context>
protected override void Seed(Context context)
Examination e1 = new Examination()
Description = "Science",
CutOffMark = 10,
QuestionID = new List<Question>()
new Question()
QuestionDes = "What is a data bus?",
Answer1 = "It carries a word to or from memory",
Answer2 = "It is used to store intermediate data and instructions",
Answer3 = "It decodes the instructions",
Answer4 = "It contains the instruction that is being executed",
Correct = 1
//ExaminationID = 1
;
Examination e2 = new Examination()
Description = "Science",
CutOffMark = 10,
QuestionID = new List<Question>()
new Question()
QuestionDes = "What is program counter?",
Answer1 = "It keeps track of the memory address of the instruction that is to be executed next.",
Answer2 = "It is used to store intermediate data and instructions",
Answer3 = "It decodes the instructions",
Answer4 = "It contains the instruction that is being executed",
Correct = 1
//ExaminationID = 1
;
Examination e3 = new Examination()
Description = "Science",
CutOffMark = 10,
QuestionID = new List<Question>()
new Question()
QuestionDes = "Expand SD RAM.?",
Answer1 = "Synchronous Dynamic Random Access Memory.",
Answer2 = "It is used to store intermediate data and instructions",
Answer3 = "It decodes the instructions",
Answer4 = "It contains the instruction that is being executed",
Correct = 1
//ExaminationID = 1
;
Examination e4 = new Examination()
Description = "Computer Science",
CutOffMark = 40,
QuestionID = new List<Question>()
new Question()
QuestionDes = "What is Instruction register?",
Answer1 = "Stores a copy of current instruction.",
Answer2 = "It is used to store intermediate data and instructions",
Answer3 = "It decodes the instructions",
Answer4 = "It contains the instruction that is being executed",
Correct = 1
//ExaminationID = 1
;
User u1 = new User()
UserName = "dayan",
Password = "dayan",
Role = "Admin"
;
User u2 = new User()
UserName = "neranjan",
Password = "neranjan",
Role = "employee"
;
context.Examinations.Add(e1);
context.Examinations.Add(e2);
context.Examinations.Add(e3);
context.Examinations.Add(e4);
context.Users.Add(u1);
context.Users.Add(u2);
//context.SaveChanges();
base.Seed(context);
我正在使用 MVC，所以我在我的 MVC 文件夹中找到了这个名为“Global.asax”的文件，并将这个“SetInitializer”添加到其中。原来是这样的……
public class MvcApplication : System.Web.HttpApplication
protected void Application_Start()
AreaRegistration.RegisterAllAreas();
WebApiConfig.Register(GlobalConfiguration.Configuration);
FilterConfig.RegisterGlobalFilters(GlobalFilters.Filters);
RouteConfig.RegisterRoutes(RouteTable.Routes);
BundleConfig.RegisterBundles(BundleTable.Bundles);
AuthConfig.RegisterAuth();
**Database.SetInitializer(new ContextSeeder());**
然后我运行了我的主页。这。它自动将我的数据对象插入到数据库中...... 我的主页是这样的......
@using (html.BeginForm("Results", "Exam"))
<table>
<tr>
<td>
@grid.GetHtml(columns: new[]
grid.Column("ID"),
grid.Column("QuestionDes"),
grid.Column("Answer1"),
grid.Column("Answer2"),
grid.Column("Answer3"),
grid.Column("Answer4")
)
</td>
<td>
@Html.DropDownList("Answer1", new SelectList(ViewBag.sel, "Value", "Text"), new @id = "1" )
@Html.DropDownList("Answer2", new SelectList(ViewBag.sel, "Value", "Text"), new @id = "2" )
@Html.DropDownList("Answer3", new SelectList(ViewBag.sel, "Value", "Text"), new @id = "3" )
@Html.DropDownList("Answer4", new SelectList(ViewBag.sel, "Value", "Text"), new @id = "4" )
</td>
</tr>
</table>
<input type="submit" value="Submit"/>
控制器：
public ActionResult Examination()
IService ser = new Service();
//taking all the list questions passed from the LoadQuestions_ToTheGridview() method
List<Entities.Question> list = ser.LoadQuestions_ToTheGridview();
ViewBag.qlist = list;
List<Models.SelectedListItems> selList = new List<Models.SelectedListItems>();
selList.Add(new Models.SelectedListItems Text = "----Select----", Value = "0" );
selList.Add(new Models.SelectedListItems Text = "Answer 1", Value = "1" );
selList.Add(new Models.SelectedListItems Text = "Answer 2", Value = "2" );
selList.Add(new Models.SelectedListItems Text = "Answer 3", Value = "3" );
selList.Add(new Models.SelectedListItems Text = "Answer 4", Value = "4" );
ViewBag.sel = selList;
return View(list);
谢谢！！！！
【讨论】：
以上是关于是否可以在实体框架（代码优先）的种子方法中添加两个表的数据？的主要内容，如果未能解决你的问题，请参考以下文章
使用实体框架和代码优先方法创建数据库时，是不是可以从 SSMS 在数据库表上创建索引