Entity Framework 学习第二天

今天记录的内容不多，只是简单用一下Model first，新建项目，然后添加新建项，选择数据中的ado.net实体数据模型

这次我们选择空模型，然后右键，新增，实体

在这项demo中我打算建两个数据实体，一个studentInfo，classInfo。

得到类似uml图

我们可以在每个图上新增属性，各新增了name属性，在studentInfo上新增cId，空白处右键，新增关联，

右键根据模型生成数据库

实现在数据库建好库，然后选择数据库，就会生成sql语句了。下面是我生成的sql语句

 -- --------------------------------------------------
 -- Entity Designer DDL Script for SQL Server , , and Azure
 -- --------------------------------------------------
 -- Date Created: // ::
 -- Generated from EDMX file: C:\Users\admin\documents\visual studio \Projects\EFConsole\ConsoleApplication1\Model1.edmx
 -- --------------------------------------------------

 SET QUOTED_IDENTIFIER OFF;
 GO
 USE [EFtest];
 GO
 IF SCHEMA_ID(N'dbo') IS NULL EXECUTE(N'CREATE SCHEMA [dbo]');
 GO

 -- --------------------------------------------------
 -- Dropping existing FOREIGN KEY constraints
 -- --------------------------------------------------

 -- --------------------------------------------------
 -- Dropping existing tables
 -- --------------------------------------------------

 -- --------------------------------------------------
 -- Creating all tables
 -- --------------------------------------------------

 -- Creating table 'Student'
 CREATE TABLE [dbo].[Student] (
     [id] int IDENTITY(,) NOT NULL,
     [name] nvarchar(max)  NOT NULL,
     [cId] nvarchar(max)  NOT NULL,
     [ClassInfo_id] int  NOT NULL
 );
 GO

 -- Creating table 'ClassInfo'
 CREATE TABLE [dbo].[ClassInfo] (
     [id] int IDENTITY(,) NOT NULL,
     [name] nvarchar(max)  NOT NULL
 );
 GO

 -- --------------------------------------------------
 -- Creating all PRIMARY KEY constraints
 -- --------------------------------------------------

 -- Creating primary key on [id] in table 'Student'
 ALTER TABLE [dbo].[Student]
 ADD CONSTRAINT [PK_Student]
     PRIMARY KEY CLUSTERED ([id] ASC);
 GO

 -- Creating primary key on [id] in table 'ClassInfo'
 ALTER TABLE [dbo].[ClassInfo]
 ADD CONSTRAINT [PK_ClassInfo]
     PRIMARY KEY CLUSTERED ([id] ASC);
 GO

 -- --------------------------------------------------
 -- Creating all FOREIGN KEY constraints
 -- --------------------------------------------------

 -- Creating foreign key on [ClassInfo_id] in table 'Student'
 ALTER TABLE [dbo].[Student]
 ADD CONSTRAINT [FK_StudentInfoClassInfo]
     FOREIGN KEY ([ClassInfo_id])
     REFERENCES [dbo].[ClassInfo]
         ([id])
     ON DELETE NO ACTION ON UPDATE NO ACTION;

 -- Creating non-clustered index for FOREIGN KEY 'FK_StudentInfoClassInfo'
 CREATE INDEX [IX_FK_StudentInfoClassInfo]
 ON [dbo].[Student]
     ([ClassInfo_id]);
 GO

 -- --------------------------------------------------
 -- Script has ended
 -- --------------------------------------------------

将代码复制到数据库中执行以下就可以了，这就是Model first。code first与Model first并不是一样的。code first 需要我们自己写类，用的不是很多。