EF基础知识小记四(数据库=>模型设计器)

EF基础知识小记三(设计器=>数据库)介绍了如何创建一个空设计器模型,并如何将模型同步到数据库的表中,本文则主要介绍如何将一个存在的数据库同步到模型设计器中。为了能快速的模拟这个过程,给出一下建表语句,代码如下:

--建表脚本
create table Student
(
    Id int not null,
    Name varchar(30) not null,
    Age int not null
)
create table Teacher
(
    Id int not null,
    Name varchar(30) not null,
    Age int not null
)

create table StudentTeacher
(
    StudentId int not null,
    TeacherId int not null
)

create table InfoCard
(
    Id int not null,
    [Money] int not null,
    StudentId int not null
)

--给表添加约束
--单主键约束
alter table Student add constraint [PK_People]
primary key clustered (Id Asc)

alter table InfoCard add constraint [PK_InfoCard]
primary key clustered (Id Asc)

alter table Teacher add constraint [PK_Teacher]
primary key clustered (Id Asc)

--双主键约束(多对多)
alter table StudentTeacher add constraint [PK_StudentTeacher]
primary key clustered (StudentId,TeacherId Asc)

--双外键约束(多对多)
alter table StudentTeacher
add constraint [FK_StudentTeacher_Student]
foreign key (StudentId) references Student (Id) on delete no action on update no action --级联更新级联删除

alter table StudentTeacher add constraint [FK_StudentTeacher_Teacher]
foreign key (TeacherId) references Teacher (Id) on delete no action on update no action 

--但外键约束(一对多)
alter table InfoCard add constraint [FK_InfoCard_Student]
foreign key (StudentId) references Student (Id) on delete no action on update no action

1、看过EF基础知识小记三(设计器=>数据库)后,省去一些简单的操作步骤,直接到下面这步操作

根据数据库生成edmx

2、选择指定的数据库,并选择响应的表生成edmx模型设计器

3、点击确认,生成成功,如下图:

4、增删查该的操作和EF基础知识小记三(设计器=>数据库)介绍的一样