【EF】EntityFramework DBFirst的施用

一、前言

       久闻EF大名,在此之前做C/S产品用的是Dapper对SqlLite实行ORM。然后接触公司授权系统后发觉用的是EntityFramework对SQLSever进行ORM。授权系统里用的是DBFirst,增删查改使用Linq
To Entity,以为不行有助于。本篇篇幅很短,老驾乘员可直接略过

 

二、添加EF       

        Step1:增添“新建项”,起个称呼,增加ADO.NET实体数据模型;

        
Step2:选取模型类型,来自数据库的EF设计器;

         Step3:选拔数据连接,新建连接,接纳要使用的数据库类型;私下认可SQLSever;

        
Step4:测验连接数据库;

        
Step5:选择EF版本;

        
Step6:采取要实体化的表,点击完结。

 

三、操作

       经过上述操作会产生八个文件:

        1.
EntityModel.Context.tt
(上下文,全数class的DBSet集结都在这些文件下的.cs文件中)

        2. EntityModel.tt      
(每种表映射后的class都放在那个文件上面)

        3. EntityModel.edmx
(可视化的表设计器)

       
若是连接的数据库下有八个表:AgencyInfo,ContractInfo,CustomerInfo。那么EntityModel.tt下就能够有八个关照的.cs文件:

//------------------------------------------------------------------------------
// <auto-generated>
//    This code was generated from a template.
//
//    Manual changes to this file may cause unexpected behavior in your application.
//    Manual changes to this file will be overwritten if the code is regenerated.
// </auto-generated>
//------------------------------------------------------------------------------

using System;
using System.Collections.Generic;

namespace HHH
{
    public partial class AgencyInfo
    {
        public System.Guid ID { get; set; }
        public string UnitName { get; set; }
        public string Phone { get; set; }
        public string Address { get; set; }
        public string comments { get; set; }
        public Nullable<System.DateTime> CreatTime { get; set; }
        public Nullable<int> ShowFlag { get; set; }
    }

}

//------------------------------------------------------------------------------
// <auto-generated>
//    This code was generated from a template.
//
//    Manual changes to this file may cause unexpected behavior in your application.
//    Manual changes to this file will be overwritten if the code is regenerated.
// </auto-generated>
//------------------------------------------------------------------------------

using System;
using System.Collections.Generic;

namespace HHH
{
    public partial class ContractInfo
    {
        public System.Guid ID { get; set; }
        public string Title { get; set; }
        public string Comment { get; set; }
        public Nullable<System.DateTime> CreateDate { get; set; }
    }

}

//------------------------------------------------------------------------------
// <auto-generated>
//    This code was generated from a template.
//
//    Manual changes to this file may cause unexpected behavior in your application.
//    Manual changes to this file will be overwritten if the code is regenerated.
// </auto-generated>
//------------------------------------------------------------------------------

using System;
using System.Collections.Generic;

namespace HHH
{
    public partial class CustomerInfo
    {
        public System.Guid ID { get; set; }
        public string Name { get; set; }
        public string ContactInfo { get; set; }
        public string Address { get; set; }
        public string Comments { get; set; }
        public string Email { get; set; }
        public string MobilePhone { get; set; }
        public string province { get; set; }
        public string City { get; set; }
        public string Type { get; set; }
        public Nullable<System.DateTime> CreateDate { get; set; }
    }

}

        

        
那么EntityModel.Context.tt是这样的:

//------------------------------------------------------------------------------
// <auto-generated>
//    This code was generated from a template.
//
//    Manual changes to this file may cause unexpected behavior in your application.
//    Manual changes to this file will be overwritten if the code is regenerated.
// </auto-generated>
//------------------------------------------------------------------------------

using System;
using System.Data.Entity;
using System.Data.Entity.Infrastructure;

namespace HHH
{
    public partial class MyEntities: DbContext
    {
        public MyEntities()
            : base("name=MyEntities")
        {
        }

        protected override void OnModelCreating(DbModelBuilder modelBuilder)
        {
            throw new UnintentionalCodeFirstException();
        }

        public DbSet<ContractInfo> ContractInfoes { get; set; }
        public DbSet<CustomerInfo> CustomerInfoes { get; set; }
        public DbSet<AgencyInfo> AgencyInfoes { get; set; }

    }
}

 

          
要求对表对象操作时,首先要:

private MyEntities dbContext = new MyEntities();

             需求对哪些表操作,就dbContext.ContractInfoes可能dbContext.CustomerInfoes那样找到数据集结,然后用Linq去操作,最后别忘dbContext.SaveChanges()保存修改就能够。

 

四、结尾

       前几天再看看写点什么,保持学习进程,再过几天要去练车了

相关文章