EF入门

傷城~ 2023-10-17 00:59 32阅读 0赞

安装ef，需要先下载连个链接工具

mysql：

[http://dev.mysql.com/downloads/windows/installer/][http_dev.mysql.com_downloads_windows_installer]

Connector/Net：

[http://dev.mysql.com/downloads/connector/net/][http_dev.mysql.com_downloads_connector_net]

MySQL for Visual Studio：

[http://dev.mysql.com/downloads/windows/visualstudio/][http_dev.mysql.com_downloads_windows_visualstudio]

\[System.Web.Http.Description.ResponseType(typeof(products))\]//设置返回值类型

using System;
    using System.Collections.Generic;
    using System.Linq;
    using System.Text;
    using System.Threading.Tasks;
    
    namespace EFTest
    {
        using System.Data.Entity;
        using System.Runtime.CompilerServices;
    
        using EFTest.Models;
    
        class Program
        {
            private static readonly laojiahenanContext dbContext = new laojiahenanContext();
            static void Main(string[] args)
            {
                //var userList = dbContext.yf_user.ToList();
                //foreach (var user in userList)
                //{
                //    System.Console.WriteLine(user.userPhone);
                //}
    
                //var addUser = dbContext.yf_user.FirstOrDefault(u => u.userPhone == "15286819573");
    
    
                dbContext.Database.Log = Console.WriteLine;
                var query = (from user in dbContext.yf_user//.Where(u=>u.userPhone=="15286819572")
                             join community in dbContext.yf_community on user.communityId equals community.id
                             orderby user.userId descending 
                            
                            select new { user, community }).Skip(1).Take(2);
    
               
    
                var list = query.ToList();
    
                foreach (var q in query)
                {
                    
                    string communityName =string.Empty;
                    string userPhone = string.Empty;
    
                    if (q.community != null)
                    {
                        communityName = q.community.communityName;
                    }
    
                    
                    if (q.user != null)
                    {
                        userPhone = q.user.userPhone;
                    }
    
                    System.Console.WriteLine("{0}---{1}", communityName, userPhone);
                }
    
    
                //if (addUser == null)
                //{
                //    dbContext.yf_user.Add(new yf_user() { userPhone = "15286819573", userPass = "123456" });
                //    dbContext.SaveChanges();
                //}
                //else
                //{
                //    //addUser.userName = "杨帆";
                //    //System.Console.WriteLine(addUser.userName);
                //    dbContext.yf_user.Remove(addUser);
                //    dbContext.SaveChanges();
                //}
    
               
    
                Console.ReadLine();
            }
        }
    }

左关联
     var query = (from user in dbContext.yf_user.Where(u=>u.userId==UserId)
                             join com2 in dbContext.yf_community
                             on user.communityId equals com2.id into JoinedEmpDept
                             from com in JoinedEmpDept.DefaultIfEmpty()
                             select new
                             {
                                 user.userId,
                                 user.userName,
                                 user.userPhoto,
                                 user.sex,
                                 user.userPhone,
                                 user.communityId,
                                 user.createTime,
                                 user.note,
                                 user.isEnable,
                                 com.communityName
                             }).FirstOrDefault();

Mode1.demx设置自动类注释和属性注释

tt文件中设置属性注释：

string summary=string.Empty;
        var simpleProperties = typeMapper.GetSimpleProperties(entity);
        if (simpleProperties.Any())
        {
            foreach (var edmProperty in simpleProperties)
            {
              if (edmProperty.Documentation != null && edmProperty.Documentation.Summary != null)
              {
                 summary=edmProperty.Documentation.Summary;
              }
              else
              {
                summary="";
              }
    #>
        /// <summary>
        /// <#=summary#>
        /// </summary>
        <#=codeStringGenerator.Property(edmProperty)#>
    <#
            }
        }

遍历input中不为空的字段，修改到oldData中，input和oldData必须为同一种Class

//遍历入参的类.找出修改了哪些类型
                    foreach (PropertyInfo p in input.GetType().GetProperties())
                    {
                        //value不为空
                        if (p.GetValue(input) != null)
                        {
                            //在数据库中找出的数据类中查找并setValue该值
                            PropertyInfo propertyName = typeof(products).GetProperty(p.Name);
                            propertyName.SetValue(oldData, p.GetValue(input), null);
                        }
                    }

EF扩展库

1.[EntityFramework-Plus][] http://entityframework-plus.net/

2.[EntityFramework.Utilities][]http://www.jianshu.com/p/dff3c684a0e4

[http_dev.mysql.com_downloads_windows_installer]: http://dev.mysql.com/downloads/windows/installer/
[http_dev.mysql.com_downloads_connector_net]: http://dev.mysql.com/downloads/connector/net/
[http_dev.mysql.com_downloads_windows_visualstudio]: http://dev.mysql.com/downloads/windows/visualstudio/
[EntityFramework-Plus]: https://github.com/zzzprojects/EntityFramework-Plus
[EntityFramework.Utilities]: https://github.com/MikaelEliasson/EntityFramework.Utilities