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  • EF 表联合查询 join

    有两张表m_Dept、m_User,联合查询

    linq方式、EF方式

            private void Add()
            {
               List<m_Dept> lst = new List<m_Dept>{
               new m_Dept { DName = "开发", ID = "1" },
               new m_Dept { DName = "测试", ID = "2" },
               new m_Dept { DName = "财务", ID = "3" }
               };
    
               List<m_User> lstU = new List<m_User>{
               new m_User { UName = "张三", ID = "1"  , DeptID="1"},
               new m_User { UName = "李四", ID = "2" , DeptID="2"},
               new m_User { UName = "王五", ID = "3" , DeptID="1"}
               };
    
                using(TESTEntities db=new TESTEntities())
                {
                    db.m_Dept.AddRange(lst);
                    db.m_User.AddRange(lstU);
                    db.SaveChanges();
                }
                
            }
            private void getlist()
            {
                using (TESTEntities db = new TESTEntities())
                {
    
                    //linq
                    var query = from a in db.m_Dept
                                join b in db.m_User
                                on a.ID equals b.DeptID
                                select new
                                {
                                    deptname = a.DName,
                                    username = b.UName
                                };
                    //ef
                    var query2 = db.m_Dept.Join(db.m_User, a => a.ID, b => b.DeptID, (a, b) => new
                        {
                            deptname = a.DName,
                            username = b.UName
                        });
    
                }
    
            }
    

      

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  • 原文地址:https://www.cnblogs.com/xiaochun126/p/5122952.html
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