Lambda表达式去重

        string sql = [email protected]"SELECT g.GroupID, g.GroupName,ge.EmployeeId,e.employeename FROM dbo.tab_UserGroup g
                                LEFT JOIN dbo.tab_GroupEmployee ge ON g.GroupId = ge.GroupID
                                LEFT JOIN dbo.tabEmployee e ON ge.EmployeeId = e.employeeid
                                WHERE g.EmployeeId = '{user.data.employeeid}'";

        var result = db.SqlQueryable<GroupInfo>(sql).ToList();


        var items = result.Where((x, i) => result.FindIndex(z => z.GroupID == x.GroupID) == i).ToList();//Lambda表达式去重