Linq查询语句

LINQ（Language Integrated Query）语言集成查询是一组用于c#和Visual Basic语言的扩展。它允许编写C#或者Visual Basic代码以操作内存数据的方式，查询数据库。

语法：

查询数据列表集合ToList
List<SelectVo> lists = (from tb in Model.SYS
                select new SelectVo
                {
                    id = tb. ID,
                    text = tb.Name
            }).ToList();
查询单行数Single
var teacher = (from tbTeacher in Model.PW_Teacher
                        where tbTeacher.UserID == intUserId
                    select tbTeacher).Single();
去重复Distinct
List<SelectVo> lists = (from tb in Model.SYS
                select new SelectVo
                {
                    id = tb. ID,
                    text = tb.Name
            }) .Distinct().ToList();;
排序
var list = from tb in Model.SYS
                orderby tb. ID
                select tb;
 子查询
List< Select> list= (from tb in Model.SYS_Modular
                      orderby tb.ModularID
                      select new Select
                      {
                       ModularID = tb.ModularID,
                       ModularName = tb.ModularName,
                       ModularDetailVos = (from tb in Model.SYS_ModularDetail
                                            where tb.ModularID == ID
                                            orderby tb.ModularDetailID
                                           	select new ModularDetailVo
                                            {
                                               id = tbModularDetail.ModularDetailID,                                                                                    OpType = tbOpType.OpType.Trim()
                                             }).ToList()
}).ToList();