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C# linq 查询

var data=from a in Table1 join b in Table2 on a.Num=b.Num where a.typeid==b.id select new {Name=a.Name,Score =a.Score ,Num =a.num,Address =b.Address };

试试这个 from item in a join b in a on a.name equals b.bname where b.bcar="abc" select new 类{ ..... }

Model.dbDataContext db = new Model.dbDataContext(ConnStr); var model = from a in db.A join g in db.G on a.ClassID equals g.ID into m from model in m.DefaultIfEmpty() select new { ID=a.ID, Title=a.Title, ...........................

linq里没有多表关联的概念 linq to sql 是面向对象级联的的概念你说你怎么写子查询? 你要是建议用子查询 直接自己拼接sql就行了

string[] ids = (from DeductionBill in t_ds_DeductionBill where t_ds_DeductionBill .BillNumber.Equals(c.BillNumber)) .ToArray(); TotalWeight= (from Order in t_kd_Order where(item => ids.Contains(item.OrderID)) select Order.Total...

我想要结果查得的CategoryID是CategoryName要怎么写这个语句 这句话什么意思。 查找 CategoryName where CategoryID=@CategoryID 可以写成 var temp=from i in Category where i.CategoryID=@CategoryID select i. CategoryName .

通过这个对象,可以遍历访问集合类对象中的每一个元素对象 2. DataTable dt = GetDetails().Tables[0]; //获取可用的DataTable// var m = dt.AsEnumerable().Last(); 返回DataTable最后一行DataRow//var m = dt.AsEnumerable().First(); 返回Dat...

var data=from l in books group l by l.fenlei into bb select new {FenLeiList= bb.fenlei } 得到分类集合,填充到界面上的选择框之类的控件在其事件里加入 var data=from l in books where l.fenlei==控件.text select l 得到所选分类的书的集合

1. 可以用查询结果的 ToList()方法 2. 示例代码如下: using System;using System.Collections.Generic;using System.Linq;using System.Text;namespace ConsoleApplication2{ class Program { static void Main(string[] args) { int[] arr = { ...

arr != null 改成 arr.count()!=0 var arr = from r in a.USER where r.USERNAME == username.Text select r; 得到的arr类似 list

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