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linq group Count

你问问题最好把表结构发出来,这样也节约你的时间。 ================================================= 应该类似如下Linq ( from c in 收藏表上下文 group c by c.产品ID into g orderby g.Count() descending select new { A=g.Key, B=g.Coun...

so easy , 直接用linq, from c in datatable group by c.name select c。

//示例,Northwind数据库,Employee表名,TitleOfCourtesy字段名 //lambda int n1 = en.Employees.Select(em => em.TitleOfCourtesy).Distinct().Count(); //linq var v = from arr in en.Employees group arr by arr.TitleOfCourtesy into g s...

int score = exams.where(p=>p.name == “wade”).score; int count = exams.shere(p=>p.scors < socre).count;

linq to sql 实现左外部连接: var query=form a0 in A join b0 in B on a0.ID equals b0.a_ID into ab from a1 in ab.DefaultIfEmpty() select a1;

Enumerable.Count 扩展方法“统一了“ Length 和 Count 属性,于是就有了下面判断非空的写法: public static void SomeAction(IEnumerable source){ if (source.Count() > 0){ //... }//... } 这种写法可以,运行也正常,但可能会产生非常严重的...

int count=dt.AsEnumerable().Where(item=>item.Field("总分")==100).Count(); 这样直接获取==100的条数 你写的那段是有问题的

1、List的基储常用方法: 声明: 1、List mList = new List(); T为列表中元素类型,现在以string类型作为例子 E.g.:List mList = new List(); 2、List testList =new List (IEnumerable collection); 以一个集合作为参数创建List E.g.: string...

from t in Articles where (from t1 in Articles group t1 by t1.Title into groupT where groupT.Count()>1 select groupT.Key).Contains(t.Title) orderby t.Title select t

from q in OneSet join x in OneSet on q.id equals x.ParentID into temp from qx in temp.DefaultIfEmpty() select new { Count = qx==null?0:temp.Count() }

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