C#中的LINQ中的SQL查询 [英] SQL Query in LINQ in C#

问题描述

你好，

我需要LINQ中的等效查询.谁能帮我吗?

Hello,

I need the equivalent query in LINQ. Can any one please help me ?

Select count(*),Name 
from Test
where convert(varchar(12),postdate,101) =  convert(varchar(12),GETDATE(),101)
group by Name

谢谢.

Thank you.

推荐答案

这是我的解决方案版本.

This is my version of the solution.

 var tomorrow = DateTime.Now.Date.AddDays(1);
 var today = DateTime.Now.Date;
 
 var ts = from t in Tests
     where t.postdate >= today && t.postdate < tomorrow
     group t by t.Name into newt
     select new { Name = newt.Key, Count = newt.Count() };
	 
foreach ( var t in ts) {
	Console.WriteLine("{0} {1}",t.Count, t.Name);
}

它查找今天发布的测试条目，并按名称分组后进行计数.

It finds the Test entries that were posted today and counts after grouping by name.

DataClasses1DataContext dc = new DataClasses1DataContext();

   var query = from c in dc.Test
        where Convert.ToString(postdate) == Convert.ToString(DateTime.Now.Date)
        group c by c.Name into g
        select new  { Count = g.Count() , Name = g.Key  };

我刚刚测试过，此代码有效.

I just tested, this code works.

我认为这或多或少是等效的:

I think this would be the more or less equivalent:

from test in testcollection
where test.postdate == DateTime.Now.Date
group test by test.name into newtest
select new { Name = newtest.Name, PostDate = newtest.postdate };

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