Linq to SQL by group by

2009-12-30 163 views 0 likes

如何在linq VB.NET中编写此查询？Linq to SQL by group by

select top 15 count(1), A.Latitude, A.Longitude 
from Bairro A 
inner join Empresa B on B.BairroID = A.BairroID 
where A.CidadeID = 4810 
group by A.Latitude, A.Longitude 
order by COUNT(1) desc

我达到了这个代码：

Dim TopBairros = (From A In Bairros _ 
        Join B In New BO.Empresa().Select On B.BairroID Equals A.BairroID Group A By A.Latitude, A.Longitude Into g = Group _ 
        Select g Distinct _ 
        Order By g.Count Descending).Take(15)

每行具有含有屡与计数数的同一对象阵列集合。例如：

行0：874个相同的对象第1排阵：710个相同的对象

等的阵列......我该怎么办每行返回只有一个对象？

来源

2009-12-30 Fernando

回答

试试这个：

var query = from a in context.Bairro 
      where a.CidadeID == 4810 
      join b in context.Empresa on a.BairroID equals b.BairroID 
      group a by new { a.Latitude, a.Longitude } into grouped 
      orderby grouped.Count() descending 
      select new { grouped.Key.Latitude, 
         grouped.Key.Longitude, 
         Count = grouped.Count() }; 
var top15 = query.Take(15);

来源

2009-12-30 23:15:40

我使用VB.NET ......我达到了这个代码：昏暗TopBairros =（从在Bairros _ JOIN B在新BO.Empresa（）。选择On B.BairroID Equals A.BairroID Group A按A.Latitude，A.Longitude进入g = Group _ 选择g Distinct _ Order by g.Count Descending）.Take（15）每行都有一个数组集合重复包含与计数相同的对象。例如：第0行：874个相同对象的数组第1行：710个相同对象的数组等等......如何才能每行只返回一个对象？ – Fernando 2009-12-30 23:51:30

@Fernando：通过使用最后得到的投影 - 选择组的关键和计数。 – 2009-12-31 00:49:06

Linq to SQL by group by

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