如何获得一个类似于tsql查询的lambda查询？

Question

有一个T-SQL查询：

select [ProductNumber] ,max([ProductRevNumber]) 
from Products 
group by [ProductNumber] 

尝试LINQ查询：

ProductsDBContext.Products.GroupBy(x => x.ProductRevNumber) 
          .Select(group => ProductNumber, 
              ProductRevNumber = group.Max(x => x.ProductRevNumber)); 

拉姆达查询不起作用。

Answer 1

我想这是你所追求的：

var latestProducts = ProductsDBContext.Products 
    .GroupBy(p => p.ProductNumber).Select(g => new 
    { 
     ProductNumber = g.Key, 
     MaxProductRevNumber = g.Max(p => p.ProductRevNumber)) 
    }); 

Answer 2

from p in db.Products 
group p by p.ProductNumber into g 
select new 
{ 
    ProductNumber = g.Key, 
    ProductRevNumber = g.Max(p => p.ProductRevNumber) 
};