如何獲得一個類似於tsql查詢的lambda查詢？

Question

有一個T-SQL查詢：

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

嘗試LINQ查詢：

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

拉姆達查詢不起作用。

Answer 1

我想這是你所追求的：

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) 
};