如何将5种不同类型的linq查询合并到一个列中

Question

我真的很困惑我需要的报告。截至今天，我的大部分报告都很简单，所以我能够轻松地做到这一点。但作为在SQL/DLINQ一个新手，我无法通过以下找到我的方式：

var closingStock = 
    (from p in session.Query<Product>() 
    select new 
    { 
     p.Id, 
     p.Name, 
     p.Batch, 
     p.Rate, 
     ClosingStock = p.Quantity - p.AllocatedQuantity, 
     p.DivisionId 
    }).ToList(); 

var distributedQuantityAfterPeriod = 
    (from i in session.Query<OutwardInvoiceItem>() 
    where i.ParentInvoice.Date > ToDate 
    select new 
    { 
     Id = i.Product.Id, 
     DistributedAfter = i.Quantity 
    }).ToList(); 

var distributedQuantityInPeriod = 
    (from i in session.Query<OutwardInvoiceItem>() 
    where i.ParentInvoice.Date >= FromDate && i.ParentInvoice.Date <= ToDate 
    select new 
    { 
     Id = i.Product.Id, 
     Distributed = i.Quantity 
    }).ToList(); 

var receivedQuantityAfterPeriod = 
    (from i in session.Query<InwardInvoiceItem>() 
    where i.ParentInvoice.Date > ToDate 
    select new 
    { 
     Id = i.Product.Id, 
     ReceivedAfter = i.Quantity 
    }).ToList(); 

var receivedQuantityInPeriod = 
    (from i in session.Query<InwardInvoiceItem>() 
    where i.ParentInvoice.Date >= FromDate && i.ParentInvoice.Date <= ToDate 
    select new 
    { 
     Id = i.Product.Id, 
     Received = i.Quantity 
    }).ToList(); 

正如你所看到的，我想建立一个特定日期的库存移动报告。我遇到以下问题：
1.如何减少五个查询？可能吗？
2.我该如何将这些查询提供的数据合并到一个表中，该表按产品ID进行分组并汇总为数量相关的列？到目前为止，我正在使用非常慢的循环。

我用的是什么：
C＃4，NHibernate的，SQLite的

任何帮助将非常高度赞赏。

Regards， Yogesh。

Answer 1

1. 减少往返使用.Future()代替.List()

2. 让所有的查询返回

   group i by i.Id into g 
   select new 
   { 
       Id = g.Key, 
       Quantity = g.Sum(x => x.Quantity) 
   }).Future(); 
   

，做

var alltogether = groupedDistributedQuantityAfterPeriod 
    .Concat(groupedDistributedQuantityInPeriod) 
    .Concate(...); 

from g in alltogether 
group g by g.key into all 
select new 
{ 
    Id = all.Key, 
    Quantity = all.Sum(x => x.Quantity) 
}; 

UPD吃：

可以减少查询的数量与

from i in session.Query<OutwardInvoiceItem>() 
where (i.ParentInvoice.Date > ToDate) || (i.ParentInvoice.Date >= FromDate && i.ParentInvoice.Date <= ToDate) 
select ... 

from i in session.Query<InwardInvoiceItem>() 
where (i.ParentInvoice.Date > ToDate) || (i.ParentInvoice.Date >= FromDate && i.ParentInvoice.Date <= ToDate) 
select ...