C# 使用GROUPBY的Linq动态查询
我需要额外的where子句用于Linq查询。例如,如果客户选择了一个日期过滤器,那么我需要对我的查询进行日期过滤器等。。。当我尝试myQuery.Where谓词时,只有group by的字段可见 如何将新的where条件附加到查询中C# 使用GROUPBY的Linq动态查询,c#,linq,entity-framework-5,C#,Linq,Entity Framework 5,我需要额外的where子句用于Linq查询。例如,如果客户选择了一个日期过滤器,那么我需要对我的查询进行日期过滤器等。。。当我尝试myQuery.Where谓词时,只有group by的字段可见 如何将新的where条件附加到查询中 //for example i need dynamically append o.OrderDate==Datetime.Now or another where clause var myQuery =(from o in _db.Orders join l
//for example i need dynamically append o.OrderDate==Datetime.Now or another where clause
var myQuery =(from o in _db.Orders
join l in _db.OrderLines.Where(x => x.ParaBirimi == model.ParaBirimi) on o.orderId equals
l.OrderId
where o.OrderDate.Value.Year == year1
group o by new {o.OrderDate.Value.Month}
into g
select
new
{
Month = g.Key.Month,
Total = g.Select(t => t.OrderLines.Sum(s => s.OrderTotal)).FirstOrDefault()
});
查询结束时,您太晚了,无法在其中添加新的
。您已经对数据进行了分组和投影,删除了几乎所有的字段
尝试:
显然,如果
,您可以有多个。每个.Where()
都位于&&
(和
)和其他条件中
请注意,join
的结果如何投影到具有两个属性的匿名类中:Order
和OrderLine
var baseQuery = from o in _db.Orders
join l in _db.OrderLines.Where(x => x.ParaBirimi == model.ParaBirimi) on o.orderId equals l.OrderId
where o.OrderDate.Value.Year == year1
select new { Order = o, OrderLine = l };
if (something)
{
baseQuery = baseQuery.Where(x => x.Order.Foo == "Bar");
}
var myQuery = (from o in baseQuery
group o by new { o.Order.OrderDate.Value.Month }
into g
select
new
{
Month = g.Key.Month,
Total = g.Sum(t => t.OrderLine.OrderTotal)
});