C# 用于其他计算的RavenDb地图索引
在开始的时候,我想说的是,我对任何类型的NoSql数据库都是非常陌生的。我想我可能误解了RavenDb中索引的概念 在我的申请书中,我收集了一份代表汽车加油历史的文件(其中包含加油路线的子集合)。简化版本如下所示:C# 用于其他计算的RavenDb地图索引,c#,asp.net-core,ravendb,C#,Asp.net Core,Ravendb,在开始的时候,我想说的是,我对任何类型的NoSql数据库都是非常陌生的。我想我可能误解了RavenDb中索引的概念 在我的申请书中,我收集了一份代表汽车加油历史的文件(其中包含加油路线的子集合)。简化版本如下所示: public class Fuel { public decimal? VolumeUsed { get; set; } public decimal CostPerLitre { get; set; } public decimal? TotalDistan
public class Fuel
{
public decimal? VolumeUsed { get; set; }
public decimal CostPerLitre { get; set; }
public decimal? TotalDistance { get; set; }
public IList<Route> Routes { get; set; }
}
public class Route
{
public string StartingAddress { get; set; }
public IList<Stop> Stops { get; set; }
}
和索引定义:
public class FuelCalculatedIndex : AbstractIndexCreationTask<Fuel, FuelCalculated>
{
public FuelCalculatedIndex()
{
Map = fuels =>
fuels.Select(f => new FuelCalculated()
{
AverageFuelConsumption = (f.VolumeUsed * 100) / f.TotalDistance,
Routes = f.Routes.Select(r => new RouteCalculated()
{
StartingAddress = r.StartingAddress,
Stops = r.Stops,
TotalDistance = r.Stops.Sum(s => s.Distance),
AverageFuelConsumption = r.Stops.Sum(s => s.AverageFuelConsumption * s.Distance) / r.Stops.Sum(s => s.Distance),
}).ToList(),
TotalCost = f.VolumeUsed * f.CostPerLitre,
TotalDistance = f.TotalDistance,
VolumeUsed = f.VolumeUsed,
});
StoreAllFields(FieldStorage.Yes);
}
}
因此,问题似乎在于C#代码。我做错了什么
更新
我刚刚试着用C#运行原始查询:
等待会话
.Advanced.AsyncRawQuery(“从索引'FuelCalculatedIndex'选择总成本”)
.ToListAsync();
令人惊讶的是,它是有效的。查询的结果总是一个文档(地图索引)。 因此,原始查询实际上应该是:
using (var session = documentStore.OpenAsyncSession())
{
return await session
.Query<FuelCalculated, FuelCalculatedIndex>()
.As<Fuel>
.ToListAsync();
}
使用(var session=documentStore.OpenAsyncSession())
{
返回等待会话
.Query()
.作为
.ToListAsync();
}
您需要使用ProjectInto来获取存储的字段:
using (var session = documentStore.OpenAsyncSession())
{
return await session
.Query<FuelCalculated, FuelCalculatedIndex>()
.ProjectInto<FuelCalculated>
.ToListAsync();
}
使用(var session=documentStore.OpenAsyncSession())
{
返回等待会话
.Query()
.项目
.ToListAsync();
}
我认为将
fuelcomputed
指定为第一个泛型类型就足够了,但我从未真正考虑过投影。谢谢,真是太棒了!
{
"volumeUsed":28.04,
"costPerLitre":4.93,
"totalDistance":467.3,
"totalCost":null, <----
"averageFuelConsumption":null, <----
"routes":[
{
"startingAddress":"Address 1",
"stops":[
{
"address":"Address 2",
"distance":351.0,
"averageFuelConsumption":6.0
}
],
"totalDistance":0, <----
"totalAverageFuelConsumption":0 <----
},
{
"startingAddress":"Address 3",
"stops":[
{
"address":"Address 4",
"distance":116.3,
"averageFuelConsumption":7.0
}
],
"totalDistance":0, <----
"totalAverageFuelConsumption":0 <----
}
]
}
from index 'FuelCalculatedIndex'
select TotalCost
await session
.Advanced.AsyncRawQuery<FuelCalculated>("from index 'FuelCalculatedIndex' select TotalCost")
.ToListAsync();
using (var session = documentStore.OpenAsyncSession())
{
return await session
.Query<FuelCalculated, FuelCalculatedIndex>()
.As<Fuel>
.ToListAsync();
}
using (var session = documentStore.OpenAsyncSession())
{
return await session
.Query<FuelCalculated, FuelCalculatedIndex>()
.ProjectInto<FuelCalculated>
.ToListAsync();
}