Indexing 如何在RavenDB中查询嵌套信息?
我有一份叫做预约的文件:Indexing 如何在RavenDB中查询嵌套信息?,indexing,ravendb,Indexing,Ravendb,我有一份叫做预约的文件: { "CustomerId": 1, "Items": [ { "EmployeeId": "employees/1", "StartTime": "2011-08-15T07:20:00.0000000+03:00", "EndTime": "2011-08-15T07:40:00.0000000+03:00" }, {
{
"CustomerId": 1,
"Items": [
{
"EmployeeId": "employees/1",
"StartTime": "2011-08-15T07:20:00.0000000+03:00",
"EndTime": "2011-08-15T07:40:00.0000000+03:00"
},
{
"EmployeeId": "employees/1",
"StartTime": "2011-08-15T07:40:00.0000000+03:00",
"EndTime": "2011-08-15T09:10:00.0000000+03:00"
},
{
"EmployeeId": "employees/3",
"StartTime": "2011-08-16T07:20:00.0000000+03:00",
"EndTime": "2011-08-16T11:35:00.0000000+03:00"
}
]
"ReservedAt": "2011-10-20T15:28:21.9941878+03:00"
}
此外,我还有以下投影类:
public class ReservationItemProjection
{
public string ReservationId { get; set; }
public string CustomerId { get; set; }
public string EmployeeId { get; set; }
public DateTime StartTime { get; set; }
public DateTime EndTime { get; set; }
}
如果要查找匹配项,我应该编写什么样的索引和查询
预订项目?例如:
// invalid example query:
var matches = docs.Query<ReservationItemProjection,
ReservationItemProjectionsIndex>()
.Where(x =>
x.EmployeeId == "employees/1" &&
x.StartTime >= minTime &&
x.EndTime <= maxTime)
.ToList();
请注意,我不希望获得预订文件列表,但希望获得
ReservationTemprojection对象的列表。报告说:
但是,尽管只获取与特定查询匹配的文档很有用,但我们可以做得更好。我希望直接从索引中获取值,而不是获取文档本身,而不获取完整文档
我已经尝试使用如下索引:
public class ReservationItemProjectionsIndex :
AbstractIndexCreationTask<Reservation, ReservationItemProjection>
{
public ReservationItemProjectionsIndex()
{
Map = reservations =>
from reservation in reservations
from item in reservation.Items
select new
{
ReservationId = reservation.Id,
CustomerId = reservation.CustomerId,
item.EmployeeId,
item.StartTime,
item.EndTime
};
Store(x => x.ReservationId, FieldStorage.Yes);
Store(x => x.CustomerId, FieldStorage.Yes);
Store(x => x.EmployeeId, FieldStorage.Yes);
Store(x => x.StartTime, FieldStorage.Yes);
Store(x => x.EndTime, FieldStorage.Yes);
}
}
不知何故,我无法让查询和索引正常工作:它要么抛出一个异常
无法从ReservationTemprojection转换到Reservation,或者
如果能够获得ReservationTemprojection对象,则它们将
包括所有预订中甚至有一个匹配项目的所有项目,即使
尽管我的查询包含Where子句x.EmployeeId==employees/1
概要:所需的索引是什么?索引是否只需要Map子句,还是还需要Reduce或TransformResults?如何用C编写查询?Kasper,
在RavenDB中,您正在查询文档。虽然从技术上讲,做你想做的事情是可能的,但这样做通常是毫无意义的,因为投射的信息没有必要的上下文来处理它
你想做什么
作为参考,该索引类似于:
from doc in docs.Items
from reservation in doc.Reservations
select new { reservation.EmployeeId, reservation.Start, reservation.End }
然后,标记EmployeeId,开始和结束为Store
现在,在您的查询中,发布:
session.Query<...,...>().AsProjection<ReservationProjection>().ToList();
AsProjection调用会让DB知道您想要的是索引中的值,而不是文档中的值这正好是我想要的结果!投影是否被视为高级功能?谷歌只返回两页的搜索结果。似乎该功能需要一些文档?谢谢,这个答案今天救了我一命!