I have an entity type:
public class Log
{
public int Id { get; set; }
public string Action { get; set; }
public string Message { get; set; }
}
And my Index:
public class LogIndex : AbstractIndexCreationTask<Log>
{
public LogIndex()
{
Map = xs => from x in xs
select new
{
x.Id,
x.Action,
x.Message
};
}
}
Then I can use them to store logs and I can use context.Query<Log, LogIndex>().Where(x => x.Action== "GetString").ToList() to get logs.
And then I try to use Commands to query my logs:
QueryResult queryResult = context.Advanced.DocumentStore.DatabaseCommands.Query("LogIndex", new IndexQuery
{
Query = "Action:(GetString)"
});
Log log = queryResult.Results.First().ToObject<Log>();
My problem is:
The log which is returned by ToObject<Log>() lose it's Id property's value(it is 0). But it's Action and Message property's value are not lost..
Is using RavenJObject.ToObject<T>() the right way to get query result(entities) ? If it is, what's wrong with my code? If it is not, which is the right way?
No, it isn't the proper way to go about it.
To start with, you are using very low level API, and should make use of the session for this.
If you'll use the session, it will take care of setting the ID properly.
Related
We have a Web app (ASP.NET/C#) with SQL Server backend. We use ServiceStack OrmLite as our POCO Micro ORM. We would now like to extend a part of our app to cache frequently-read data (mainly a collection of POCO objects as values, with numeric keys). But I'm not sure how to go about integrating a simple caching solution (in-memory or Redis based) that works seamlessly with OrmLite and MSSQL as the Master database.
I've read about the ServiceStack Redis Client, MemoryCacheClient and Multi nested database connections (OrmLiteConnectionFactory), but I couldn't find any examples, tutorial or code samples to learn more about implementing caching that works with OrmLite.
Any suggestions or links will be helpful and much appreciated.
I use this extension to help simplify the integration between the db and the cache.
public static class ICacheClientExtensions
{
public static T ToResultUsingCache<T>(this ICacheClient cache, string cacheKey, Func<T> fn, int hours = 1) where T : class
{
var cacheResult = cache.Get<T>(cacheKey);
if (cacheResult != null)
{
return cacheResult;
}
var result = fn();
if (result == null) return null;
cache.Set(cacheKey, result, TimeSpan.FromHours(hours));
return result;
}
}
public class MyService : Service
{
public Data Get(GetData request)
{
var key = UrnId.Create<Data>(request.Id);
Func<Data> fn = () => Db.GetData(request.Id);
return Cache.ToResultUsingCache(key, fn);
}
[Route("/data/{id}")]
public class GetData: IReturn<Data>
{
public int Id{ get; set; }
}
}
You'd need to implement the caching logic yourself, but it's not much work - here's a pseudocode example:
public class QueryObject
{
public DateTime? StartDate { get; set; }
public string SomeString { get; set; }
}
public class Foo
{
public DateTime DateTime { get; set; }
public string Name { get; set; }
}
public class FooResponse
{
public List<Dto> Data { get; set; }
}
public FooResponse GetFooData(QueryObject queryObject)
{
using (var dbConn = connectionFactory.OpenDbConnection())
using (var cache = redisClientsManager.GetCacheClient())
{
var cacheKey = string.Format("fooQuery:{0}", queryObject.GetHashCode()); //insert your own logic for generating a cache key here
var response = cache.Get<Response>(cacheKey);
//return cached result
if (response != null) return response;
//not cached - hit the DB and cache the result
response = new FooResponse()
{
Data =
dbConn.Select<Foo>(
x => x.DateTime > queryObject.StartDate.Value && x.Name.StartsWith(queryObject.SomeString)).ToList()
};
cache.Add(cacheKey, response, DateTime.Now.AddMinutes(15)); //the next time we get the same query in the next 15 mins will return cached result
return response;
}
}
Have you checked Service stack caching wiki. It gives detailed info about caching. Now in your case from the details you are providing I can say that you can go for any kind of caching. As of now it will not make any difference.
PS: A piece of advice caching should be done when there is no option or the only thing pending in application. Because it comes with it's own problem is invalidating caching, managing and all that. So, if you application is not too big, just leave it for now.
I need to make a query against a document collection that matches several properties.
(Cross post from the mailing list: https://groups.google.com/forum/?fromgroups=#!topic/ravendb/r5f1zr2jd_o)
Here is the document:
public class SessionToken
{
[JsonProperty("jti")]
public string Id { get; set; }
[JsonProperty("aud")]
public Uri Audience { get; set; }
[JsonProperty("sub")]
public string Subject { get; set; }
[JsonProperty("claims")]
public Dictionary<string, string> Claims { get; set; }
}
And here is the test:
[TestFixture]
public class RavenDbTests
{
private IDocumentStore documentStore;
[SetUp]
public void SetUp()
{
this.documentStore = new EmbeddableDocumentStore() { RunInMemory = true };
this.documentStore.Initialize();
}
[Test]
public async void FirstOrDefault_WhenSessionTokenExists_ShouldReturnSessionToken()
{
var c = new SessionToken()
{
Audience = new Uri("http://localhost"),
Subject = "NUnit",
Claims = new Dictionary<string, string>()
{
{ ClaimTypes.System, "NUnit" }
}
};
using (var session = this.documentStore.OpenAsyncSession())
{
await session.StoreAsync(c);
await session.SaveChangesAsync();
// Check if the token exists in the database without using Where clause
var allTokens = await session.Query<SessionToken>().ToListAsync();
Assert.That(allTokens.Any(x => x.Subject == "NUnit" && x.Audience == new Uri("http://localhost")));
// Try getting token back with Where clause
var token = await session.Query<SessionToken>().Customize(x => x.WaitForNonStaleResults()).Where(x => x.Subject == "NUnit" && x.Audience == new Uri("http://localhost")).ToListAsync();
Assert.IsNotNullOrEmpty(token.First().Id);
}
}
}
The last Assert is the one that is failing.
I must admit Im not sure whether this is a bug or a failure on my part.
As far as I understand, this is supposed to work.
PS. I´ve tried with a standalone document store as well as embedded without running in memory, but with same result.
You are getting stale results. In a unit test, you need to allow time for indexing to occur.
Add .Customize(x=> x.WaitForNonStaleResults()) to your queries and the test should pass.
Also, I think you left the Id property off your question when you cut/paste because it doesn't compile as-is.
UPDATE
Per discussion in comments, the issue was that you were applying the [JsonProperty] attribute to the Id property. Since the Id property represents the document key, and is not serialized as part of the JSON document, you can't apply the [JsonProperty] attribute to it.
I have a record structure where I have a parent record with many children records. On the same page I will have a couple queries to get all the children.
A later query I will get a record set when I expand it it shows "Proxy". That is fine an all for getting data from the record since everything is generally there. Only problem I have is when I go to grab the record "ID" it is always "0" since it is proxy. This makes it pretty tough when building a dropdown list where I use the record ID as the "selected value". What makes this worse is it is random. So out of a list of 5 items 2 of them will have an ID of "0" because they are proxy.
I can use evict to force it to load at times. However when I am needing lazy load (For Grids) the evict is bad since it kills the lazy load and I can't display the grid contents on the fly.
I am using the following to start my session:
ISession session = FluentSessionManager.SessionFactory.OpenSession();
session.BeginTransaction();
CurrentSessionContext.Bind(session);
I even use ".SetFetchMode("MyTable", Eager)" within my queries and it still shows "Proxy".
Proxy is fine, but I need the record ID. Anyone else run into this and have a simple fix?
I would greatly appreciate some help on this.
Thanks.
Per request, here is the query I am running that will result in Patients.Children having an ID of "0" because it is showing up as "Proxy":
public IList<Patients> GetAllPatients()
{
return FluentSessionManager.GetSession()
.CreateCriteria<Patients>()
.Add(Expression.Eq("IsDeleted", false))
.SetFetchMode("Children", Eager)
.List<Patients>();
}
I have found the silver bullet that fixes the proxy issue where you loose your record id!
I was using ClearCache to take care of the problem. That worked just fine for the first couple layers in the record structure. However when you have a scenario of Parient.Child.AnotherLevel.OneMoreLevel.DownOneMore that would not fix the 4th and 5th levels. This method I came up with does. I also did find it mostly presented itself when I would have one to many followed by many to one mapping. So here is the answer to everyone else out there that is running into the same problem.
Domain Structure:
public class Parent : DomainBase<int>
{
public virtual int ID { get { return base.ID2; } set { base.ID2 = value; } }
public virtual string Name { get; set; }
....
}
DomainBase:
public abstract class DomainBase<Y>, IDomainBase<Y>
{
public virtual Y ID //Everything has an identity Key.
{
get;
set;
}
protected internal virtual Y ID2 // Real identity Key
{
get
{
Y myID = this.ID;
if (typeof(Y).ToString() == "System.Int32")
{
if (int.Parse(this.ID.ToString()) == 0)
{
myID = ReadOnlyID;
}
}
return myID;
}
set
{
this.ID = value;
this.ReadOnlyID = value;
}
}
protected internal virtual Y ReadOnlyID { get; set; } // Real identity Key
}
IDomainBase:
public interface IDomainBase<Y>
{
Y ID { get; set; }
}
Domain Mapping:
public class ParentMap : ClassMap<Parent, int>
{
public ParentMap()
{
Schema("dbo");
Table("Parent");
Id(x => x.ID);
Map(x => x.Name);
....
}
}
ClassMap:
public class ClassMap<TEntityType, TIdType> : FluentNHibernate.Mapping.ClassMap<TEntityType> where TEntityType : DomainBase<TIdType>
{
public ClassMap()
{
Id(x => x.ID, "ID");
Map(x => x.ReadOnlyID, "ID").ReadOnly();
}
}
I am trying to create a static index for the following sample class:
public class Board {
...other assorted fields
List<dynamic> Messages {get; set;}
internal Board() {Messages = new List<dynamic>();}
}
The index is to filter boards which have messages which are a older than a certain date. The aim is to perform an "update" operation on messages which are due today, update their content, and persist them back. The index is needed to avoid traversing all the messages for a board for all clients as that may be computationally expensive. Messages is a list of message types which inherit from a base class which contains a property ExpiryDate.
Trying to create an index like follows results in an "An expression tree may not contain a
dynamic operation" error. I know that the dynamic type does not play well with Linq queries hence the need to use LuceneQueries instead of Query() in RavenDB. Is there any way to make this index work with dynamic properties? Thanks!
public class ScanBoardMessagesIndex : AbstractIndexCreationTask<Board>
{
public ScanBoardMessagesIndex () {
Map = boards => from board in boards
where board.Messages.Any(msg => ((MessageItem) msg).ExpiryDate <= DateTime.UtcNow.Date)
select board;
}
}
EDIT:
I ran into a raven serialization issue because the metadata clr-type of existing Board documents was set to a class namespace which was not valid anymore. I am doing a migration project so I went ahead and first issued a patch to change the metadata clr-type of the existing documents before migrating them to the new data structure which uses a base/abstract class for list of Messages instead of type dynamic.
A Map/Reduce index seems more appropriate for the given requirements. Effectively, you want to be able to query boards by the oldest expiry date of messages in the board. This is an aggregating operation, exactly what Map/Reduce was designed to solve. Also, using a base class for messages will allow you to define the index without resorting to the lower level IndexDefinition:
public class Message
{
public DateTime ExpiryDate { get; set; }
}
public class Board
{
public string Id { get; set; }
public List<Message> Messages { get; set; }
}
public class OldestExpiryDateMessageInBoard : AbstractIndexCreationTask<Board, OldestExpiryDateMessageInBoard.Result>
{
class Result
{
public string BoardId { get; set; }
public DateTime OldestExpiryDate { get; set; }
}
public OldestExpiryDateMessageInBoard()
{
this.Map = boards => from board in boards
from message in board.Messages
select new
{
BoardId = board.Id,
OldestExpiryDate = message.ExpiryDate
};
this.Reduce = results => from result in results
group result by result.BoardId into g
select new
{
BoardId = g.Key,
OldestExpiryDate = g.Min(x => x.OldestExpiryDate)
};
}
}
You can then query this index with Lucene syntax.
Imagine a database table that looks like this:
create table [dbo].[user]
(
id int IDENTITY(1,1),
username varchar(50) NOT NULL,
firstname varchar(20) NOT NULL,
lastname varchar(30) NOT NULL,
currentid int NULL,
processedby varchar(50) NOT NULL,
processeddate varchar(50) NOT NULL
processedaction varchar(50) NOT NULL
)
What I want to do is to setup NHibernate to load it into my user object, but I only want the current version of the object "user" to be brought back. I know how to do a SQL select to do this on my own, and I feel as if there's something in nHibernate with the usage of triggers and event listeners, but can anyone tell me how to implement the nHibernate repository so I can:
{Repository}.GetCurrent(id) <- pass it any of the ids that are assigned to any of the historical or the current record, and get back the current object.
{Repository}.Save(user) <- I want to always insert the changes to a new row, and then update the old versions to link back to the new id.
Edit
So, there's some confusion here, and maybe I explained it wrong... What I'm trying to do is this, in regards to always getting the current record back...
Select uc.*
FROM User uo
JOIN User uc on uo.currentid=uc.id
WHERE uo.id==:id
But, I don't want to expose "CurrentID" to my object model, since it has no bearing on the rest of the system, IMHO. In the above SQL statement, uo is considered the "original" object set, and uc is considered the current object in the system.
Edit #2:
Looking at this as a possible solution.
http://ayende.com/blog/4196/append-only-models-with-nhibernate
I'm honestly being pigheaded, as I'm thinking about this backward. In this way of running a database, the autoincrementing field should be the version field, and the "id" field should be whatever the autoincrementer's value has at the time of the initial insert.
Answer:
I don't want to take #Firo's fury, and I'm not going to remove it from him, as he took me down the right path... what I wound up with was:
Created a base generic class with two types given
a. type of the object's "ID"
b. type of the object itself.
instantiate all classes.
create a generic interface IRepository class with a type of the object to store/retrieve.
create an abstract generic class with a type of the object to store/retrieve.
create a concrete implementation class for each type to store/retrieve.
inside of the create/update, the procedure looks like:
Type Commit(Type item)
{
var clone = item.DeepClone();
_Session.Evict(item);
clone.Id = 0;
clone.ProcessedDate = DateTime.Now;
if (clone.Action.HasValue)
{
if (clone.Action == ProcessedAction.Create)
clone.Action = ProcessedAction.Update;
}
else
{
clone.Action = ProcessedAction.Create;
}
clone.ProcessedBy = UserRepos.Where(u => u.Username == System.Threading.Thread.CurrentPrincipal.Identity.Name).First().Current;
var savedItem = (_Session.Merge(clone) as Type);
_Session.CreateQuery("UPDATE Type SET CurrentID = :newID where ID=:newID OR CurrentID=:oldID")
.SetParameter("newID", savedItem.Id)
.SetParameter("oldID", item.Id)
.ExecuteUpdate();
return savedItem;
}
In the delete method, we simply update the {object}.Action = ProcessedAction.Delete
I wanted to do this another way, but realizing we need to eventually do historical comparisons, we weren't able to ask nHibernate to filter the deleted objects, as the users will want to see that. We'll create a business facade to take care of the deleted records.
Again, much thanks to #Firo for his help with this.
So, with all that, I can finally do this:
var result = {Repository}.Where(obj => obj.Id == {objectID from caller}).FirstOrDefault();
if (result != null)
{
return result.Current;
}
else
{
return null;
}
and always get my current object back for any requesting ID. Hope it helps someone that is in my situation.
in mapping if you use FluentNHibernate
public UserMap : ClassMap<User>
{
public UserMap()
{
Where("id = currentid"); // always bring back the most recent
}
}
// in Userrepository
public void Update(User user)
{
var clone = user.Clone();
session.Evict(user); // to prevent flushing the changes
var newId = session.Save(clone);
session.CreateQuery("UPDATE User u SET u.currentid = :current") // <-- hql
.SetParameter("current", newId)
.ExecuteUpdate();
}
objectgraphs are a lot trickier with this simple code. I would then do one of the following:
use NHibernate.Envers to store auditing information for me
explicitly creating new entities in BL code
i once saw an append-only-model doing something like the following
// UserBase is there to ensure that all others referencing the User doesnt have to update because user properties changed
class UserBase
{
public virtual int Id { get; set; }
public virtual ICollection<PersonDetails> AllDetails { get; private set; }
public virtual PersonDetails CurrentDetails
{
get { return _currentDetauils; }
set { _currentDetauils = value; AllDetails.Add(value); }
}
// same as above
public virtual ICollection<ConfigDetails> AllConfigs { get; set; }
}
class Order
{
public virtual int Id { get; set; }
public virtual UserBase User { get; set; }
public virtual IList<OrderDetail> AllDetails { get; private set; }
public virtual IList<OrderDetail> ActiveDetails { get; private set; }
public virtual void Add(OrderDetail detail)
{
AllDetails.Add(detail);
ActiveDetails.Add(detail);
}
public virtual void Delete(OrderDetail detail)
{
detail.Active = false;
ActiveDetails.Remove(detail);
}
}
class OrderDetail
{
public virtual int Id { get; set; }
public virtual Order Parent { get; set; }
public virtual bool Active { get; set; }
}
class OrderMap : ClassMap<Order>
{
public OrderMap()
{
HasMany(o => o.AllDetails);
HasMany(o => o.ActiveDetails).Where("active=1");
}
}
// somewhere
public void UpdateTaxCharge(OrderDetail detail, TaxCharge charge)
{
var clone = detail.Clone();
clone.TaxCharge = charge;
detail.Order.Delete(detail);
detail.Order.Add(clone);
}
You can tell NHibernate what exactly SQL it should generate when persisting and loading an entity. For example you can tell NHibernate to use a stored procedure instead of a plain SQL statement. If this is an option for you I can farther elaborate my answer.