I have a base class called Entry:
[BsonDiscriminator(RootClass = true)]
[BsonKnownTypes(typeof(AccountEntry))]
public class Entry
{
public ObjectId Id { get; set; }
public string Register { get; set; }
}
With a derived class called AccountEntry as example
public class AccountEntry : Entry
{
public Account Account { get; set; }
}
When I try to do an Update, a compile time error shows that says, AccountEntry cannot be converted to Entry
var filter = Builders<AccountEntry>.Filter.Where(x => x.Id = id);
await context.Entries.UpdateOneAsync(filter, new AccountEntry()
{
Account = debitAccount,
}, new UpdateOptions() { IsUpsert = true });
Inserting the derived class does not cause the same problem.
Your filter needs to be of type Entry, not AccountEntry.
var filter = Builders<Entry>.Filter.Where(x => x.Id == id);
This is because filter is not covariant (I think that's the right one). So, the compiler can't just use a FilterDefinitionBuilder in place of a FilterDefinitionBuilder.
We have a ticket open to better handle derived types: https://jira.mongodb.org/browse/CSHARP-1194.
Related
In my EF Core solution I have the following model:
public class Deal
{
public string Id { get; set; }
public ResponsiblePerson ResponsiblePerson1 { get; set; }
public ResponsiblePerson ResponsiblePerson2 { get; set; }
public ResponsiblePerson ResponsiblePerson3 { get; set; }
}
public class ResponsiblePerson
{
public string Id { get; set; }
public string Name { get; set; }
}
When I am trying to update Deal navigations properties:
private void UpdateResponsiblePersons(string dealId, string person1Id, string person2Id, string person3Id)
{
var existingdeal = _dbContext.Deals
.Include(d => d.ResponsiblePerson1)
.Include(d => d.ResponsiblePerson2)
.Include(d => d.ResponsiblePerson3)
.Single(d => d.Id == dealId);
existingDeal.ResponsiblePerson1 = new ResponsiblePerson { Id = person1Id };
existingDeal.ResponsiblePerson2 = new ResponsiblePerson { Id = person2Id };
existingDeal.ResponsiblePerson3 = new ResponsiblePerson { Id = person3Id };
_dbContext.Entry(deal.ResponsiblePerson1).State = EntityState.Unchanged;
_dbContext.Entry(deal.ResponsiblePerson3).State = EntityState.Unchanged;
_dbContext.Entry(deal.ResponsiblePerson3).State = EntityState.Unchanged;
_dbContext.SaveChanges();
}
EF often fails with
System.InvalidOperationException: The instance of entity type 'ResponsiblePerson' cannot be tracked because another instance with the key value '{Id: 1}' is already being tracked. When attaching existing entities, ensure that only one entity instance with a given key value is attached.
That is because sometimes existingdeal already contains the link to ResponsiblePerson with one of provided IDs in either ResponsiblePerson1 of ResponsiblePerson2 or ResponsiblePerson3 Navigation properties.
I know that one of possible solutions will be first to get ResponsiblePersons used for update from dbContext like
existingDeal.ResponsiblePerson1 = _dbContext.ResponsiblePersons.Find(person1Id)
But that means extra DB roundtrips.
Another solution is to expose foreign keys instead of navigation properties but it would make Deal model quite ugly.
Please advice me what is the best way of updating such references?
Im trying to save a rating against a place, I have the code below, but it doesnt seems to save rating (to the ratings table) for an existing entity
place.Ratings.Add(rating);
_placeRepository.AddPlaceIfItDoesntExist(place);
_placeRepository.Save();
This is the repository method
public void AddPlaceIfItDoesntExist(Place place)
{
var placeItem = context.Places.FirstOrDefault(x => x.GooglePlaceId == place.GooglePlaceId);
if(placeItem==null)
{
context.Places.Add(place);
}
else
{
context.Entry(placeItem).State = EntityState.Modified;
}
}
and this is the poco
public class Place
{
public Place()
{
Ratings = new List<Rating>();
}
public int Id { get; set; }
public string Name { get; set; }
public string GooglePlaceId { get; set; }
}
I think the crux of the problem is because i need to check if the place exists based on googleplaceid(a string) rather than the id (both are unique per place btw)
Here
context.Entry(placeItem).State = EntityState.Modified;
you just mark the existing placeItem object as modified. But it's a different instance than the passed place object, hence contains the orginal values.
Instead, replace that line with:
context.Entry(placeItem).CurrentValues.SetValues(place);
Alternatively, you can use the DbSetMigrationsExtensions.AddOrUpdate method overload that allows you to pass a custom identification expression:
using System.Data.Entity.Migrations;
public void AddPlaceIfItDoesntExist(Place place)
{
context.Places.AddOrUpdate(p => p.GooglePlaceId, place);
}
I have an EF6 setup against a sql server db with about 60 tables in it.
I have entities for each table. What i'm trying to do is run the same method against a set of these entities that will be known at runtime.
The method is a qa/qc routine that does some data check on particular fields that are assured to be in each table.
I guess what i want to do is make the entity a parameter to the method so i can call it consecutive times.
I would also want to make a set of entities to pass as the parameter.
something like this:
List<string> entList = new List<string>(){"Table1","Table2","Table3"};
foreach (entName in entList)
{
//create an entity with the string name
//call myQAQCMethod with the entity
}
MyQAQCMethod (entity SomeEntity)
{
//run against this entity
doQAQC(SomeEntity);
}
Can this be done? Is it a job for reflection?
EDIT
using (var context = new Context())
{
var results = context.EntityAs.Where(a => a.Prop1 == e.Prop1)
.Where(a => a.Prop2 == e.Prop2)
.Select(a => new
{
APropertyICareAbout = a.Prop1,
AnotherPropertyICareAbout = a.Prop2
}).ToArray();
}
is precisely want i want to do. The thing is I want to avoid typing this loop 60 times. I think i'm looking for a way to "feed" a set of entities to this single method.
Also, thank you very much for helping me. I'm learning a lot.
You need to abstract an interface (entity framework won't even notice):
interface IQaQcable
{
int CommonInt { get; set; }
string CommonString { get; set; }
}
public class EntityA : IQaQcable
{
public int Id { get; set; }
public int CommonInt { get; set; }
public string CommonString { get; set; }
// other properties and relations
}
public class EntityB : IQaQcable
{
public int Id { get; set; }
public int CommonInt { get; set; }
public string CommonString { get; set; }
// other properties and relations
}
// in some unknown utility class
void MyQaQcMethod<T>(T entity) where T : IQaQcable
{
doSomethingWithIQaQcableProperties(entity.CommonInt, entity.CommonString);
}
// in some unknown test class
void Test()
{
var entities = new List<IQaQcable> { new EntityA(), new EntityB() };
foreach (var e in entities)
MyQaQcMethod(e);
}
Now, you could extract a base class from which each derives that actually implements the CommonInt and CommonString properties for each entity needing them, but that can get kind of tricky with Table-Per-Type/Table-Per-Hierarchy, so I'd start with this, and then consider introducing either an abstract or concrete base class as an improvement.
EDIT
Maybe your looking for something simpler than I first thought, based on your last comment.
Let's give ourselves what the DbContext for this might look like:
class Context : DbContext
{
public virtual DbSet<EntityA> EntityAs { get; set; }
public virtual DbSet<EntityB> EntityBs { get; set; }
}
So, it could just be that you wish to do this:
using (var context = new Context())
{
var results = context.EntityAs.Where(a => a.Prop1 == e.Prop1)
.Where(a => a.Prop2 == e.Prop2)
.Select(a => new
{
APropertyICareAbout = a.Prop1,
AnotherPropertyICareAbout = a.Prop2
}).ToArray();
}
Keeping in mind, if there is some set of properties in common across entity classes, you could still do something like the following:
IEnumerable<T> MyQaQcMethod(IQueryable<T> entities, T referenceEntity) where T : IQaQcAble
{
return entities.Where(e => SomePredicate(e, referenceEntity));
}
void Test()
{
using (var context = new Context())
{
// EntityA implements IQaQcAble
var resultsForA = MyQaQcMethod(context.EntityAs, defaultEntity).ToArray();
// so does EntityB, so can call with either
var resultsForB = MyQaQcMethod(context.EntityBs, defaultEntity).ToArray();
}
}
Keep in mind, to avoid modifying the generated entity classes, you could implement the interface members — and the interface — in a separate source file using partial classes. E.g.
// IQaQcAble.cs
internal interface IQaQcAble
{
int CommonInt { get; set; }
string CommonString { get; set; }
}
// a class whose existing property names match the interface
public partial class EntityA : IQaQcAble
{
int IQaQcAble.CommonInt
{
get { return CommonInt; }
set { CommonInt = value; }
}
string IQaQcAble.CommonString
{
get { return CommonString; }
set { CommonString = value; }
}
}
// a class whose property names differ
public partial class EntityB : IQaQcAble
{
int IQaQcAble.CommonInt
{
get { return SomeOtherInt; }
set { SomeOtherInt = value; }
}
string IQaQcAble.CommonString
{
get { return SomeOtherInt.ToString(); }
set { SomeOtherInt = Convert.ToInt32(value); }
}
}
I want to retrieve an object plus its filtered/ordered collection property using EF 5. However, my current code throws an exception:
The Include path expression must refer to a navigation property
defined on the type. Use dotted paths for reference navigation
properties and the Select operator for collection navigation
properties
Here is the class of the object I want to retrieve:
public class EntryCollection
{
[Key]
public int Id { get; set; }
public ICollection<Entry> Entries { get; set; }
...
}
And here is the definition of Entry:
public class Entry
{
[Key]
public int Id { get; set; }
public DateTime Added { get; set; }
...
}
I wanted to retrieve the EntryCollection which contains only the most recent entries, so here is the code I tried:
using (var db = new MyContext())
{
return db.EntryCollections
.Include(ec => ec.Entries.OrderByDescending(e => e.Added).Take(5))
.SingleOrDefault(ec => ec.Foo == "bar');
}
Any ideas?
You cant use OrderBy inside an include.
what about the following
using (var db = new MyContext())
{
return db.EntryCollections
.Where(ec => ec.Foo == "bar")
.Select(ec=> new Something{Entries = ec.Entries.OrderByDescending(e => e.Added).Take(5) }, /*some other properties*/)
.SingleOrDefault();
}
or do it in two seperate queries
When serializing a MongoDB document to a POCO is there any way to make properties map case insensitive? For example I'd like this document:
{
"id": "1"
"foo": "bar"
}
to map to this class:
public MyObj
{
public int Id {get; set;}
public string Foo {get; set;}
}
To do that I think you will have 2 options.
The first would be to write out a class map manually
BsonClassMap.RegisterClassMap<MyClass>(cm => {
cm.AutoMap();
cm.GetMemberMap(c => c.Foo).SetElementName("foo");
});
The second would be to decorate your class with the following attributes
public class MyObj
{
[BsonElement("id")]
public int Id { get; set; }
[BsonElement("foo")]
public string Foo { get; set; }
}
The CSharp driver team have a good tutorial on serialization on the following link
http://docs.mongodb.org/ecosystem/tutorial/serialize-documents-with-the-csharp-driver/
Update
I have just tried the following and this works for me, obviously I'm sure this is a much more simplified version of your code but taking a guess at how it might look.
I have registered the two class maps separately and added the BsonKnownType to the base class.
[BsonKnownTypes(typeof(GeoJSONObject))]
public class Point
{
public string Coordinates { get; set; }
}
public class GeoJSONObject : Point
{
public string Type { get; set; }
}
static void Main(string[] args)
{
var cn = new MongoConnectionStringBuilder("server=localhost;database=MyTestDB;");
var settings = MongoClientSettings.FromConnectionStringBuilder(cn);
var client = new MongoClient(settings);
BsonClassMap.RegisterClassMap<Point>(cm =>
{
cm.AutoMap();
cm.GetMemberMap(c => c.Coordinates).SetElementName("coordinates");
});
BsonClassMap.RegisterClassMap<GeoJSONObject>(cm =>
{
cm.AutoMap();
cm.GetMemberMap(c => c.Type).SetElementName("type");
});
var result = client.GetServer()
.GetDatabase("MyTestDB")
.GetCollection("MyCol")
.Find(Query.EQ("type", BsonValue.Create("xxxx")));
}
I see that it is old question, but people still may search it. At least I found it while was asking the same question.
The CamelCaseElementNameConvention can be used to apply this globally.
var pack = new ConventionPack();
pack.Add(new CamelCaseElementNameConvention());
ConventionRegistry.Register("Camel case convention", pack, t => true);
Documentation: https://mongodb.github.io/mongo-csharp-driver/2.14/reference/bson/mapping/conventions/