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/
Related
I am trying to separate my contexts using DDD. I have two domains, Instruments and Advertisements with its aggregate roots (the example is hypothetical). Instrument AR owns many InstrumentPictures and I would like to have that information in the Advertisement domain as well via proxy entity.
To ensure good database integrity it would be better to create foreign key from AdvertisementPicture.Guid to InstrumentPicture.Guid but as far as I know this can be done only through HasOne/HasMany model configuration.
Am I using the owner relationship wrong?
(Note: I do not want to configure the FK with custom sql migration.)
Instrument AR:
public class Instrument
{
protected Instrument()
{
}
public Instrument(string name, IEnumerable<InstrumentPicture> pictures)
{
Name = name;
_instrumentPictures.AddRange(pictures);
}
protected List<InstrumentPicture> _instrumentPictures = new List<InstrumentPicture>();
public IReadOnlyCollection<InstrumentPicture> InstrumentPictures
=> _instrumentPictures.AsReadOnly();
public Guid Guid { get; private set; }
public string Name { get; private set; }
}
InstrumentPicture owned collection:
public class InstrumentPicture
{
protected InstrumentPicture()
{
}
public InstrumentPicture(Guid guid, string url)
{
Guid = guid;
Url = url;
}
public Guid Guid { get; set; }
public string Url { get; set; }
public DateTime Created { get; set; }
}
Advertisiment AR
public class Advertisement
{
protected Advertisement()
{
}
public Advertisement(Guid instrumentGuid, string name, IEnumerable<AdvertisementPicture> pictures)
{
InstrumentGuid = instrumentGuid;
Name = name;
_advertisementPictures.AddRange(pictures);
}
protected List<AdvertisementPicture> _advertisementPictures = new List<AdvertisementPicture>();
public IReadOnlyCollection<AdvertisementPicture> AdvertisementPictures
=> _advertisementPictures.AsReadOnly();
public Guid Guid { get; private set; }
public Guid InstrumentGuid { get; private set; }
public string Name { get; private set; }
}
AdvertisementPicture proxy
public class AdvertisementPicture
{
protected AdvertisementPicture()
{
}
public AdvertisementPicture(Guid guid, string url)
{
Guid = guid;
Url = url;
}
public Guid Guid { get; set; }
public string Url { get; set; }
}
Model configuration:
protected override void OnModelCreating(ModelBuilder modelBuilder)
{
modelBuilder.Entity<Instrument>()
.HasKey(e => e.Guid);
modelBuilder.Entity<Instrument>()
.OwnsMany(e => e.InstrumentPictures, pic =>
{
pic.HasKey(e => e.Guid);
});
modelBuilder.Entity<Advertisement>()
.HasKey(e => e.Guid);
modelBuilder.Entity<Advertisement>()
.HasOne<Instrument>()
.WithMany()
.HasForeignKey(e => e.InstrumentGuid);
modelBuilder.Entity<Advertisement>()
.OwnsMany(e => e.AdvertisementPictures, pic =>
{
pic.HasKey(e => e.Guid);
// How can I add a foreign key to original InstrumentPicture for database integrity?
});
}
I've been struggling with this for hours and finding lots of answers on SO saying this isn't possible. Turns out this is possible using EntityFrameworkCore so I'll post what I've found on my Top Google Search for this problem.
As soon as you add a foreign key you will find the migration tool attempting to create the table in the second DBContext (unless you add ModelBuilder.Ignore<>() which will either do nothing or ignore your foreign key depending on your order of operations).
You can however do something like this:
protected override void OnModelCreating(ModelBuilder modelBuilder)
{
modelBuilder.Entity<IdentityUser>()
.ToTable("AspNetUsers", t => t.ExcludeFromMigrations());
}
This will allow you to reference tables in other DBContext's but exclude any changes to them from the one you're working in. This is outlined in the MS documentation here.
If you have used Fluent API you may still need to apply those configurations in the referencing DB Context. This is easily achieved if you have used the IEntityTypeConfiguration<T> implementation by an additional call to ModelBuilder.ApplyConfigurationsFromAssembly(typeof(T).Assembly);.
In such a use case as above you may find yourself excluding a lot of different entities from your DB context. If you have these defined in their own library like I have to follow a DDD pattern you may find an extension method useful to exclude all of them at once:
public static class ExcludeEntitiesInAssemblyFromMigrationsExtension
{
public static void ExcludeEntitiesInAssemblyFromMigrations(this ModelBuilder builder, Assembly assembly)
{
var assemblyTypes = assembly.GetExportedTypes().Where(t => t.IsClass && !t.IsAbstract);
foreach (var assemblyType in assemblyTypes)
{
var entityBuilder = builder.Entity(assemblyType);
var entityTablename = entityBuilder.Metadata.GetTableName();
if (entityTablename != null)
{
entityBuilder.ToTable(entityTablename, t => t.ExcludeFromMigrations());
}
}
}
}
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.
I looking for some help on how to implement IN clause in the repository pattern. Rather than making single call for each and every record, I will have set of IDs, pass on this IDs to Context to get entities which satisfies the condition using Repository Pattern with EF.
I knew we can have something like this:
context.Students.Where( x => StudentIDs.contains(x.ID))
How to implement same in the repository layer or pattern with single call to DB?
If you really are a purist, yes you should abstract the DbContext entirely as you seem to imply.
I'm not sure I completely understand the issue, but something like that should do the job:
namespace EFRepo
{
class Student
{
public long Id { get; set; }
public string Name { get; set; }
}
class SchoolContext : DbContext
{
public DbSet<Student> Students { get; set; }
}
class SchoolRepository
{
private SchoolContext context = new SchoolContext();
public Student Add(string name)
{
Student student = new Student { Name = name };
context.Students.Add(student);
context.SaveChanges();
return student;
}
public IEnumerable<Student> GetStudentsByIds(IEnumerable<long> ids)
{
return context.Students.Where(x => ids.Contains(x.Id));
}
}
class Program
{
static void Main(string[] args)
{
SchoolRepository repo = new SchoolRepository();
repo.Add("Bully");
repo.Add("Crawler");
repo.Add("Tart");
foreach (Student s in repo.GetStudentsByIds(new[] { 1L, 3 }))
{
Console.WriteLine(s.Name);
}
}
}
}
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
I am in the process of creating a domain model and would like to have a "BaseEntity" class with an "Id" property (and some other audit tracking stuff). The Id property is the primary key and each Entity in my Domain Model will inherit from the BaseEntity class. Pretty straightforward stuff.....
public class BaseEntity
{
[Key]
public int Id { get; set; }
public DateTime LastUpdate { get; set; }
public string LastUpdateBy { get; set; }
}
public class Location : BaseEntity
{
[Required]
public string Name { get; set; }
public string Description { get; set; }
}
Using the example above, I would like to map the "Id" field to a "LocationId" column. I understand that I can use the modelBuilder to do this for each entity explicitly by doing something like this:
modelBuilder.Entity<Location>().Property(s => s.Id).HasColumnName("LocationId");
But I would like to do this for every Entity in my domain model and it would be ugly.
I tried the following bit of reflection but did not have any luck. For whatever reason, the compiler "cannot resolve symbol type":
foreach (var type in GetTypesInNamespace(Assembly.Load("Domain.Model"),"Domain.Model"))
{
modelBuilder.Entity<type>().Property(x=>x.Id).....
}
Is there a way to define a convention to override the default PrimaryKey convention to map my "Id" property to a "ClassNameId" property in the database? I am using Entity Framework 6.
You should take a look at Custom Code First Conventions. You need EF6 for it to work, but it looks like you're already using it.
Just to give you an overview, take a look at the following convention I've used to convert PascalCase names to underscore names. It includes a convention for id properties... It also includes an optional table name prefix.
public class UnderscoreNamingConvention : IConfigurationConvention<PropertyInfo, PrimitivePropertyConfiguration>,
IConfigurationConvention<Type, ModelConfiguration>
{
public UnderscoreNamingConvention()
{
IdFieldName = "Id";
}
public string TableNamePrefix { get; set; }
public string IdFieldName { get; set; }
public void Apply(PropertyInfo propertyInfo, Func<PrimitivePropertyConfiguration> configuration)
{
var columnName = propertyInfo.Name;
if (propertyInfo.Name == IdFieldName)
columnName = propertyInfo.ReflectedType.Name + IdFieldName;
configuration().ColumnName = ToUnderscore(columnName);
}
public void Apply(Type type, Func<ModelConfiguration> configuration)
{
var entityTypeConfiguration = configuration().Entity(type);
if (entityTypeConfiguration.IsTableNameConfigured) return;
var tableName = ToUnderscore(type.Name);
if (!string.IsNullOrEmpty(TableNamePrefix))
{
tableName = string.Format("{0}_{1}", TableNamePrefix, tableName);
}
entityTypeConfiguration.ToTable(tableName);
}
public static string ToUnderscore(string value)
{
return Regex.Replace(value, "(\\B[A-Z])", "_$1").ToLowerInvariant();
}
}
You use it like this
modelBuilder.Conventions.Add(new UnderscoreNamingConvention { TableNamePrefix = "app" });
EDIT: In your case, the Apply method should be something like this:
public void Apply(PropertyInfo propertyInfo, Func<PrimitivePropertyConfiguration> configuration)
{
if (propertyInfo.Name == "Id")
{
configuration().ColumnName = propertyInfo.ReflectedType.Name + "Id";
}
}
Try this out in your DbContext class;
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
modelBuilder.Properties<int>()
.Where(p => p.Name.Equals("Id"))
.Configure(c => c.HasColumnName(c.ClrPropertyInfo.ReflectedType.Name + "Id"));
}
int is the CLR Type of my Primary Key fields. I want to refer to all keys in code as Id but DBA's require keys to be Id with Table entity name prefix. Above gives me exactly what I want in my created database.
Entity Framework 6.x is required.
In Entity Framework 6 Code First:
modelBuilder.Entity<roles>().Property(b => b.id).HasColumnName("role_id");
and update-database...
Change in model
[Key]
[DatabaseGenerated(DatabaseGeneratedOption.Identity)]
public long id { get; set; }
to:
[Key]
[DatabaseGenerated(DatabaseGeneratedOption.Identity)]
public long role_id { get; set; }
Then remove this:
//modelBuilder.Entity<roles>().Property(b => b.id).HasColumnName("role_id");
A start to the Dynamic approach if NOT using custom conventions
modelBuilder.Entity<Location>().Property(s => s.Id).HasColumnName("LocationId");
You can do this using reflection on the context. Pseudo Code as explanation:
Reflect Context to get a list of POCO names
For each POCO in a dbcontext.
Map Property Id -> string PocoName+Id
Here are the extensions I use for this type of solution.
// DBSet Types is the Generic Types POCO name used for a DBSet
public static List<string> GetModelTypes(this DbContext context) {
var propList = context.GetType().GetProperties();
return GetDbSetTypes(propList);
}
// DBSet Types POCO types as IEnumerable List
public static IEnumerable<Type> GetDbSetPropertyList<T>() where T : DbContext {
return typeof (T).GetProperties().Where(p => p.PropertyType.GetTypeInfo()
.Name.StartsWith("DbSet"))
.Select(propertyInfo => propertyInfo.PropertyType.GetGenericArguments()[0]).ToList();
}
private static List<string> GetDbSetTypes(IEnumerable<PropertyInfo> propList) {
var modelTypeNames = propList.Where(p => p.PropertyType.GetTypeInfo().Name.StartsWith("DbSet"))
.Select(p => p.PropertyType.GenericTypeArguments[0].Name)
.ToList();
return modelTypeNames;
}
private static List<string> GetDbSetNames(IEnumerable<PropertyInfo> propList) {
var modelNames = propList.Where(p => p.PropertyType.GetTypeInfo().Name.StartsWith("DbSet"))
.Select(p => p.Name)
.ToList();
return modelNames;
}
However, you will still need to employee dynamic lambda to finish.
Continue that topic here: Dynamic lambda example with EF scenario
EDIT:
Add link to another question that address the common BAse Config class approach
Abstract domain model base class when using EntityTypeConfiguration<T>
Piggybacking on #Monty0018 's answer but this just need to be updated a little if, like me, you're using Entity Framework 7 and/or SQLite.
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
try
{
_builder = modelBuilder;
var typeName = typeof(T).Name;
_builder
.Entity(typeof(T))
.Property<int>("Id")
.ForSqliteHasColumnName(typeName + "Id");
}
catch (Exception e)
{
throw e;
}
}