DbSet Class

Definition

A non-generic version of DbSet<TEntity> which can be used when the type of entity is not known at build time.

[System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Naming", "CA1710:IdentifiersShouldHaveCorrectSuffix", Justification="Name is intentional")]
[System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Naming", "CA1709:IdentifiersShouldBeCasedCorrectly", Justification="Casing is intentional")]
public abstract class DbSet : System.Data.Entity.Infrastructure.DbQuery
[System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Design", "CA1010:CollectionsShouldImplementGenericInterface")]
[System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Naming", "CA1710:IdentifiersShouldHaveCorrectSuffix", Justification="Name is intentional")]
public abstract class DbSet : System.Data.Entity.Infrastructure.DbQuery
type DbSet = class
    inherit DbQuery
Public MustInherit Class DbSet
Inherits DbQuery
Inheritance
DbSet
Attributes

Constructors

DbSet()

Creates an instance of a DbSet when called from the constructor of a derived type that will be used as a test double for DbSets. Methods and properties that will be used by the test double must be implemented by the test double except AsNoTracking, AsStreaming, an Include where the default implementation is a no-op.

Properties

ElementType

The IQueryable element type.

(Inherited from DbQuery)
Local

Gets an ObservableCollection<T> that represents a local view of all Added, Unchanged, and Modified entities in this set. This local view will stay in sync as entities are added or removed from the context. Likewise, entities added to or removed from the local view will automatically be added to or removed from the context.

Sql

Gets a String representation of the underlying query.

(Inherited from DbQuery)

Methods

Add(Object)

Adds the given entity to the context underlying the set in the Added state such that it will be inserted into the database when SaveChanges is called.

AddRange(IEnumerable)

Adds the given collection of entities into context underlying the set with each entity being put into the Added state such that it will be inserted into the database when SaveChanges is called.

AsNoTracking()

Returns a new query where the entities returned will not be cached in the DbContext.

(Inherited from DbQuery)
AsStreaming()
Obsolete.

Returns a new query that will stream the results instead of buffering.

(Inherited from DbQuery)
Attach(Object)

Attaches the given entity to the context underlying the set. That is, the entity is placed into the context in the Unchanged state, just as if it had been read from the database.

Cast<TEntity>()

Returns the equivalent generic DbSet<TEntity> object.

Create()

Creates a new instance of an entity for the type of this set. Note that this instance is NOT added or attached to the set. The instance returned will be a proxy if the underlying context is configured to create proxies and the entity type meets the requirements for creating a proxy.

Create(Type)

Creates a new instance of an entity for the type of this set or for a type derived from the type of this set. Note that this instance is NOT added or attached to the set. The instance returned will be a proxy if the underlying context is configured to create proxies and the entity type meets the requirements for creating a proxy.

Equals(Object)

Determines whether the specified object is equal to the current object.

Find(Object[])

Finds an entity with the given primary key values. If an entity with the given primary key values exists in the context, then it is returned immediately without making a request to the store. Otherwise, a request is made to the store for an entity with the given primary key values and this entity, if found, is attached to the context and returned. If no entity is found in the context or the store, then null is returned.

FindAsync(CancellationToken, Object[])

Asynchronously finds an entity with the given primary key values. If an entity with the given primary key values exists in the context, then it is returned immediately without making a request to the store. Otherwise, a request is made to the store for an entity with the given primary key values and this entity, if found, is attached to the context and returned. If no entity is found in the context or the store, then null is returned.

FindAsync(Object[])

Asynchronously finds an entity with the given primary key values. If an entity with the given primary key values exists in the context, then it is returned immediately without making a request to the store. Otherwise, a request is made to the store for an entity with the given primary key values and this entity, if found, is attached to the context and returned. If no entity is found in the context or the store, then null is returned.

GetHashCode()

Serves as the default hash function.

GetType()

Gets the Type of the current instance.

Include(String)

Specifies the related objects to include in the query results.

(Inherited from DbQuery)
Remove(Object)

Marks the given entity as Deleted such that it will be deleted from the database when SaveChanges is called. Note that the entity must exist in the context in some other state before this method is called.

RemoveRange(IEnumerable)

Removes the given collection of entities from the context underlying the set with each entity being put into the Deleted state such that it will be deleted from the database when SaveChanges is called.

SqlQuery(String, Object[])

Creates a raw SQL query that will return entities in this set. By default, the entities returned are tracked by the context; this can be changed by calling AsNoTracking on the DbRawSqlQuery returned. Note that the entities returned are always of the type for this set and never of a derived type. If the table or tables queried may contain data for other entity types, then the SQL query must be written appropriately to ensure that only entities of the correct type are returned.

As with any API that accepts SQL it is important to parameterize any user input to protect against a SQL injection attack. You can include parameter place holders in the SQL query string and then supply parameter values as additional arguments. Any parameter values you supply will automatically be converted to a DbParameter. context.Set(typeof(Blog)).SqlQuery("SELECT * FROM dbo.Posts WHERE Author = @p0", userSuppliedAuthor); Alternatively, you can also construct a DbParameter and supply it to SqlQuery. This allows you to use named parameters in the SQL query string. context.Set(typeof(Blog)).SqlQuery("SELECT * FROM dbo.Posts WHERE Author = @author", new SqlParameter("@author", userSuppliedAuthor));

ToString()

Returns a String representation of the underlying query.

(Inherited from DbQuery)

Explicit Interface Implementations

IDbAsyncEnumerable.GetAsyncEnumerator()

Returns an IDbAsyncEnumerator which when enumerated will execute the query against the database.

(Inherited from DbQuery)
IEnumerable.GetEnumerator()

Returns an IEnumerator which when enumerated will execute the query against the database.

(Inherited from DbQuery)
IListSource.ContainsListCollection

Returns false.

(Inherited from DbQuery)
IListSource.GetList()

Throws an exception indicating that binding directly to a store query is not supported. Instead populate a DbSet with data, for example by using the Load extension method, and then bind to local data. For WPF bind to DbSet.Local. For Windows Forms bind to DbSet.Local.ToBindingList().

(Inherited from DbQuery)
IQueryable.Expression

The IQueryable LINQ Expression.

(Inherited from DbQuery)
IQueryable.Provider

The IQueryable provider.

(Inherited from DbQuery)

Applies to