ReferenceOwnershipBuilder<TEntity,TRelatedEntity>.HasOne Method
Definition
Important
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Overloads
| HasOne<TNewRelatedEntity>(Expression<Func<TRelatedEntity,TNewRelatedEntity>>) |
Configures a relationship where this entity type has a reference that points to a single instance of the other type in the relationship. Note that calling this method with no parameters will explicitly configure this side of the relationship to use no navigation property, even if such a property exists on the entity type. If the navigation property is to be used, then it must be specified. After calling this method, you should chain a call to WithMany(Expression<Func<TRelatedEntity,IEnumerable<TEntity>>>) or WithOne(Expression<Func<TRelatedEntity,TEntity>>) to fully configure the relationship. Calling just this method without the chained call will not produce a valid relationship. |
| HasOne<TNewRelatedEntity>(String) |
Configures a relationship where this entity type has a reference that points to a single instance of the other type in the relationship. Note that calling this method with no parameters will explicitly configure this side of the relationship to use no navigation property, even if such a property exists on the entity type. If the navigation property is to be used, then it must be specified. After calling this method, you should chain a call to WithMany(String) or WithOne(String) to fully configure the relationship. Calling just this method without the chained call will not produce a valid relationship. |
HasOne<TNewRelatedEntity>(Expression<Func<TRelatedEntity,TNewRelatedEntity>>)
Configures a relationship where this entity type has a reference that points to a single instance of the other type in the relationship.
Note that calling this method with no parameters will explicitly configure this side of the relationship to use no navigation property, even if such a property exists on the entity type. If the navigation property is to be used, then it must be specified.
After calling this method, you should chain a call to WithMany(Expression<Func<TRelatedEntity,IEnumerable<TEntity>>>) or WithOne(Expression<Func<TRelatedEntity,TEntity>>) to fully configure the relationship. Calling just this method without the chained call will not produce a valid relationship.
public virtual Microsoft.EntityFrameworkCore.Metadata.Builders.ReferenceNavigationBuilder<TRelatedEntity,TNewRelatedEntity> HasOne<TNewRelatedEntity> (System.Linq.Expressions.Expression<Func<TRelatedEntity,TNewRelatedEntity>> navigationExpression = default) where TNewRelatedEntity : class;override this.HasOne : System.Linq.Expressions.Expression<Func<'RelatedEntity, 'NewRelatedEntity>> -> Microsoft.EntityFrameworkCore.Metadata.Builders.ReferenceNavigationBuilder<'RelatedEntity, 'NewRelatedEntity (requires 'RelatedEntity : null and 'NewRelatedEntity : null)> (requires 'NewRelatedEntity : null)Public Overridable Function HasOne(Of TNewRelatedEntity As Class) (Optional navigationExpression As Expression(Of Func(Of TRelatedEntity, TNewRelatedEntity)) = Nothing) As ReferenceNavigationBuilder(Of TRelatedEntity, TNewRelatedEntity)Type Parameters
- TNewRelatedEntity
The entity type that this relationship targets.
Parameters
- navigationExpression
- Expression<Func<TRelatedEntity,TNewRelatedEntity>>
A lambda expression representing the reference navigation property on this entity type that represents
the relationship (post => post.Blog). If no property is specified, the relationship will be
configured without a navigation property on this end.
Returns
An object that can be used to configure the relationship.
Applies to
HasOne<TNewRelatedEntity>(String)
Configures a relationship where this entity type has a reference that points to a single instance of the other type in the relationship.
Note that calling this method with no parameters will explicitly configure this side of the relationship to use no navigation property, even if such a property exists on the entity type. If the navigation property is to be used, then it must be specified.
After calling this method, you should chain a call to WithMany(String) or WithOne(String) to fully configure the relationship. Calling just this method without the chained call will not produce a valid relationship.
public virtual Microsoft.EntityFrameworkCore.Metadata.Builders.ReferenceNavigationBuilder<TRelatedEntity,TNewRelatedEntity> HasOne<TNewRelatedEntity> (string navigationName) where TNewRelatedEntity : class;override this.HasOne : string -> Microsoft.EntityFrameworkCore.Metadata.Builders.ReferenceNavigationBuilder<'RelatedEntity, 'NewRelatedEntity (requires 'RelatedEntity : null and 'NewRelatedEntity : null)> (requires 'NewRelatedEntity : null)Public Overridable Function HasOne(Of TNewRelatedEntity As Class) (navigationName As String) As ReferenceNavigationBuilder(Of TRelatedEntity, TNewRelatedEntity)Type Parameters
- TNewRelatedEntity
The entity type that this relationship targets.
Parameters
- navigationName
- String
The name of the reference navigation property on this entity type that represents the relationship. If no property is specified, the relationship will be configured without a navigation property on this end.
Returns
An object that can be used to configure the relationship.
Applies to
Entity Framework