EntityTypeConfiguration<TEntityType>.HasRequired<TTargetEntity> Method
[This page is specific to the Entity Framework version 6. The latest version is available as the 'Entity Framework' NuGet package. For more information about Entity Framework, see msdn.com/data/ef.]
Configures a required relationship from this entity type. Instances of the entity type will not be able to be saved to the database unless this relationship is specified. The foreign key in the database will be non-nullable.
Namespace: System.Data.Entity.ModelConfiguration
Assembly: EntityFramework (in EntityFramework.dll)
Syntax
'Declaration
<SuppressMessageAttribute("Microsoft.Design", "CA1011:ConsiderPassingBaseTypesAsParameters")> _
<SuppressMessageAttribute("Microsoft.Design", "CA1006:DoNotNestGenericTypesInMemberSignatures")> _
Public Function HasRequired(Of TTargetEntity As Class) ( _
navigationPropertyExpression As Expression(Of Func(Of TEntityType, TTargetEntity)) _
) As RequiredNavigationPropertyConfiguration(Of TEntityType, TTargetEntity)
'Usage
Dim instance As EntityTypeConfiguration
Dim navigationPropertyExpression As Expression(Of Func(Of TEntityType, TTargetEntity))
Dim returnValue As RequiredNavigationPropertyConfiguration(Of TEntityType, TTargetEntity)
returnValue = instance.HasRequired(navigationPropertyExpression)
[SuppressMessageAttribute("Microsoft.Design", "CA1011:ConsiderPassingBaseTypesAsParameters")]
[SuppressMessageAttribute("Microsoft.Design", "CA1006:DoNotNestGenericTypesInMemberSignatures")]
public RequiredNavigationPropertyConfiguration<TEntityType, TTargetEntity> HasRequired<TTargetEntity>(
Expression<Func<TEntityType, TTargetEntity>> navigationPropertyExpression
)
where TTargetEntity : class
[SuppressMessageAttribute(L"Microsoft.Design", L"CA1011:ConsiderPassingBaseTypesAsParameters")]
[SuppressMessageAttribute(L"Microsoft.Design", L"CA1006:DoNotNestGenericTypesInMemberSignatures")]
public:
generic<typename TTargetEntity>
where TTargetEntity : ref class
RequiredNavigationPropertyConfiguration<TEntityType, TTargetEntity>^ HasRequired(
Expression<Func<TEntityType, TTargetEntity>^>^ navigationPropertyExpression
)
[<SuppressMessageAttribute("Microsoft.Design", "CA1011:ConsiderPassingBaseTypesAsParameters")>]
[<SuppressMessageAttribute("Microsoft.Design", "CA1006:DoNotNestGenericTypesInMemberSignatures")>]
member HasRequired :
navigationPropertyExpression:Expression<Func<'TEntityType, 'TTargetEntity>> -> RequiredNavigationPropertyConfiguration<'TEntityType, 'TTargetEntity> when 'TTargetEntity : not struct
JScript does not support generic types and methods.
Type Parameters
- TTargetEntity
The type of the entity at the other end of the relationship.
Parameters
- navigationPropertyExpression
Type: System.Linq.Expressions.Expression<Func<TEntityType, TTargetEntity>>
A lambda expression representing the navigation property for the relationship. C#: t => t.MyProperty VB.Net: Function(t) t.MyProperty
Return Value
Type: System.Data.Entity.ModelConfiguration.Configuration.RequiredNavigationPropertyConfiguration<TEntityType, TTargetEntity>
A configuration object that can be used to further configure the relationship.