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ColumnAttribute.IsPrimaryKey Property

Gets or sets whether this class member represents a column that is part or all of the primary key of the table.

Namespace:  System.Data.Linq.Mapping
Assembly:  System.Data.Linq (in System.Data.Linq.dll)

'Declaration
Public Property IsPrimaryKey As Boolean
'Usage
Dim instance As ColumnAttribute 
Dim value As Boolean 

value = instance.IsPrimaryKey

instance.IsPrimaryKey = value

Property Value

Type: System.Boolean
Default = false.

Assuming an entity class, you must provide at least one member with this attribute, and it must be mapped to the primary key or a unique key in the corresponding table or view. Failure to do this prompts LINQ to SQL to consider instances of the class as read-only for submitting changes to the database.

If you designate more than one member of the class by using this property, the key is said to be a composite of the associated columns.

NoteNote:

LINQ to SQL does not support computed columns as primary keys.

	<Column(Storage:="_ProductID", DbType:="Int NOT NULL", IsPrimaryKey:=true)>  _
	Public Property ProductID() As Integer 
		Get 
			Return Me._ProductID
		End Get 
		Set 
			If ((Me._ProductID = value)  _
						= false) Then 
				If Me._Product.HasLoadedOrAssignedValue Then 
					Throw New System.Data.Linq.ForeignKeyReferenceAlreadyHasValueException
				End If 
				Me.OnProductIDChanging(value)
				Me.SendPropertyChanging
				Me._ProductID = value
				Me.SendPropertyChanged("ProductID")
				Me.OnProductIDChanged
			End If 
		End Set 
	End Property

Windows 7, Windows Vista, Windows XP SP2, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003

The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

.NET Framework

Supported in: 3.5

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