MetaDataMember.IsPrimaryKey Property

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Gets whether this member is part of the type's identity.

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


Public MustOverride ReadOnly Property IsPrimaryKey As Boolean
public abstract bool IsPrimaryKey { get; }

Property Value

Type: System.Boolean
true if this member is part of the type's identity; otherwise, false.


If this property is true, the class member represents a column that is part of the table’s unique key. More than one member of the class can have this property set to true for a key that is a composite of the associated columns. For an entity class, at least one member must have this attribute and should be mapped to the primary key or a unique key in the corresponding table or view. Otherwise, LINQ to SQL considers instances of the class as read-only for the purpose of submitting changes to the database.

The set of columns identified with IsPrimaryKey are not required to be the primary key. They simply denote a set that uniquely identifies the entity. Common alternatives include clustering index columns or other unique key columns.

Version Information

Silverlight for Windows Phone

Supported in: Windows Phone OS 7.1


For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.