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DataTable::PrimaryKey Property

Gets or sets an array of columns that function as primary keys for the data table.

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

public:
property array<DataColumn^>^ PrimaryKey {
	array<DataColumn^>^ get ();
	void set (array<DataColumn^>^ value);
}

Property Value

Type: array<System.Data::DataColumn>
An array of DataColumn objects.

ExceptionCondition
DataException

The key is a foreign key.

The primary key of a table must be unique to identify the record in the table. It's also possible to have a table with a primary key made up of two or more columns. This occurs when a single column can't contain enough unique values. For example, a two column primary key might consist of a "FirstName" and "LastName" column. Because primary keys can be made up of more than one column, the PrimaryKey property consists of an array of DataColumn objects.

The first example shows how to return the primary key columns for a DataTable displayed in a DataGrid. The second example demonstrates how to set the primary key columns for a DataTable.

No code example is currently available or this language may not be supported.

.NET Framework

Supported in: 4.5, 4, 3.5, 3.0, 2.0, 1.1, 1.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

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

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