The UniqueConstraint Class

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The UniqueConstraint Class You use an object of the UniqueConstraint class to ensure that a DataColumn value, or combination of DataColumn values, is unique for each DataRow in a DataTable.

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Nội dung Text: The UniqueConstraint Class

The UniqueConstraint Class You use an object of the UniqueConstraint class to ensure that a DataColumn value, or combination of DataColumn values, is unique for each DataRow in a DataTable. The UniqueConstraint class is derived from the System.Data.Constraint class. Table 12.1 shows the UniqueConstraint properties. Table 12.1: UniqueConstraint PROPERTIES PROPERTY TYPE DESCRIPTION Columns DataColumn[] Gets the array of DataColumn objects for the UniqueConstraint. ConstraintName string Gets the name of the UniqueConstraint. ExtendedProperties PropertyCollection Gets the PropertyCollection object that you can use to store strings of additional information. IsPrimaryKey bool Gets a bool that indicates whether the UniqueConstraint is a primary key. Table DataTable Gets the DataTable on which the UniqueConstraint was created.