AreKeysUnique (clsColumn)
.gif "ms132850.note(ru-ru,SQL.90).gif") Примечание. |
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| В следующей версии Microsoft SQL Server эта возможность будет удалена. Не используйте ее при работе над новыми приложениями и как можно быстрее измените приложения, в которых она в настоящее время используется. |
The AreKeysUnique property of a clsColumn object indicates whether key columns (that is, a clsColumn object with an IsKey property set to True) defined in the Columns collection uniquely identify members in the case table.
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| This property applies only to columns that belong to mining model objects of SubClassType sbclsRelational. |
Data Type
Boolean
Access
Read/write for columns with a SubClassType of sbclsNested, read-only for all others.
Замечания
The AreKeysUnique property determines whether the relational mining model adds the DISTINCT keyword to the SQL SELECT query used to retrieve the training data set from the case tables. If the values for the key columns identified in the data mining model are unique in the case tables, setting this property to True can improve performance when the relational data mining model is trained.
For columns with a SubClassType of sbclsRegular, this property returns the AreKeysUnique property value of the parent, either an object of ClassType clsColumn with a SubClassType of sbclsNested or an object of ClassType clsMiningModel.