TCustomBufDataset.UniDirectional property

Declaration

property UniDirectional: Boolean read GetBufUniDirectional write SetBufUniDirectional default False;

Description

UniDirectional is a Boolean property which indicates if the dataset is limited to forward navigation through its records. The default value for the property is False.

UniDirectional is used, along with ReadOnly, to determine if the dataset can be modified. When either property contains True, the dataset cannot be changed.

UniDirectional also affects the index storage metchanisms created when indexes are initialized. When UniDIrectional is True, the TUniDirectionalBufIndex type (which omits bookmarks and record numbers) is used for index storage mechanisms. In addition, the custom index ('CUSTOM_ORDER') is skipped for the uni-directional dataset.

Setting the value in UniDirectional requires the dataset to be inactive (Active contains False) to allow existing indexes to be cleared and rebuilt. Use the Close method to cl;osr the dataset prior to setting the value in the UniDIrectional property.

See also

• TDataset.ReadOnly
• TDataset.Active