High Quality Content by WIKIPEDIA articles! AutoNumber is a type of data used in Microsoft Access tables to generate an automatically incremented numeric counter. It may be used to create an identity column which uniquely identifies each record in a table. Only one AutoNumber field is allowed in each table. The default AutoNumber type is a start+increment counter, with a start value of 1 and an increment of 1. Although in many instances such an AutoNumber field will appear as if it contains the row count, it does not. Deletion of rows from a table, for example, does not cause AutoNumber fields to be re-numbered, but instead leaves "holes" in the numbering. Similarly, if a transaction to add a row to a table is begun but later aborted, the AutoNumber assigned for that row will not be re-used. The default start+increment form with the start value of 1 and increment of 1 is not suitable for all circumstances. There are reasons to choose each form, and trade-offs in doing so.

Данное издание не является оригинальным. Книга печатается по технологии принт-он-деманд после получения заказа.