Updating statistics about indexes  How defaults and rules work


Chapter 13: Defining Defaults and Rules for Data

A default is a value that Adaptive Server inserts into a column if a user does not explicitly enter a value for that column. In database management, a rule specifies what you are or are not allowed to enter in a particular column or in any column with a given user-defined datatype. You can use defaults and rules to help maintain the integrity of data across the database.





Copyright © 2005. Sybase Inc. All rights reserved. How defaults and rules work

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