Validating isbn 10 c
The best trick is not to put bad data in your schema in the first place. Verification is done after you have the schema and the data.Modification is done as the external world changes around you.One piece of advice from him was to add ‘reasonableness checks’ to code, to prevent bad data. For example, it’s perfectly reasonable for the Dairy Queen chain to buy 5000 bananas.In fact,that might even be a little low for them, given the number of banana splits their stores make in a given day.However, the admonition about not allowing negative numbers in floating-point column is also worth considering.Gerald Weinberg is one of the founders of modern software engineering (The Psychology of Computer Programming: Silver Anniversary Edition; ISBN-13: 978-0932633422).
I’d like to add another desirable property, modification, to this list.
A proper database design is very important, and changes to fix problems after the fact are expensive.
In this article, Joe Celko discusses three aspects of database design that are often overlooked: validation, verification, and modification.
Validating a data type should not be a problem unless for some reason you try to represent it as character strings or numerics.
The real problem with dates is that people use a local dialect to display them instead of the ANSI/ISO Standard ISO 8601 format.