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The Programmer’s Guide to iSeries Navigator by Paul Touhy

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Referential Integrity

You may not be familiar with the term Referential Integrity, but you are familiar with what it is because, traditionally, you have been implementing it in your application programs for years.

Take a simple example of a Customer table and an Invoice table. You should not be able to delete a customer from the Customer table if invoices for the customer exist on the Invoice table. How would you implement this rule in an application program? Create an index (or logical file) over the invoice file keyed by Invoice Number within Customer Code. Within the Customer Maintenance program, include logic that uses the Customer/Invoice index to ensure that no dependent invoices exist for the customer. However, this means that every programmer ...

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