![]() If your customer has two or more phone numbers, you should create distinct phone number fields in the customers table. Note that the address and phone numbers have been split into separate fields holding one item of information apiece. The essence of data normalization is just this: pull out repeating and reusable items and put them in their own, separate tables.įigure 3-2. A normalized customers table. Fortunately, you can leave the theoretical stuff to the experts following a few simple rules will suffice for most needs. They also make a big difference in performance as your database grows. Such well-designed tables are essential to maintaining data integrity and the long-term health of your database. The objective is to isolate data so that additions, deletions, and modifications of a field can be made in just one table and then propagated through the rest of the database via the defined relationships.” As the esteemed Webopedia ( ) pithily puts it, it involves “dividing a database into two or more tables and defining relationships between the tables. THE FIX: Normalizing basically means organizing data to reduce redundancy. Why do I need an advanced degree to create a simple contacts database? “Primary keys,” “foreign keys"…what are they talking about? And “Boyce-Codd normal form” sounds like a disease. THE ANNOYANCE: I’ve heard that I’m supposed to “normalize” my tables, but the books that discuss this are really confusing. ![]()
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