Beginning SQL Queries: From Novice to Professional

This book is for anyone who has a well-designed relational database and needs to extract information from it. You might have noticed in the previous sentence that the database must be “well designed.” I can’t overemphasize this point. If your database is badly designed, then it will not be able to store accurate and consistent data, and so the information your queries retrieve will always be prone to inaccuracies. If you are looking to design a database from scratch, you should read my first book Beginning Database Design .” The final chapter in this book will outline a few common design problems you are likely to come across and give some advice about how to mitigate the impact or correct the problem.