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Oops - I got my initial database design wrong
Just once in a while a question comes up on our Opentalk Forum that's so good and of such general interest that a longer answer is worthwhile. Such a question came up yesterday ... and elegantly asked and worded too, so it was a delight to read and answer.
You want a simple database application? Great - so you write the application using MySQL (or some other database) and you hold your data in a single table. Works well at first but then ... the design starts to creak at the seams. Perhaps you have a number of customers listed, and some of them make multiple purchases ... your database starts to contain a whole lot of repeated information which makes it hard to edit when someone changes their address, for example ... [b]It's so easy to design a database in this way, but how can it be sorted out later?[/b] It's not going to be easy - but I've set down a scheme, with various options, and a piece of PHP to do the task automatically ... and you can find that in the forum archive Beware - "normalising" your tables - changing from one table to two of more appropriate design - is likely to take you quite a while as you match up entries that aren't quite identical in their common fields but should be, and you're going to have to modify and add an element of complexity to your applications ... they'll have to update multiple tables rather than just one as data is being entered and changed, and they'll need to use MySQL Joins to connect the tables. (written 2005-07-12 13:09:59) Associated topics are indexed under S154 - MySQL - Designing an SQL Database System
Some other Articles
Getting the lighting rightA word of admiration for the London cabbie A Strengthened City What brings people to my web site? Oops - I got my initial database design wrong Instant availability Vik, Iceland to Melksham, England Time calculation in PHP The training team that's looking out for you From Iceland 1637 posts, page by page
Link to page ... 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33 at 50 posts per pageThis is a page archived from The Horse's Mouth at http://www.wellho.net/horse/ - the diary and writings of Graham Ellis. Every attempt was made to provide current information at the time the page was written, but things do move forward in our business - new software releases, price changes, new techniques. Please check back via our main site for current courses, prices, versions, etc - any mention of a price in "The Horse's Mouth" cannot be taken as an offer to supply at that price. Link to Ezine home page (for reading). Link to Blogging home page (to add comments). |
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