You would be able to sort on the second word in each category if you wanted. You could also added more data to your categories, like a sort order field or a weighting field for relevance sorting. Since you are actually using a database table, you are not just stuck with using a word, you can link other data to the category and use it for calculations or sorting. You could even create subcategories, and sort on category/subcategory.
On Apr 8, 2005, at 12:25 PM, Marilyn Davis wrote:
On Thu, 7 Apr 2005, Brent Baisley wrote:
Thank you Brent.
As mentioned in the manual you specified, there are limits to how many items you can have in a set, among other issues. My biggest issue against using sets is that you need alter the table structure whenever you want to change the set. Usually I would want the user to be able to add, modify or delete list items. You do NOT want a user being able to alter the table structure. The three table layout gives you basically unlimited scalability, easier and quicker modification, dynamic sorting, more flexible searching and no character restrictions.
I can see the unlimited scalability, quicker modification, and no character restrictions. "Dynamic sorting"? Do you mean there's a sort that the three table layout can do that can't be done with the set type? Or a search?
I'm sorry to be so dense, but can you give me an example?
Thank you again.
Marilyn Davis
On Apr 7, 2005, at 5:20 PM, Marilyn Davis wrote:
Hi MySQL people.
I'm trying to understand the pros and cons of the "set" column type.
Here is an excerpt from the article:
http://dev.mysql.com/tech-resources/articles/mysql-set-datatype.html
Why You Shouldn't Use SET
"Third, using a set means your data is not normalized. In our above
example, we are tracking a person's interests for a hypothetical
dating site. In a normalized schema, there should be three tables: one
for the person, one for all possible interests, and one that links a
person to their particular interests."
The "above example" is:
CREATE TABLE set_test( rowid INT UNSIGNED NOT NULL AUTO_INCREMENT PRIMARY KEY, myset SET('Travel','Sports','Dancing','Fine Dining') );
I guess I'm not understanding the point here. What practical advantage is there to creating three tables instead of using a set column type?
Thank you for any help.
Marilyn Davis
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