MySQL question: Ignoring rows with repeat values?

[igowerf]

I have a large two column table. The first column contains tons of URL's and the second column contains the catagory that the URL falls under.

Example:

www.anandtech.com Computer
www.dell.com Merchant
www.hardocp.com Computer
www.nvidia.com Hardware
www.ati.com Hardware
www.newegg.com Merchant
www.macromedia.com Software

I want to do a query that gives me the catagories but ignores any repeats. So from my example, it would return just 4 results: Computer, Merchant, Hardware, and Software.

 

[manly]

SQL Select Distinct

 

[Superwormy]

SELECT category, COUNT(*) FROM tablename GROUP BY category

Or something like that, group by should work too, DISTINCT works also

 

[igowerf]

Thanks for the help guys. DISTINCT is exactly what I need.

 

[Haircut]

If I was designing something like that then I would have two tables.

Table 1: Categories, columns category_id and category_name

Table 2: URLS, columns URL and category_id

Then make category_id in URLS table foreign key to category_id in Categories table.

Just my 2 cents.

 

[kt]

Originally posted by: Superwormy
SELECT category, COUNT(*) FROM tablename GROUP BY category

Or something like that, group by should work too, DISTINCT works also

Ideally, you want to use SELECT DISTINCT because it is a more efficient way.