removing duplicate values from mysql_fet

[Anon]

I'm fetching values from a single column with multiple rows using mysql_fetch_array and want to remove duplicate values before using those values to build a pulldown menu.

How is this done?

The rows in my table contain the names of countries with many duplicate values. I want to be able to search against the table using a pulldown select menu, the options of which are populated only by unique values.

I'm guessing array_unique holds the key but I can't get it to work in this context.

TIA
js

[brandonschnell]

either:
SELECT DISTINCT country FROM table;

or:
run through the entire result set using mysql_fetch_array. if the country doesn't already exist in a 2nd array you've created, add it. once finished, run through the new array outputing the values into a pull down menu.

[Anon]

SELECT DISTINCT -- so simple, thanks!

Under what circumstances would the second method be preferable?

js

Brandon Schnell wrote:

either:
SELECT DISTINCT country FROM table;

or:
run through the entire result set using mysql_fetch_array. if the country doesn't already exist in a 2nd array you've created, add it. once finished, run through the new array outputing the values into a pull down menu.

[brandonschnell]

the second method is preferable when you can't use DISTINCT as part of a current query. it avoids taking the performance hit database side to run another query just for the DISTINCT col.

for example if you had a query to return a result set of customer data to be outputted to the screen. using a distinct could screw up the query and using another query just for the country list does mean a slight performance hit.

but in most cases its easier to read/code a new query that only gets a list of unique countries. using SELECT DISTINCT will also scale well, unlike the second method described.