select each unique one from table

[admin]

Hi,

Would someone let me know or point me to somewhere how I "SELECT" each unique element in a database table?

Suppose that I have a table like this

userid quizID questID answer
....
....
....

There will be the same userids tor each quizID. What I want to do is

Selecting each userid in the userids and save them in an array....

[This goes in scoring function; then insert or update the score table accordingly...]

Thanks for reading this!