problem to count (distinct number)

Hi,

I have a table with a column (int4), and I want to know how many
different numbers there are.  In an example book I saw the query

SELECT COUNT (DISTINCT data ) FROM media;

by then I get 

ERROR:  parser: parse error at or near "distinct"

Is the query in error or does PostgreSQL not support this?  How do I
then get the number of distinct data from my table?

TIA,

Micce 


-- 
Mikael Hedin, MSc                   +46 (0)980 79176
Swedish Institute of Space Physics  +46 (0)8 344979 (home)
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