"G. Anthony Reina" <reina(at)nsi(dot)edu> writes:
> I'd like to find out how many times a unique 'subject_name' is in the
> table. My SQL book says that I should be able to do this:
> select COUNT(DISTINCT subject_name) from table1;
> However, the psql program is giving me an "ERROR: parser: parse error
> at or near "distinct"".
6.5 doesn't have aggregate(DISTINCT ...). 7.0 does, though.
If you don't want to upgrade right now, you could do something like
SELECT DISTINCT subject_name INTO temp_table FROM table1;
SELECT count(*) FROM temp_table;
DROP TABLE temp_table;
regards, tom lane