Thread: 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) S-Box 812, 981 28 KIRUNA, Sweden +46 (0)70 5891533 (mobile)
hi,there, I don't see the problem except extra space, try: SELECT COUNT(DISTINCT data) FROM media; Jie LIANG Internet Products Inc. 10350 Science Center Drive Suite 100, San Diego, CA 92121 Office:(858)320-4873 jliang@ipinc.com www.ipinc.com On 17 Jan 2001, Mikael Hedin wrote: > 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) > S-Box 812, 981 28 KIRUNA, Sweden +46 (0)70 5891533 (mobile) >
Mikael Hedin <mikael.hedin@irf.se> writes:
> SELECT COUNT (DISTINCT data ) FROM media;
> ERROR: parser: parse error at or near "distinct"
This is supported since 7.0. I suspect you are running an old release.
regards, tom lane
What version are you using? I believe this was added in 7.0.x, but I could be wrong about that. A query of this sort works on my 7.1beta3 system. On 17 Jan 2001, Mikael Hedin wrote: > 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?