a bit confused about distinct() function - Mailing list pgsql-sql

<p><font size="2">Hi Everybody,<br /><br /> I am a bit confused about distinct() function.<br /><br /> I wrote a simple
querylike this:<br /><br />  select subjectid, markerid, allele1id, allele2id<br />   from tsakai.mygenotype2<br />
 wheresubjectid in (53684, 53688, 53699, 53700, 53704, 53705, 53713, 53714, 53716, 53724)<br />        and<br />       
markeridin  (1259501, 1259504, 1260210, 1260211, 1260212, 1260214, 1260215, 1260238, 1260248, 1260562)<br />  order<br
/>    by subjectid;<br /><br /> Here's what I got back:<br /><br />   subjectid | markerid | allele1id | allele2id<br
/> -----------+----------+-----------+-----------<br />       53684 |  1260214 |   2521543 |   2521543<br />      
53684|  1260214 |   2521543 |   2521543<br />       53684 |  1260215 |   2521537 |   2521538<br />       53688 | 
1260562|   2522243 |   2522243<br />       53688 |  1260562 |   2522243 |   2522243<br />       53699 |  1260562 |  
2522243|   2522243<br />       53699 |  1260214 |   2521543 |   2521544<br />       53699 |  1260214 |   2521543 |  
2521544<br/>       53704 |  1260215 |   2521537 |   2521537<br />       53714 |  1260214 |   2521543 |   2521543<br />
 (10rows)<br /><br /> Which is good, but seeing the duplicate rows in result<br /> made me want to write:<br /><br />
 selectdistinct (subjectid, markerid, allele1id, allele2id)<br />    from tsakai.mygenotype2<br />   where subjectid in
(53684,53688, 53699, 53700, 53704, 53705, 53713, 53714, 53716, 53724)<br />         and<br />         markerid in 
(1259501,1259504, 1260210, 1260211, 1260212, 1260214, 1260215, 1260238, 1260248, 1260562)<br />   order<br />      by
subjectid;<br/><br /> and what I got back was:<br />  ERROR:  could not identify an ordering operator for type
record<br/>  HINT:  Use an explicit ordering operator or modify the query.<br /><br /> Could somebody give me a tip as
towhat I could do<br /> to get what I want?  Ie., I want get back is:<br /><br />   subjectid | markerid | allele1id |
allele2id<br/>  -----------+----------+-----------+-----------<br />       53684 |  1260214 |   2521543 |   2521543<br
/>      53684 |  1260215 |   2521537 |   2521538<br />       53688 |  1260562 |   2522243 |   2522243<br />       53699
| 1260562 |   2522243 |   2522243<br />       53699 |  1260214 |   2521543 |   2521544<br />       53704 |  1260215 |  
2521537|   2521537<br />       53714 |  1260214 |   2521543 |   2521543<br /><br /> Regards,<br /><br /> Tena Sakai<br
/>tsakai@gallo.ucsf.edu<br /></font>