Re: Selecting newly added column returns empty but only when selecting with other columns in table

Sure. I copied my email submisison from my stack exchange posting so
couldn't submit the formatted tables there. Below is an example and you are
correct that features_bin is the newly added column. I mean EMPTY ROW in
that features_bin returns empty.

id | state | features_bin
------------+-------+--------------
23621407_1 | CA |
15892423_1 | CA |
15892423_2 | CA |
15892423_3 | CA |
23614571_2 | CA |
20908052_1 | CA |
23614571_3 | CA |
20908052_2 | CA |
20908052_3 | CA |
20908066_1 | CA |
20908066_2 | CA |
20908066_3 | CA |
20908072_1 | CA |
20908072_2 | CA |
20908072_3 | CA |
20909002_1 | CA |
20909002_2 | CA |
23599675_1 | CA |
23599675_2 | CA |
23599675_3 | CA |
18545613_1 | CA |
18545613_2 | CA |

The stdout for the other query without 'where' ( select id, state,
features_bin from data;) is too messy to show here. The very long binary
array really messes with the formatting but main point is that the row
result starts with | | \x8481e7dec36500 indicating that the id
and state columns are returning empty.

On Thu, Nov 26, 2015 at 6:46 PM, Adrian Klaver <adrian(dot)klaver(at)aklaver(dot)com>
wrote:

> On 11/26/2015 06:10 PM, mrtruji wrote:
>
>> Hi,
>>
>> Thanks for the reply. The limit is just to simplify results for the
>> examples. The same behavior occurs when each of the three queries are
>> not limited. Whenever I try to filter by the original columns and select
>> the new column the resultant values for the new column are empty.
>> Conversely, whenever I select the new column along with original columns
>> without any filtering the resultant values for the original columns
>> return empty. It's as if the added column is disconnected to the table
>> in some way causing problems with queries that combine original columns
>> and the new one.
>>
>
> Can you show one of the unlimited(well at least as much as seems
> reasonable) query result sets, cut and pasted directly from a psql session?
>
>
>> I created and filled in the new column externally using psycopg2 in
>> Python so I'm not sure if that could be the source of the problem...
>>
>> On Thu, Nov 26, 2015 at 5:39 PM, Melvin Davidson <melvin6925(at)gmail(dot)com
>> <mailto:melvin6925(at)gmail(dot)com>> wrote:
>>
>> Is it possible you have more than one row where state = 'CA'?
>> Putting a LIMIT 1 would then restrict to only 1 row.
>> Have you tried with no limit? IE:|SELECT new_col FROM data;
>>
>> |
>>
>> On Thu, Nov 26, 2015 at 7:13 PM, mrtruji <mrtruji(at)gmail(dot)com
>> <mailto:mrtruji(at)gmail(dot)com>> wrote:
>>
>> Just added a new bytea type column to an existing psql table and
>> populated the column entirely with row data. Running into some
>> strange query results:
>>
>> When I select the newly added column by itself I get all the
>> data as expected:
>>
>> |SELECT new_col FROM data LIMIT 1; Result:
>> \x8481e7dec3650040b.... |
>>
>> When I try to filter with 'where' on another column in the
>> table, I get the values from the other columns as expected but
>> empty from my new_column:
>>
>> |SELECT id, state, new_col FROM data WHERE state='CA' limit 1;
>> Result: 123456_1; CA; EMPTY ROW |
>>
>> The reverse is also true. If I select my new column in
>> combination with other columns with no 'where' I get the correct
>> value from my new column but empty for the other columns:
>>
>> |SELECT id, state, new_col FROM data limit 1; Result: EMPTY ROW;
>> EMPTY ROW; \x8481e7dec3650040b....|
>>
>> Thanks to anyone with advice!
>>
>>
>>
>>
>> --
>> *Melvin Davidson*
>> I reserve the right to fantasize. Whether or not you
>> wish to share my fantasy is entirely up to you.
>>
>>
>>
>
> --
> Adrian Klaver
> adrian(dot)klaver(at)aklaver(dot)com
>