Re: sql-porting-problem oracle to postgresql with UPDATE/IS NOT NULL - Mailing list pgsql-sql

On Jul 28, 2009, at 5:10 PM, nha wrote:

> Hello,
>
> Le 28/07/09 14:25, Daryl Richter a écrit :
>>
>> On Jul 28, 2009, at 5:58 AM, Gau, Hans-Jürgen wrote:
>>
>>> hello list,
>>> i have some problems with an sql-statement which runs on oracle but
>>> not on postgresql (i want update only if result of SELECT is not
>>> empty, the SELECT-queries are identical):
>>>
>>> UPDATE table1 t1
>>>        SET (t1.id) =
>>>                (SELECT h.id FROM table2 t2,table3 t3, table1 t1
>>>                WHERE t3.field = t2.field
>>>                        AND t2.id = t1.id
>>>                        AND t1.id <> t3.id)
>>>        WHERE
>>>                (SELECT h.id FROM table2 t2,table3 t3, table1 t1
>>>                        WHERE t3.field = t2.field
>>>                                AND t2.id = t1.id
>>>                                AND t1.id <> t3.id) IS NOT NULL;
>>>
>> Try this:
>>
>> UPDATE table1 t1 [...]
>>        WHERE
>>            EXISTS (SELECT 1 FROM table2 t2,table3 t3, table1 t1
>>                        WHERE t3.field = t2.field
>>                                AND t2.id = t1.id
>>                                AND t1.id <> t3.id
>>
>>                AND h.id IS NOT NULL);
>>
>
> Beyond the solution brought by Daryl Richter, it seems that "h" is an
> unbound alias in the original (and also in the suggested) query. Some
> clarification would be helpful for further investigation.

Ahh, you're right.  I didn't even notice that, just reformatted the
OPs query.

>
> Regards.
>
> --
> nha / Lyon / France.
>
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--
Daryl