Re: Sequence

Поиск
Список
Период
Сортировка
От Simon Mitchell
Тема Re: Sequence
Дата
Msg-id 3E20C297.9020201@jseb.com
обсуждение исходный текст
Ответ на Re: Sequence  (Dave Cramer <Dave@micro-automation.net>)
Ответы Re: Sequence  (Dave Cramer <Dave@micro-automation.net>)
Список pgsql-jdbc
Alan,
            Just doing some test from psql prompt.

After your insert into the table the id sequence is available by

select currval('table_id_seq');
 currval
---------
    5006
(1 row)


If your session has not done an insert you should get an error.
select currval('table_id_seq');
ERROR:  table_id_seq.currval is not yet defined in this session

Do a describe (\d) on your table to check seq name.

So this is equivalent to MySql   >   last_insert_id() .

***************************************************
If you wont the last value of the sequence (which could be your current
session or another session) you can select it with

SELECT last_value FROM  table_id_seq;
 last_value
------------
       5006
(1 row)

**This is not transaction safe as another session could have done an
insert. Please use select currval('table_id_seq');**
It is just nice to know.
***************************************************

Simon






Dave Cramer wrote:

>Alan,
>
>You can't, get the sequence before and insert it.
>
>Dave
>On Thu, 2003-01-09 at 14:35, Alan Roberto Romaniuc wrote:
>
>
>>I have a table with sequence field (id).
>>
>>I insert a new row in this table, and I would like to get the sequence
>>number that postgresql assign to id.
>>
>>How can I get it???  ... Max function is not nice.......
>>
>>jdbc2 ....
>>
>>
>>---------------------------(end of broadcast)---------------------------
>>TIP 3: if posting/reading through Usenet, please send an appropriate
>>subscribe-nomail command to majordomo@postgresql.org so that your
>>message can get through to the mailing list cleanly
>>
>>



В списке pgsql-jdbc по дате отправления:

Предыдущее
От: Dave Cramer
Дата:
Сообщение: Re: persistent JDBC connections with a daemon
Следующее
От: Dave Cramer
Дата:
Сообщение: Re: Sequence