Re: Scrolling/Updating Cursors
От | Kevin Wooten |
---|---|
Тема | Re: Scrolling/Updating Cursors |
Дата | |
Msg-id | 49897DD1-F979-43C0-9667-312CEA8807FF@me.com обсуждение исходный текст |
Ответ на | Re: Scrolling/Updating Cursors (John Meyer <johnmeyer@pueblocomputing.com>) |
Список | pgsql-general |
On Nov 22, 2013, at 2:32 PM, John Meyer <johnmeyer@pueblocomputing.com> wrote: > Why not both? I keep on searching even when I post up a question. > Just attempting to be polite and not cross post to too much. I have pretty much exhausted my own search and now am relyingon the kindness and knowledge of others ;) > On 11/22/2013 2:27 PM, Kevin Wooten wrote: >> On Nov 19, 2013, at 6:33 PM, Kevin Wooten <kdubb@me.com> wrote: >> >>> My apologies for posting what is almost certainly somewhat of a repeat question but I have searched and attempted everythingI can think of and cannot figure it out myself. >>> >>> The basic question is… Is it possible to get a scrollable cursor that, within a transaction, can insert/update/deleterows and see those changes? >>> >>> Why you ask? Because I am implementing the JDBC 4.1 spec and it (optionally) provides this ability and I’d like to provideit if possible. I thought just using a scrollable cursor with the isolation-level set to repeatable-read would dothe trick but it still seems to see no changes (inserts/updates/deletes). >>> >>> Effectively I want roughly this sequence of events to work. >>> >>> CREATE TABLE test (val text); >>> >>> BEGIN; # Could include ISOLATION LEVEL REPEATABLE READ >>> >>> DECLARE c1 CURSOR FOR SELECT * FROM test; >>> >>> FETCH ABSOLUTE 1; # Returns No Row >>> >>> INSERT INTO test VALUES (‘1'); >>> INSERT INTO test VALUES (‘2'); >>> INSERT INTO test VALUES (‘3'); >>> >>> FETCH ABSOLUTE 1; # Returns “1” >>> FETCH NEXT: # Returns “2" >>> DELETE FROM test WHERE CURRENT OF c1; # Deletes “2” >>> >>> FETCH ABSOLUTE 1; # Returns “1” >>> FETCH NEXT; # Returns “3” >>> UPDATE test SET val=‘4' WHERE CURRENT OF c1; >>> FETCH RELATIVE 0; # Returns “4” >>> >>> COMMIT; >>> >>> Thanks! >>> >>> -kw >>> >> >> Should I take silence to mean this cannot be done? Or should I send to -hackers? >> >> >>
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