Re: Help on Procedure running external function - Mailing list pgsql-sql

From Din Adrian
Subject Re: Help on Procedure running external function
Date
Msg-id opstgnoyj9awcxfg@adi
Whole thread Raw
In response to Re: Help on Procedure running external function  (Zac <zaccheob@inwind.it>)
List pgsql-sql
I 'solved' my 'relation with OID  ##### does not exist' problem using only  
execute on temp table ...
Is no need for me to 'lock'(for update) the temp table - is temporary  
(lock at 'create temp table MagMaxNrBon')- everybody has his own copy ....

Your right I should change the get_number procedure to create 'on the fly  
sequences' for each new user settings (in our app the user have the power  
to set the way of generating number for every type of document) (for that  
I need time wich I don't have now :) )...
anyway .. is working (not how I wanted but it's ok)

thank you,
Adrian Din


On Tue, 05 Jul 2005 13:47:24 +0200, Zac <zaccheob@inwind.it> wrote:

> I think you should use 'FOR UPDATE' clause in your first "select":
>
> select into vnrBon maxnrbon+1 from MagMaxNrBon where magazie =  
> dsgroup.magazie_implicita_lansare FOR UPDATE;
>
> In this way you lock the rows eventually returned and no one can update  
> them (or select them "for update") until your transaction finished.
>
> Is this good for you?
>
> However IMHO you should think your procedures to use sequences...
>
>
>> 1. the function get_me_next_number is runing from this procedure (same   
>> trans) but it's an external one ...
>> 2. the second solution I'am using now (using temp a table to store  
>> each  maxnrdoc value - but the temp table give me sometimes a relation  
>> with OID  ##### does not exist - problem that I can only   solve by  
>> using only  execute - but I don't think I can ...?! :))
>> here is the example:
>>   create temp table MagMaxNrBon
>> (
>> magazie varchar(5),
>> MaxNrBon int8,
>> CONSTRAINT temp_magbon_pkey PRIMARY KEY (magazie)
>> );
>> ...
>>      select into vnrBon maxnrbon+1 from MagMaxNrBon where magazie =   
>> dsgroup.magazie_implicita_lansare;
>>     if vnrbon is null
>>     then
>>     select into vNrBon o_gen_calc_nr_doc from o_gen_calc_nr_doc('BC'   
>> ,vEmitent,dsgroup.magazie_implicita_lansare,dsMasterBon.dataBon);
>>     insert into MagMaxNrBon values   
>> (dsgroup.magazie_implicita_lansare,vNrBon);
>>     else
>>      update MagMaxNrBon set maxnrbon=vNrBon where magazie =   
>> dsgroup.magazie_implicita_lansare;
>>     end if;
>> ...
>>  and in this way vNrBon is correct one ... I will try to use oly  
>> execute on  insert,update and select on temp table MagMaxNrBon ....  
>> (o_gen_calc_nr_doc  is the "get_me_next_number" function)
>>  thank you,
>> Adria Din
>>   On Mon, 04 Jul 2005 17:27:20 +0200, Zac <zaccheob@inwind.it> wrote:
>>
>>> Din Adrian wrote:
>>>
>>>>  Yes , I know what sequence is, but our procedure for generating  
>>>> doc   numbers is v. big and has manny (4) parameters  and we did'nt  
>>>> use  sequence  in it for this reason ....
>>>>  any other advice ?
>>>
>>> I think there is no way to have any information about non committed   
>>> transactions.
>>> I don't know if I understand well your problem but from what I see   
>>> "get_me_next_number" function runs in a different transaction (Why?  
>>> Is  it an externale procedure that make its own connection to the  
>>> DB?)),  otherwise it would see the new inserted number. The better  
>>> solution is  to run "get_me_next_number" in the same transaction.
>>> Another solution (not so good but should work) is to generate by   
>>> yourself the number (as you do) and lock the table until you end to   
>>> prevent others inserting documents.
>>> I hope this helps you.
>>> Bye
>>>
>>>>  thak you,
>>>> Adi
>>>>  On Mon, 04 Jul 2005 14:47:16 +0200, Zac <zaccheob@inwind.it> wrote:
>>>>
>>>>> Din Adrian wrote:
>>>>>
>>>>>> Hello,
>>>>>> I have a 'big' problem:
>>>>>> I am trying to run from a procedure a function witch generate a  
>>>>>> new    document number (max from table +1 ) and after to insert a  
>>>>>> document   with  this number, but the function returns me the same  
>>>>>> number each   time because  the tranzaction is not finished and the  
>>>>>> inserts are  not  commited and of  course the next document number  
>>>>>> is the same.
>>>>>> ...
>>>>>>  for ...
>>>>>> loop
>>>>>> nr=get_me_next_number(params);
>>>>>> insert into table values (nr,...)
>>>>>> end loop
>>>>>> ...
>>>>>>  ...
>>>>>> error inserting in table .. primary_key nr .....
>>>>>>  Is any way in making the external function to 'know' that I   
>>>>>> inserted   another row but this insert is in a tranzaction that is   
>>>>>> not finish yet  ?  ar onother solution ?
>>>>>>  for now I 'solved'  by asking for a nr once and generate myself   
>>>>>> next   number (+1) but this is not a correct solution (in this  
>>>>>> time  somebody  else  could insert a document with the same nr as  
>>>>>> the  procedure  )
>>>>>>  thank you,
>>>>>> Adi
>>>>>>
>>>>> I think the best solution is to use a sequence, not "select max(id)   
>>>>> +1  from table". Look here:
>>>>> http://www.postgresql.org/docs/8.0/interactive/sql-createsequence.html
>>>>> http://www.postgresql.org/docs/8.0/interactive/functions-sequence.html
>>>>> Bye
>>>>>
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>>>>>
>>>>
>>>
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>>>
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>>>
>>
>
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