Automatic row fetch and items initialization

Hi team,
I was modifying a page and I came across the following situation:
I had a form with MRU processing and automatic row fetch and I wanted to make SAVE and DELETE buttons conditional basing on a certain flag contained in the row being read.
The flag is read into a hidden item having sequence number lower than any button, however I found out that the condition could not be reliably tested as the value in the session state was coming from a previous visit to the page. Some times the buttons were there, some not, at the beginning it was puzzling.
So, I added a computation based on a SQL query where the hidden flag was computed before the header, basing on the primary key being passed from the calling page and the problem was gone, but for some reason I didn't feel satisfied, it was too cumbersome.
I thought session state items would be assigned beforehand, but for some reason it looked like they were assigned at a later time, even if the automatic fetch process is supposed to run before the header.
Then I noticed an "innocent" option in the fetch process definition saying "set memory cache on Fetch / set memory cache on Display".
In my case was checked the former, but as soon as I checked the latter, I could remove the unnecessary SQL query computation.
So, I started off posting a problem and ended up with the solution...
Bye,
Flavio

Flavio,
Thanks for the testimonial. That feature (new in 1.6) is for the very situation you described. When you create new row fetch processes they will have the "set memory cache on Fetch" option selected by default. For existing processes, the option must be manually changed.
Scott

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Bug Report: Automatic Row Fetch/Automatic Row Processing and invalid column

Hi,
if an invalid column name is specified for a page item of type "Database Column", no error is reported by the Automatic Row Fetch/Automatic Row Processing process. It's just ignored and nothing is returned!!! That makes it kind of hard to identify such an error.
The problem can happen for example when a column is renamed or if there is a typo in the column name during creation.
The problem seems to be related to the following query which doesn't use an outer join.
SELECT C.COLUMN_NAME, C.DATA_TYPE, I.NAME, I.FORMAT_MASK, I.DISPLAY_AS
FROM
SYS.ALL_TAB_COLUMNS C, WWV_FLOW_STEP_ITEMS I WHERE C.OWNER = :B4 AND
C.TABLE_NAME = :B3 AND I.SOURCE = C.COLUMN_NAME AND I.SOURCE_TYPE =
'DB_COLUMN' AND I.FLOW_ID = :B2 AND I.FLOW_STEP_ID = :B1 AND (C.DATA_TYPE
IN ('DATE','NUMBER','CLOB','LONG','FLOAT') OR C.DATA_TYPE LIKE 'NUMBER%' OR
C.DATA_TYPE = 'CHAR' OR C.DATA_TYPE LIKE '%VARCHAR%' OR C.DATA_TYPE LIKE
'TIMESTAMP%') ORDER BY C.COLUMN_IDBTW, if an invalid table/view name is specified for a Automatic Row Fetch/Automatic Row Processing process, the error message during runtime isn't very speaking.
ORA-06550: line 1, column 17: PL/SQL: ORA-00936: missing expression ORA-06550: line 1, column 9: PL/SQL: SQL Statement ignoredMaybe that could be changed too.
Thanks
Patrick
My APEX Blog: http://www.inside-oracle-apex.com
The APEX Builder Plugin: http://builderplugin.oracleapex.info/
The ApexLib Framework: http://apexlib.sourceforge.net/

It says filed (with an L) not fixed (with an X). That means they have noted down the bug, but it may or may not have been fixed yet.

ORA-01403: no data found Problem when using AUTOMATIC ROW FETCH to populate

ORA-01403: no data found Problem when using AUTOMATIC ROW FETCH to populate a form.
1) Created a FORM on EMP using the wizards. This creates an AUTOMATIC ROW FETCH
TABLE NAME - EMP
Item Containing PRIMARY KEY - P2099_EMPNO
Primary key column - EMPNO
By default the automatic fetch has a ‘Process Error Message’ of ‘Unable to fetch row.’
2) Created a HTML region. Within this region add
text item P2099_FIND_EMPNO
Button GET_EMP to submit
Branch Modified the conditional branch created during button creation to set P2099_EMPNO with &P2099_FIND_EMPNO.
If I then run the page, enter an existing employee number into P2099_EMPNO and press the GET_EMP button the form is populated correctly. But if I enter an employee that does not exist then I get the oracle error ORA-01403: no data found and no form displayed but a message at the top of the page ‘Action Processed’.I was expecting a blank form to be displayed with the message ‘Unable to fetch row.’
I can work around this by making the automated fetch conditional so that it checks the row exists first. Modify the Fetch row from EMP automated fetch so that it is conditional
EXIST (SQL query returns at least one row)
select 'x'
from EMP
where EMPNO = :P2099_EMPNO
But this means that when the employee exists I must be fetching from the DB twice, once for the condition and then again for the actual row fetch.
Rather than the above work around is there something I can change so I don’t get the Oracle error? I’m now wondering if the automatic row fetch is only supposed to be used when linking a report to a form and that I should be writing the fetch process manually. The reason I haven’t at the moment is I’m trying to stick with the automatic wizard generation as much as I can.
Any ideas?
Thanks Pete

Hi Mike,
I've tried doing that but it doesn't seem to make any difference. If I turn debug on it shows below.
0.05: Computation point: AFTER_HEADER
0.05: Processing point: AFTER_HEADER
0.05: ...Process "Fetch Row from EMP": DML_FETCH_ROW (AFTER_HEADER) F|#OWNER#:EMP:P2099_EMPNO:EMPNO
0.05: Show ERROR page...
0.05: Performing rollback...
0.05: Processing point: AFTER_ERROR_HEADER
I don't really wan't the error page, either nothing with the form not being populated or a message at the top of the page.
Thanks Pete

Automatic row fetch based on a select list

db11gxe , apex 4.0 , firefox 24 ,
hi all ,
i want to do automatic row fetch when the value of a select list changes ?
but first i should ofcourse create a tabular form to fetch the data into it , but what i want is ,if i fetch 2 rows then the report contains only two rows , if i fetch 3 , the report contains only 3
, if i fetch nothing , the report has nothing ?
thanks

Assuming all your page items are on separate rows, under your Page Attributes Header and Footer section, add the below function under Header Text:
<script>
function f_toggleNM() {
   // if P2_ATTACHMENT_TYPE value is D, then show row holding P2_CUSTOM_NAME and P2_CUSTOM_MSG. Else hide them
   $f_Show_On_Value_Item_Row('P2_ATTACHMENT_TYPE', [ 'P2_CUSTOM_NAME', 'P2_CUSTOM_MSG' ], 'C');
   // if P2_ATTACHMENT_TYPE value is C, then show row holding P2_DEFAULT_NAME and P2_DEFAULT_MSG. Else hide them
   $f_Show_On_Value_Item_Row('P2_ATTACHMENT_TYPE', [ 'P2_DEFAULT_NAME', 'P2_DEFAULT_MSG' ], 'D');
</script>Under Footer Text, add the below:
<script>
f_toggleNM();
</script>And on the P2_ATTACHMENT_TYPE item, Element tab, HTML Form Element Attributes, add below:
onchange="f_toggleNM();"Hope this helps. Thanks!
JMcG

Call a Automatic Row Fetch from a Dynamic Action

Hi,
can I execute the Automatic Row Fetch from a dynamic action?
I only found this post (Dynamic Actions to call Automatic Row Processing (DML) but the link where the solution is does not work :(
Thanks,
Edited by: Elena.mtc on 09-nov-2012 5:46

Elena.mtc wrote:
I forgot to say, for several reasons, I don't want to submit the page. So that's where I find the complexity in calling the ARf.
Thanks.You cannot fire the ARF because it is designed to run when the page is rendered and it cannot be called as a standalone
Create a dynamic action as follows to fetch the form detials
Action: Execute PL/SQL Code
PL/SQL Code:
begin
select ename, job, mgr, hiredate, sal
    into :P4_ENAME, :P4_JOB, :P4_MGR, :P4_HIREDATE, :P4_SAL
    from emp
   where empno = :P4_EMPNO;
exception
when others then
    null;
end;
Page Items to Submit: P4_EMPNO
Page Items to Return: P4_ENAME,P4_JOB,P4_MGR,P4_HIREDATE,P4_SAL
See this working example: http://apex.oracle.com/pls/apex/f?p=32940:4
Login as test/test
If you want to make it more dynamic you can query the APEX metadata to find the form items on your current page
select * from apex_application_page_db_items
where page_id =:APP_PAGE_ID
and application_id = :APP_ID;

Multiple Automatic Row Fetches

Hello All,
Is is possible to have two "Automatic Row Fetches" on a single page. Each fetch pointing to a separate table.
For example, one fetch gets employee data (name, address, etc.), the other getting time-off details.
Thanks
-redapple

Ok, then why can't I make this work?
Region 1 is a form and already exists on the page. Fully functional.
I need to add a region to get supporting data from another table.
Using the new region wizard, I create a new form region. A new "Automatic Row fetch" is created as sequence 10 as a "After Header" process. The "item containing "and "primary key" column are set accordingly.
Whenever I run the page I get a "no data found" error.
However if I delete the region, and recreate it as a report region, the report displays the data!
What am I missing?
Any ideas?
thsanks
-redapple

How to use Automatic Row Fetch programmatically ?

Hi
I like to use Automatic Row Fetch (AFR) of APEX to populate data into a DML form page by clicking a button with a defined where_clause, and like to update the record accordingly as we did in Oracle forms execute_query procedure. I prefer Oracle provided facilities, don't want to do it manually. Any help ?....
Hasan Al Mamun

You will probably get a better answer if you ask this in the Apex - Oracle Application Express- forum.
Sorry, I don't have an immediate answer for your question ;(

Creating an Automatic Row Fetch

Hello,
I'm trying to make an Automatic Row Fetch. The problem is that I have 3 values as a primary key in my table and I can fill in only two in the Row Fetch.
Does anyone have a solution to this?
Thanks in advance.

Hi "user573175",
I don't think APEX can do Automatic Row Fetch based on a pk of 3 values.
I always try to limit my pk to 1 or 2 columns (as APEX has this limit).
So my solution for you would be:
- Use a PK of 1 or 2 columns and use Automatic Row Fetch
- or Keep your 3 value PK and use a PLSQL function instead of the automatic row fetch
Dimitri

2 automatic row fetches based on the same variable

I have a select list with a submit that contains all products that are currently stored in the database. The select list reloads the page and passes the value of the product id selected in the list to P3_PRODUCT_ID.
I then use this value (P3_PRODUCT_ID) for two process under page rendering. One to fetch the associated fields in the Product table for the P3_Product_Id as this is the primary key and One to fetch the associated filed's in the Nutrion table for the P3_product_Id.
This works fine if i only do one fetch process but if i try to both of the process i get
ORA-01403: no data found
Error ORA-01403: no data found
OK
which seems strange to me as the processes work fine individually.
Anyone have any ideas or point me in the way of some reading? Is this even possible to use two automatic row fetches or do i need to write my own PL\SQL block?
Many Thanks
Daniel Stead
Message was edited by:
Dan Stead

Only one ARF per page is supported.
Scott

Custom row-fetch and how to get column values from specific row of report

Hi -- I have a case where a table's primary key has more than 3 columns. My report on the
table has links that send the user to a single-row DML form, but of course the automatic
fetch won't work because 1) I can't set more than 3 item values in the link and 2) the
auto fetch only handles 2 PK columns.
1)
I have written a custom fetch (not sure it's the most elegant, see second question) that is working
for 3 or few PK columns (it references the 1-3 item values set in the link), but when there are
more than 3, I don't know how to get the remaining PK column values for the specific row that was
selected in the report. How can I access that row's report column values? I'll be doing it from the
form page, not the report page. (I think... unless you have another suggestion.)
2)
My custom fetch... I just worked something out on my own, having no idea how this is typically
done. For each dependent item (database column) in the form, I have a source of PL/SQL
function that queries the table for the column in question, using the primary key values. It works
beautifully, though is just a touch slow on my prototype table, which has 21 columns. Is there
a way to manually construct the fetch statement once for the whole form, and have APEX be smart
about what items get what
return values, so that I don't have to write PL/SQL for every item? Because my query data sources
are sometimes in remote databases, I have to write manual fetch and dml anyway. Just would like
to streamline the process.
Thanks,
Carol

HI Andy -- Well, I'd love it if this worked, but I'm unsure how to implement it.
It seems I can't put this process in the results page (the page w/ the link, that has multiple report rows), because the link for the row will completely bypass any after-submit processes, won't it? I've tried this in other conditions; I thought the link went directly to the linked-to page.
And, from the test of your suggestion that I've tried, it's not working in the form that allows a single row edit. I tried putting this manually-created fetch into a before header process, and it seems to do nothing (even with a hard-coded PK value, just to test it out). In addition, I'm not sure how, from this page, the process could identify the correct PK values from the report page, unless it can know something about the row that was selected by clicking on the link. It could work if all the PK columns in my edit form could be set by the report link, but sometimes I have up to 5 pk columns.
Maybe part of the problem is something to do with the source type I have for each of the form items. With my first manual fetch process, they were all pl/sql functions. Not sure what would be appropriate if I can somehow do this with a single (page level?) process.
Maybe I'm making this too hard?
Thanks,
Carol

No automatic row fetching (DML)

All,
I want to generate a process which fetches my rows automatically.
I've done this before several times.
But now my new process is not fetching rows.
I don’t get an error message, the text fields are just empty.
During creating the new process I see an empty LOV
for field ‘Item Containing Primary Key Column Value’
in section ‘Source: Automatic Row Processing (DML)’
although there are about 7 items (text fields) at this page.
Any help appreciated,
lucio

Lucio:
I think you need to set the 'Source Type' attribute of the form fields to be 'Database Column' and in the 'Source value or Expression' field provide the database column to which the page item corresponds to.
varad

Automatic Row Processing and Casade Delete

I have Automatic Row Processing for delete on a table, however I have FK's dependent on this table. How do I do a cascade delete using Automatic Row Processing DML for a delete ?
Any way besides writing a trigger ?

My fault, my constraint was not written properly to indicate on delete cascade.

Problem with type conversion and primary key during row fetch

[Note, this error occurs in Oracle XE, APEX 2.1.0.00.39]
I have been having a problem with Automatic Row Fetch:
ORA-01460: unimplemented or unreasonable conversion requested
So in an effort to resolve this, I created a PL/SQL process with the query below and was able to isolate the same error. The problem seems to come from one of the primary keys being a "number" type (APP_ID). The error occurs on the line:
where u.app_id=:P5_APP_ID
I have tried the following variations on this line in an effort to resolve this, but all generate the same error:
1) where to_char(u.app_id) = :P5_APP_ID
2) where u.app_id = to_number(:P5_APP_ID)
3) where to_char(u.app_id) = to_char(:P5_APP_ID)
I've also tried the laternate syntax "&__." and "#__#", but these don't function in the Source field and show up as syntax errors.
Any suggestions are welcome.
begin
for r in (
select app_name, apptype, appcreator, appurl
from application_users u, application_info i
where u.app_id=:P5_APP_ID
and i.app_id=u.app_id
and u.username=:P5_USERNAME)
loop
begin
:P5_APP_NAME := r.app_name;
:P5_APPURL := r.appurl;
exception
when others then
raise_application_error(-20000,'In Loop Failure',true);
end;
end loop;
exception
when others then
raise_application_error(-20000,'Out of Loop Failure',true);
end;
Thanks in advance,
Barney

I found a prior post referencing a similar issue and it was solved by using the "v(__)" syntax. This did resolve my issue, however, I have a quick follow-on which I'm hoping someone can answer quickly...
Since the "v(__)" syntax won't work for the Automatic Row Fetch (at least to the best of my knowledge), I have to do a manual process. However, the manual query as shown above doesn't actually populate any of the form values through the bind variables. They all remain at their cached values from prior data entry on the form.
Is using the bind variables for assignment incorrect, or is there something that must be done to get the updates to show up in the form (ordering of processes, etc.).
My manual process is running in the Load: Before Header state so I would have expected it to update all of the fields.
Thanks in advance,
Barney

Processing Static (via automatic row processing) & Dynmaic fields

Hi,
I have a page that has 2 sections. Section S is statically driven which I'd like to process via a Automatic Row Process DML. Section D is for dynamic fields which I process via a PL/SQL script.
I need to process Section D (dynamic) first.
Now they're 2 things that I'm noticing when I try this. Can someone please confirm.
- After my process of Section D it seems to make a commit. I know this since I have a error in Section S, and the values from Section D are committed to the DB. I need to make sure a commit only occurs after all page processes have completed error free.
- My Automatic Row Process DML for Section S doesn't seem to work at all. It can't seem to read the values at all. I know this since I have several columns which are "NOT NULL" and the appropriate error messages are being raised. The Automatic Row Fetch for Section S does work properly.
For the time being the work around is writing a process for the entire page which includes both Section S and Section D. The thing is I thought that HTMLDB would be able to help me out a lot with Section S since it had static fields etc.

Martin - I would try to debug these two processes separately. If the Auto DML process isn't firing, perhaps the button used to submit the page isn't setting the request to one of the standard values recognized by the Auto DML package ('INSERT','CREATE','CREATE_AGAIN','CREATEAGAIN' for inserts and 'SAVE','APPLY CHANGES','UPDATE','UPDATE ROW','CHANGE','APPLY' or like 'APPLY%CHANGES%' for update).
A commit happens whenever session state is changed, so if your process saves an item value, that would do it. If you think that is not the cause of the commit, let me know the details of the process and I'll take a closer look. There is no way to prevent the commit when session state is updated.
Scott

Row fetching, session state, multi-page processing of 1 row - problems

I'm building an application that's updating a couple of tables via an updateable view and an instead-of trigger. That portion of it works OK, EXCEPT for the problems that I'm having with the APEX end.
I've got 3 pages; the first page reads the row in via the automated row fetch and has, say columns 1-20.
Page 2 has, say, columns 20-40 and page 3 has the remainder.
I have the row fetch set up conditionally so that it only executes the first time that page 1 is displayed. All the columns are set as Database Columns.
It seems that if I fill in fields on page 1, move to page 2, and back to page 1, the contents of the fields on page 1 are destroyed unless I set their 'Source used' to 'Only when the current value in session state is null'.
Furthermore, upon update (which is on page 3, via an automated row update), the only columns that get updated are those that exist on page 3. The column values from the other pages no longer exist.
Does navigation to another page not retain the session-state of database-column items?
Am I better off just writing my own processes to perform the updates?
Any other suggestions?
Frank

Hello Frank,
>>I have the row fetch set up conditionally so
that it only executes the first time that page 1 is
displayed …
It seems that if I fill in fields on page 1, moveto page 2, and back to page 1, the contents of the
fields on page 1 are destroyed unless I set their
'Source used' to 'Only when the current value in
session state is null'.
It seems that the first sentence is not consistent
with the second one. The only reason the values are
destroyed, as you call it, is that the ARF is running
again. What condition are you using on your ARF?
In any case, the right way to deal with it is to
change the source used to "Only …", as I understand
you already did.
Hi Arie,
I set an item after the first ARF. I then have the ARF set to execute conditionally based on the presence of that item. (I also display a success message on the ARF, so I know that the ARF is only occurring once). I move to subsequent pages by submitting the current pages.
>>Does navigation to another page not retain the
session-state of database-column items?
Navigating to another page does retain the session state values.
It's depends on what you mean by navigating.
Submitting the page set/update session state.
Redirect without submitting the page will not
set/update the session state.
>>Furthermore, upon update (which is on page 3,
via an automated row update), the only columns that
get updated are those that exist on page 3. The
column values from the other pages no longer
exist.
Automatic DML is working only with the current page
items. You can't use it to insert/update other page
items, even if they are in session state. However, in
your case, it's not the Automatic DML performing the
actual updates, but your triggers. Are your triggers
relying on session state values?
I think this statement 'Automatic DML is working only with the current page
items.' answers my question. My trigger is working on session state values. It's an 'instead-of' trigger, so I was letting the automatic DML perform the 'update' on the view, while allowing the trigger to do the actual update of several tables that the view joins by referring to their :NEW. values in the trigger. Since the DML occurs on my last page, those were the only session state values that my trigger ultimately saw.
>>Am I better off just writing my own processes to
perform the updates?
I believe the correct way is to submit the page and
then branch to the next one. Submitting the page will
save all your items in session state, and allow these
items to be available for page 3 DML.
Regards,
Arie.I'm doing that already - all the values do appear to be in session sate, except only the items that are on the last page actually make it to the automatic DML update, which seems to agree with your previous statement.
I suppose I could write my own process to perform the update, as the values are available in session state.
Thanks,
Frank

Automatic row fetch and items initialization

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