note to mezelf: chunk CLOB?

Ever had a trouble while you were trying to print a variable, got an ORA-06502 error?

ORA-06502: PL/SQL: numeric or value error string

Cause: An arithmetic, numeric, string, conversion, or constraint error occurred. For example, this error occurs if an attempt is made to assign the value NULL to a variable declared NOT NULL, or if an attempt is made to assign an integer larger than 99 to a variable declared NUMBER(2).

Action: Change the data, how it is manipulated, or how it is declared so that values do not violate constraints.

If your variable is a CLOB it might be confusing as it was for me..

However, you ‘ll figure out the reason soon enough: Those string parts that you were collecting are bigger than 32K

And you ‘ll realize that you should tell it what to do.

Here is what I came across to. A big and special thanks to oracle forums, of course :)


PROCEDURE chunk_clob(p_clob CLOB) IS
v_buf_size VARCHAR2(32000);
v_offset PLS_INTEGER DEFAULT 1;
v_size PLS_INTEGER;
v_len PLS_INTEGER;
v_chunk PLS_INTEGER;
v_clob CLOB := p_clob;
BEGIN
v_chunk := dbms_lob.getchunksize(v_clob);
v_len := dbms_lob.getlength(v_clob);
WHILE v_offset v_chunk
THEN v_size := v_chunk;
ELSE v_size := v_len - (v_offset - 1);
END IF;
v_buf_size := NULL;
dbms_lob.READ(v_clob, v_size, v_offset, v_buf_size);
htp.prn(v_buf_size);
v_offset := v_offset + v_size;
END LOOP;
END;

– OKAY what is this and what am I going to do with this?

It ‘ll take care of your oversized strings so you get to see what your VAR has in it.


my_pck.chunk_clob(l_show_html);

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APEX: Form on a Procedure

Hi!

You have a procedure.

And you want to prepare an interface for enduser so they could execute it by themselves.

however, your procedure is expecting some input parameters which are not so-easy for the users to get..

Let ‘s go with an example:

form_on_a_proc_1

example

Say this procedure is taking an account number and generating a risk report for that customer.

So you decided to publish a form on one of your APEX user dashboards:

form_on_a_proc
Building form on a procedure

After a few easy steps with this wizard, you ‘ll have your form with a field (i.e. :p_acc)on it prompting you to enter an account number

Although it works just fine, it is not that easy for users to know which company has which number. It would be way easier if they could go with company name for instance..

If you have no chance to touch to that procedure, means you can ‘t modify it to make it work with another parameter instead of v_acc (account number), you still can do something similar.

i. Create a Page Item on your page region

ii. Display as: Text with autocomplete

iii. Give your new page item a unique name (i.e. :p_cust_name)

iv. Adjust the population logic of your text field to make auto-complete thing work.

v. Then take a look at execution statement which runs your SP. You can see it by double-clicking Run Stored Procedure

form_on_a_proc_2

vi. You ‘ll see something like this

#OWNER#.basitmis_proc(V_ACC => :p_acc);

vii. Now let ‘s modify it so it could work with our other parameter :p_cust_name

form_on_a_proc_3

Let ‘s see what we did here:

 

i.We declared another variable p_cust

ii.Use it to collect account number. To know which customer ‘s account should return, we used our Page Item p_cust_name and remember, this information was provided by user.

iii.Then we bind it to our SP

**

Now your users can type ABC to automatically get ABC Company in the company name field, then click the button that triggers your execution process. Your little declaration above will do the rest :)

Tschau!

 

 

APEX: dbms_scheduler

Bir sorgu hazirladiniz ve bu sorgudan donen sonucu periyodik olarak bir tabloya yazmak istiyorsunuz..

Ya da bu bir rapor ve bu rapora bakarak periyodik olarak bir kisi ya da ekibe mail gondermek istiyorsunuz..

APEX icinden nasil mail gonderilecegine dair kucuk bir ornegi su yazimda anlatmaya calismistim.

Simdi ise bunu “otomatik” hale getirmeyi deneyelim.

Farkli yontemler elbette var, ama ben -veri tabaninizin “eski” bir versiyonda olmadigini varsayarak- dogrudan dbms_scheduler uzerinden bir procedure ile ilerleyecegim.

i. Oncelikle sorgumuzu bir procedure haline getirerek objemizi olusturalim. Bunu APEX ‘in etkilesimli menulerine yaptirabilecegimiz gibi SQL konsolunda elle de yapabiliriz.

create or replace procedure “ORNEK_BASITMIS” is 

Sorgunun detaylari bu yazinin konusu degil. Fakat soz gelimi, belirli bir data setini dinamik olarak sececegimiz alicilara gondermek istiyorsak

  • Bir cursor acabilir,
  • Sonra bu cursor ‘i loop icinde %NOTFOUND oluncaya kadar fetch ederek aksiyonumuzu aldirabiliriz: mesela her defasinda bir email gondermek gibi.

Schedule etmeye karar verdiginiz islem sisteme periyodik olarak email gonderme isi vermekse ve ornek mail gonderme kismini burada isledigimiz gibi apex_mail.send uzerinden kotariyorsaniz, dikkat etmemiz gereken aslinda belki de tek onemli nokta su:

Hazirladiniz SP icinde BEGIN END arasinda APEX Workspace ID ‘nizi assign emelisiniz..

Aksi takdirde schedule ettiginiz Job ‘un calisma vakti geldiginde

ORA-20001: This procedure must be invoked from within an application session.

gibi bir hata ile karsilasirsiniz :)

apex_about

APEX Workspace ID

Bu ID bilgisine ustteki gibi erisebilirsiniz. Set etmek icin asagidaki gibi bir ifade kullaniyoruz:

wwv_flow_api.set_security_group_id();

 

Stored Procedure ‘imizi hazirladik ve ORNEK_PROCEDURE ismi ile create ettik diyelim. Simdi sirasi ile DBMS_SCHEDULER ile once bir program create etmeliyiz:

dbms_create_prog
DBMS_SCHEDULER.CREATE_PROGRAM

Ardindan bir schedule create ediyoruz:

dbms_create_sched
DBMS_SCHEDULER.CREATE_SCHEDULE

repeate_interval degiskenine dikkat edelim. Burada frekans, saat, dakika, saniye turunden bir cok deger verme sansimiz var..

Dolayisiyla, Ayin belirli bir gunu, Haftanin belirli gunleri, gunun belirli saatleri gibi spesifik periyod tanimlari yapabiliyoruz. Detayli bilgiye Oracle dokumanlarindan erisebilirsiniz.

Simdi de job create edelim:

dbms_create_job
DBMS_SCHEDULER.CREATE_JOB

 

Artik veri tabaninda bir SP ‘miz var ve bu SP ‘nin istedigimiz zaman araliklarinda otomatik calismasi icin bir Program tanimimiz, bir Schedule ‘imiz ve bir de Job ‘imiz var..

Simdi program ve job ‘imizi “acalim”.

dbms_enable
Enable

Hazir.. Artik repeat_interval olarak verdigimiz vakit geldigi zaman job ‘in calismadigini kontrol edebiliriz.

Mesela az once enable ettigimiz Job ‘u suradan gorebiliriz:

select * from dba_scheduler_jobs;

Zamani geldiginde islemin calisip calismadigini ise su tablodan takip edebiliriz:

select * from user_scheduler_job_run_details;

Yaptiklarimizi drop etmek icinse yine DBMS_SCHEDULER icindeki

  • drop_job
  • drop_schedule
  • drop_program

yapilarini kullanabiliriz. Fakat tahmin edebileceginiz gibi bunlari “sirali” yapmalisiniz, aksi takdirde sistem dependency nedeniyle kizacaktir :)

dbms_drops

DROP etmek..

Gorusmek uzere!

APEX: Send Mail Thru Report Page

Hi,

You published a useful interactive report for your users and now want to let them sending emails through that page.

Here you can find a basic example..

  • Go to your report page from Application Builder panel
  • Create a page item button 
    • Pick Defined by Dynamic Action as button action
  • Right click to your brand new Dynamic Action and select Create.
dyn_act
APEX Dynamic Action

As you can see above, we have to create this action with some conditions. Such as:

  • Event: Click
  • Selection Type: Button
  • Button: address your button which you ‘ve just created. This item will trigger your email sending process.

Once we completed these steps, we can add a True action. You ‘ll see a button named Add True Action at your Dynamic Action Edit page. You can also create one by choosing from right click menu.

true_act
Adding a TRUE action

You may want to uncheck Fire On Page Load. Because.. Well we want to trigger it by clicking our button, manually :)

So.. Now we need this PL/SQL code which will take care of sending email via Oracle APEX.

I ‘ll share 2 basic examples with you. One for plain-text emails, one for HTML based ones.

I personally prefer to send mails in HTML format… But it ‘s up to you and depends on your needs..

It is pretty easy, right? Just give the right parameters and a simple sentence as email body. You can always use variables to collect these informations like i did..

If you want to go with HTML format, then you ‘ll need some extra time to create a good-looking and small-sized body. That ‘s all :)

Once you store these codes you ‘ve wrote and apply the changes onto your report page, you can start using your button. It should be sending emails to given address. Click on your button and wait couple of minutes to receive it.

I am not going to remind you not to copy everything from my sample snapshots. You do need to change email addresses etc. :)

Should you want to add some extra features on this dynamic action, you can add another True action(s) as well.

You may need to.. Otherwise someone would be able to click on that button more than necessary and we don ‘t want to spam people :)

Let ‘s add a Confirmation action..

 

conf_act

  • Right Click, Create
  • Action: CONFIRM

Now you ‘ll be prompted to click OK everytime you click on your email button..

O.K. but not enough? Well let ‘s hide the button after it ‘s got clicked.

hide

  • Now we have a button on our report page
  • Our authorized report viewers can click on it to send email
  • We have a confirmation dialog before trigger
  • Our email send button will be hidden right after our user click on it.

Dag!