To achieve this you need to create a small package and run a query :

 

Package Specification :

CREATE OR REPLACE PACKAGE get_user_pwd

AS

   FUNCTION decrypt (KEY IN VARCHAR2, VALUE IN VARCHAR2)

      RETURN VARCHAR2;

END get_user_pwd;
/

Package Body:

CREATE OR REPLACE PACKAGE BODY get_user_pwd

AS

   FUNCTION decrypt (KEY IN VARCHAR2, VALUE IN VARCHAR2)

      RETURN VARCHAR2

   AS

      LANGUAGE JAVA

      NAME 'oracle.apps.fnd.security.WebSessionManagerProc.decrypt(java.lang.String,java.lang.String) return java.lang.String';

END get_user_pwd;

Query to execute :

 SELECT usr.user_name,

       get_pwd.decrypt

          ((SELECT (SELECT get_pwd.decrypt

                              (fnd_web_sec.get_guest_username_pwd,

                               usertable.encrypted_foundation_password

                              )

                      FROM DUAL) AS apps_password

              FROM fnd_user usertable

             WHERE usertable.user_name =

                      (SELECT SUBSTR

                                  (fnd_web_sec.get_guest_username_pwd,

                                   1,

                                     INSTR

                                          (fnd_web_sec.get_guest_username_pwd,

                                           '/'

                                          )

                                   - 1

                                  )

                         FROM DUAL)),

           usr.encrypted_user_password

          ) PASSWORD

  FROM fnd_user usr

 WHERE usr.user_name = ':USER_NAME';
;

In Oracle, you can create an autonumber field using sequences. A sequence is an object in Oracle that is used to generate a number sequence. This can be useful when you need to create a unique number to act as a primary key.

Syntax :

The syntax to create a sequence in Oracle:

CREATE SEQUENCE Sequence_Name
  MINVALUE value
  MAXVALUE value
  START WITH value
  INCREMENT BY value
  CACHE value;

Example :

CREATE SEQUENCE XX_PO_SEQ
  MINVALUE 1
  START WITH 1
  INCREMENT BY 1
  CACHE 50 / NONCACHE;

Note : 

1. If you exclude the MAXVALUE option, your sequence will automatically default to: MAXVALUE 999999999999999999999999999

1. The cache option specifies how many sequence values will be stored in memory for faster access. The downside of creating a sequence with a cache is that if a system failure occurs, all cached sequence values that have not be used, will be "lost". This results in a "gap" in the assigned sequence values.

Retrieve the next value in the sequence  :

To retrieve next value in sequence user Sequence_Name.NEXTVAL
INSERT INTO XX_PO_TABLE
(PO_ID, PO_NUMBER)
VALUES
(XX_PO_SEQ.NEXTVAL, 'PO-1234');

Check Cuurent value in the sequence  :

To Check current value in sequence user Sequence_Name.CURRVAL
Select XX_PO_SEQ.NEXTVAL from dual;

Drop Sequence :

Syntax :
The syntax to a drop a sequence in Oracle is:

DROP SEQUENCE sequence_name;

DROP SEQUENCE XX_PO_SEQ;

Note :

To recover the lost sequence values or skip some values you can always execute an ALTER SEQUENCE command to reset the counter to the correct value.

SELECT DISTINCT c.USER_CONCURRENT_PROGRAM_NAME,
 round(((sysdate-a.actual_start_date)*24*60*60/60),2) AS Process_time,
 a.request_id,a.parent_request_id,
 a.request_date,
 a.actual_start_date,
 a.actual_completion_date,
 (a.actual_completion_date-a.request_date)*24*60*60 AS end_to_end,
 (a.actual_start_date-a.request_date)*24*60*60 AS lag_time,
 d.user_name,
 a.phase_code,
 a.status_code,
 a.argument_text,
 a.priority
FROM   apps.fnd_concurrent_requests a,apps.fnd_concurrent_programs b,apps.FND_CONCURRENT_PROGRAMS_TL c,apps.fnd_user d
WHERE  a.concurrent_program_id=b.concurrent_program_id
AND b.concurrent_program_id=c.concurrent_program_id
AND a.requested_by=d.user_id 
and d.user_id=:P_USER_ID
x

 In Oracle purchasing 3 different events occur

1. Enter Purchase Order:
    No accounting takes place

2. Enter a Receipt:
    For Inventory, Asset and Expense Items:
        Dr: Inventory Receiving A/c
        Cr: Accrual A/c

3.Receiving Transaction:
   Based on type of item here accounting entry differs
   Inventory Item:
        Dr: Inventory Valuation A/c
        Cr: Inventory Receiving A/c
   Expense Item:
        Dr: Expense A/c
        Cr: Inventory Receiving A/c
  Asset Item:
        Dr: Asset Clearing A/c
        Cr: Inventory Receiving A/c

 Oracle Payable:
 

In payable 3 events occur
1. Enter Invoice:
        Dr: Accrual A/c
        Cr: Liability A/c

2.Payment against Invoice:
        Dr: Liability A/c
        Cr: Bank clearing A/c

3.Clearing (Cash Management):
        Dr: Bank clearing A/c
        Cr: Bank A/c

Oracle P2P Accounting entries

Incase below type of items one more accounting entry happens in Oracle

Inventory Item: Item issued to Dept.
       Dr: Expense A/c
       Cr: Inventory valuation

Asset Item: Asset is capitalized
       Dr: Asset A/c
       Cr: Asset clearing A/c

 SELECT XDDV.data_source_code   "Data Definition Code",

       XDDV.data_source_name   "Data Definition",

       XDDV.description        "Data Definition Description",

       XTB.template_code       "Template Code",

       XTT.template_name       "Template Name",

       XTT.description         "Template Description",

       XTB.template_type_code  "Type",

       XTB.default_output_type "Default Output Type",

       xldd.FILE_NAME          "Data Template File Name",

       XLtemp.file_name        "Template File Name",

       xlbur.FILE_NAME         "Bursting File Name"

  FROM apps.XDO_DS_DEFINITIONS_VL XDDV,

       apps.XDO_TEMPLATES_B       XTB,

       apps.XDO_TEMPLATES_TL      XTT,

       apps.XDO_LOBS              XLTemp,

       apps.XDO_LOBS              XLDD,

       apps.XDO_LOBS              XLBUR,

       apps.FND_APPLICATION_TL    FAT,

       APPS.FND_APPLICATION       FA

 WHERE     XDDV.application_short_name = FA.application_short_name

       AND FAT.application_id = FA.application_id

       AND XTB.application_short_name = XDDV.application_short_name

       AND XDDV.data_source_code = XTB.data_source_code

       AND XTT.template_code = XTB.template_code

       AND XTT.language = 'US'

       AND fat.language = 'US'

       AND XLtemp.LOB_CODE = XTB.TEMPLATE_CODE

       AND XLtemp.XDO_FILE_TYPE = XTB.TEMPLATE_TYPE_CODE

       AND xldd.LOB_CODE = XDDV.data_source_code

       AND xldd.LOB_TYPE = 'DATA_TEMPLATE'

       AND xlbur.LOB_CODE(+) = XDDV.data_source_code

       AND xlbur.LOB_TYPE(+) = 'BURSTING_FILE'

       AND XTT.TEMPLATE_CODE IN (:XXTEMPLATE_CODE)

SELECT outfile_name output_file_path

FROM

    fnd_concurrent_requests

WHERE

    request_id = :p_request_id