What are triggers?
---- triggers are similar to procedures, in that they are the named
pl/sql blocks with declarative, executable and exception-handling
sections, how ever a procedure is executed explicitly from another block
via a procedure call, which can also pass arguments.
---- A trigger is executed implicitly when ever a particular event task places. And is nothing but a event.
---- The triggering event is a DML (insert, update, delete) operations on a data base table
----- fires whenever a data event(such as DML) or system event(such as login or shutdown) occurs on a schema or database
Trigger timing : 1) before
2) after
3) instead of ( this is used for views)
Triggering events : 1) insert
2)update
3) delete
Trigger type : 1) statement level
2) row level.
Firing sequence of database triggers
1) before statement trigger
2) before row trigger
3) after row trigger
4) after statement trigger
Ex:
1) Create or replace trigger secure_emp
Before
Insert on emp
Begin
If (to_char(sysdate,’dy’) in(‘sat’,’sun’)) or
To_char(sysdate,’hh24:mi’)
Not between ’08:00’ and ’18:00’)
Then raise_application_error(-20500,’u can insert in the office timings’)
End if;
End;
Ex :- 2) write a program to all transitions with name smith?
Create or replace
Trigger trigger_name
Before insert or update or delete
On emp
For each row
When (old.ename =’smith’ or
New.ename =’smith’)
Begin
Raise_application_error(-20003,’smith’);
End;
57) Difference between triggers and procedures?
Defined with create trigger
|
Defined with create procedure
|
The data dictionary contains source code in the user_triggers.
|
Data dictionary contains source code in user_source
|
Implicitly invoked
|
Explicitly invoked
|
Commit, save point and rollback are not allowed(TCL)
|
Those are allowed
|
58) What are LOCKS?
-- Is to reduce concurrency
1) share lock
---it allows the other users for only reading not to insert or update or delete.
2) exclusive lock
--- only one user can have the privileges of insert or update and delete of particular object
--- others can only read.
3) update lock
----multiple user can read, update delete
Lock levels :
1) table level 2) table space 3) data base level.
58) What is template.fmb?
a) The TEMPLATE form is the required starting point for all development of new
Forms.
b) The TEMPLATE form includes platform–independent attachments of several
Libraries.
APPSCORE :- It contains package and procedures that are required of all forms to support the MENUS ,TOOLBARS.
APPSDAYPK :- It contains packages that control the oracle applications CALENDER FEATURES.
FNDSQF :- it contains packages and procedures for MESSAGE DICTONARY, FLEX FIELDS, PROFILES AND CONCURRENT PROCESSING.
CUSTOM :-
it allows extension of oracle applications forms with out modification
of oracle application code, you can use the custom library for
customization such as zoom ( such as moving to another form and querying up specific records)
59) What are ad-hoc reports?
Ans.: Ad-hoc Report is made to meet one-time reporting needs. Concerned with or formed for a
particular purpose. For example, ad hoc tax codes or an ad hoc database query
60) What is responsibility in Oracle Applications?
Is collection of menus, request security groups and data groups
Menus: collection of forms is nothing but menus
Request security groups: collection of programs.
Data groups: is a group of modules to be made accessible by the user through
Responsibility
Navigations are :
System admin --> security --> define
Security--> user --> define
61) What are different execution methods of executables in Oracle Applications Concurrent program?
FlexRpt The execution file is wrnitten using the FlexReport API.
FlexSql The execution file is written using the FlexSql API.
Host The execution file is a host script.
Oracle Reports The execution file is an Oracle Reports file.
PL/SQL Stored Procedure The execution file is a stored procedure.
SQL*Loader The execution file is a SQL script.
SQL*Plus The execution file is a SQL*Plus script.
SQL*Report The execution file is a SQL*Report script.
Spawned The execution file is a C or Pro*C program.
Immediate
The execution file is a program written
to run as a subroutine of the concurrent manager. We recommend against
defining new immediate concurrent programs, and suggest you use either a
PL/SQL Stored Procedure or a Spawned C Program instead.
Composite Datatypes :
– PL/SQL TABLES
– PL/SQL RECORDS
- Nested TABLE
- VARRAY
What is the sequence of functions – group by,having,orderby in a select statements ?
Select…..
Group by…
Having…
Orderby..
Difference between User and Super User?
User : login user or front end user
Super user : it has full access of particular module
52) what is REF Cursor?
To
execute a multi-row query, oracle opens an unnamed work area that
stores processing information, to access the information, an explicit,
which names the work area or, a cursor variable, which points to the
work area.
where as a cursor always refers to the same query work area, a
cursor variable can refer to a different work areas, cursor variable
area like ‘c’ or ‘pascal’ pointers, which hold the memory
location(address) of some object instead of the object itself.
So, declaring a cursor variable creates a pointers, not an object.
32) Can u define exceptions twice in same block?
No
33) Can you have two functions with the same name in a pl/sql block?
Yes
34) Can you have two stored functions with in the same name?
Yes
35) Can function be overload?
Yes
36) What is the maximum number of statements that can be specified in a trigger statement?
One.
32) Stored procedure?
Stored procedure is a sequence of statements that perform specific function.
53) What is procedure?
---- is a named pl/sql block to perform a specific task.
---- A procedure may have DML statements.
---- It may or may not return a value.
---- Procedure can return more than one value.
Example for procedure
1) To accept the year as a parameter and list emp belong to the year?
Create or replace
Procedure empy(y number) is
Cursor emp_cursor is
Select * from emp where to_char(hiredate,’yyyy’)=’y’;
Emp_record emp%rowtype;
Begin
For emp_record in emp_cursor loop
Print (emp_record.empno);
Print (emp_record.ename);
Print (emp_record.sal);
End loop;
End;
Output :
var empx number;
Begin
:empx := ‘1234’;
End;
Exec empy(:empx);
Print empy;
54) What is function?
---- is a named pl/sql block to perform a specific task, is mainly used for calculation purpose.
---- A function is called as part of an exception.
---- Every function should return a value
Example for function
Create or replace
Function get_sal(p_id in emp.emp_no% type)
Return number
Is
v_sal emp.sal%type :=0;
Begin
Select salary into v_salary
From emp
Where emp_no = p_id;
Return v_salary
End get_sal;
End;
Output :
var g_sal number;
Exec :g_sal := get_sal(99);
Print g_salary;
9.Can functions be overloaded ?Yes.
10.Can 2 functions have same name & input parameters but differ only by return datatype
No.
55) What is the package?
---- Group logically related pl/sql types, items and subprograms.
1) package specification
2) package body
Advantages of a package:
· Modularity
· Easier Application Design
· Information Hiding
· Overloading
You cannot overload:
•Two subprograms if their formal parameters differ only in name or parameter mode. (datatype and their total number is same).
•Two
subprograms if their formal parameters differ only in datatype and the
different datatypes are in the same family (number and decimal belong to
the same family)
•Two
subprograms if their formal parameters differ only in subtype and the
different subtypes are based on types in the same family (VARCHAR and
STRING are subtypes of VARCHAR2)
•Two functions that differ only in return type, even if the types are in different families.
56) What is FORWARD DECLARATION in Packages?
PL/SQL
allows for a special subprogram declaration called a forward
declaration. It consists of the subprogram specification in the package
body terminated by a semicolon. You can use forward declarations to do
the following:
• Define subprograms in logical or alphabetical order.
• Define mutually recursive subprograms.(both calling each other).
• Group subprograms in a package
Example of forward Declaration:
CREATE OR REPLACE PACKAGE BODY forward_pack
IS
PROCEDURE calc_rating(. . .); -- forward declaration
PROCEDURE award_bonus(. . .)
IS -- subprograms defined
BEGIN -- in alphabetical order
calc_rating(. . .);
. . .
END;
PROCEDURE calc_rating(. . .)
IS
BEGIN
. . .
END;
END forward_pack;
33) FLEX FIELDS?
Used to capture the additional business information.
DFF
|
KFF
|
Additional
|
Unique Info, Mandatory
|
Captured in attribute prefixed columns
|
Segment prefixed
|
Not reported on standard reports
|
Is reported on standard reports
|
To provide expansion space on your form With the help of []. [] Represents
descriptive Flex field.
FLEX FILED : DESCRIPTIVE : REGIGSTER
|
Used for entering and displaying key information
For example Oracle General uses a key Flex field called Accounting Flex field to
uniquely identifies a general account.
FLEX FILED : KEY : REGIGSTER
|
Oracle Applications KEY FLEX FIELDS
1) GL :- ACCOUNTING
2) AR :- SALES TAX LOCATION, TERRITORY,
3) AP :- BANK DETAILS, COST ALLOCATION, PEOPLE GROUP
Oracle Applications DESCRIPTIVE FLEX FIELDS (Partial)
1) GL :- daily rates
2) AR :- credit history, information
3) PA :- bank branch, payment terms, site address,
34) What are the requests groups?
a) Single request: - this allows you to submit an individual request.
b) Request set : - this allows you to submit a pre-defined set of requests.
35) Sys Admin Module?
a) Define Custom Users, b) Define Login Users, c) Register oracle DB users,
d) Define Concurrent Programs, e) Register Concurrent Executables, f) Setting Profile Option Values, g) Define Request Types.
36) AOL?
a) Registering tables. b) Registering views c) Registering db sequences
d) Registering profile options e) Registering lookups and lookup codes
f) Registering forms g) Registering Form and Non-Form functions i) registering
Menus and sub-menus. j) Registering DFF and KFF. k) Libraries
37) What r the type Models in the system parameters of the report?
1) Bit map 2) Character mode
38) .What is SRW Package? (Sql Report Writer)
The Report builder Built in package know as SRW Package This package extends reports ,Control report execution, output message at runtime, Initialize layout fields, Perform DDL statements used to create or Drop temporary table, Call User Exist, to format width of the columns, to page break the column, to set the colors
Ex: SRW.DO_SQL, It’s like DDL command, we can create table, views , etc.,
SRW.SET_FIELD_NUM
SRW. SET_FILED_CHAR
SRW. SET FILED _DATE
37) Difference between Bind and Lexical parameters?
BIND VARIABLE :
-- are used to replace a single value in sql, pl/sql
-- bind variable may be used to replace expressions in select, where, group, order
by, having, connect by, start with cause of queries.
-- bind reference may not be referenced in FROM clause (or) in place of
reserved words or clauses.
LEXICAL REFERENCE:
-- you can use lexical reference to replace the clauses appearing AFTER select,
from, group by, having, connect by, start with.
-- you can’t make lexical reference in a pl/sql statmetns.
38) Matrix Report: Simple, Group above, Nested
Simple Matrix Report : 4 groups
1.Cross Product Group
2. Row and Column Group
3. Cell Group
4. Cell column is the source of a cross product summary that
becomes the cell content.
Frames: 1.Repeating frame for rows(down direction)
2.Repeating frame for columns(Across )
3.Matrix object the intersection of the two repeating frames
39) what is Flex mode and Confine mode?
Confine mode
On: child objects cannot be moved outside their enclosing parent objects.
Off: child objects can be moved outside their enclosing parent objects.
Flex mode:
On: parent borders "stretch" when child objects are moved against them.
Off: parent borders remain fixed when child objects are moved against
them.
A
placeholder is a column is an empty container at design time. The
placeholder can hold a value at run time has been calculated and placed
in to It by pl/sql code from anther object.
You can set the value of a placeholder column is in a Before Report trigger.
Store a Temporary value for future reference. EX. Store the current max salary as records are retrieved.
A formula column performs a user-defined computation on another column(s) data, including placeholder columns.
A summary column performs a computation on another column's data. Using the Report Wizard or Data Wizard, you can create the following summaries: sum, average, count, minimum, maximum, % total. You
can also create a summary column manually in the Data Model view, and
use the Property Palette to create the following additional summaries: first, last, standard deviation, variance.
50) What is cursor?
A
Cursor is a pointer, which works on active set, I.e. which points to
only one row at a time in the context area’s ACTIVE SET. A cursor is a
construct of pl/sql, used to process multiple rows using a pl/sql block.
28) Types of cursors?
1) Implicit: declared for all DML and pl/sql statements.
By default it selects one row only.
2) Explicit: Declared and named by the programmer.
Use explicit cursor to individually process each row returned by a
Multiple statements, is called ACTIVE SET.
Allows the programmer to manually control explicit cursor in the
Pl/sql block
a) declare: create a named sql area
b)Open: identify the active set.
c) Fetch: load the current row in to variables.
d)Close: release the active set.
CURSOR ATTRIBUTES
a) %is open: evaluates to true if the cursor is open.
b) %not found: evaluates to true if the most recent fetch does not return a row
c) %found: evaluates to true if the most recent fetch returns a row.
d) %row count: evaluates to the total number of rows returned to far.
Example for cursor:
1) Declare
Vno emp.empno%type;
Vname emp.ename %type;
Cursor emp_cursor is
Select empno,ename
From emp;
Begin
Open cursor;
For I in 1..10 loop
Fetch emp_cursor into vno,vname;
Dbms_output.putline(to_char(vno) ||’ ‘||vname);
End if;
E nd;
2) Begin
Open emp_cursor;
Loop
Fetch when emp_cursor % rowcount >10 or
Emp_curor % not found;
Bdms_output_put_line(to_char(vno)||’ ‘|| vname);
End loop;
Close emp_cursor;
End;
CURSOR FOR LOOP
A) cursor for loop is a short cut to process explicit cursors
B) it has higher performance
C) cursor
for loop requires only the declaration of the cursor, remaining things
like opening, fetching and close are automatically take by the cursor
for loop
Example:
1) Declare
Cursor emp_cursor is
Select empno,ename
From emp;
Begin
For emp_record in emp_cursor loop
Dbms_output.putline(emp_record.empno);
Dbms_output.putline(emp_record.ename)
End loop
End;
Can we create a cursor without declaring it?
Yes – by using cursor for loop using subqueries.
BEGIN
FOR emp_record IN ( SELECT empno, ename
FROM emp) LOOP
-- implicit open and implicit fetch occur
IF emp_record.empno = 7839 THEN
...
END LOOP; -- implicit close occurs
END;
a) for update clause:
1) use explicit locking to deny access for the duration of a transaction
2) lock the rows before update or delete
Ex : select …….
From…….
For update[ of column ref] [no_wait]
b) where current of clause?
1) use cursor to update or delete the current row
Where current of <>
29) Attribute data types?
1) %type 2) %row type.
30) Exception Handilings?
Is a mechanism provided by pl/sql to detect runtime errors and process them with out halting the program abnormally
1) pre-defined
2) user-defined.
PRE-DEFINED:
1) cursor_already_open--------attempted to open an already open cursor.
2) Dup_val_on_index --------attempted to insert a duplicate values.
3) Invalid_cursor -------- illegal cursor operation occurred.
4) Invalid_number -------- conversion of character string to number fails.
5) Login_denied ---------loging on to oracle with an invalid user name
and password.
6) program_error -------- pl/sql has an internal problem.
7) storage_error -------- pl/sql ran out of memory or memory is
corrupted.
8) to_many_row ---------single row select returned more than one row.
9) value_error -------- arithmetic,conversion,truncation or size
constraint error occurred.
10) zero_devided -------- attempted to divided by zero.
USER-DEFINED:
Declare : name the exception
Raise : explicitly raise the exception by using the raise statements
Reference: exception handing section.
The Raise_Application_Error_Procedure:
n You can use this procedure to issue user-defined error messages from stored sub programs.
n You can report errors to your applications and avoid returning unhandled exceptions.
Raise_Application_Error(error_number,message[,{true/false}]
Error number è between -20000 to -20999
pragma exception_init?
It tells the compiler to associate an exception with an oracle error. To get an error message of a specific oracle error.
Ex: pragma exception_init(exception name, oracle error number)
Example for Exceptions?
1) Check the record is exist or not?
Declare
E emp% rowtype
Begin
e.empno := &empno;
select * into e from emp where empno =e.empno;
Dbms_output.putline(‘empno’ || e.empno);
Exception
When no_data_found then
Dbms_output.putline(e.empno ||’doest exist’);
End;
2) User defined exceptions?
Define p_dept_desc =’gvreddy’
Define p_dept_number =1236
Declare
E_invalid_dept exception;
Begin
Update departments
Set dept_name=’&p_dept_desc’
Where dept_id =’&p_dept_number’;
If sql% not found then
Raise e_invalid_departments;
End if;
Commit;
Exception
When e_invalid_departments then
Dbms_output.putline(‘no such dept’);
End;
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