CoolInterview.com - World's Largest Collection of Interview Questions
Start Your Own website Now
Sponsored Links

Interview Questions
Our Services

Get 9,000 Interview Questions & Answers in an eBook.


  • 9500+ Pages
  • 9000 Question & Answers
  • All Tech. Categories
  • 14 MB Content

    Get it now !!



    Send your Resume to 6000 Companies


  • INTERVIEW QUESTIONS ORACLE PL-SQL DETAILS
    Question :
    What is trigger,cursor,functions in pl-sql and we need sample programs about it?

    Posted by: dilson on 5/19/2008

    Contact dilson Contact dilson
    Category PL-SQL Interview Questions
    Rating (0.4) By 1896 users
    Added on 5/19/2008
    Views 4307
    Rate it!
    Answers:

    Trigger is an event driven PL/SQL block. Event may be any DML transaction.

    Cursor is a stored select statement for that current session. It will not be stored in the database, it is a logical component.

    Function is a set of PL/SQL statements or a PL/SQL block, which performs an operation and must return a value.



    Posted by: Girish P    

    Contact Girish P Contact Girish P

    Cursor
    cursor is a private sql work area.
    Every sql statement executed
    by oracle server has an individual
    cursor associated with it.
    Cursor are two types
    1.Implicit cursor
    2.Explicit cursor
    Implicit cursor: Implicit cursors
    are declared by pl/sql implicitly
    at the time of DML statement and select statement in pl/sql including queries that returns single row.
    cursor have four attributes
    1. SQL%ROWCOUNT
    2. SQL%ISOPEN
    3. SQL%NOTFOUND
    4. SQL%FOUND
    SQL%ROWCOUNT-Basically it returns
    number.
    means number of rows
    affected by present sql statement.
    SQL%ISOPEN-Always evalutes false
    because implicit cursor automatically closed after execution of sql statement.
    SQL%FOUND-Always evalutes true
    because one or more rows are affected by recent sql statement
    SQL%NOTFOUND-Always evalutes true when no rows are affected by
    present sql statement.

    example of explicit cursor
    DECLARE
    v_empno employees.employee_id%TYPE;
    v_name employees.last_name%TYPE;
    CURSOR emp_cur IS
    SELECT employee_id,last_name
    FROM employees
    BEGIN
    OPEN emp_cur;
    LOOP
    FETCH emp_cur INTO v_empno,v_name ;
    EXIT WHEN emp_cur%ROWCOUNT>10 OR
    emp_cur%NOTFOUND;

    DBMS_OUTPUT.PUT_LINE('employee_id:'||TO_CHAR(v_empno) || 'employee_name:'||'v_name');

    END LOOP;
    CLOSE emp_cur;
    END;

    Trigger:-Trigger is pl/sql block or
    procedure that is associated with table,view,schema and database.
    Execute immidiately when particular event take place.
    there are two types of trigger
    1.Application trigger:fires automatically when event occurs with particular application.
    2.Database trigger:Fires when
    data such as DML oparation occured at that time.
    DML triggers are two types
    1.Statementlevel trigger
    2.Rowlevel trigger

    statement level trigger-statement level trigger means trigger body
    execute once for the triggering event.this is default.A statement level trigger fire once even no rows are affected at all.
    Row level- Trigger body execute
    once for each row affected by triggering event.if no rows are
    affected in that case trigger body
    not executed.
    trigger example
    CREATE OR REPLACE TRIGGER secure_emp
    BEFORE INSERT ON employees
    BEGIN
    TO_CHAR(SYSDATE,'DY')IN('SUN','SAT') OR TO_CHAR((SYSDATE,'HH24:MI')NOT BETWEEN '08:00' AND '18:00')THEN
    RAISE_APPLICATION_ERROR(-20253,'u may insert employee information at business hrs');
    END;



    Posted by: Sudipta Das    

    Contact Sudipta Das Contact Sudipta Das

    Cursor:
    cursor is temporary work area in
    pl/sql.
    Type of cusor:
    1.Implict Cursor
    2.Explicit Cursor
    3.Cursor for loop
    4.Cursor With Parametter
    5.Cursor for Update
    6.Ref Cursor

    Curosr Attributes:
    %foud
    %notfound
    %rowCount
    %isopen

    Trigger:
    Trigger is asscoiated with table or database event(when a table affect like dml operation that time occurs fire)

    Types of Trigger:
    we can write 12 types trigger



    Posted by: raja    

    Contact raja Contact raja

    Trigger is a stored procedure that invokes automatically when the event occurs.
    We can write 12 types of triggers on table and 15 types of triggers on views.
    Cursor pointer or handler to the context area . 2 types of cursors are there
    implicit and explicit cursors.



    Posted by: Aruna    

    Contact Aruna Contact Aruna

    DTHDTH



    Posted by: lal bahadur chaubey    

    Contact lal bahadur chaubey Contact lal bahadur chaubey

    Trigger
    -------
    Trigger is a pl/sql block which is executed whenever any dml statement(insert,update,delete)issued against the table.

    Cursor
    ------
    Cursor is a memory area in which all the statement are executed and store the result. cursor is 2 types namely implicit cursor and explicit cursor.
    Implicit cursor fetches only one row (normal select into statement) where as Explicit cursor is fetching more than one row and process one by one. In explicit cursor user have to explicitily name the cursor.

    Function
    --------
    Function is a named pl/sql block which is stored in database. We can invoke by calling the name of the function whenever we need. Function is always return a value.



    Posted by: Vivekanandhan H    

    Contact Vivekanandhan H Contact Vivekanandhan H

    Syntax for Trigger
    ******************

    CREATE [OR REPLACE ] TRIGGER trigger_name
    {BEFORE | AFTER | INSTEAD OF }
    {INSERT [OR] | UPDATE [OR] | DELETE}
    [OF col_name]
    ON table_name
    [REFERENCING OLD AS o NEW AS n]
    [FOR EACH ROW]
    WHEN (condition)
    BEGIN
    --- sql statements
    END;



    Posted by: Mathankumar R    

    Contact Mathankumar R Contact Mathankumar R

    Some specialists tell that <a href="http://goodfinance-blog.com/topics/home-loans">home loans</a> aid people to live their own way, because they can feel free to buy necessary goods. Moreover, some banks offer car loan for different persons.



    Posted by: RobinsonValarie    

    Contact RobinsonValarie Contact RobinsonValarie

    If you have the better answer, then send it to us. We will display your answer after the approval.
    Rules to Post Answers in CoolInterview.com:-

  • There should not be any Spelling Mistakes.
  • There should not be any Gramatical Errors.
  • Answers must not contain any bad words.
  • Answers should not be the repeat of same answer, already approved.
  • Answer should be complete in itself.
  • Name :*
    Email Id :*
    Answer :*
    Verification Code Code Image - Please contact webmaster if you have problems seeing this image code Not readable? Load New Code
    Process Verification  Enter the above shown code:*
    Inform me about updated answers to this question

       
    Related Questions
    View Answer
    Can Commit,Rollback ,Savepoint be used in Database Triggers?If yes than HOW? If no Why?With Reasons
    View Answer
    In pl/sql functions what is use of out parameter even though we have return statement.
    View Answer
    How we can create a table through procedure ?
    View Answer
    What is ref cursor?
    View Answer
    What is pl/sql?what are the advantages of pl/sql?
    View Answer
    State the advantage and disadvantage of Cursor?

    View Answer
    State the difference between implicit and explicit cursor's.

    View Answer
    What is difference between stored procedures and application procedures,stored function and application function?

    View Answer
    Explian rowid,rownum?What are the pseduocolumns we have?

    View Answer
    1)What is the starting "oracle error number"?
    2)What is meant by forward declaration in functions?

    View Answer
    In a Distributed Database System Can we execute two queries simultaneously ? Justify ?

    View Answer
    How we can create a table in PL/SQL block. insert records into it??? is it possible by some procedure or function?? please give example...

    View Answer
    How to avoid using cursors? What to use instead of cursor and in what cases to do so?

    View Answer
    How to disable multiple triggers of a table at at a time?

    View Answer
    Can we declare a column having number data type and its scale is larger than pricesion
    ex: column_name NUMBER(10,100),
    column_name NUMBAER(10,-84)

    View Answer
    What are the Restrictions on Cursor Variables?
    View Answer
    What will the Output for this Coding?
    Declare
    Cursor c1 is select * from emp FORUPDATE;
    Z c1%rowtype;
    Begin
    Open C1;
    Fetch c1 into Z;
    Commit;
    Fetch c1 in to Z;
    end;


    View Answer
    What is PL/SQL ?
    View Answer
    What is the basic structure of PL/SQL ?
    View Answer
    What are the components of a PL/SQL block ?
    View Answer


    Please Note: We keep on updating better answers to this site. In case you are looking for Jobs, Pls Click Here Vyoms.com - Best Freshers & Experienced Jobs Website.

    View ALL PL-SQL Interview Questions

    User Options
    Sponsored Links


    Copyright ©2003-2014 CoolInterview.com, All Rights Reserved.
    Privacy Policy | Terms and Conditions

    Download Yahoo Messenger | Placement Papers| FREE SMS | ASP .Net Tutorial | Web Hosting | Dedicated Servers | C Interview Questions & Answers

    Testing Articles | Testing Books | Testing Certifications | Testing FAQs | Testing Downloads | Testing Interview Questions | Testing Jobs | Testing Training Institutes


    Cache = 0.015991 Seconds