Read and download CBSE Class 12 Informatics Practices Transactions Procedures and Functions in NCERT book for Class 12 Informatics Practices. You can download latest NCERT eBooks chapter wise in PDF format free from Studiestoday.com. This Informatics Practices textbook for Class 12 is designed by NCERT and is very useful for students. Please also refer to the NCERT solutions for Class 12 Informatics Practices to understand the answers of the exercise questions given at the end of this chapter
NCERT Book for Class 12 Informatics Practices Transactions Procedures And Functions
Class 12 Informatics Practices students should refer to the following NCERT Book Transactions Procedures And Functions in Class 12. This NCERT Book for Class 12 Informatics Practices will be very useful for exams and help you to score good marks
Transactions Procedures And Functions NCERT Book Class 12
Chapter – 4
Transactions, Procedures and
Functions
(Informatics Practices)
A transaction is a sequence of SQL statements to accomplish a single task.
Example: Transfer funds between bank accounts.
-- assume source_acct, dest_acct, amount,
-- and source_balance are defined
BEGIN
SELECT balance INTO source_balance
FROM Accounts WHERE acct# = source_acct;
-- check whether sufficient funds
UPDATE Accounts SET balance = balance-amount
WHERE acct# = source_acct;
UPDATE Accounts SET balance = balance+amount
WHERE acct# = dest_acct;
COMMIT;
END;
Oracle treats such a sequence as an indivisible unit, to ensure that database is left in a consistent state. PL/SQL gives fine-grained control over progress of transaction. This also gives responsibility to ensure that transaction completes ok. The first SQL statement begins a transaction. COMMIT forces any changes made to be written to database. ROLLBACK restores database to state at start of transaction. Both COMMIT and ROLLBACK finish the transaction. Can achieve finer-grained rollback via savepoints:
BEGIN
...
UPDATE Employees SET ... WHERE id# = emp_id;
DELETE FROM Employees WHERE ...
...
SAVEPOINT more_changes;
...
-- make changes to Employees
-- possibly raise some_exception
...
COMMIT;
EXCEPTION
WHEN some_exception THEN ROLLBACK TO more_changes;
END;
Locking with Cursors
When accessing tables via a cursor, normally the table is locked. PL/SQL provides a mechanism to lock individual rows instead:
DECLARE
CURSOR managers IS
SELECT emp#, job, salary
FROM Employees WHERE job = 'Manager'
FOR UPDATE OF salary;
BEGIN
FOR e IN managers LOOP
UPDATE Employees SET salary = new_sal
WHERE CURRENT OF managers;
COMMIT;
END LOOP;
END;
PL/SQL provides packaging mechanism for small blocks of procedural code:
PROCEDURE ProcName(ArgList) IS
declarations;
BEGIN
statements;
EXCEPTION handlers;
END ProcName;
FUNCTION FuncName(ArgList) RETURN Type IS
declarations;
BEGIN
statements; -- including RETURN Expr;
EXCEPTION handlers;
END FuncName;
Please refer to attached file for CBSE Classs 12 Informatics Practices Transactions Procedures and Functions
Informatics Practices NCERT Book Class 12 Transactions Procedures And Functions
The above NCERT Books for Class 12 Informatics Practices Transactions Procedures And Functions have been published by NCERT for latest academic session. The textbook by NCERT for Transactions Procedures And Functions Informatics Practices Class 12 is being used by various schools and almost all education boards in India. Teachers have always recommended students to refer to Transactions Procedures And Functions NCERT etextbooks as the exams for Class 12 Informatics Practices are always asked as per the syllabus defined in these ebooks. These Class 12 Transactions Procedures And Functions book for Informatics Practices also includes collection of question. We have also provided NCERT solutions for Class 12 Informatics Practices which have been developed by teachers of StudiesToday.com after thorough review of the latest book and based on pattern of questions in upcoming exams for Class 12 students.
NCERT Book Class 12 Informatics Practices Transactions Procedures And Functions
The latest NCERT book for Transactions Procedures And Functions pdf have been published by NCERT based on the latest research done for each topic which has to be taught to students in all classes. The books for Class 12 Informatics Practices Transactions Procedures And Functions are designed to enhance the overall understanding of students. All Class 12 NCERT textbooks have been written in an easy to understand language which will help to enhance the overall level of Class 12 students.
Transactions Procedures And Functions NCERT Book Class 12 Informatics Practices
As the students of Class 12 need the books for their regular studies, we have provided all NCERT book for Transactions Procedures And Functions in pdf here for free download. All pdf NCERT books available here for Class 12 will help them to read on their mobile or computers. They can take a print of the Class 12 Informatics Practices NCERT Book Transactions Procedures And Functions pdf easily and use them for studies. The NCERT textbooks for Class 12 Informatics Practices have been provided chapter-wise and can be downloaded for free of cost.
Class 12 Informatics Practices Transactions Procedures And Functions NCERT Book
Along with Informatics Practices Class 12 NCERT Book in Pdf for Transactions Procedures And Functions we have provided all NCERT Books in English Medium for Class 12 which will be really helpful for students who have opted for english language as a medium. Class 12 students will need their books in English so we have provided them here for all subjects in Class 12.
Class 12 Transactions Procedures And Functions NCERT Book Informatics Practices
For Class 12 Transactions Procedures And Functions we have provided books for students who have opted for Hindi and Urdu medium too. You can click on the links provided above to download all Hindi medium Class 12 Informatics Practices Transactions Procedures And Functions book in easy to read pdf format. These books will help Class 12 Informatics Practices students to understand all topics and also strictly follow latest syllabus for their studies. If you are looking to download the pdf version of Class 12 Informatics Practices Transactions Procedures And Functions textbook issued by NCERT then you have come to the correct website
You can download the NCERT Book for Class 12 Informatics Practices Transactions Procedures And Functions for latest session from StudiesToday.com
Yes, you can click on the link above and download chapter wise NCERT Books in PDFs for Class 12 for Informatics Practices Transactions Procedures And Functions
Yes, the NCERT Book issued for Class 12 Informatics Practices Transactions Procedures And Functions have been made available here for latest academic session
You can easily access the link above and download the Class 12 NCERT Books Informatics Practices Transactions Procedures And Functions for each chapter
There is no charge for the NCERT Book for Class 12 Informatics Practices Transactions Procedures And Functions you can download everything free
Regular revision of NCERT Books given on studiestoday for Class 12 subject Informatics Practices Transactions Procedures And Functions can help you to score better marks in exams