Already have an account? Get multiple benefits of using own account!
Login in your account..!
Remember me
Don't have an account? Create your account in less than a minutes,
Forgot password? how can I recover my password now!
Enter right registered email to receive password!
Transaction Control
The Oracle is transaction oriented; that is, Oracle uses the transactions to make sure the data integrity. The transaction is a sequence of SQL data manipulation statements that does a logical unit of work. For illustration, the two UPDATE statements might credit one bank account and debit another.
At the same time, the Oracle makes permanent or undoes all the database changes made by a transaction. If your program fails in the middle of the transaction, the Oracle detects the error and rolls back the transaction. Therefore, the database is restored to its previous state automatically.
You use the ROLLBACK, COMMIT, SAVEPOINT, & SET TRANSACTION commands to control the transactions. The COMMIT makes everlasting and any database changes made during the present transaction. The ROLLBACK ends the present transaction and undoes any changes made as the transaction began. The SAVEPOINT marks the present point in the processing of a transaction. Used with the ROLLBACK, SAVEPOINT undoes part of a transaction. The SET TRANSACTION sets the transaction properties like the read/write access and isolation level.
What Are Subprograms? The Subprograms are named PL/SQL blocks which can take parameters and be invoked. The PL/SQL has 2 types of subprograms known as the procedure s and func
Updating by replacement Syntax: UPDATE ENROLMENT SET Name = 'Ann' WHERE StudentId = SID ('S1'); Note the use of SET, as already noted in connection with direct a
Overloading The PL/SQL overloads the subprogram names. That is, you can use similar name for few different subprograms as long as their formal parameters differ in the number
%FOUND Subsequent to a cursor or cursor variable is opened but before the first fetch, the %FOUND yields NULL. Afterward, it yields TRUE when the last fetch returned a row, or
Using Aliases The Select-list items fetched from a cursor related with the %ROWTYPE should have simple names or, if they are expressions, should have aliases. In the example bel
Implicit Cursor Attributes The Implicit cursor attributes returns the information about the execution of an INSERT, DELETE, UPDATE, or SELECT INTO statement. The cursor attribu
Using EXCEPTION_INIT To handle unnamed internal exceptions, you should use the OTHERS handler or the pragma EXCEPTION_INIT. The pragma is a compiler directive that can be th
MILLER-UREY' S EXPERIMENTAL PROCEDURES - They recreated the probable conditions on the primitive earth in the laboratory. An atmosphere containing hydrogen, ammonia, me
Identifiers You use identifiers to name the PL/SQL program items and units that include constants, variables, cursors, exceptions, cursor variables, subprograms, and packages.
%ROWCOUNT When its cursor or cursor variable is opened, the %ROWCOUNT is zeroed. Before the first fetch, the %ROWCOUNT yields 0. Afterward, it yields the number of rows fetche
Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!
whatsapp: +91-977-207-8620
Phone: +91-977-207-8620
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd