At the end of a transaction that makes database changes, Oracle makes all the changes permanent or undoes them all.
If your program fails in the middle of a transaction, Oracle detects the error and rolls back the transaction, restoring the database to its former state.
WHERE CURRENT OF & FOR UPDATE The WHERE CURRENT OF clause is used in some UPDATE and DELETE statements.
The WHERE CURRENT OF clause in an UPDATE or DELETE statement states that the most recent row fetched from the table should be updated or deleted.
The Oracle PL/SQL language was designed to be a portable, high-performance transaction processing language that is tightly integrated with the SQL language.
It is rare, indeed, to find a PL/SQL program that does not either read from or make changes to tables in a database.
Visit PL/SQL Challenge to read a complete explanation of the answers to this quiz. If the SELECT statement identifies more than one row to be fetched, Oracle Database will raise the TOO_MANY_ROWS exception.Tables are made up of rows of data, each consisting of one or more columns, so it stands to reason that Oracle Database would make it as easy as possible to work with those rows of data inside a PL/SQL program.And it does precisely that through its implementation of the datatype, such as a number or string.By extending SQL, PL/SQL offers a unique combination of power and ease of use.You can manipulate Oracle data flexibly and safely because PL/SQL fully supports all SQL data manipulation statements (except ), transaction control statements, functions, pseudocolumns, and operators.When the session opens a cursor with the FOR UPDATE clause, all rows in the return set will hold row-level exclusive locks.