BEGIN Parameter Description in pl sql:
BEGIN:
This keyword signals the beginning of the executable section of a PL/SQL block, that contains executable statements. The executable section of a block is needed. That is, the PL/SQL block should contain at least one executable statement. The NULL statement meets this necessity.
Statement:
This is an executable (that is not declarative) statement which you use to create the algorithms. A series of statements can involve the procedural statements like RAISE, SQL statements like the UPDATE, and PL/SQL blocks (sometimes known as the "block statements").
The PL/SQL statements are free format. That is, they can continue from line to line if you do not crack keywords, delimiters, or literals across the lines. A semicolon (;) serve as the statement terminator.
The PL/SQL supports a subset of the SQL statements which involves the cursor control, data manipulation, and transaction control statements but exclude the data definition and data control statements like CREATE, ALTER, GRANT, and REVOKE.
EXCEPTION:
This keyword signals the beginning of the exception-handling section of the PL/SQL block. When an exception is raised, the normal execution of the block stops and control transfers to the suitable exception handler. After the exception handler complete, the execution proceeds with the statement following the block.
If there is no exception handler for the raised exception in the present block, the control passes to the enclosing block. This process repeat until an exception handler is found or there are no more enclosing blocks. If the PL/SQL can find no exception handler for the exception, the execution stops and an unhandled exception error is returned to the host atmosphere.
exception_handler:
This construct relates an exception with a series of statements that is executed when the exception is raised.
END:
This keyword signals the end of the PL/SQL block. It should be the last keyword in a block. Neither the END IF in an IF statement nor the END LOOP in a LOOP statement can replace for the keyword END. The END does not signal the end of a transaction. Merely as a block can span the multiple transactions, a transaction can span the multiple blocks.