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!
GOTO StatementThe GOTO statement branches to a label unconditionally. The label must be exclusive within its scope and should precede an executable statement or a PL/SQL block. If executed, the GOTO statement transfers control to the labeled statement or block. In the following illustration, you go to an executable statement farther down in a series of statements:BEGIN...GOTO insert_row;...<>INSERT INTO emp VALUES...END;In the next illustration, you go to a PL/SQL block farther up in a series of statements:BEGIN...<>BEGINUPDATE emp SET ......END;...GOTO update_row;...END;The label end_loop in the example below is illegal as it does not precede an executable statement:DECLAREdone BOOLEAN;BEGIN...FOR i IN 1..50 LOOPIF done THENGOTO end_loop;END IF;...<> -- illegalEND LOOP; -- not an executable statementEND;To debug the last illustration, now add the NULL statement, as shown:FOR i IN 1..50 LOOPIF done THENGOTO end_loop;END IF;...<>NULL; -- an executable statementEND LOOP;As the following illustration shows, a GOTO statement can branch to an enclosing block from the present block:DECLAREmy_ename CHAR(10);BEGIN<>SELECT ename INTO my_ename FROM emp WHERE...BEGIN...GOTO get_name; -- branch to enclosing blockEND;END;RestrictionsSome likely destinations of a GOTO statement are illegal. Particularly, a GOTO statement cannot branch into an IF statement, LOOP statement, or sub-block. For illustration, the following GOTO statement is illegal:BEGIN...GOTO update_row; -- illegal branch into IF statement...IF valid THEN...<>UPDATE emp SET...END IF;END;A GOTO statement also cannot branch from one IF statement clause to another, as the following illustration shows:BEGIN...IF valid THEN...GOTO update_row; -- illegal branch into ELSE clauseELSE...<>UPDATE emp SET...END IF;END;The next illustration shows that a GOTO statement cannot branch from an enclose block into a sub-block:BEGIN...IF status = ’OBSOLETE’ THENGOTO delete_part; -- illegal branch into sub-blockEND IF;...BEGIN...<>DELETE FROM parts WHERE...END;END;A GOTO statement also cannot branch out of a subprogram, as the following illustration shows:DECLARE...PROCEDURE compute_bonus (emp_id NUMBER) ISBEGIN...GOTO update_row; -- illegal branch out of subprogramEND;BEGIN...<>UPDATE emp SET...END;Finally, the GOTO statement cannot branch from an exception handler into the present block. For illustration, the following GOTO statement is illegal:DECLARE...pe_ratio REAL;BEGIN...SELECT price / NVL(earnings, 0) INTO pe_ratio FROM ...<>INSERT INTO stats VALUES (pe_ratio, ...);EXCEPTIONWHEN ZERO_DIVIDE THENpe_ratio := 0;GOTO insert_row; -- illegal branch into current blockEND;Though, a GOTO statement can branch from an exception handler into the enclosing block.
TYPES OF EVOLUTION - Sequential evolution : Minor changes in the gene pool of a population from one generation to the next, with the resul
Using TRIM This process has two forms. The TRIM removes an element from the end of the collection. The TRIM(n) removes the n elements from the end of the collection. For e.g.
Cursors The Oracle uses work areas to execute the SQL statements and to store process information. A PL/SQL construct known as the cursor. Let's you assume name a work area and
CHECK Constraints in SQL A CHECK constraint is a table constraint defined using the key word CHECK, as already illustrated in several examples in this chapter. In particular,
LOOP Statements The LOOP statements execute a series of statements at multiple times. The loops enclose the series of statements that is to be repeated. The PL/SQL provides typ
Running the PL/SQL Wrapper To run the PL/SQL Wrapper, go through the wrap command at your operating system prompt by using the syntax as shown: wrap iname=input_file [oname=
Example of Check Constraints Example: Workaround for when subqueries not permitted in CHECK constraints CREATE FUNCTION NO_MORE_THAN_20000_ENROLMENTS ( ) RETURNS BOOLEAN
Operators on Tables and Rows Row Extraction TUPLE FROM r, SQL has row subqueries. These are just like scalar subqueries except that they may specify more than one column.
Positional and Named Notation You can write the actual parameters when calling a subprogram, using either positional or named notation. That is, you can point to the relationsh
Pl/SQL Expressions The Expressions are constructed by using the operands and operators. An operand is a constant, literal, variable, or function call which contributes a value
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