Using operator value in pl sql, PL-SQL Programming

Assignment Help:

Using Operator VALUE:

As you may expect, the operator VALUE returns the value of an object. The VALUE takes its argument a correlation variable.  For illustration, to return a result set of the Person objects, you can use the VALUE as shown below:

BEGIN

INSERT INTO employees

SELECT VALUE(p) FROM persons p

WHERE p.last_name LIKE '%Smith';

In the next example, you use VALUE to return a specific Person object:

DECLARE

p1 Person;

p2 Person;

...

BEGIN

SELECT VALUE(p) INTO p1 FROM persons p

WHERE p.last_name = 'Kroll';

p2 := p1;

...

END;

At this position, p1 holds a local Person object, that is a copy of the stored object whose last name is 'Kroll', and p2 holds the other local Person object, that is a copy of p1. As the illustration below shows, you can use these variables to access and update the objects they have:

BEGIN

p1.last_name := p1.last_name || 'Jr';

Currently, the local Person object held by p1 has the last name 'Kroll Jr'.


Related Discussions:- Using operator value in pl sql

Keyword and parameter description - goto statement, Keyword and Parameter D...

Keyword and Parameter Description: label_name: This is an undeclared identifier which labels an executable statement or the PL/SQL block. You can use a GOTO statement to

Laws / rules associated with evolution, LAWS / RULES - Dollo's Law    ...

LAWS / RULES - Dollo's Law                     :           Living organisms do exhibit evolutionary irreversibility or evolution is irreversible. Williston's Law

Group and having query, Using a join on 2 tables, select all columns and 10...

Using a join on 2 tables, select all columns and 10 rows from the 2 tables without the use of a Cartesian product. Query: SELECT * FROM EMPLOYEE1 E JOIN STAFF S ON E.EMP_

Negation - sql, Negation (NOT, ¬) - SQL There are three rows instead o...

Negation (NOT, ¬) - SQL There are three rows instead of just two. As you can see, ¬ p is defined as in two-valued logic (2VL) when p is either true or false, but ¬ (unknown) i

Row counterparts of table operators - sql, Row Counterparts of Table Operat...

Row Counterparts of Table Operators SQL does not have counterparts tuple rename, tuple projection, tuple extension, tuple join and tuple compose. To obtain the same effects as

Example of coalesce operator - sql, Example of COALESCE operator Examp...

Example of COALESCE operator Example: Give the total of marks for each exam (simplified solution) SELECT CourseId, COALESCE ((SELECT SUM (Mark) FROM EXAM_MARK AS EM

Defining and declaring collections, Defining and Declaring Collections T...

Defining and Declaring Collections To create the collections, you must define a collection type, and then declare the collections of that type. You can define the VARRAY types a

Processing transactions, Processing Transactions This part describes ho...

Processing Transactions This part describes how to do the transaction processing. You learn the fundamental techniques that safeguard the consistency of your database, involvin

Use of table expressions - expressing constraint conditions, Use of Table E...

Use of Table Expressions - Expressing Constraint Conditions With the exception of key constraints, the examples in the theory book all explicitly reference at least one relvar

Parameter default values, Parameter Default Values As the illustration ...

Parameter Default Values As the illustration below shows, you can initialize the IN parameters to the default values. In that way, you can pass various numbers of actual par

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

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!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd