Attributes:

Just similar to variable, an attribute is declared with a name and datatype. The name should be exclusive within the object type. The datatype can be any Oracle type excluding:

(i) LONG & LONG RAW

(ii)NCHAR, NCLOB, & NVARCHAR2

(iii)ROWID & UROWID

(iv)The PL/SQL-specific types BINARY_INTEGER (and its subtypes), PLS_INTEGER, BOOLEAN, RECORD, REF CURSOR, %TYPE, & %ROWTYPE

(v)The types defined within the PL/SQL package

You cannot initialize an attribute in its declaration by using the assignment operator or the DEFAULT clause. You cannot also impose the NOT NULL constraint on an attribute. Though, an object can be stored in the database tables on which you can impose the constraints.

The type of data structure formed by the set of attributes depends on the real-world object being modeled. For illustration, a rational number can present, that has a numerator and a denominator, you require only two INTEGER variables. On another hand, to present a college student, you require quite a few VARCHAR2 variables to hold the name, status, address, phone number, and so on, in addition to a VARRAY variable to hold the courses and grades.

The data structure can be mush complex. For illustration, the datatype of an attribute can be another object type (known as the nested object type). That lets you construct a complex object type from the simpler object types. Some object types like lists, queues, and trees are dynamic, meaning that they can grow as they are used. The Recursive object types, that contain direct or indirect references to themselves, permit for highly complicated data models.

Posted Date: 10/6/2012 8:02:41 AM | Location : United States

Ask an Expert

Related Discussions:- Components of an object type - attributes in pl/sql, Assignment Help, Ask Question on Components of an object type - attributes in pl/sql, Get Answer, Expert's Help, Components of an object type - attributes in pl/sql Discussions

Write discussion on Components of an object type - attributes in pl/sql
Your posts are moderated

Write your message here..

Related Questions

Triffic light control system, write the program for traffic control system ... write the program for traffic control system with 10 second, 15 secod, and 20 second delay

Overview of control structures-comparison operators, Overview of control st... Overview of control structures According to the structure theorem, any computer program can be written by using the basic control structures as shown in figure below. They can b

Control structure, Control Structures The Control structures are the mo... Control Structures The Control structures are the most important PL/SQL extension to the SQL. Not only does PL/SQL let you manipulate Oracle data, it lets you process the data

Loop statements, LOOP Statements The LOOP statements execute a series o... 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

Organic evolution, Organi c Evolution Evolution is a slow continuou... Organi c Evolution Evolution is a slow continuous, irreversible and natural process of change to give rise to advance and diverse forms of life i.e. formation of new specie

Defining records, Defining and Declaring Records To create records, yo... Defining and Declaring Records To create records, you have to define a RECORD type, and then declare records of that type. You may also define RECORD types in the declarative

Oracle development , Write a stored procedure that accepts the post code in... Write a stored procedure that accepts the post code in which the customer resides as the input parameter. The procedure should then use an explicit cursor to display comprehensive

Tautology - equivalences rules, Tautology - Equivalences Rules: If the... Tautology - Equivalences Rules: If there Tautologies are not all the time as much easy to note as the one above so than we can use these truth tables to be definite that a sta

Benefit of the dynamic sql pl sql, Benefit of the dynamic SQL: This pa... Benefit of the dynamic SQL: This part shows you how to take full benefit of the dynamic SQL and how to keep away from some of the common pitfalls. Passing the Names of Sc

How pl/sql resolves the calls? , How Calls Are Resolved? The figure sho... How Calls Are Resolved? The figure shows that how the PL/SQL compiler resolves the subprogram calls. When the compiler encounters the procedure or function call, it tries to di