Package specification, PL-SQL Programming

Assignment Help:

The Package Specification

The package specifications contain the public declarations. The scopes of these declarations are local to your database representation and global to the package. Therefore, the declared items are available from your application and from anyplace in the package. The figure describes the scoping.

1386_package specification.png

Figure: Package Scope

The specification lists the package resources accessible to the applications. All the information that your application require to use the resources is in the specification. For illustration, the declaration below shows that the function named the fac takes one argument of the type INTEGER and returns a value of type INTEGER:

FUNCTION fac (n INTEGER) RETURN INTEGER; -- returns n!

That is all the information you require to call the function. You do not require to consider its underlying implementation (whether it is recursive or iterative for illustration). The subprograms and cursors only have an underlying implementation or definition. Therefore, if a specification declares only the constants, types, variables, exceptions, and call specifications, the package body is unessential. Consider the bodiless package which is as shown below:

-- a bodiless package

CREATE PACKAGE trans_data AS

TYPE TimeRec IS RECORD (

minutes SMALLINT,

hours SMALLINT);

TYPE TransRec IS RECORD (

category VARCHAR2,

account INTEGER,

amount REAL,

time_of TimeRec);

minimum_balance CONSTANT REAL := 10.00;

number_processed INTEGER;

insufficient_funds EXCEPTION;

END trans_data;

The package trans_data requires no body as the constants, types, variables, and the exceptions do not have an underlying implementation. These packages define the global variables-usable by the subprograms and database triggers-that persist throughout a session.


Related Discussions:- Package specification

Between operator-comparison operators, BETWEEN Operator The operator BET...

BETWEEN Operator The operator BETWEEN, tests whether the value lies in a specified series. That means "greater than or equivalent to low value and less than or equivalent to hig

Effects of null operator, Effects of NULL Operator As a general rule-b...

Effects of NULL Operator As a general rule-but not a universal one-if NULL is an argument to an invocation of a system-defined read-only operator, then NULL is the result of t

Table literals - sql, Table Literals - SQL One might expect SQL to sup...

Table Literals - SQL One might expect SQL to support table literals in the manner illustrated in Example 2.2, but in fact that is not a legal SQL expression. Example: Not a

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

Parameter modes, Parameter Modes   To define the behavior of formal pa...

Parameter Modes   To define the behavior of formal parameters you use the parameter modes. The 3 parameter modes, IN, OUT, & IN OUT, can be used with any subprogram. Though, a

Theory of panspermia - origin of life, THEO R Y OF PANSPERMIA - Arrh...

THEO R Y OF PANSPERMIA - Arrhenius (1908) postulated the cosmic panspermia theory that claims that organisms existed throughout the universe, and their spores, etc., could

Pragma restrict_references in pl sql, Using Pragma RESTRICT_REFERENCES: ...

Using Pragma RESTRICT_REFERENCES: The function called from the SQL statements should obey certain rules meant to control the side effects. To check for violation of the rules,

Calculate the total shopper spending, Many of the reports generated from th...

Many of the reports generated from the system calculate the total dollars in purchases for a shopper. Complete the following steps to create a function named TOT_PURCH_SF that acce

Scoping-naming conventions, Scoping Within the similar scope, all the de...

Scoping Within the similar scope, all the declared identifiers should be unique. So, even if their datatypes differ, the variables and parameters cannot share the similar name.

Declaring exceptions - user-defined exceptions, Declaring Exceptions T...

Declaring Exceptions The Exceptions can be declared only in the declarative part of the PL/SQL subprogram, block, or package. By introducing its name, you can declare an excep

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