What is a Package Body?

• PL/SQL package body is the main component for the development of the modularity of the code and maintenance of the code in the environment of the Oracle serves.
• It serves the implementation of the PL/SQL package and complements its specification of the package.
• In PL/SQL, the package body can bind the procedures implementation details, functions implementation details, and another construct declared within the specification of the package.
• It provided a way to code organization and code modularization, hiding the data and managing the effective dependencies.

Syntax of PL/SQL package body:

CREATE OR REPLACE PACKAGE BODY package_name AS
    -- Declaration of variables, constants, cursors, types, etc.
    -- These are private to the package body and can be accessed by all procedures and functions within the package body.
    -- For example:
    --   my_variable NUMBER := 10;
    
    -- Procedure declarations
    PROCEDURE procedure_name(parameter1 IN datatype1, parameter2 OUT datatype2) IS
    BEGIN
        -- Procedure logic
        -- For example:
        --   parameter2 := parameter1 * my_variable;
    END procedure_name;
    
    -- Function declarations
    FUNCTION function_name(parameter IN datatype) RETURN datatype IS
        -- Variable declaration specific to the function
        -- For example:
        --   result datatype;
    BEGIN
        -- Function logic
        -- For example:
        --   result := parameter * my_variable;
        --   RETURN result;
    END function_name;

    -- Additional procedures and functions can be declared here

BEGIN
    -- Initialization code
    -- This is executed once when the package is first loaded into memory
    -- For example:
    --   my_variable := 20;
    
    -- Additional initialization code can be written here

EXCEPTION
    -- Exception handling code
    -- This section handles any exceptions that may occur within the package body
    -- For example:
    --   WHEN OTHERS THEN
    --       DBMS_OUTPUT.PUT_LINE('An error occurred: ' || SQLERRM);

END package_name;
/

Explanation:

• The “CREATE OR REPLACE PACKAGE BODY” statement is used to the create or replace the PL/SQL package body. When the body of the PL/SQL package is already exists, the “OR REPLACE” clause is replaced with the another new definition.
• The “package_name” is nothing but, it is the name of the package which is defined in the body.
• The “PROCEDURE”s and “FUNCTION”s are the subprograms in the body of the package. Procedures are used to perform some specific tasks such as, In functions returning the single value.
• The “DECLARE” section is used to declare the variables, constants, types, cursors and etc.
• The “BEGIN” and “END” keywords are indicate the beginning and end of the execution sections in the functions, procedures, and the whole body of the package.
• The “EXCEPTION” section is used to handle the exceptions, it can be occurred the while during the execution of body of the package.
• The “DBMS_OUTPUT.PUT_LINE” is the built-in procedure in the Oracle database. It used to display the messages to the users.
• If we want to terminate the body of the package, we must use forward slash ‘ / ‘ in a new line. It indicates the end of the SQL statement.

Note: This is the basic template of PL/SQL package body. If we want more functions, procedures and logics we can defiantly add the more procedures, functions, and logics which is used to our requirements.

A PL/SQL package body serves as an important component in developing modular and maintainable code within the Oracle database environment. It complements the package specification by providing the implementation details for procedures, functions, and other constructs declared in the package.

The package body organizes and modularizes code, hides data, and manages dependencies effectively. In this article, We will explore What is a Package Body, How to create a Package body, How to compile a Package Body along with real-life examples, and so on.