Packages in PL/SQL group logically related types, variables, and subprograms. A package has a specification and body. The specification declares public objects available outside the package. The body defines private objects and code for methods in the specification. Public package elements can be called using package_name.element_name. Packages allow organizing program logic and controlling access.

1. PL/SQL Packages

2. Packages
•Packages are schema objects that groups
logically related PL/SQL types, variables, and
subprograms.
•A package will have two mandatory parts −
•Package specification
•Package body or definition

3. PL/SQL PACKAGES

4. Package Specification
• The specification is the interface to the package. It just DECLARES the
types, variables, constants, exceptions, cursors, and subprograms that
can b
• All objects placed in the specification are called public objects. Any
subprogram not in the package specification but coded in the package
body is called a private object. e referenced from outside the package.

5. Package Body
• The package body has the codes for various methods declared in the
package specification and other private declarations, which are
hidden from the code outside the package.

6. Referring Package Elements
• All the public elements of the package can be referred by calling the
package name followed by the element name separated by period i.e.
'<package_name>.<element_name>'.

7. For Example: package specification
CREATE PACKAGE emp_bonus
AS
PROCEDURE calc_bonus (date_hired employees.hire_date%TYPE);
END emp_bonus;
/

8. Package Body
CREATE PACKAGE BODY emp_bonus
AS
PROCEDURE calc_bonus (date_hired employees.hire_date%TYPE)
IS
BEGIN
DBMS_OUTPUT.PUT_LINE('Employees hired on ' || date_hired || ' get bonus.');
END;
END emp_bonus;
/

9. PL/SQL block
SQL> Declare
hire_dt employees.hire_date%TYPE:=&hire_dt;
Begin
emp_bonus.calc_bonus(hire_dt);
End;
/

10. Example 2:
CREATE PACKAGE cust_sal AS
PROCEDURE find_sal(c_id customers.id%type);
END cust_sal;
/ CREATE OR REPLACE PACKAGE BODY cust_sal AS
PROCEDURE find_sal(c_id customers.id%TYPE) IS
c_sal customers.salary%TYPE;
BEGIN
SELECT salary INTO c_sal
FROM customers
WHERE id = c_id;
dbms_output.put_line('Salary: '|| c_sal);
END find_sal;
END cust_sal;
/

11. Calling in PLSQL Block
DECLARE
code customers.id%type := &cc_id;
BEGIN
cust_sal.find_sal(code);
END;
/
OUTPUT:
Enter value for cc_id: 1
Salary: 3000
PL/SQL procedure successfully completed.

12. For Example 3
CREATE OR REPLACE PACKAGE personnel AS
-- get employee's fullname
FUNCTION get_fullname(n_emp_id NUMBER)
RETURN VARCHAR2;
-- get employee's salary
FUNCTION get_salary(n_emp_id NUMBER)
RETURN NUMBER;
END personnel;

13. CREATE OR REPLACE PACKAGE BODY personnel AS
-- get employee's fullname
FUNCTION get_fullname(n_emp_id NUMBER) RETURN VARCHAR2 IS
v_fullname VARCHAR2(46);
BEGIN
SELECT first_name || ',' || last_name
INTO v_fullname
FROM employees
WHERE employee_id = n_emp_id;
RETURN v_fullname;
EXCEPTION
WHEN NO_DATA_FOUND THEN
RETURN NULL;
WHEN TOO_MANY_ROWS THEN
RETURN NULL;
END;

14. -- get salary
FUNCTION get_salary(n_emp_id NUMBER) RETURN NUMBER IS
n_salary NUMBER(8,2);
BEGIN
SELECT salary
INTO n_salary
FROM employees
WHERE employee_id = n_emp_id;
RETURN n_salary;
EXCEPTION
WHEN NO_DATA_FOUND THEN
RETURN NULL;
WHEN TOO_MANY_ROWS THEN
RETURN NULL;
END;
END personnel;

15. SET SERVEROUTPUT
DECLARE
n_salary NUMBER(8,2);
v_name VARCHAR2(46);
n_emp_id NUMBER := &emp_id;
BEGIN
v_name := personnel.get_fullname(n_emp_id);
n_salary := personnel.get_salary(n_emp_id);
IF v_name IS NOT NULL AND n_salary IS NOT NULL
THEN
dbms_output.put_line('Employee: ' || v_name);
dbms_output.put_line('Salary:' || n_salary);
END IF;
END;

16. CREATE OR REPLACE PACKAGE c_package
AS
PROCEDURE addCustomer(c_id customers.id%type,
c_name customerS.Name%type,
c_age customers.age%type,
c_addr customers.address%type,
c_sal customers.salary%type);
PROCEDURE delCustomer(c_id customers.id%TYPE);
PROCEDURE listCustomer;
END c_package; /

17. CREATE OR REPLACE PACKAGE BODY c_package
AS
PROCEDURE addCustomer(c_id customers.id%type,
c_name customer.name%type,
c_age customers.age%type,
c_addr customers.address%type,
c_sal customers.salary%type)
IS
BEGIN
INSERT INTO customers (id,name,age,address,salary)
VALUES(c_id, c_name, c_age, c_addr, c_sal);
END addCustomer;
PROCEDURE delCustomer(c_id customers.id%type)
IS
BEGIN DELETE FROM customers WHERE id = c_id;
END delCustomer;

18. PROCEDURE listCustomer
IS
CURSOR c_customers is SELECT name FROM customers;
TYPE c_list is TABLE OF customerS.No.ame%type;
name_list c_list := c_list();
counter integer :=0;
BEGIN
FOR n IN c_customers
LOOP
counter := counter +1;
name_list.extend; name_list(counter) := n.name;
dbms_output.put_line('Customer(' ||counter|| ')'||name_list(counter));
END LOOP;
END listCustomer;
END c_package;
/

19. PL/SQL Block
DECLARE
code customers.id%type:= 8;
BEGIN
c_package.addcustomer(7, 'Rajnish', 25, 'Chennai', 3500);
c_package.addcustomer(8, 'Subham', 32, 'Delhi', 7500);
c_package.listcustomer;
c_package.delcustomer(code);
c_package.listcustomer;
END;
/