1. PL/SQL (Embedded SQL) Introduction Benefits Basic Constructs
Anonymous blocks
Procedures
Functions
Packages
Triggers
Cursors
Dynamic SQL

2. Introduction Embedded SQL (PL/SQL, JAVA/ VB & DB)
Database Server Level Programming (PL/SQL, Transact-SQL, IBM DB2-Cobol, ProC, ProCobol)
Database Client Programming
Developer 9i, JDeveloper 9i, Java (J2EE), VB, .Net

3. - Benefits
More powerful than pure SQL because it combines the power of SQL and
Iteration (loops)
Selection (Ifs)
Cursors
Block Structures
Stored Procedures
etc.

4. - Basic Constructs Basic Structure Running a program Variables
SELECT INTO
Comments
IFs
LOOPs
Output

5. -- Basic Structure
DECLARE
BEGIN
EXCEPTION
END;

6. - OUTPUT … SET SERVEROUTPUT ON; BEGIN
DBMS_OUTPUT.PUT_LINE('This is my fist program');
END; /
Before executing code that contains DBMS_OUTPUT.PUT_LINE,
must run (in a current session) at SQL prompt: set serveroutput on

7. --- Basic Structure: Example
DECLARE
v_id INTEGER;
v_empno NUMBER;
BEGIN
v_id := ;
SELECT EMPNO
INTO V_EMPNO
FROM EMP
WHERE empno = v_id;
DBMS_OUTPUT.PUT_LINE('Value is '||v_empno);
EXCEPTION
WHEN NO_DATA_FOUND THEN
DBMS_OUTPUT.PUT_LINE('No record exists');
END; /

8. --- Basic Structure: Example
DECLARE
v_id INTEGER;
BEGIN
v_id := ;
DELETE
FROM EMP
WHERE id = v_id;
END; /

9. -- Running a Program
DECLARE
BEGIN
EXCEPTION
END; /

10. -- Variables Common Data Types Declaration NUMBER DATE INTEGER
VARCHAR2
CHAR
BOOLEAN
Declaration
V_salary NUMBER(9,2);
V_id INTEGER;
V_dob DATE;
V_name VARCHAR2(35);
V_gender CHAR;
V_salary emp.salary%TYPE;

11. -- SELECT INTO DECLARE v_job emp.job%TYPE; v_sal emp.sal%TYPE;
v_empno emp.empno%TYPE;
BEGIN
v_empno := ;
SELECT job, sal
INTO v_job,v_sal
FROM emp
WHERE empno = v_empno;
END; /

12. -- Another Example declare v_ename emp.ename%TYPE; v_sal emp.sal%TYPE;
begin
select ename, sal
into v_ename, v_sal
from emp
where empno = '7844';
DBMS_OUTPUT.PUT_LINE('solution is:'||v_ename||'---'||v_sal);
exception
When others then
DBMS_OUTPUT.PUT_LINE('no record');
end; /
Before executing code that contains DBMS_OUTPUT.PUT_LINE,
must run at SQL prompt: set serveroutput on

13. -- Comments DECLARE /* This block will do so and so and so. */
v_job emp.job%TYPE;
v_sal emp.sal%TYPE;
v_empno emp.empno%TYPE;
BEGIN
v_empno := ; -- The use of this sentence is so and so.
-- The following SELECT INTO statement will do so and so.
SELECT job, sal
INTO v_job,v_sal
FROM emp
WHERE empno = v_empno;
END; /

14. -- IFs
IF – END IF
IF – ELSE – END IF
IF – ELSIF – ELSE – END IF

15. --- IF – END IF DECLARE … BEGIN v_commison := 7500;
IF v_dept = 10 THEN
v_commision := 5000;
END IF;
END; /

16. --- IF – ELSE – END IF DECLARE … BEGIN IF v_dept = 10 THEN
v_commision := 5000;
ELSE
v_commision := 7500;
END IF;
END; /

17. --- IF – ELSIF – ELSE – END IF
DECLARE …
BEGIN
IF v_dept = 10 THEN
v_commision := 5000;
ELSIF v_dept = 20 THEN
v_commison := 5500;
ELSIF v_dept = 30 THEN
v_commison := 6200;
ELSE
v_commision := 7500;
END IF;
END; /

18. -- LOOPs LOOP – EXIT WHEN – END LOOP FOR – LOOP – END LOOP
WHILE – LOOP – END LOOP

19. --- LOOP – EXIT WHEN – END LOOP
DECLARE …
v_deptno dept.deptno%TYPE := 50;
v_counter integer := 1;
BEGIN
LOOP
INSERT INTO dept(deptno)
VALUES(v_deptno);
v_counter := v_counter + 1;
v_deptno := v_deptno + 10;
EXIT WHEN v_counter > 5;
END LOOP;
END; /

20. --- FOR – LOOP - END LOOP DECLARE … v_deptno dept.deptno%TYPE := 50;
v_counter integer;
BEGIN
FOR v_counter IN 1..5 LOOP
INSERT INTO dept(deptno)
VALUES(v_deptno);
v_deptno := v_deptno + 10;
END LOOP;
END; /

21. --- WHILE – LOOP - END LOOP
DECLARE …
v_deptno dept.deptno%TYPE := 50;
v_counter integer;
BEGIN
v_counter := 1;
WHILE v_counter <= 5 LOOP
INSERT INTO dept(deptno)
VALUES(v_deptno);
v_deptno := v_deptno + 10;
END LOOP;
END; /

22. … - OUTPUT SET SERVEROUTPUT ON; DECLARE v_sum_sal emp.sal%TYPE;
v_deptno emp.deptno%TYPE := 10;
BEGIN
SELECT SUM(sal)
INTO v_sum_sal
FROM emp
WHERE deptno = v_deptno;
DBMS_OUTPUT.PUT_LINE('The sum is ‘ || TO_CHAR(v_sum_sal));
END; /

23. - Anonymous Block DECLARE v_id INTEGER; BEGIN v_id := 1234567; DELETE
FROM EMP
WHERE id = v_id;
EXCEPTION
WHEN NO_DATA_FOUND THEN
DBMS_OUTPUT.PUT_LINE('No record exists');
END; /

24. -- Nesting Anonymous Blocks

25. Exceptions Examples are NO_DATA_FOUND OTHERS
To display details of oracle standard error message
EXCEPTION
WHEN OTHERS THEN
DBMS_OUTPUT.PUT_LINE(‘Error detail is: ‘||SQLERRM)

26. - Procedure Is a block with a name The DECLARE key word is not used
Parameters can be IN
OUT
IN OUT
Is stored (USER_SOURCE)

27. -- Creating or Replacing a Procedure …
CREATE OR REPLACE PROCEDURE pname( ) IS
BEGIN
EXCEPTION
END; /

28. … -- Creating or Replacing a Procedure
SET SERVEROUTPUT ON;
CREATE OR REPLACE PROCEDURE proc_test(p_empno IN VARCHAR2) IS
v_job EMP.job%TYPE;
v_sal EMP.sal%TYPE;
BEGIN
SELECT job, sal
INTO v_job,v_sal
FROM emp
WHERE empno = p_empno;
DBMS_OUTPUT.PUT_LINE('job is '||v_job);
EXCEPTION
WHEN OTHERS THEN
DBMS_OUTPUT.PUT_LINE('ERROR...');
END; /
SQL> Show errors
SQL> execute proc_test(5893);

29. -- Invoking a Procedure
DECLARE …
BEGIN
proc_test(’23’);
END; / Or
SQL> exec proc_test(‘1123’)

30. Another Example SQL> ed Wrote file afiedt.buf
1 create or replace procedure test_proc is
v_id INTEGER;
v_empno emp.empno%TYPE;
4 BEGIN
v_id := ;
select empno into v_empno
FROM EMP
WHERE empno = v_id;
9 EXCEPTION
WHEN NO_DATA_FOUND THEN
DBMS_OUTPUT.PUT_LINE('No record exists');
12* END;
SQL> /
Procedure created.
SQL> exec test_proc
No record exists
PL/SQL procedure successfully completed.
SQL> show errors (to see errors for procedures, functions)

31. - Function Is a block with a name Returns one value only.
The DECLARE key word is not used
Parameters can only be IN
Is stored

32. -- Creating or Replacing a Function …
CREATE OR REPLACE FUNCTION fname( )
RETURN datatype IS
BEGIN
EXECPTION
END; /

33. … -- Creating or Replacing a Function
CREATE OR REPLACE FUNCTION sum_dept_sal(p_deptno IN NUMBER)
RETURN emp.sal%TYPE IS
v_sum_sal emp.sal%TYPE;
BEGIN
SELECT SUM(sal)
INTO v_sum_sal
FROM emp
WHERE deptno = p_deptno;
RETURN v_sum_sal;
END; /

34. -- Invoking a Function SET SERVEROUTPUT ON; DECLARE …
v_sal emp.sal%TYPE;
BEGIN
v_sal := sum_dept_sal(10);
DBMS_OUTPUT.PUT_LINE(TO_CHAR(v_sal));
END; /

35. Example, passing parameters

36. Exercise
Write down a procedure that displays all records (all columns) from EMP table. Make sure program should restricted to fix number of records of this table. Display Date and TIME portions of column that has data type DATE.
Write down a procedure that can insert large number of records entered at the time of its execution. You can use EMP table and appending counter with some columns’ values

37. - Packages Package Invoking Package subprogram Package Specification
Package Body
Invoking Package subprogram

38. -- Package Specification
CREATE OR REPLACE PACKAGE emp_info is
v_count INTEGER;
PROCEDURE insert_record( p_empno IN NUMBER
, p_ename IN VARCHAR2
, p_job IN VARCHAR2
, p_sal IN NUMBER
, p_comm IN NUMBER
, p_deptno IN VARCHAR2);
PROCEDURE delete_record(p_empno IN NUMBER);
FUNCTION sum_dept_sal( p_deptno IN dept.deptno%TYPE) RETURN is dept.sal%TYPE;
END emp_info; /

39. -- Package Body CREATE OR REPLACE PACKAGE BODY emp_info is`
PROCEDURE insert_record(p_empno IN NUMBER,p_ename IN VARCHAR2,
p_job IN VARCHAR2,p_sal IN NUMBER,
p_comm IN NUMBER,p_deptno IN VARCHAR2) IS
BEGIN
INSERT INTO EMP(empno,ename,job,sal,comm,deptno)
VALUES(p_empno,p_ename,p_job,p_sal,p_comm,p_deptno);
END insert_record;
PROCEDURE delete_record(p_empno IN NUMBER) IS
DELETE FROM EMP
WHERE empno=p_empno;
END delete_record;
FUNCTION sum_dept_sal(p_deptno IN NUMBER) RETURN emp.sal%TYPE IS
v_sum_sal emp.sal%TYPE;
SELECT SUM(sal)
INTO v_sum_sal
FROM emp
WHERE deptno = p_deptno;
RETURN v_sum_sal;
END;
END emp_info; --end of package body /

40. -- Invoking Package Subprogram
DECLARE
v_sum_sal emp.sal%TYPE;
BEGIN …
v_sum_sal := emp_info.sum_dept_sal(10);
emp_info.delete_record( );
END; / Or
SQL> exec emp_info.insert_record(…,…)

41. - Triggers Is a stored subprogram associated with a table.
Are fired by an event
Are mainly used for
Security
Enforce complex integrity constraint
Prevent invalid transaction
Event logging

42. -- Creating or Replacing Triggers
CREATE OR REPLACE TRIGGER del_emp( p_empno emp.empno%TYPE)
BEFORE DELETE ON emp
FOR EACH ROW
BEGIN
INSERT INTO emp_audit
VALUES(p_empno, USER, sysdate);
END; /

43. … -- Trigger with function usage Example

44. … --Exercise Write a trigger for the following:
When a record is added or deleted from an employee table, DEPT.NoOfEmp column gets updated accordingly to number of employees in EMP table corresponding to department number.

45. - Cursors … Is a pointer to a row.
Its is mainly used with tables which return more than one row.
It is handled implicitly and explicitly.

46. … - Cusrors … CURSOR c_emp IS SELECT empno, ename, job FROM emp
WHERE deptno = 20;
Smith Clerk
Jones Manager current row
SCOTT Analyst
Adams Clerk
FORD Analyst

47. … - Cursors DECLARE CURSOR c_emp IS SELECT empno, ename, job FROM emp
WHERE deptno = 20;
BEGIN
FOR v_c IN c_emp LOOP …
DBMS_OUTPUT.PUT_LINE(v_c.ename);
END LOOP;
end; /

48. - Example
Given a table with first three columns are composite keys. Write a PL/SQL program using cursor to update cat_template1 with LONG column cat_template. Assuming this tables contains more than 40,000 records.

49. … - Example’s solution

50. Dynamic SQL begin execute immediate 'create table tt(id number(3))';
end; /