plsql notes new-1

7/28/2019 Plsql Notes New-1

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PLSQL NOTES

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PLSQL NOTES

INDEX

VARIABLE DECLARATION . . . . . . . . 05 CONTROL STATEMENTS . . . . . . . . . 18. COMPOSITE VARIABLES . . . . . . . . 26

EXPLICIT CURSORS . . . . . . . . . . 31 EXCEPTIONS . . . . . . . . . . . . . 43 PROCEDURES . . . . . . . . . . . . . 52 FUNCTIONS . . . . . . . . . . . . . 55 PACKAGES . . . . . . . . . . . . . . 58 ORACLE PACKAGES . . . . . . . . . . 67 DYNAMIC SQL . . . . . . . . . . . . 75 TRIGGERS . . . . . . . . . . . . . . 77

PLSQL NOTES



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Server Connection



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Important Instructions

Each student has his own unix login id to server. Use ssh -l command to login to server.e.g. ssh -l nagnath 172.24.8.60

in above case nagnath is unix id. Default password is xxxxxx for all students. Change password usingpasswdcommand after first

login.

After login in server, set database name in ORACLE_SID

variable.

e.g. export ORACLE_SID=DB11G

in above case DB11G is database name. Conncet to database using your oracle sql login name

and password.

e.g. sqlplus nagnath/nagnath

In above case username is nagnath and password is also

nagnath.

For each student oracle login id and password will be

his name.

Connect to oracle from where you are

writing your

plsql programs.

e.g.[nagnath@server1 ~]$ cd plsql/

[nagnath@server1 ~]$ sqlplus nagnath/nagnath



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PLSQLENGINE


PLSQL BLOCK

PLSQL ENGINE

PL/SQL

BLOCK

PROCEDURAL

STATEMENT

EXECUTION

SQL ENGINE

SQL statement executor


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VARIABLE DECLARATION



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DATA DICTIONARY VIEWS

USER_OBJECTS

USER_TABLE USER_VIEW USER_INDEX USER_SEQUENCE USER_SOURCE USER_CONSTRAINTS


DBA_TABLES

All tables in the entire database. Reserved

for user accounts that have dba privileges

ALL_TABLES

All tables owned by a user plus all

tables to which the user has been

granted access.

USER_TABLES

All tables owned by a particular database

user.


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Types of variables

CHAR [(maximum length)]

VARCHAR2 (maximum length)

LONG

NUMBER [(precision , scale)]

BINARY INTEGER

PLS_INTEGER

BOOLEAN

BINARY INTEGER:-

Base type for integer between -2,147,483,647 and 2,147,483,647

PLS_INTEGER :-

Base type for signed integers between -

2,147,483,647 and 2,147,483,647.PLS_INTEGER values require

less storage and are faster than NUMBER and BINARY_INTEGER

values

BOOLEAN :-

Base type that stores one of three

possible values used for logical

calculations:TRUE,FALSE,NULL



10/86

This is the first program in plsql to print hello

world.

create or replace procedure sp11

as

-- First Program of Plsql-- This Program Prints-- Hello World on the Screenbegin

dbms_output.put_line('Hello World');

end;

To Compile Stored Procedures Type @file name/procedure name.sql on SQL Prompt To see the output on sql prompt type command

set serveroutput on when you are logged in.

TO Execute Stored Procedures Type exec procedure_name

--OUTPUT

SQL> @sp11.sql

Procedure

created.

No errors.

SQL> exec sp11

Hello Word

PL/SQL procedure successfully completed.



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PLSQL NOTES

This program shows how to check errors in procedures.

create or replace procedure sp11_1

as

--This Program shows how to Read Errors

begin

dbms_output.put_line('Hello World')

--Semi colon missing at the end

end;

/

To See Errors Type 'show errors' on SQL prompt You can write 'show errors' at the end of procedure.

OUTPUTSQL> @sp11_1.sql

Warning: Procedure created with compilation errors.SQL> show errors

Errors for PROCEDURE SP11_1:

LINE/COL ERROR

-----------------------------------------------------------------

7/1 PLS-00103: Encountered the symbol

"END" when expecting

one of the following:

:= . ( % ;

The symbol ";" was substituted

for "END" to continue.



12/86

Variable declaration and assigning value to

variables.


--This Program Shows How to declare variables, assign values

and constants.

as

v_myname

CHAR(50);

v_myage NUMBER(2) NOT NULL := 21;

v_mycity VARCHAR2(13) := Pune;

v_salary CONSTANT NUMBER := 1400;

begin

v_myname := Nagnath;

dbms_output.put_line('My Name is '||v_myname);

dbms_output.put_line('My Age is '||v_myage);

end;

/

show errors

OUTPUT:

SQL> @sp12.sqlProcedure created.

No errors.

SQL> exec sp12

My Name is Nagnath

My Age is 21

PL/SQL procedure successfully completed



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Passing value to variables.

create or replace procedure sp13(l_name

varchar2,l_age number default 100)

--This Program shows how to

--Pass Values to procedures

--Accept values in variable

--without specifying its

--length

as

begindbms_output.put_line('Name Entered By User: '||l_name);

dbms_output.put_line('Age Entered By User: '||l_age);

end;

/

show errors

OUTPUT:SQL> @sp13.sql

Procedure created.

No errors.SQL> exec sp13('nagnath',21);

Name Entered By User: nagnath

Age Entered By User: 21




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Selecting values from database tables.


--This Programs Shows how to

--Execute SQL quries from plsql

as

l_employee_id Number := 100;

l_employee_name varchar2(30);

begin

select last_nameinto l_employee_name

from Employees

where employee_id = l_employee_id;

--into clause copies selected column's value

--into given variables

dbms_output.put_line('Employees Name is: '||

l_employee_name);

end;

/show errors

OUTPUT

SQL> @sp13_1.sql

Procedure created.

No errors.

SQL> exec sp13_1

Employees Name is: King




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Use of %type variable.

create or replace procedure sp15(l_employee_id number)

--This Program shows

--how to use variables with same data type from tables

--Objective

--Accept EmployeeID From User

--Print Name of That Employee

as

l_last_name employees.last_name%type;

begin

select last_name into

l_last_name from

employees


dbms_output.put_line('Name of Employee is: '||l_last_name);

end;

/

show errors

SQL> @sp15

Procedure created.

No errors.

SQL> set serveroutput onSQL> exec sp15(200);

Name of Employee is: Whalen




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Use of %type variable

create or replace procedure sp14--This Program shows

--how to declare Variables With %Type Attribute

--Means Same Data Type as in Table

as


--In this case data type of

--l_last_name is same as

--data type of column last_name from employees

begin

select last_name

into l_last_name

from employees

where employee_id = 101;

dbms_output.put_line(l_last_name);

end;

/

show errors

OUTPUT:

SQL> @sp14.sql

Procedure created.

No errors.

SQL> exec sp14

Kochhar




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PLSQL NOTES

Composite Variable:Records


--This program shows how to

--create composite data types

--First Composite data type is record

as

TYPE emp_sal_record is RECORD

(last_name varchar2(20),

salary number(10));

emp_sal emp_sal_record;

--emp_sal_record can store

--last_name and salary of employee

--in single variable

begin

select last_name,salary

into emp_sal

from employees


dbms_output.put_line('Employee Name: '||emp_sal.last_name);

dbms_output.put_line('Employees Salary: '||emp_sal.salary);end;

/

show errors

Composite Data type Records stores more than one data type undersingle record.

OUTPUT:

SQL> @sp31.sql

Procedure created.

No errors.

SQL> set serveroutput on

SQL> exec sp31

Employee Name: King

Employees Salary: 24000




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PLSQL NOTES

Composite Data type:%rowtype


--This program shows how to

--create composite data types

--Second composite data type is %rowtype

as

emp_record employees%rowtype;

--emp_record stores

--all values of all columns

--from employees table

begin select *

into emp_record

from employees


dbms_output.put_line('Name: '||emp_record.last_name);

dbms_output.put_line('Department Id: '||

emp_record.department_id);

end;/

show errors

%rowtype variable is used to store all column data types insingle variable.

OUTPUT:

SQL> @sp32.sql

Procedure created.

No errors.


SQL> exec sp32

Name: King

Department Id: 90




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Scope of variables in procedure.


--This Program shows--Scope Of Variable in Stored Procedure

as

l_no number := 600;

l_msg varchar2(20) := 'Global Variable';

Begin

declare

l_no Number := 1;

l_msg varchar2(20) := 'Local variable';

begin

l_no := l_no +1;dbms_output.put_line('In Inner Block1');

dbms_output.put_line(l_no);

dbms_output.put_line(l_msg);

end;

Declare

l_no number :=100;

Begin

dbms_output.put_line('In Inner Block2');


dbms_output.put_line(sp16.l_msg);end;

dbms_output.put_line('In Main');


dbms_output.put_line(l_msg);

end;

/

show errors

Variables declared in main procedure (Outermost variable) areglobal variables.

Global variables can be accessable in all inner procedures. Inner procedures can define their own variables with same name

as global variable and access.

But it is not good programing practice.



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OUTPUT

SQL> @sp16.sql

Procedure created.

No errors.

SQL> exec sp16

In Inner

Block2 2

Local Variable

In Inner

Block2 100

Global

Variable In

Inner Main 600

Global Variable

PL/SQL procedure successfully completed



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DML Statements in Procedure


--This Programs shows

--Executing DML statement in Plsql

as

begin

--Inserting Data From Plsql Procedure

insert into test(test_id,test_name)

values(1,'sql');

insert into test(test_id,test_name)

values(2,'plsql');

--Updating Data From Plsql Procedureupdate test

set test_id = 20

where test_id = 2;

--Deleting Data From Plsql Procedure

delete from test

where test_id = 20;

commit;

end;

/

show errors

--OUTPUT

create table test(test_id number,test_name varchar2(10));

Table created.

SQL> @sp17.sql

Procedure created.

No errors.

SQL> exec sp17


SQL> select * from test;

TEST_ID TEST_NAME

---------- ----------

1 sql



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CONTROL STATEMENTS


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Control Statement : If -Else Condition

create or replaceprocedure sp21(p_employee_id in number)

as

This procedure will give a salary raise

-- to an employee. Rules for the raise are as follows-- 1. 20% for Employees working with us for at least 12 years-- and whose salary is less than Rs. 6000/--- 2. 15% for Employees whose salary less than Rs. 6000/--- 3. 10% for employees working with us for at least 12 yearsl_hire_date employees.hire_date%type;

l_salary employees.salary%type;l_years_of_service number := 0;

l_new_salary number := 0;

begin

select hire_date,

salary

into l_hire_date,

l_salary

from employees

where employee_id = p_employee_id;

l_years_of_service := months_between(sysdate, l_hire_date)/12;

if l_salary < 6000 and l_years_of_service > 12 then

l_new_salary := l_salary * 1.2;

dbms_output.put_line('Giving 20% raise');

elsif l_salary < 6000 then



elsif l_years_of_service > 12 then



else



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l_new_salary := l_salary;

dbms_output.put_line('No salary raise ');

end if;

update employees

set salary = l_new_salary

where employee_id = p_employee_id;

commit;

end;

/

show errors

IF condition THEN

statements;

[ELSIF condition THEN

statements;]

[ELSE

statements;]

END IF;



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OUTPUT

SQL> @sp21.sql

Procedure created.No errors.

SQL> select salary from employees where employee_id=101;

SALARY

----------

17000

SQL> exec sp21(101);

Giving 10% raise


SQL> select salary from employees where employee_id=101;

SALARY

----------18700



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PLSQL NOTES

Control Statement : Case

create or replace procedure sp22(p_grade in varchar2)

as

-- Case Statement-----------------

--CASE selector

-- WHEN expression1 THEN result1-- WHEN expression2 THEN result2-- ...-- WHEN expressionN THEN resultN-- [ELSE resultN+1;]--END;--A CASE expression selects a result and returns it

l_appraisal varchar2(100);

begin

l_appraisal := CASE p_grade

WHEN 'A' THEN 'Excellent'

WHEN 'B' THEN 'Very Good'

WHEN 'C' THEN 'Good'ELSE 'No such grade'

END;

DBMS_OUTPUT.PUT_LINE ('Grade: '|| p_grade ||

' Appraisal ' || l_appraisal);

end;

/

show errors

OUTPUT

SQL> @sp22.sql

Procedure created.

No errors.

SQL> exec sp22('C');

Grade: C Appraisal Good




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PLSQL NOTES

Control Statements : Basic Loop

create or replace procedure sp23 ( p_loop_counter in number)

as

-- Basic Loop construct

------------------------

--LOOP

-- statement1;

-- ...

-- EXIT [WHEN condition ];

--END LOOP;

--Use the basic loop when the statements inside the-- loop must execute at least once.

i number;

Begin

i := 1;

loop

dbms_output.put_line(to_char(i) );

exit when i >= p_loop_counter;

i := i +

1; end loop;

end;/

show errors

Basic loop perform repetative actions. Programer can use exit condition to terminate the loop.

OUTPUT

SQL> @sp23.sql


SQL> exec sp23(5);

1 2 3 4 5




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PLSQL NOTES

Control Statement : While Loop

create or replace procedure sp24 ( p_loop_counter in number)

as

-- While Loop construct

------------------------

--WHILE condition LOOP

-- statement1;

-- statement2;

-- ...

--END LOOP;

-- Use the WHILE loop if the condition has to be-- evaluated at the start of each iteration.i number;

begin

i := 1;

while i @sp24.sql

Procedure created.

No errors.

SQL> exec sp24(5);

1 2 3 4 5




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PLSQL NOTES

Control Statement : For Loop

create or replace procedure sp25( p_loop_counter in number)

as

-- For Loop construct

------------------------

--FOR counter IN [REVERSE]

-- lower_bound..upper_bound LOOP

-- ...--END LOOP;

-- Use a FOR loop if the number of iterations is known.i number;

begin-- Naming a loop is optional

for i in

1..p_loop_counter loop

sp5(to_char(i) , 2);

end loop my_for_loop;

dbms_output.put_line('------------------------');

-- now the reverse for loop

for i in reverse 1..p_loop_counter

loop

dbms_output.put_line(to_char(i) );end loop;

end;

/

show errors

OUTPUT

SQL> @sp25.sql

Procedure created.

No errors.

SQL> exec sp25(3);

1 2 3

------------------------

3

2

1




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PLSQL NOTES

Infinite Loop


as

-- How to write an infinite loop

begin

while (999 = 999)

loop

dbms_output.put_line('Hi');

end loop;

while ( true)

loop

dbms_output.put_line('Hi');

end loop;

end;

/

show errors

As programer did not mentioned exit condition, Proram will repeat printing infinitelly. This is bad programming.



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PLSQL NOTES

EXPLICIT CURSORS

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PLSQL NOTES

Explicit Cursors Attribute

%ISOPEN AttributeA cursor attribute that can be appended to the name of a cursor or

cursor variable. If a cursor is open, cursor_name%ISOPEN returns

TRUE; otherwise, it returns FALSE.

%NOTFOUND AttributeA cursor attribute that can be appended to the name of a cursor or

cursor variable. Before the first fetch from an open cursor,

cursor_name%NOTFOUND returns NULL. Thereafter, it returns FALSE if

the last fetch returned a row, or TRUE if the last fetch failed to

return a row.

%ROWCOUNT AttributeA cursor attribute that can be appended to the name of a cursor or

cursor variable. When a cursor is opened, %ROWCOUNT is zeroed. Before

the first fetch, cursor_name%ROWCOUNT returns 0. Thereafter, itreturns the number of rows fetched so far. The number is incremented

if the latest fetch returned a row.



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Explicit Cursors



--How to write explicit

cursor --How to open cursor

--How to fetch data from cursor

--How to close cursor

as

cursor c1 is select last_name,salary

from employees

where department_id = 20;

--Declaration of cursor

l_emp_name employees.last_name%type;

l_sal employees.salary%type;begin

open c1;

--Opening of a Cursor

loop

fetch c1 into l_emp_name,l_sal;

exit when c1%notfound;

--Fetching Data from Cursor

dbms_output.put_line(l_emp_name||'

'||to_char(l_sal));

end loop;

close c1;--Closing of Cursor

end;

/

show errors

For every SQL statement execution, certain area in memory isallocated.

Programer can give name to that area and as known as cursor. Using cursor, fetched rows can be process one by one.



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PLSQL NOTES

OUTPUT

SQL> !vi sp61.sqlSQL> @sp61.sql

Procedure created.

No errors.

SQL> exec sp61

Hartstein

13000 Fay 6000




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PLSQL NOTES

Explicit cursor : Fetching Data into records



--How to fetch data from cursor into records

as

cursor c1 is select *

from employees

where department_id=50;

--Cursor Declaration

rec_c1 c1%rowtype;

--Record Declarationbegin

open c1;

loop

fetch c1 into rec_c1;


--Fetching Data from cursor into record

dbms_output.put_line('Name: '||

rec_c1.last_name);

dbms_output.put_line('Salary: '||

rec_c1.salary);

end loop;close c1;

end;

/

show errors

OUTPUT

SQL> @sp62.sql

Procedure created.

No errors.

SQL> exec sp62

Name: Hartstein

Salary: 13000

Name: Fay

Salary: 6000




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PLSQL NOTES

Explicit Cursor : Use of For Loop



--Cursor For

as

cursor c1 is select *

from employees


begin

for rec_c1 in c1

loop -implicit opendbms_output.put_line('Name: '||rec_c1.last_name);

dbms_output.put_line('salary: '||

to_char(rec_c1.salary));

end loop;

end;

/

show errors

OUTPUT:

SQL> @sp63.sql

Procedure created.

No errors.

SQL> exec sp63

Name: Hartstein

salary:

Hartstein Name:

Fay salary: FayPL/SQL procedure successfully completed.



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PLSQL NOTES

Explicit Cursor : Subqueries


--Cursor for loop using subqueries

as

l_last_name

varchar2(30);

begin

for l_last_name in (select last_name from employees where

department_id=20) loop

dbms_output.put_line('Name: '|| l_last_name);

end loop;

end;

/

OUTPUT:

SQL> @sp64.sql


SQL> exec sp64

Name: Hartstein

Salary: 13000

Name: Fay

Salary: 6000




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PLSQL NOTES

Explicit Cursor : Passing parameters to cursors

create or replace procedure sp65(deptno number,job varchar2)


--How to pass parameters to cursor

as

cursor c1(l_deptno number,l_job varchar2) is

select employee_id,last_name

from employees

where department_id = l_deptno

and job_id = l_job;

rec_c1 c1%rowtype;

--Declaration of cursor

begin

for rec_c1 in c1(90,'AD_VP') loop

--Passing Paramenters to cursor

dbms_output.put_line('Depatment 80 '||' Job

id is SA_MAN');

dbms_output.put_line('Employee ID:'||

to_char(rec_c1.employee_id));dbms_output.put_line('Employee Name: '||

rec_c1.last_name);

end loop;

open c1(deptno,job);

--Passing Paramenters to cursor

loop



dbms_output.put_line(deptno||' Job id is '||

job);

dbms_output.put_line('Employee ID:'|| to_char(rec_c1.employee_id));

dbms_output.put_line('Employee Name: '||

rec_c1.last_name);

end loop;

close c1;

end;

/

show errors



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PLSQL NOTES

SQL> @sp65.sql

Procedure created.

No errors.

SQL> exec sp65(60,'IT_PROG');

Depatment 80 Job id is SA_MAN

Employee ID: 101

Employee Name: Kochhar

Depatment 80 Job id is SA_MAN

Employee ID: 102

Employee Name: De Haan

60 Job id is IT_PROG

Employee ID: 103

Employee Name: Hunold

60 Job id is IT_PROG

Employee ID: 104

Employee Name: Ernst




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PLSQL NOTES

Explicit Cursor : Update Clause



--The For Update Clause in cursor

as

cursor c1 is

select *

from employees

where department_id = 20 for

update of salary nowait;

rec_c1 c1%rowtype;l_new_sal number;

begin

dbms_output.put_line(rpad('Employee',10)||

rpad('Old Salary',10)||

rpad('New Salary',10));

open c1;

loop



if rec_c1.salary < 7000 then l_new_sal:= rec_c1.salary * 1.25;

update employees set salary = l_new_sal

where employee_id = rec_c1.employee_id;

else

l_new_sal := rec_c1.salary * 1.15;

update employees set salary = l_new_sal

where employee_id = rec_c1.employee_id;

end if;

dbms_output.put_line

(rpad(rec_c1.last_name,10)||

rpad(rec_c1.salary,10)||rpad(l_new_sal,10));

end loop;

close c1;

end;

/

show errors



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PLSQL NOTES

Programer can lock rows Before performing any update or delete using cursor. While cursor is open no one can access selected rows.

SQL> @sp66.sql

Procedure created.

No errors.

SQL> exec sp66

Employee Old SalaryNew Salary

Hartstein 19771.38 22737.087

Fay 9918.75 11406.5625




42/86

PLSQL NOTES

Explicit Cursor : Where current of clause



--The use of where current of clause

as

cursor c1 is

select employee_id,salary

from employees

where department_id = 20 for

update of salary nowait;

l_new_sal number; rec_c1c1%rowtype;

begin

dbms_output.put_line(rpad('Employee',10)||

rpad('Old Salary',10)||

rpad('New Salary',10));

open c1;

loop



if rec_c1.salary < 7000 thenl_new_sal := rec_c1.salary * 1.25;

update employees set salary =

l_new_sal

where current of c1;

else

l_new_sal := rec_c1.salary * 1.25;

update employees set salary =

l_new_sal

where current of c1;

end if;

end loop;close c1;

dbms_output.put_line(rpad(rec_c1.employee_id,10)||

rpad(rec_c1.salary,10)||

rpad(l_new_sal,10));

end;

/

show errors



43/86

PLSQL NOTES

Programer can update or delete only current row in cursor by defining 'where current of clause'

SQL> @sp67.sql Procedure created. No errors.

SQL> exec sp67

Employee Old SalaryNew Salary 202 11406.56 14258.2




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45/86

Implicit Cursors in Plsql


--This Program shows how to use

--Sql Cursor Attributes(Set by default by sql)

--SQL%ROWCOUNT

--SQL%FOUND

--SQL%NOTFOUND

--SQL%ISOPEN

as

begin

insert into test(test_id,test_name) values(3,'Red Hat');

if sql%found then

dbms_output.put_line('Row is inserted');

end if;

delete

from test;

dbms_output.put_line(sql%rowcount ||'

Rows are selected');

delete

from test;

if sql%notfound then

dbms_output.put_line('No row is deleted');

end if;

end;

/

show errors

Implicit cursors are implicitly define by oracle. They return information about result of query. SQL%ROWCOUNT returns number of rows affected by query. SQL%FOUND return true if atleast one row is affected by query. SQL%NOTFOUND return true if zero rows are affected by query.



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SQL> @sp18.sql Procedure created. No errors.

SQL> select * from test; TEST_ID TEST_NAME

---------- ----------

1 sql SQL> exec sp18 Row is inserted

2 Rows are selected No row is deleted




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PLSQL NOTES

EXCEPTIONS



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PLSQL NOTES

Exceptions: Predefined Exceptions



--How to handle Predefine exceptions

as


begin

select last_name

into l_last_name

from employees


dbms_output.put_line(l_last_name);

exception

when no_data_found then

--No_data_found is one of predefined exception

dbms_output.put_line('Employee Not exist');

end;

/

show errors



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PLSQL NOTES

Exception is a kind of error that turminates user's programexecution example 'divide by 0'.

Oracle has defined approximately 20 errors occur most often. Known as 'Predefine Exceptions'.

OUTPUT

SQL> @sp81.sql

Procedure created.

No errors.

SQL> exec sp82

Employee Not exist




50/86

PLSQL NOTES

Exceptions : Non Predefined Exceptions


--This program shows

--How to handle non predefine exceptions

as

duplicate_key exception;

PRAGMA EXCEPTION_INIT

(duplicate_key , -00001);

begin

insert into departments values(20,'New

Department',200,1800);

commit;

exception

when duplicate_key then dbms_output.put_line('Cannot

insert duplicate

department, department already exist');

end;

/

show errors

Non Predefine exceptions are defined by oracle server,but has no name.

Use Pragma exception to give name to respective exception.

SQL> @sp82.sql

Procedure created.

No errors.


SQL> exec sp82

Cannot insert duplicate department, department already exist




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PLSQL NOTES

Exceptions : Others


as

begin

delete from departments


exception when others then

dbms_output.put_line('In Exception');

dbms_output.put_line(SQLCODE||SQLERRM);end;

/

show errors

Exception Others is used when programer does not knowthe oracle number associated with error.

Programer can find error associated number and error messageusing SQLCODE , SQLERRM

OUTPUT

SQL> @sp83.sql

Procedure created.

No errors.

SQL> exec sp83

In Exception

-2292ORA-02292: integrity constraint (HR.EMP_DEPT_FK) violated -

child record

found




52/86

PLSQL NOTES

Exceptions : User Defined Exceptions


as


l_salary employees.salary%type;

l_new_sal float;

invalid_raise exception;

begin

select last_name,salaryinto l_last_name,l_salary

from employees


l_new_sal := l_salary * 1.20;

if l_new_sal > 2000 then

raise invalid_raise;

end if;

exception when invalid_raise then

dbms_output.put_line('Not Applicable Salary raise');

end;

/

show errors

Programer can introduce errors on certain conditions. Those errors are known as user define exception.

--OUTPUTSQL> @sp84.sqlProcedure created.

No errors.

SQL> exec sp84

Not Applicable Salary raise




53/86

PLSQL NOTES

Exceptions : Raise Application Errors


as


l_salary employees.salary%type; l_new_sal

float;

new_exception exception;

PRAGMA EXCEPTION_INIT(new_exception,-20999);

begin

select last_name,salary

into l_last_name,l_salaryfrom employees


l_new_sal := l_salary * 1.20;

if l_new_sal > 2000 then

raise_application_error(-20999,'This is not valid

salary increase');

end if;

exception when new_exception then

dbms_output.put_line('in exception');dbms_output.put_line(SQLCODE||SQLERRM);

end;

/

show errors

Programer can issue user define error messagesusing 'raise_application_error' procedure.

Progrmer can assign error code and error messagefor new exceptions.

Error code should be greater than 20,000.--OUTPUT

SQL> @sp85.sql

Procedure created.

No errors.

SQL> exec sp85

in exception

-20999ORA-20999: This is not valid salary increase




54/86

PLSQL NOTES

Exception : Flow through Procedures

create or replace procedure sp86(l_employee_id number)


--How exception handling passes from one procedure to other

as

l_salary number; l_last_name

varchar2(30);

begin

dbms_output.put_line('In outer Block');select salary

into l_salary

from employees


begin

dbms_output.put_line('In Inner Block');

select last_name

into l_last_namefrom employees;

end;

exception


dbms_output.put_line('No data found');

when too_many_rows then

dbms_output.put_line('too many rows');

end;/

show errors



55/86

PLSQL NOTES

OUTPUT

SQL> @sp86.sql

Procedure created.

No errors.


In outer Block

In Inner Block

too many rows



In outer Block

No data found




56/86

PLSQL NOTES

Most Occurring Errors

Select:ORA-01403 : no data found

ORA-00913 : too many values

ORA-00902 : invalid datatype

ORA-00903 : invalid table name

ORA-00904 : invalid column name

ORA-00905 : missing keywordORA-00253 : length num of specified archive string 'name'

exceeds limit of num

Insert:ORA-02259 : duplicate UNIQUE/PRIMARY KEY specifications

ORA-02260 : table can have only one primary keyORA-02273 : this unique/primary key is referenced by some

foreign keys

ORA-02252 : check constraint condition not properly ended

ORA-01400 : mandatory (NOT NULL) column is missing or NULL

during insert

ORA-01556 : maximum number of extents exceededDelete:

ORA-02273 : this unique/primary key is referenced by some

foreign keys



57/86

PLSQL NOTES

PROCEDURES



58/86

PLSQL NOTES

Procedures : IN , OUT parameters

create or replace procedure sp91(l_emp_id in number,

l_salary out number)


--How to use in,out parameter

as

begin

select salary

into l_salary

from Employees

where employee_id = l_emp_id;end;

/

show errors


as

salary number;

begin

sp91(100,salary);

--salary used as out parameter in sp91

dbms_output.put_line(salary);end;

/

show errors

In parameter used to pass value to procedure. Out parameter is used to pass value from parameter.

OUTPUT

SQL> @sp91.sql

Procedure created.

No errors.

SQL> @sp92.sql

Procedure created.

No errors.

SQL> exec sp92

24000




59/86

PLSQL NOTES

Procedures : IN OUT Parameters



--How to use inout parameter

as

p_phone_no varchar2(20);

begin

p_phone_no := '1234567890';

sp94(p_phone_no);

dbms_output.put_line(p_phone_no);

end;/

show errors


(p_phone_no IN OUT varchar2)

is

begin

p_phone_no := '(' || substr(p_phone_no,1,3) ||

')'||' '|| substr(p_phone_no,4,3) ||

'-' || substr(p_phone_no,7);end;

/

show errors

IN OUT parameter used to pass value to procedure and return somevalue in the same variable.

i.e. Programer need only 1 variable.OUTPUT

SQL> @sp94.sql

Procedure created.

No errors.

SQL> @sp93.sql

Procedure created.

No errors.

SQL> exec sp93

(123) 456-7890




60/86

PLSQL NOTES

FUNCTIONS



61/86

PLSQL NOTES

Functions

create or replace function get_dept_name(dept_no

departments.department_id%type)

return varchar2


--How to write user define functions

is

l_dept_name departments.department_name%type;

begin

select department_name

into l_dept_name

from Departments

where department_id = dept_no;

return l_dept_name;

end;

/

show errors

Functions are used when one task is executed repeatedly. Functions are similar to procedures. Functions always returns some value to callie. After functions are created,

they can be called from sql query also.



62/86

PLSQL NOTES

OUTPUT

SQL> @sp10_1.sql

Function created.

No errors.

SQL> select last_name,department_name

2 from employees e,departments d

3 where e.department_id = d.department_id

4 and employee_id = 100;

LAST_NAME DEPARTMENT_NAME

------------------------- ------------------------------

King Executive

SQL> select last_name,get_dept_name(department_id)

2 from employees

3 where employee_id = 100;

LAST_NAME GET_DEPT_NAME(DEPARTMENT_ID)

------------------------ ------------------------------

King Executive



63/86

PLSQL NOTES

PACKAGES



64/86

PLSQL NOTES

Packages

create or replace package calculator as

--This Programs shows package declaration/specification

--How to create package with public procedures

procedure add(no1 number, no2 number);

procedure subtract(no1 number, no2 number);

end calculator;

/show errors

Package use to group related procedures together. In Package declaration declare names of procedures and global

variables.

In Package body write code for those procedures.create or replace package body calculator is


--How to declare body of package

procedure add(no1 number,no2 number)

is

begin

dbms_output.put_line('Addition is: '||to_char(no1 +

no2));

end add;

procedure subtract(no1 number,no2 number)

is

begin

dbms_output.put_line('Subtraction is: '||to_char(no1

- no2));

end subtract;

end calculator;

/

show errors



65/86

PLSQL NOTES

SQL> @cal_pac.sql

Package created.

No errors.

SQL> @cal.sql

Package body

created. No errors.

SQL> exec calculator.add(20,30);

Addition is: 50


SQL> exec calculator.subtract(30,40);

Subtraction is: -10




66/86

PLSQL NOTES

Package

create or replace package calculator as



--How to define global variables with default values

--How to define public functions

count_add number := 0;

count_subtract number := 0;


procedure subtract(no1 number, no2 number);

function get_add_count return number;

function get_subtract_count return number;

end calculator;

/

show errors



67/86

PLSQL NOTES

create or replace package body calculator is


--How to define private procedures in package body

procedure print(text varchar2);

function get_add_count return number

as

begin

return count_add;

end get_add_count;

function get_subtract_count return number

as

begin

return count_subtract;

end get_subtract_count;


is

begin

count_add := count_add + 1; print('Addition

is: '||to_char(no1 + no2));

end add;

procedure subtract(no1 number,no2 number)

is

begin

count_subtract := count_subtract + 1;

print('Subtraction is: '||to_char(no1 - no2));

end subtract;

procedure print(text varchar2)

is

begin

dbms_output.put_line(text);

end print;

end calculator;

/

show errors



68/86

PLSQL NOTES

SQL> @cal1.sql

Package body

created. No errors.

SQL> !vim cal1.sql

SQL> @cal_pac1.sql

Package created.

No errors.

SQL> @cal1.sql

Package body

created. No errors.

SQL> exec calculator.add(5,2);

Addition is: 7


SQL> exec calculator.subtract(10,5);

Subtraction is: 5




69/86

PLSQL NOTES

Package : Procedure Overloading

create or replace package calculator1 as



--And Procedure overloading


procedure add(no1 varchar2, no2 varchar2);

procedure add(no1 number, no2 number, no3 number);

end calculator1;

/

show errors



70/86

PLSQL NOTES

create or replace package body calculator1 is


is

begin

dbms_output.put_line('Addition is: '||to_char(no1 +

no2));

end add;

procedure add(no1 varchar2,no2 varchar2)

is

begin

dbms_output.put_line('Concatination is: '||no1 ||

no2);

end add;

procedure add(no1 number,no2 number,no3 number)

is

begin

dbms_output.put_line('Subtraction is: '||to_char(no1

+ no2 + no3));

end add;

end calculator1;

/

show errors

Procedure Overloading means defining procedure withsame name but with different parameters,data types.

In above package procedure add is overloaded.



71/86

PLSQL NOTES

SQL> exec calculator1.add(10,20);

Addition is: 30


SQL> exec calculator1.add('scott','tiger');

Concatination is: scott tiger


SQL> exec calculator1.add(10,20,30);

Addition is: 60




72/86

PLSQL NOTES

ORACLE PACKAGES



73/86

PLSQL NOTES

Default Packages : UTL_FILE



--How to send mails using UTL_MAIL package

as

ora_no number; ora_msg

varchar2(100);

begin

UTL_MAIL.SEND

( sender => '[email protected]',recipients => '[email protected]',

cc => '[email protected]',

bcc => '[email protected]',

subject => 'test mail',

message => 'hi how r u??');

dbms_output.put_line('Message send successfully');


ora_no := sqlcode;

ora_msg := sqlerrm;

dbms_output.put_line('Message not send');

dbms_output.put_line(ora_no ||' '||ora_msg);

end;

/

show errors



74/86

PLSQL NOTES

OUTPUT

SQL> @sp11_1.sql

Procedure created.

No errors.

SQL> exec sp11_1

Message send successfully




75/86

PLSQL NOTES

Default Packages : UTL_FILE


--This programs show

--How to read data from text file

--using UTL_FILE Package

as

v_dir varchar2(200);

--Specify Directory name and path

v_file_name varchar2(100);

--Specify File Name

v_line varchar2(500)--Accept file line by line in this variable

v_file UTL_FILE.FILE_TYPE;

--File Handler

begin

v_dir := '/home/gaurav/plsql/';

v_file_name :='utl_file.txt';

v_file :=

UTL_FILE.FOPEN(v_dir,v_file_name,'r');

--File Open in read only modeloop

begin

UTL_FILE.GET_LINE(v_file,v_line);

exception


exit;

end;

dbms_output.put_line(v_line);

end loop;end;

/

show errors



76/86

PLSQL NOTES

OUTPUT

[gaurav@server1 plsql]$ cat utl_file.txt

hello

how r u??

gaurav

OUTPUT

SQL> !vim sp11_2.sql

SQL> @sp11_2.sql

Procedure created.

No errors.

SQL> exec

sp11_2 hello

how r u??

gaurav




77/86

PLSQL NOTES

Default Packages : DBMS_SCHEDULER


--This procedure shows

--How to use default package

--DBMS_SCHEDULER to schedule some task

as

orr_code number;

orr_msg varchar2(500);

begin

--create_job is inbuild procedure in DBMS_SCHEDULER

DBMS_SCHEDULER.CREATE_JOB (

job_name => 'update_sales',

job_type => 'STORED_PROCEDURE',

job_action => 'sp11_4',

start_date => '20-APR-10 03.10.00.000000000 PM

ASIA/CALCUTTA',

repeat_interval => 'FREQ=SECONDLY;INTERVAL=10',

end_date => '20-APR-10 03.11.00.000000000 PM

ASIA/CALCUTTA',

comments => 'My new job');


orr_code := sqlcode;

orr_msg := sqlerrm;

dbms_output.put_line(orr_code||' '||orr_msg);

end;

/

show errors



78/86

PLSQL NOTES

OUTPUT

15:04:48 SQL> truncate table test_sch;

Table truncated.

15:04:57 SQL> @sp11_6.sql

Procedure created.

No errors.

15:05:01 SQL> exec sp11_6


15:05:06 SQL> execdbms_scheduler.set_scheduler_attribute('MAX_JOB_SLAVE_PROCESSES',

2);

-- requires manage scheduler privilegePL/SQL procedure successfully completed.

15:05:22 SQL> exec dbms_scheduler.enable('update_sales');

-- enable the job


15:05:43 SQL> select * from test_sch;

no rows selected

15:07:31 SQL> select count(*) from test_sch;

COUNT(*)

----------0

15:09:41 SQL> /

COUNT(*)

----------

100



79/86

PLSQL NOTES

15:10:04 SQL> /

COUNT(*)

----------

200

15:10:14 SQL> /

COUNT(*)

----------

300

15:10:27 SQL> /

COUNT(*)

----------

400

15:10:37 SQL> /

COUNT(*)

----------

500

15:10:46 SQL> /

COUNT(*)

----------

600

15:10:53 SQL> /

COUNT(*)

----------600



80/86

PLSQL NOTES

DYNAMIC SQL



81/86

PLSQL NOTES

Dynamic Sql

create or replace procedure sp12_1(l_table_name varchar2)


--How to build dynamic sql

queries. as

sql_query varchar2(50);

l_count number;

begin

sql_query := 'select count(*) from '||l_table_name;

execute immediate sql_query into l_count;

--Write sql command in a varchar2 variable

--And then use command 'execute immediate'

--Accept returing value in appropriate variable

dbms_output.put_line(l_count);

end;

/

show errors

OUTPUT

SQL> @sp12_1.sql

Procedure created.

No errors.

SQL> exec sp12_1('REGIONS');

4




82/86

PLSQL NOTES

TRIGGERS



83/86

PLSQL NOTES

Trrigers

create or replace trigger chk_emp_sal

--This programs shows

--How to declare

triggers --for each row

before insert or update

of salary

on employees

for each row

declare

v_error VARCHAR2(2000);

begin

if :new.salary > 25000 then

v_error:=:old.first_name||' cannot have that much!';

raise_application_error(-20999,v_error);

end if;

end;

/show errors

Oracle lets you define procedures called triggers

that run implicitly when an INSERT, UPDATE, or

DELETE statement is issued against the associated

table or, in some cases, against a view, or when

database system actions occur.



84/86

PLSQL NOTES

OUTPUT

SQL> @14_1.sql

Trigger created.

No errors.

SQL> insert into

employees(EMPLOYEE_ID,LAST_NAME,EMAIL,HIRE_DATE,JOB_ID,SALARY)

2 values(215,'Bhide','[email protected]',sysdate,'IT_PROG',26000);

insert into

employees(EMPLOYEE_ID,LAST_NAME,EMAIL,HIRE_DATE,JOB_ID,SALARY)

*

ERROR at line 1:

ORA-20999: cannot have that much!

ORA-06512: at "HR.CHK_EMP_SAL", line 7

ORA-04088: error during execution of trigger 'HR.CHK_EMP_SAL'



85/86

PLSQL NOTES

Triggers : Updating,Inserting,Deleting

create or replace trigger trig_example

before insert or delete or update on trig_eg

for each row

declare

ChangeType varchar2(10);

begin

/* Use 'I' for an INSERT, 'D' for DELETE, and 'U' for UPDATE. */

if inserting then

ChangeType := 'I';

elsif updating then

ChangeType := 'U';

else

ChangeType := 'D';

end if;

insert into changes_record values(ChangeType,USER,SYSDATE);

end trig_example;

/

show errors



86/86

PLSQL NOTES

OUTPUT

SQL> @sp14_2.sql

Trigger created.

No errors.

SQL> select * from CHANGES_RECORD;no rows selected

SQL> insert into trig_eg values(1,'aaa');

1 row created.

SQL> insert into trig_eg values(2,'bbb');

1 row created.

SQL> update trig_eg set name = 'xxxx' where id = 2;

1 row updated.

SQL> delete from trig_eg where id = 2;

1 row deleted.

SQL> select * from CHANGES_RECORD;

CHANGE USER_NAME CHANGE_DA---------- ---------- ---------

I GAURAV 18-APR-10

I GAURAV 18-APR-10

U GAURAV 18-APR-10

D GAURAV 18-APR-10

SQL> select * from trig_eg;

ID NAME

plsql notes new-1

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