Program3- Advance concept : Write a program to add two number using the function and procedure.

Write a program to add two number using the function  named as find_sum  and procedure.

Method-1

Input-Suppose two input values are n1 and n2
Output-Add of two numbers in third variable

Code-
SQL> create or replace function find_sum
  2  (n1 in number, n2 in number)
  3  return number
  4  as
  5  v_sum number;
  6  begin
  7  v_sum := n1+n2;
  8  return v_sum;
  9  end;
 10  /

Function created.

--Perform the sum using function find_sum

SQL> select find_sum (10, 30) sum from dual;

      SUM
----------
        40

SQL> select find_sum (10, 30)  from dual;

FIND_SUM(10,30)
---------------
             40

SQL> select find_sum (10, 30) "Sum of two numbers" from dual;

Sum of two numbers
------------------
                40


=================================================================
Method-2 :Procedure
==================================================================

SQL> create or replace procedure find_sum_procedure
  2  (n1 in number, n2 in number)
  3  as
  4  v_sum number;
  5  begin
  6  v_sum := n1+n2;
  7  DBMS_OUTPUT.PUT_LINE('Sum of two numbers='||v_sum);
  8  end;
  9  /

Procedure created.

SQL> execute find_sum_procedure(10,20);

Sum of two numbers=30

PL/SQL procedure successfully completed.

SQL>

Program2-Write a program to add two number in PL/SQL

This program can be solved in many ways. So Let us understand how the add is performed
Method-1:
Suppose we have two constant value 2 and 3 .So we need the addition operator(+) to add these two numbers
Input-2 and 3
Output-5
Operation- addition so use addition operator (+)

Code-
SQL> set serveroutput on
SQL>
SQL>
SQL> Begin
  2  Dbms_output.put_line(2+3);
  3  End;
  4  /
5

PL/SQL procedure successfully completed.

SQL>


Method-2:
Suppose you want to add two values taken at run time
Input-Take two variable and store two value into it.Assume two variable are n1 and n2.
Output- addition a+b
Operation- addition (+)
Code-
SQL> declare
  2  n1 number;
  3  n2 number;
  4  Begin
  5  n1 :=2;
  6  n2 :=3;
  7  Dbms_output.put_line(n1+n2);
  8  End;
  9  /
5

PL/SQL procedure successfully completed.

SQL>



Method-3:
Take two number n1 and n2 and store it into third variable result.
Input-Take two variable and store the result into third variable result.
Output- Result of addition
Operation- addition (+)

SQL> declare
  2    n1 number;
  3    n2 number;
  4    result number;
  5    Begin
  6     n1 :=2;
  7     n2 :=3;
  8     result:=n1+n2;
  9    Dbms_output.put_line(result);
 10    End;
 11    /
5

PL/SQL procedure successfully completed.

SQL>
Method-4:
Ask user to enter two number n1 and n2 and store it into third variable result.
Input-Take two variable and store the result into third variable result.
Output- Result of addition
Operation- addition (+)

Code-
SQL> declare
  2    n1 number;
  3    n2 number;
  4    result number;
  5    Begin
  6     n1 :=&n1;
  7     n2 :=&n2;
  8     result:=n1+n2;
  9    Dbms_output.put_line(result);
 10    End;
 11    /
Enter value for n1: 10
old   6:    n1 :=&n1;
new   6:    n1 :=10;
Enter value for n2: 20
old   7:    n2 :=&n2;
new   7:    n2 :=20;
30

PL/SQL procedure successfully completed.

SQL>

Note- This program can be solved in many ways .I have taken from very basic to often used method.
I hope you can get the idea how to approach the problem to solve in real-time in PL/SQL.

SQL-Primary key and foreign key Relation/Parent-child relationship between tables/ On delete cascade/foreign key constraint with Example

SQL-Primary key and foreign key Relation/Parent-child relationship between tables/ On delete cascade/foreign key constraint with Example

Suppose we have two table customer and supplier
CREATE TABLE supplier
( supplier_id numeric(10) not null,
 supplier_name varchar2(50) not null,
 contact_name varchar2(50),
 CONSTRAINT supplier_pk PRIMARY KEY (supplier_id)
);

insert into supplier values(1,'Sarat','Chand');
insert into supplier values(2,'Sartaj','Ahmed');
insert into supplier values(3,'Saral','Chand');


CREATE TABLE products
( product_id numeric(10) not null,
 supplier_id numeric(10) not null,
 CONSTRAINT fk_supplier
   FOREIGN KEY (supplier_id)
  REFERENCES supplier(supplier_id)
  ON DELETE CASCADE
);

insert into products values(101,1);
insert into products values(102,2);
insert into products values(103,3);

--Check/verify the entered data into the table using below command

select * from products;
select * from supplier ;

--not Allowed to add the product into the supplier table because the supplier id is not exist in the parent table name supplier

insert into products values(103,4);

--Error Message
--ORA-02291: integrity constraint (HR.FK_SUPPLIER) violated - parent key not found

So we can say that the table relation between table is established

--The data can be deleted from the supplier table because it is parent table but cannot delete the data into child table
--delete the data from supplier table whose supplier_id is 1;
delete from supplier where supplier_id=1;

delete from products where supplier_id=1;
--check the constraints
select * from user_cons_columns;
select * from user_constraints;

Program1- Write a program to print the Hello Message to the terminal

Solution-often we start writing the first program as hello Message.


So let us write the first hello program using various methods.

Method-1:Using Anonymous block 
Code-
SQL> begin
  2  dbms_output.put_line('HELLO');
  3  end;
  4  /
HELLO
PL/SQL procedure successfully completed.
SQL>

Method-2:Using PROCEDURE 
code-
SQL> SET SERVEROUTPUT ON
SQL> CREATE OR REPLACE PROCEDURE hello
  2  AS
  3  BEGIN
  4     dbms_output.put_line('Hello World!');
  5  END;
  6  /

Procedure created.

SQL>

Note- we can execute the procedure in two way -
Use SET SERVEROUTPUT ON  command to view the output on terminal-
1.
SQL> EXECUTE hello;
Hello World!

PL/SQL procedure successfully completed.
SQL>

2.
SQL> BEGIN
  2    hello;
  3  END;
  4  /
Hello World!

PL/SQL procedure successfully completed.
SQL>

Oracle-Concatenation Operator(||)

Concatenation Operator(||)

Concatenation operator is used to concatenate the column or string to another column or string and it is represented by two vertical bar (||).

SQL Statement-

select 'The employee Name '||Ename||' and employee id is '||empno As   "Employee Information" from emp

Result-
             Employee Information
The employee Name KING and employee id is 7839
The employee Name BLAKE and employee id is 7698
The employee Name CLARK and employee id is 7782
The employee Name JONES and employee id is 7566
The employee Name SCOTT and employee id is 7788
The employee Name FORD and employee id is 7902
The employee Name SMITH and employee id is 7369

Arithmatic Expression in MySQL-Addition,subtraction Multiplication and modulo operator

Arithmatic Expression in MySQL

Arithmatic Expression are the combination of arithmatic operator,constant numeric value and column name  in the SQL statements.
A list of arithmatic opertors are given below -
1.Addition(+)
2.Subtraction(-)
3.Multiplication(*)
4.Division(/)
5.Remainder or Modulo operator(%)

Note-
1.You can use arithmatic operator in any clause in SQL statement except FROM cluase.
2.The operator priority list is given below-
  * / + and -
 Priority Rule -Multiplication and division take the priority over Addition and Division.operators of same priority can be evaluated from left to right.
Parentheses are used to define the priority explicitly to remove the ambiguity.

Example: SQL Arithmetic Operators
1.SELECT 150+10-5*5/5;

Result:
Number of Records: 1
150+10-5*5/5
155

=======

Suppose we have the empsal table with five record and its details are given below-
Create table empsal ( id nuber , name varchar2(30),salary number(8,2));
insert into empsal(id,name, salary) values(1,'Ajay', 10000);
insert into empsal (id,name, salary) values(2,'Amit', 11000);
insert into empsal (id,name, salary) values(3,'Ashok', 7000);
insert into empsal (id,name, salary) values(4,'Aarif', 6000);
insert into empsal (id,name, salary) values(5,'Vinod', 5000);
2. verify the record
Result:
Number of Records: 5
id name salary
1 Ajay 10000
2 Amit 11000
3 Ashok 7000
4 Aarif 6000
5 Vinod 5000

SQL plus (+) operator:It is used to add two or more numbers/expressions
Example-
1.For Number computation
SELECT 150+10;

2.Write a query to find the the increment of the salary of employee by Rs 300.
SELECT Id, name , salary+300 as " Salary" from empsal;
Result:
Number of Records: 5
id name Salary
1 Ajay 10300
2 Amit 11300
3 Ashok 7300
4 Aarif 6300
5 Vinod 5300

2.SQL minus (-) operator -subtract one expression /number from another expression /number.

Example-
1.select 150-5;

Number of Records: 1
150-5
145

2.Write a query to display the Ashok monthly salary after PF deduction of Rs 1500.
 SELECT name, salary-1500 "Ashok In hand Salary" FROM empsal where id=3;

Result:
Number of Records: 1
name Ashok In hand Salary
Ashok 5500

3.SQL multiply ( * ) operator  used to multiply two or more expressions or numbers.

Example-

1.Display the Ashok's Annual salary.
SELECT Id, name , salary as "Monthly Salary", 12*salary as "Yearly Salary" from empsal

Result:
Number of Records: 1
id name Monthly Salary Yearly Salary
3 Ashok 7000         84000

4.SQL divide ( / ) operator-divide one expressions /numbers by another.
1.Write a query to share the Ashok's Annual salary among his four friends equally.
SELECT Id, name ,(12*salary)/4 as "Ashok's friend share" from empsal where id=3

Result:
Number of Records: 1
id name Ashok's friend share
3 Ashok 21000

Sorting ASC,DESC-ORDER BY clause display the rows in ASC|DESC order for an expression,column position or an alias.

ORDER BY Clause-
The ORDER BY clause is used to sort the data in ascending(its default ) or 
descending order of one or more columns and use the key word ORDER BY.
ORDER BY clause display the rows in ASC|DESC order for an expression,column position or an alias. 

Syntax-

SELECT   *|[DISTINCT]Column|expression [Alias]
From Table_Name
[WHERE <Condition(s)>]
[ORDER BY Column|Expression [ASC|DESC]];

SELECT -a list of columns
* -Select the all columns 
DISTINCT-suppresses the duplicates 
alias-alternate name of the colunm(s) that is/are used as the heading of that column(s).  
Table_name-specifies the table name containing the column(s). 
WHERE<Condition(s)>- the condition must meet to retrieve the data from the database.
ORDER BY Column|Expression -order the rows in Acending or descending order 

Example- 

1.Write the query to find employee information order by name.

Query-    SELECT * FROM employee order by name;
Output-
Number of Records: 5
ID Name email          address phone_number salary
2 Ajay ajay@gmail.com Hyderbad 16756890 51000
4 Aman Aman@gmail.com Lucknow         26756890 51000
3 Amit amit@gmail.com Delhi         16756890 51000
5 Hari Hari@gmail.com Lucknow         36756890 15000
1 sharat sarat@gmail.com Hyderbad 123456890 5000

2.Write the query to selects all employees from the "employee" table, sorted by the "Name" and the "Salary" column.

Query- SELECT * FROM employee order by name, salary;
Output-
Number of Records: 5
ID Name email          address phone_number salary
2 Ajay ajay@gmail.com Hyderbad 16756890 51000
4 Aman Aman@gmail.com Lucknow         26756890 51000
3 Amit amit@gmail.com Delhi         16756890 51000
5 Hari Hari@gmail.com Lucknow          36756890 15000
1 sharat sarat@gmail.com Hyderbad 123456890 5000

3.Display the name and the salary of the employees from the "employee" table, sorted ascending by the name and descending by the salary. 

Query- SELECT name,salary FROM employee order by name, salary DESC;
Output-
Number of Records: 5
Name salary
Ajay 51000
Aman 51000
Amit 51000
Hari 15000
sharat 5000

4.Display the name and the yearly salary of the employees from the employee table and sort by Annual_salary in ascending. 

Query-SELECT Name , salary*12  Annual_salary FROM employee  order by Annual_salary;
 Alternate -SELECT Name , salary*12  Annual_salary FROM employee  order by 2;
Output-
Number of Records: 5
Name Annual_salary
sharat 60000
Hari 180000
Ajay 612000
Amit 612000
Aman 612000

5.Display the name as Employee Name  and the yearly salary  as Annual_salary of the employees from the employee table and 
sorted descending order by the Annual_salary

Query-SELECT Name "Employee Name", salary*12  Annual_salary FROM employee  order by 2 DESC;
Output-
Number of Records: 5
Employee Name Annual_salary
Ajay           612000
Amit           612000
Aman           612000
Hari           180000
sharat           60000