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different operators in sql

The different operators in SQL

Introduction:

An SQL operator is a special word or character used to perform tasks like addition, subtraction, division, modulus, comparison, etc.  There are different types of SQL operators

Arithmetic Operators

Arithmetic Operators are used for addition(+),subtraction(-),multiplication(*), division(/).

Addition

We can add columns and get the result. As in the below example we can find the monthly salary by using literals, any value we are using in the query can be done by using ‘ +’ and  If we want to modify something in the column name as they vanish, that’s the reason the new column is given as increased_salary.

Employee Table
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Department Table
sql

Problem Statement:

Find out  salary and salary  increased by 3000 of employees

Query:

select salary, salary+3000 as increased_salary

from employee;

Output Screen
sql
Subtraction

We can subtract columns and get the result. As in the below example we can find the monthly salary by using literals, any value we are using in the query can be done by using ‘ -’ and If we want to modify something in the column name as they vanish, that’s the reason the new column is given as decreased_salary.

 Problem Statement:

 Find out  salary and salary decreased by 300 of employees

Query:

select salary, salary-300 as decreased_salary

from employee;

Output Screen
sql 2
Multiplication

We can multiply columns and get the result. As in the below example we can find the yearly salary by using literals any value we are using in the query can be done by using ‘ *’ and  If we want to modify something in the column name as they vanish, that’s the reason the new column is given as yearly_salary.

Problem Statement:

Find out the salary and monthly salary of employees

Query:

select salary, salary*12 as monthy_salary

from employee;

Output Screen
sql
Division

We can divide columns and get the result. As in the below example we can find the per day salary by using literals, any value we are using in the query can be done by using ‘ /’, and If we want to modify something in the column name as they vanish, that’s the reason the new column is given as perday_salary.

Problem Statement:

Find out the salary and per day salary  of employees

Query:

select salary, salary/30 as perday_salary

from employee;

sql
Conditional Operators

Conditional Operators are greater than(>),smaller than(<),greater than or equals to(>=),smaller than or equals to(<=),assisgnment(=),comparison(==),not equals to(<> or !=)

  • Operator greater than(>)

In this ‘>’ operator we get values greater than the value given.

Problem Statement:

Find out those employees who have a salary greater than 2000

Query:

select ename,salary

from employee

where salary>2000;

Output Screen
sql
  • Operator lesser than(<)

The ‘<’ operator we can get those values that are lesser than the value given.

Problem Statement:

Find out those employees who have salaries less than 7000

Query:

select ename,salary

from employee

where salary<7000;

Output Screen
sql
  • Operator greater than(>=)

The’ >=’ operator we can get values greater and equal to the value given.

Problem Statement:

Find out those employees who have salaries greater than and equal to 2000

Query:

select ename,salary

from employee

where salary>=2000;

Output Screen
SQL
  • Operator lesser than(<=)

The ‘<=’ operator we can get those values that are lesser and equal to the value given.

Problem Statement;

Find out those employees who have a salary lesser than and equal to 2000

Query:

select ename,salary

from employee

where salary<=2000;

Output Screen
sql
  • Assignment Operator (=)

The ‘ =’ operator we assign values from right to left.

Problem Statement:

Find out the manager ID of that employee whose name is Ward.

Query:

select ename,Mgr

from employee

where ename=’ward’;

Output Screen
sql
  • Not Equals to Operator (!=)

The  ‘!=’ operator we find a value that is not equal to.

Problem Statement:

Display all the employees except those who are working in dept 30

Query:

select ename,DEPT_NO

from employee

where dept_no !=30;

Output Screen
sql
Logical Operators

Logical operators are ‘And’, ‘Or’

  1. And Operator

  The ‘and’ operator, if both conditions are True, only it will display the output.

Problem Statement:

Display those employees who have a salary greater than 2000 and  belong to dept_no 10

Query:

select ename,dept_no

from employee

where salary>2000 and dept_no=10;

Output Screen
sql
  • OR Operator

 The  ‘or’ operator, if either of the conditions is True, will display output.

Problem Statement:

Display employees whose salary is greater than 800 and less than 4000.

Query:

select ename,salary

from employee

where salary>800 or salary<4000;

Output Screen
sql
  • Special Operators

Special operators are ‘Like’,; is’, ‘in’, and ‘between’.

like operator

 The ‘like’ operator searches single characters or multicharacter searches.

a)Multicharacter search- We search by using ‘%’.

Problem Statement:

Display those employees whose names start with ‘m’.

Query:

select ename

from employee

Where ename like ‘m%’;

Output Screen
sql

b) Single character search- We search by using ‘_’.

Problem Statement:

Display those employees whose names have exactly four characters in their name.

Query:

select ename

from employee

Where ename like ‘____’;

Output Screen
sql

2) ls operator

     The ‘Is’ operator is used to compare null values.

Problem Statement:

Display those employees whose commission(comm) is null.

Query:

select ename, comm

from employee

Where comm is null;

Output Screen
sql

3) In operator

 The  ‘In’ operator displays two values of the same column name together.

Problem Statement:

Display those employees who belong to dept 10 and 20.

Query:

select ename,dept_no

from employee

Where dept_no in(10,20);

Output Screen
sql

4) between operator

The ‘between’ operator displays a range of two values between the same column name.

Problem Statement:

Display those employees whose salary is between 1000 and 2000.

Query:

select ename,salary

from employee

Where salary  between 1000 and 2000;

Output Screen
sql
Special Operators with NOT
  1. not like operator

The ‘Like not’ operator is used for searching single characters or multicharacter searches which are not required.

a)Multicharacter search- We search by  ‘not like  %’.

Problem Statement:

Display those employees except for those whose names start with ‘m’.

Query:

select ename

from employee

Where ename not like ‘m%’;

Output Screen
sql

b) Single character search- We search by  ‘ not like _’.

Problem Statement:

Display those employees except for those whose names have exactly four characters in their name.

Query:

select ename

from employee

Where ename not  like ‘____’;

Output Screen
sql

2) is not operator

The  ‘Is not’ operator is used to compare not null values.

Problem Statement:

Display those employees whose commission(comm) is not null.

Query:

select ename, comm

from employee

Where comm is not null;

Output Screen
sql

3) not In operator

The ‘Not In’ operator is used not to display two values of the same column name together.

Problem Statement:

Display those employees who do not belong to dept 10 and 20.

Query:

select ename,dept_no

from employee

Where dept_no not  in(10,20);

Output Screen
sql

4) not between operator

The ‘not between’ operator is not used to display a range of two values between the same column name.

Problem Statement:

Display those employees whose salary is not between 1000 and 2000.

Query:

select ename,salary

from employee

Where salary not between 1000 and 2000;

Output Screen
sql
Conclusion

SQL operators ease the process of data manipulation. SQL operators, we can perform arithmetic, comparison, and logical operations to fetch and retrieve data from the database. We can use operators and run queries to get the desired result.

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