SQL

sql in

Used alongside a WHERE clause as a shorthand for multiple OR conditions.
So instead of:
SELECT * FROM users
WHERE country = 'USA' OR country = 'United Kingdom' OR
country = 'Russia' OR country = 'Australia';
You can use:
SELECT * FROM users
WHERE country IN ('USA', 'United Kingdom', 'Russia',
'Australia');

operator in sql

=	Checks if the values of two operands are equal or not, if yes then condition becomes true.	(a = b) is not true.
!=	Checks if the values of two operands are equal or not, if values are not equal then condition becomes true.	(a != b) is true.
<>	Checks if the values of two operands are equal or not, if values are not equal then condition becomes true.	(a <> b) is true.
>	Checks if the value of left operand is greater than the value of right operand, if yes then condition becomes true.	(a > b) is not true.
<	Checks if the value of left operand is less than the value of right operand, if yes then condition becomes true.	(a < b) is true.
>=	Checks if the value of left operand is greater than or equal to the value of right operand, if yes then condition becomes true.	(a >= b) is not true.
<=	Checks if the value of left operand is less than or equal to the value of right operand, if yes then condition becomes true.	(a <= b) is true.
!<	Checks if the value of left operand is not less than the value of right operand, if yes then condition becomes true.	(a !< b) is false.
!>	Checks if the value of left operand is not greater than the value of right operand, if yes then condition becomes true.	(a !> b) is true.

in in sql

(IN) operator in sql like "OR" operator
For example: 
Select * From employees
Where department_id "IN" (60,90); 

SQL IN Operator

SELECT first_name, country
FROM Customers
WHERE country IN ('USA', 'UK');

in operator sql

SELECT FullName
FROM EmployeeDetails
WHERE FullName LIKE ‘__hn%’;

in operator sql

SELECT EmpId,
Salary+Variable as TotalSalary 
FROM EmployeeSalary;

in operator sql

SELECT EmpId FROM EmployeeDetails
UNION 
SELECT EmpId FROM EmployeeSalary;

in operator in sql

(IN) operator in sql like "OR" operator
For example: 
Select * From employees
Where department_id "IN" (60,90);