SQL IN operator

The IN operator is used to compare one or more values given in list of values in the parenthesis with each values separated by comma.
Syntax is as:
SELECT * FROM table_name WHERE column_name IN ('value1','value2','value3',...)

As in example we have table employees
id first_name last_name salary city
1 Johan Sumith 200000 Delhi
2 Ansh Kumar 300000 Mumbai
3 Sameer Seth 100000 Delhi
4 Pyush   250000 Kolkata
We want to find employees who are either in Delhi or Kolkata or Chennai.
SELECT * FROM employees WHERE city IN ('Delhi','Kolkata','Chennai' )

We get
id first_name last_name salary city
1 Johan Sumith 200000 Delhi
3 Sameer Seth 100000 Delhi
4 Pyush   250000 Kolkata