in clause in sql code example

Example 1: 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');

Example 2: in query in sql

SELECT Id, FirstName, LastName, Country  FROM Customer WHERE Country IN        (SELECT Country           FROM Supplier)

Example 3: in in sql

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

Example 4: in condition in sql

IN condition allows you to easily test
if an expression matches any value
in a list of values.
It is for reducing  multiple OR
conditions in a SELECT, INSERT, 
UPDATE, or DELETE statement.

Example 5: where query in sql server

SELECT * FROM Customers
WHERE Country='Mexico';