SQL

sql OR

SELECT * FROM employees WHERE dept='sales' OR salary>=25000; 

sql or

Used alongside WHERE to include data when either condition is true.
Example: Returns users that live in either Sheffield or Manchester.
SELECT * FROM users
WHERE city = 'Sheffield' OR 'Manchester';

logical operators in sql

LOGICAL OPERATORS?
ALL	    (TRUE if all of the subquery values meet the condition)	
AND	    (TRUE if all the conditions separated by AND is TRUE)	
ANY	    (TRUE if any of the subquery values meet the condition)	
BETWEEN	(TRUE if the operand is within the range of comparisons)	
EXISTS	(TRUE if the subquery returns one or more records)
IN	    TRUE if the operand is equal to one of a list of expressions)	
LIKE	(TRUE if the operand matches a pattern)	
NOT	    (Displays a record if the condition(s) is NOT TRUE)	
OR	    (TRUE if any of the conditions separated by OR is TRUE)	
SOME	(TRUE if any of the subquery values meet the condition)

SQL AND Operator

SELECT first_name, last_name
FROM Customers
WHERE country = 'USA' AND last_name = 'Doe';

sql and or

AND (
  f.termination_date IS NULL
  OR 
  f.termination_date > CURRENT_DATE
)

SQL OR Operator

SELECT first_name, last_name
FROM Customers
WHERE country = 'USA' OR last_name = 'Doe';