MySQL OR Condition

Last updated: October 19, 2026Oct 19, 2026 4 min read

The OR operator combines conditions so that a row is returned if at least one of them is true. Use it for alternatives: hotels in Goa or with a pool, orders that are either cancelled or refunded.

1. Syntax and Meaning

WHERE condition1 OR condition2 [OR condition3 ...]

Table: hotels (7 rows)

2. Basic OR

SELECT name, city, pool FROM hotels WHERE city = 'Goa' OR pool = TRUE;

Result: 4 rows

3. Several OR Conditions

SELECT name, price, rating FROM hotels WHERE price < 3000 OR rating >= 4.5 OR spa = TRUE;

Result: 5 rows

4. OR Truth Table (with NULL)

SELECT (1=1) OR NULL AS true_or_null, (1=2) OR NULL AS false_or_null, (1=2) OR (2=3) AS false_or_false;

Result: 1 row

Snow Peak has NULL rating and NULL pool. It is returned only when one condition is definitely TRUE:

SELECT name FROM hotels WHERE rating > 4 OR pool = TRUE;

Snow Peak not included (both NULL)

SELECT name FROM hotels WHERE rating > 4 OR city = 'Shimla';

Snow Peak included (city is TRUE)

5. OR on One Column: Use IN

SELECT name, city FROM hotels WHERE city = 'Goa' OR city = 'Shimla' OR city = 'Ooty';

Result: 5 rows

SELECT name, city FROM hotels WHERE city IN ('Goa', 'Shimla', 'Ooty');

Result: 5 rows

Same result; IN is shorter and easier to maintain.

6. Mixing OR with AND

AND binds tighter than OR. Without parentheses, this means city = 'Goa' OR (city = 'Jaipur' AND price < 5000):

SELECT name, city, price FROM hotels WHERE city = 'Goa' OR city = 'Jaipur' AND price < 5000;

Result: 4 rows

SELECT name, city, price FROM hotels WHERE (city = 'Goa' OR city = 'Jaipur') AND price < 5000;

Result: 2 rows

See MySQL AND with OR for more.

7. XOR: Exactly One of Two

MySQL also has XOR: true when exactly one side is true. Hotels with a pool or a spa, but not both:

SELECT name, pool, spa FROM hotels WHERE pool XOR spa;

Result: 2 rows

8. OR in UPDATE

UPDATE hotels SET price = ROUND(price * 0.9)
WHERE rating < 4 OR rating IS NULL;
SELECT name, rating, price FROM hotels WHERE rating < 4 OR rating IS NULL;

Result: 3 rows

9. OR and Indexes

An index on one column can't serve a = 1 OR b = 2 by itself. MySQL may combine two indexes (index merge union) or fall back to a full scan. For large tables, rewriting as UNION of two indexed queries is a classic fix:

SELECT name FROM hotels WHERE city = 'Goa'
UNION
SELECT name FROM hotels WHERE spa = TRUE;

Result: 5 rows

10. Practice Exercises

SELECT name, price FROM hotels WHERE price < 3000 OR price > 10000;

SELECT name, city, rating FROM hotels WHERE (city = 'Shimla' OR city = 'Jaipur') AND rating >= 4;

11. Summary

• OR returns rows where at least one condition is TRUE.
• TRUE OR NULL is TRUE; FALSE OR NULL is NULL.
• Use IN for many ORs on one column; use parentheses when mixing OR with AND.
• XOR means exactly one; OR across columns may need index merge or a UNION rewrite.