MySQL の IS NULL

SELECT COLUMN_LIST
FROM TABLE_NAME
WHERE COLUMN_NAME IS NULL;

SELECT title, original_language_id
FROM film
ORDER BY title
LIMIT 3;

+------------------+----------------------+
| title            | original_language_id |
+------------------+----------------------+
| ACADEMY DINOSAUR |                 NULL |
| ACE GOLDFINGER   |                 NULL |
| ADAPTATION HOLES |                 NULL |
+------------------+----------------------+
3 rows in set (0.00 sec)

SELECT title FROM film WHERE original_language_id IS NULL ORDER BY title LIMIT 3;

+------------------+
| title            |
+------------------+
| ACADEMY DINOSAUR |
| ACE GOLDFINGER   |
| ADAPTATION HOLES |
+------------------+
3 rows in set (0.00 sec)

SELECT title FROM film WHERE original_language_id IS NOT NULL ORDER BY title;

Empty set (0.00 sec)

SELECT address_id, address, address2
FROM address
WHERE address2 IS NULL
ORDER BY address_id;

+------------+----------------------+----------+
| address_id | address              | address2 |
+------------+----------------------+----------+
|          1 | 47 MySakila Drive    | NULL     |
|          2 | 28 MySQL Boulevard   | NULL     |
|          3 | 23 Workhaven Lane    | NULL     |
|          4 | 1411 Lillydale Drive | NULL     |
+------------+----------------------+----------+
4 rows in set (0.00 sec)

SELECT address_id, address2
FROM address
WHERE address2 = ''
ORDER BY address_id
LIMIT 3;

+------------+----------+
| address_id | address2 |
+------------+----------+
|          5 |          |
|          6 |          |
|          7 |          |
+------------+----------+
3 rows in set (0.00 sec)

SELECT title FROM film WHERE original_language_id = NULL ORDER BY title;

Empty set (0.01 sec)