MySQL のテーブルエイリアス

SELECT ALIAS_NAME.COLUMN_NAME
FROM TABLE_NAME AS ALIAS_NAME;

SELECT film.title, language.name
FROM film
JOIN language ON film.language_id = language.language_id
ORDER BY film.title
LIMIT 3;

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

SELECT f.title, l.name
FROM film AS f
JOIN language AS l ON f.language_id = l.language_id
ORDER BY f.title
LIMIT 3;

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

SELECT language_id
FROM film
JOIN language ON film.language_id = language.language_id
LIMIT 1;

ERROR 1052 (23000): Column 'language_id' in field list is ambiguous

SELECT film.title
FROM film AS f
JOIN language AS l ON f.language_id = l.language_id
LIMIT 1;

ERROR 1054 (42S22): Unknown column 'film.title' in 'field list'