mysql> SHOW databases; +--------------------+ | Database | +--------------------+ | information_schema | | mysql | | performance_schema | | q1 | | rezodb | | sys | +--------------------+ 6 rows in set (0.01 sec) mysql> CREATE DATABASE Q2; Query OK, 1 row affected (0.02 sec) mysql> SHOW databases; +--------------------+ | Database | +--------------------+ | information_schema | | mysql | | performance_schema | | q1 | | q2 | | rezodb | | sys | +--------------------+ 7 rows in set (0.00 sec) mysql> USE q2; Database changed mysql> SHOW tables; Empty set (0.00 sec) mysql> CREATE TABLE item_category(category_id INT, category_name VARCHAR(256)); Query OK, 0 rows affected (0.03 sec) mysql> SELECT * FROM item_category; Empty set (0.00 sec) mysql> CREATE TABLE items(item_id INT, name VARCHAR(256), price INT, category_id INT); Query OK, 0 rows affected (0.03 sec) mysql> SELECT * FROM item_category; Empty set (0.00 sec) mysql> INSERT INTO item_category VALUES(1, '家具'), (2, '飲料'), (3, '食品'); Query OK, 3 rows affected (0.01 sec) Records: 3 Duplicates: 0 Warnings: 0 mysql> SELECT * FROM item_category; +-------------+---------------+ | category_id | category_name | +-------------+---------------+ | 1 | 家具 | | 2 | 飲料 | | 3 | 食品 | +-------------+---------------+ 3 rows in set (0.00 sec) mysql> SELECT * FROM item; ERROR 1146 (42S02): Table 'q2.item' doesn't exist mysql> SELECT * FROM items; Empty set (0.00 sec) mysql> INSERT INTO items VALUES(1, 'ローマのテーブル', 150000, 1), (2, 'げーたるーど2000 500ml', 370, 2), (3, '原始肉' 2500, 3), (4, '魅惑の椅子' 100000, 1); ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '2500, 3), (4, '魅惑の椅子' 100000, 1)' at line 1 mysql> INSERT INTO items VALUES(1, 'ローマのテーブル', 150000, 1), (2, 'げーたるーど2000 500ml', 370, 2), (3, '原始肉', 2500, 3), (4, '魅惑の椅子' 100000, 1); ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '100000, 1)' at line 1 mysql> INSERT INTO items VALUES(1, 'ローマのテーブル', 150000, 1), (2, 'げーたるーど2000 500ml', 370, 2), (3, '原始肉', 2500, 3), (4, '魅惑の椅子', 100000, 1); Query OK, 4 rows affected (0.00 sec) Records: 4 Duplicates: 0 Warnings: 0 mysql> SELECT * FROM items; +---------+------------------------+--------+-------------+ | item_id | name | price | category_id | +---------+------------------------+--------+-------------+ | 1 | ローマのテーブル | 150000 | 1 | | 2 | げーたるーど2000 500ml | 370 | 2 | | 3 | 原始肉 | 2500 | 3 | | 4 | 魅惑の椅子 | 100000 | 1 | +---------+------------------------+--------+-------------+ 4 rows in set (0.00 sec) mysql> SELECT * FROM items, item_category; +---------+------------------------+--------+-------------+-------------+---------------+ | item_id | name | price | category_id | category_id | category_name | +---------+------------------------+--------+-------------+-------------+---------------+ | 1 | ローマのテーブル | 150000 | 1 | 3 | 食品 | | 1 | ローマのテーブル | 150000 | 1 | 2 | 飲料 | | 1 | ローマのテーブル | 150000 | 1 | 1 | 家具 | | 2 | げーたるーど2000 500ml | 370 | 2 | 3 | 食品 | | 2 | げーたるーど2000 500ml | 370 | 2 | 2 | 飲料 | | 2 | げーたるーど2000 500ml | 370 | 2 | 1 | 家具 | | 3 | 原始肉 | 2500 | 3 | 3 | 食品 | | 3 | 原始肉 | 2500 | 3 | 2 | 飲料 | | 3 | 原始肉 | 2500 | 3 | 1 | 家具 | | 4 | 魅惑の椅子 | 100000 | 1 | 3 | 食品 | | 4 | 魅惑の椅子 | 100000 | 1 | 2 | 飲料 | | 4 | 魅惑の椅子 | 100000 | 1 | 1 | 家具 | +---------+------------------------+--------+-------------+-------------+---------------+ 12 rows in set (0.00 sec) mysql> SELECT * FROM items JOIN item_category; +---------+------------------------+--------+-------------+-------------+---------------+ | item_id | name | price | category_id | category_id | category_name | +---------+------------------------+--------+-------------+-------------+---------------+ | 1 | ローマのテーブル | 150000 | 1 | 3 | 食品 | | 1 | ローマのテーブル | 150000 | 1 | 2 | 飲料 | | 1 | ローマのテーブル | 150000 | 1 | 1 | 家具 | | 2 | げーたるーど2000 500ml | 370 | 2 | 3 | 食品 | | 2 | げーたるーど2000 500ml | 370 | 2 | 2 | 飲料 | | 2 | げーたるーど2000 500ml | 370 | 2 | 1 | 家具 | | 3 | 原始肉 | 2500 | 3 | 3 | 食品 | | 3 | 原始肉 | 2500 | 3 | 2 | 飲料 | | 3 | 原始肉 | 2500 | 3 | 1 | 家具 | | 4 | 魅惑の椅子 | 100000 | 1 | 3 | 食品 | | 4 | 魅惑の椅子 | 100000 | 1 | 2 | 飲料 | | 4 | 魅惑の椅子 | 100000 | 1 | 1 | 家具 | +---------+------------------------+--------+-------------+-------------+---------------+ 12 rows in set (0.00 sec) mysql> SELECT item_category.category_id, items.item_id, items.name, items.price, item_category.name FROM item_category INNER JOIN items ON item_category.category_id; ERROR 1054 (42S22): Unknown column 'item_category.name' in 'field list' mysql> SELECT item_category.category_id, items.item_id, items.name, items.price, item_category.name FROM item_category INNER JOIN items ON item_category.category_id = item_category.category_id; ERROR 1054 (42S22): Unknown column 'item_category.name' in 'field list' mysql> SELECT item_category.category_id, items.item_id, items.name, items.price, item_category.name FROM item_category INNER JOIN items ON item_category.category_id = items.category_id; ERROR 1054 (42S22): Unknown column 'item_category.name' in 'field list' mysql> SELECT item_category.category_id, items.item_id, items.name, items.price, item_category.name FROM item_category INNER JOIN items ON items.category_id = item_category.category_id; ERROR 1054 (42S22): Unknown column 'item_category.name' in 'field list' mysql> SELECT * FROM items; +---------+------------------------+--------+-------------+ | item_id | name | price | category_id | +---------+------------------------+--------+-------------+ | 1 | ローマのテーブル | 150000 | 1 | | 2 | げーたるーど2000 500ml | 370 | 2 | | 3 | 原始肉 | 2500 | 3 | | 4 | 魅惑の椅子 | 100000 | 1 | +---------+------------------------+--------+-------------+ 4 rows in set (0.00 sec) mysql> SELECT * FROM item_category; +-------------+---------------+ | category_id | category_name | +-------------+---------------+ | 1 | 家具 | | 2 | 飲料 | | 3 | 食品 | +-------------+---------------+ 3 rows in set (0.00 sec) mysql> SELECT category_id, item_id, name, price FROM items INNER JOIN item_category ON category_id = category_id; ERROR 1052 (23000): Column 'category_id' in field list is ambiguous mysql> SELECT category_id, item_id, name, price FROM items INNER JOIN item_category ON category_id = items.category_id; ERROR 1052 (23000): Column 'category_id' in field list is ambiguous mysql> SELECT category_id, item_id, name, price FROM items INNER JOIN item_category ON item_category.category_id = items.category_id; ERROR 1052 (23000): Column 'category_id' in field list is ambiguous mysql> SELECT * FROM item_category INNTER JOIN items ON item_category.category_id = items.category_item; ERROR 1054 (42S22): Unknown column 'item_category.category_id' in 'on clause' mysql> SELECT * FROM item_category INNER JOIN items ON item_category.category_id = items.category_item; ERROR 1054 (42S22): Unknown column 'items.category_item' in 'on clause' mysql> SELECT item_category.category_id as category_id, items.item_id as item_id, items.name as name, items.price as price, item_category.name as name FROM item_category INNER JOIN items ON item_category.category_id = items.category_id; ERROR 1054 (42S22): Unknown column 'item_category.name' in 'field list' mysql> mysql> SELECT item_category.category_id as category_id, items.item_id as item_id, items.name, items.price as price, item_category.name as name FROM item_category INNER JOIN items ON item_category.category_id = items.category_id; ERROR 1054 (42S22): Unknown column 'item_category.name' in 'field list' mysql> SHOW COLUMNS FROM -> ; ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '' at line 1 mysql> SELECT * FROM items INNER JOIN item_category USING(category_id); +-------------+---------+------------------------+--------+---------------+ | category_id | item_id | name | price | category_name | +-------------+---------+------------------------+--------+---------------+ | 1 | 1 | ローマのテーブル | 150000 | 家具 | | 2 | 2 | げーたるーど2000 500ml | 370 | 飲料 | | 3 | 3 | 原始肉 | 2500 | 食品 | | 1 | 4 | 魅惑の椅子 | 100000 | 家具 | +-------------+---------+------------------------+--------+---------------+ 4 rows in set (0.00 sec) mysql> SELECT * FROM items; +---------+------------------------+--------+-------------+ | item_id | name | price | category_id | +---------+------------------------+--------+-------------+ | 1 | ローマのテーブル | 150000 | 1 | | 2 | げーたるーど2000 500ml | 370 | 2 | | 3 | 原始肉 | 2500 | 3 | | 4 | 魅惑の椅子 | 100000 | 1 | +---------+------------------------+--------+-------------+ 4 rows in set (0.00 sec) mysql> SELECT * FROM item_category; +-------------+---------------+ | category_id | category_name | +-------------+---------------+ | 1 | 家具 | | 2 | 飲料 | | 3 | 食品 | +-------------+---------------+ 3 rows in set (0.00 sec) mysql> SELECT * FROM items INNER JOIN item_category USING(category_id); +-------------+---------+------------------------+--------+---------------+ | category_id | item_id | name | price | category_name | +-------------+---------+------------------------+--------+---------------+ | 1 | 1 | ローマのテーブル | 150000 | 家具 | | 2 | 2 | げーたるーど2000 500ml | 370 | 飲料 | | 3 | 3 | 原始肉 | 2500 | 食品 | | 1 | 4 | 魅惑の椅子 | 100000 | 家具 | +-------------+---------+------------------------+--------+---------------+ 4 rows in set (0.00 sec) mysql> SELECT * FROM items INNER JOIN item_category USING(category_id) as ktable; ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'as ktable' at line 1 mysql> CREATE table SELECT * FROM items INNER JOIN item_category USING(category_id); ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'SELECT * FROM items INNER JOIN item_category USING(category_id)' at line 1 mysql> SELECT * FROM items INNER JOIN item_category USING(category_id); +-------------+---------+------------------------+--------+---------------+ | category_id | item_id | name | price | category_name | +-------------+---------+------------------------+--------+---------------+ | 1 | 1 | ローマのテーブル | 150000 | 家具 | | 2 | 2 | げーたるーど2000 500ml | 370 | 飲料 | | 3 | 3 | 原始肉 | 2500 | 食品 | | 1 | 4 | 魅惑の椅子 | 100000 | 家具 | +-------------+---------+------------------------+--------+---------------+ 4 rows in set (0.00 sec) mysql> SELECT * FROM category_id ORFER BY price; ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'BY price' at line 1 mysql> SELECT * FROM items INNER JOIN item_category USING(category_id); +-------------+---------+------------------------+--------+---------------+ | category_id | item_id | name | price | category_name | +-------------+---------+------------------------+--------+---------------+ | 1 | 1 | ローマのテーブル | 150000 | 家具 | | 2 | 2 | げーたるーど2000 500ml | 370 | 飲料 | | 3 | 3 | 原始肉 | 2500 | 食品 | | 1 | 4 | 魅惑の椅子 | 100000 | 家具 | +-------------+---------+------------------------+--------+---------------+ 4 rows in set (0.00 sec) mysql> SELECT * FROM ORFER BY price; ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'BY price' at line 1 mysql> SELECT * FROM items INNER JOIN item_category USING(category_id) ORDER BY price; +-------------+---------+------------------------+--------+---------------+ | category_id | item_id | name | price | category_name | +-------------+---------+------------------------+--------+---------------+ | 2 | 2 | げーたるーど2000 500ml | 370 | 飲料 | | 3 | 3 | 原始肉 | 2500 | 食品 | | 1 | 4 | 魅惑の椅子 | 100000 | 家具 | | 1 | 1 | ローマのテーブル | 150000 | 家具 | +-------------+---------+------------------------+--------+---------------+ 4 rows in set (0.00 sec)