Many-to-Many Tables SQL - mysql

Question

I have to do a many to many tables between a table MEAL and a table RESTAURANT. First I created the two tables:
CREATE TABLE RESTAURANT (
ID_Restaurant VARCHAR(10) NOT NULL,
ID_Hotel VARCHAR(10) NOT NULL,
Name VARCHAR(30) NOT NULL,
Number_of_Tables INT(3) NOT NULL,
PRIMARY KEY (ID_Restaurant),
FOREIGN KEY (ID_Hotel) REFERENCES HOTEL (ID_Hotel));
CREATE TABLE MEAL(
ID_Meal VARCHAR(10) NOT NULL,
Name VARCHAR(30) NOT NULL,
Preparation_Time VARCHAR(20),
Cooking_Time VARCHAR(20),
PRIMARY KEY (ID_Meal));
Then I created the 'joint' tables:
CREATE TABLE MEAL_SERVED(
ID_Meal VARCHAR(10) NOT NULL,
ID_Restaurant VARCHAR(10) NOT NULL,
Price INT(5) NOT NULL,
PRIMARY KEY (ID_Meal, ID_Restaurant, Price),
FOREIGN KEY(ID_Meal) REFERENCES MEAL(ID_Meal),
FOREIGN KEY(ID_Restaurant) REFERENCES RESTAURANT (ID_Restaurant));
I entered some data in the first two tables:
INSERT INTO RESTAURANT(ID_Restaurant, ID_Hotel, Name, Number_of_Tables)
VALUES ('REST1', 'H1', 'Benares Indisk Restaurant', 26);
('REST2', 'H2', 'La Gaichel', 35),
('REST3', 'H3', 'Tapas Restaurant', 17),
('REST4', 'H4', 'Faubourg 101', 19),
('REST5', 'H5', 'Pizzeria Roma', 38);
INSERT INTO MEAL(ID_Meal, Name, Preparation_Time, Cooking_Time)
VALUES ('MEAL1', 'Croque-Monsieur', '5 min', '4 min'),
('MEAL2', 'Salad', '6 min', NULL),
('MEAL3', 'Hot Dog', '3 min', '2min'),
('MEAL4', 'Panini', '6 min', '5 min'),
('MEAL5', 'Coca-Cola', NULL, NULL);
Until, now there is no problem, but when I tried to enter data in the third tables with:
INSERT INTO MEAL_SERVED(ID_Meal, ID_Restaurant, Price)
VALUES ('MEAL1', 'REST1', 50),
('MEAL4', 'REST1', 50),
('MEAL5', 'REST1', 35),
('MEAL1', 'REST2', 3.5),
('MEAL2', 'REST2', 3.5),
('MEAL4', 'REST2', 5);
for instance, then I have an error message:
FOREIGN KEY constraint failed: INSERT INTO MEAL_SERVED(ID_Meal, ID_Restaurant, Price)
I don't understand why I have this message and how to correct it. Thanks in advance.

Answer 1

As Shadow said in the comment section.
First, fix your typo in one of your SQL statements:
INSERT INTO RESTAURANT(ID_Restaurant, ID_Hotel, Name, Number_of_Tables)
VALUES ('REST1', 'H1', 'Benares Indisk Restaurant', 26);
('REST2', 'H2', 'La Gaichel', 35),
('REST3', 'H3', 'Tapas Restaurant', 17),
('REST4', 'H4', 'Faubourg 101', 19),
('REST5', 'H5', 'Pizzeria Roma', 38);
should be:
INSERT INTO RESTAURANT(ID_Restaurant, ID_Hotel, Name, Number_of_Tables)
VALUES ('REST1', 'H1', 'Benares Indisk Restaurant', 26),
('REST2', 'H2', 'La Gaichel', 35),
('REST3', 'H3', 'Tapas Restaurant', 17),
('REST4', 'H4', 'Faubourg 101', 19),
('REST5', 'H5', 'Pizzeria Roma', 38);
Second:
Do yourself a favor and use integers for primary keys and with the auto_increment option, you can just ignore the id.
CREATE TABLE RESTAURANT (
`id` INT NOT NULL AUTO_INCREMENT,
`hotel` INT NOT NULL,
`name` VARCHAR(30) NOT NULL,
`numberOfTables` INT NOT NULL,
PRIMARY KEY (`id`),
FOREIGN KEY (hotel) REFERENCES HOTEL (`id`));
CREATE TABLE MEAL(
`id` INT NOT NULL AUTO_INCREMENT,
`name` VARCHAR(30) NOT NULL,
`preparationTime` VARCHAR(20),
`cookingTime` VARCHAR(20),
PRIMARY KEY (`id`));
CREATE TABLE MEAL_SERVED(
`id` INT NOT NULL AUTO_INCREMENT,
`meal` INT NOT NULL,
`restaurant` INT NOT NULL,
Price FLOAT NOT NULL,
PRIMARY KEY (`id`),
FOREIGN KEY(meal) REFERENCES MEAL(`id`),
FOREIGN KEY(restaurant) REFERENCES RESTAURANT (`id`));
Data:
INSERT INTO RESTAURANT(`hotel`, `name`, `numberOfTables`)
VALUES ('1', 'Benares Indisk Restaurant', 26),
(2, 'La Gaichel', 35),
(3, 'Tapas Restaurant', 17),
(4, 'Faubourg 101', 19),
(5, 'Pizzeria Roma', 38);
INSERT INTO MEAL(`name`, `preparationTime`, `cookingTime`)
VALUES ('Croque-Monsieur', '5 min', '4 min'),
('Salad', '6 min', NULL),
('Hot Dog', '3 min', '2min'),
('Panini', '6 min', '5 min'),
('Coca-Cola', NULL, NULL);
INSERT INTO MEAL_SERVED(`meal`, `restaurant`, `price`)
VALUES (1, 1, 50),
(4, 1, 50),
(5, 1, 35),
(1, 2, 3.5),
(2, 2, 3.5),
(4, 2, 5);
Third:
INT(3) has no effects. The space for the INT will be allocated anyway.
You can use TINYINT or SMALLINT instad, maybe. Look here: https://dev.mysql.com/doc/refman/5.7/en/integer-types.html
Fourth:
Use camel-case or snake-case but not both please ;-)