如何创建两个与外键链接的表

Question

This is my problem: I´m working in a database named David , there I´m trying to create two tables: colores and productos which will be linked by a foreign key where the father table will be colores and the son table will be productos , but when I click continue this message appears:

errno: 150 "Foreign key constraint is incorrectly formed"

someone could help me?

This is the code that I wrote:

create table `color`(
    id_color int(3)not null AUTO_INCREMENT,
    nombre varchar(30)not null,
    PRIMARY KEY(id_color)
) ENGINE=INNODB;


create table`producto`(
    id_producto int(3)NOT null AUTO_INCREMENT,
    nombre varchar(30)not null,
    id_color int(3)not null,
    precio decimal(10) not null,
    PRIMARY KEY(id_producto),
    INDEX(id_color),
    FOREIGN KEY(id_color)
    REFERENCES`color`(id_color) on UPDATE CASCADE
) ENGINE= INNODB;

This is the code that I wrote.

This is the error that appears.

Answer 1

The problem technically is just the missing space after the word references but the whole thing needs a few more spaces.

create table `color`(
    id_color int(3) not null AUTO_INCREMENT,
    nombre varchar(30) not null,
    PRIMARY KEY(id_color)
) ENGINE=INNODB;

create table`producto`(
    id_producto int(3) NOT null AUTO_INCREMENT,
    nombre varchar(30) not null,
    id_color int(3) not null,
    precio decimal(10) not null,
    PRIMARY KEY(id_producto),
    INDEX(id_color),
    FOREIGN KEY(id_color)
    REFERENCES `color`(id_color) on UPDATE CASCADE
) ENGINE= INNODB;

Also, NOT NULL is not necessary on PK columns. Just saying. It becomes automatic and redundant.