Adding a foreign key in mySQL

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I'm still learning how to create tables in MySQL and I'm having some difficulty. If it were to create a table with your relationship, it would create like this: 

CREATE TABLE estilo (
    codigo BIGINT(20) PRIMARY KEY AUTO_INCREMENT,
    nome VARCHAR(50) NOT NULL
) ENGINE=InnoDB DEFAULT CHARSET=utf8;



CREATE TABLE cerveja (
    codigo BIGINT(20) PRIMARY KEY AUTO_INCREMENT,
    sku VARCHAR(50) NOT NULL,
    nome VARCHAR(80) NOT NULL,
    descricao TEXT NOT NULL,
    valor DECIMAL(10, 2) NOT NULL,
    teor_alcoolico DECIMAL(10, 2) NOT NULL,
    comissao DECIMAL(10, 2) NOT NULL,
    sabor VARCHAR(50) NOT NULL,
    origem VARCHAR(50) NOT NULL,
    codigo_estilo BIGINT(20) NOT NULL,
    FOREIGN KEY (codigo_estilo) REFERENCES estilo(codigo)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

To know how to add a foreign key to my table, let's assume my table looks like this: 

CREATE TABLE estilo (
    codigo BIGINT(20) PRIMARY KEY AUTO_INCREMENT,
    nome VARCHAR(50) NOT NULL
) ENGINE=InnoDB DEFAULT CHARSET=utf8;



CREATE TABLE cerveja (
    codigo BIGINT(20) PRIMARY KEY AUTO_INCREMENT,
    sku VARCHAR(50) NOT NULL,
    nome VARCHAR(80) NOT NULL,
    descricao TEXT NOT NULL,
    valor DECIMAL(10, 2) NOT NULL,
    teor_alcoolico DECIMAL(10, 2) NOT NULL,
    comissao DECIMAL(10, 2) NOT NULL,
    sabor VARCHAR(50) NOT NULL,
    origem VARCHAR(50) NOT NULL,
    codigo_estilo BIGINT(20) NOT NULL
 ) ENGINE=InnoDB DEFAULT CHARSET=utf8;

What command can be run in MySQL to add a foreign key? 

FOREIGN KEY (codigo_estilo) REFERENCES estilo(codigo)
    
asked by anonymous 12.09.2016 / 19:55

1 answer

1

Try this code, it works well in WorkBench 

alter table cerveja add foreign key(codigo_estilo) references estilo(codigo);
    
13.09.2016 / 03:38
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