不能在mysql中添加外鍵約束

Question

create table buys ( 
user_id INT(11) not null,  
software_id INT(11) not null,  
associated_id INT(11) not null,  
primary key (associated_id),  
foreign key (software_id) references software,  
foreign key (user_id) references users,  
foreign key (associated_id) references associated); 

我有全員參與，一鍵約束的三元關係，關聯表，但不能添加外鍵約束

Answer 1

檢查以下查詢：

CREATE TABLE products(
    prd_id int not null auto_increment primary key, 
    cat_id int not null, 
    FOREIGN KEY fk_cat(cat_id) 
    REFERENCES categories(cat_id) 
)ENGINE=InnoDB; 

你的情況：

foreign key (software_id) references software -> here column name is missing in software table