php - 如何解决mysql代码的errno 150？

Question

为什么创建第二个表(标签)时出现错误？

$sql = "CREATE TABLE IF NOT EXISTS Articls (
            id INT(10) UNSIGNED AUTO_INCREMENT PRIMARY KEY,     
            name VARCHAR(254) COLLATE utf8_persian_ci NOT NULL,                     
            alias INT(10) UNSIGNED NOT NULL
)   DEFAULT COLLATE utf8_persian_ci";


/////////////////////////////////////////////////////////////////////////

$sql = "CREATE TABLE IF NOT EXISTS Tags (
            id INT(10) UNSIGNED AUTO_INCREMENT PRIMARY KEY,  
            alias INT(10) UNSIGNED NOT NULL,    
            name VARCHAR(256) COLLATE utf8_persian_ci NOT NULL,    
            FOREIGN KEY (alias) REFERENCES Articls (alias)      
) DEFAULT COLLATE utf8_persian_ci";

错误:

Table Articls created successfully / Error creating Tags: Can't create table 'admin_pars.Tags' (errno: 150)

Answer 1

您的外键引用正在引用 Articles 中的任意列。要么你想要:

FOREIGN KEY (alias) REFERENCES Articls (id)  
                                      //^^ 

或者，您希望将 alias 声明为 Articles 中的唯一键。