mysql - 无法添加外键 MySQL :errno 150

Question

我尝试添加外键:

   CREATE TABLE `invoices` (
   `id` int(11) NOT NULL AUTO_INCREMENT,
  ` name` varchar(255) NOT NULL,
   `code_text` text NOT NULL,
   PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;




  CREATE TABLE `leads` (
  `lead_id` int(11) NOT NULL AUTO_INCREMENT,
   ...
   PRIMARY KEY (`lead_id`)
  );



CREATE TABLE `leads_invoices` (
leads_invoice_id int(11) AUTO_INCREMENT NOT NULL,
   invoice_id int(11) NOT NULL,
   lead_id_i  int(11) NOT NULL,
   PRIMARY KEY(leads_invoice_id),
    FOREIGN KEY (invoice_id) REFERENCES invoices(id),
    FOREIGN KEY (lead_id_i) REFERENCES leads(lead_id)
    ON UPDATE CASCADE
    ON DELETE RESTRICT
) ENGINE=InnoDB DEFAULT CHARSET=utf8

但是我的 lead_id_i key 出错了:

Can't create table crm_test.leads_invoices (errno: 150 "Foreign key constraint is incorrectly formed")

我检查了所有类型和表格，似乎它们是正确的.. 我怎么解决这个问题？希望你能帮助我。谢谢!

Answer 1

您必须将 ENGINE=InnoDB DEFAULT CHARSET=utf8 添加到 leads 表

CREATE TABLE `leads` (
  `lead_id` int(11) NOT NULL AUTO_INCREMENT,
   ...
   PRIMARY KEY (`lead_id`)
  )ENGINE=InnoDB DEFAULT CHARSET=utf8;

因为如果要加外键，两个表必须有相同的引擎