通过 My-SQL Workbench 在 SQL 中添加外键给出错误 1064

Question

我想将外键添加到名为“地址”的 table。

ALTER TABLE `students1`.`address` 
ADD CONSTRAINT `id_country`
FOREIGN KEY ()
REFERENCES `students1`.`country` ()
ON DELETE NO ACTION
ON UPDATE NO ACTION;

此请求由 MySQLWorkbench 自动生成。但是得到这个错误

ERROR 1064: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ')
REFERENCES `students1`.`country` ()
ON DELETE NO ACTION
ON UPDATE NO ACT' at line 3

如何解决这个问题？

Answer 1

我不知道你的两个表是否有相同的列id_country。

但这种情况下的语法是：

ALTER TABLE `students1`.`address` 
    ADD CONSTRAINT 
    FOREIGN KEY (`id_country`)
    REFERENCES `students1`.`country`(`id_country`)
    ON DELETE NO ACTION
    ON UPDATE NO ACTION;

通过 My-SQL Workbench 在 SQL 中添加外键给出错误 1064

Add Foreign Key in SQL by My-SQL Workbench gives Error 1064

mysql

sql

foreign-keys

mysql-workbench