Question

我正在尝试创建一个在名为“country”的表中具有外键的表，如下所示：

CREATE TABLE country (
   name varchar2(50),
   region varchar2(60),
   area number(10,0),
   population number(11,0),
   gdp number,
   CONSTRAINT country_PK primary key (name)
 );

每次我尝试在“City”创建表中引用“country”时，我都会收到此错误ORA-00904 ::标识符无效。有人可以告诉我我做错了什么吗？谢谢。

CREATE TABLE City(
CityName varchar2(50) not null,
CityCountry varchar2(60),
CityPopulation number(11,0),
IsCapital char(1),
CONSTRAINT CityName_pk PRIMARY KEY (CityName),
CONSTRAINT CityCountry_fk FOREIGN KEY (CityCountry) REFERENCES country (name),
);

Answer 1

从,表DDL的最后一行删除尾随逗号Country

CONSTRAINT CityCountry_fk FOREIGN KEY (CityCountry) REFERENCES country (name),

应该成为：

CONSTRAINT CityCountry_fk FOREIGN KEY (CityCountry) REFERENCES country (name)

无法使用外键创建表。错误：ORA-00904 ::标识符无效

1 个答案: