Question

我创建了一些看起来像这样的表

CREATE TABLE sickness
(
sickness_id     number(2),
sickness_name   varchar2(20),
PRIMARY KEY (sickness_id)
);

CREATE TABLE cover
(
cover_needed char(1) NOT NULL,
employee_id number(3),
responsibilities varchar2(50),
notes varchar2(50),
PRIMARY KEY (cover_needed, employee_id)
);

这很好用然后当我尝试制作一个父表（见下文）时，我得到了错误。

ORA-02270: no matching unique or primary key for this column-list

然而，我把它缩小到最后一行，但我不能为我的生活弄清楚，谢谢

CREATE TABLE absences
(
absences_id  number(2) NOT NULL,
manager_id number(3),
employee_id number(3) NOT NULL,
absence_name varchar2(15) NOT NULL,
sickness_id number(2),
date_from date NOT NULL,
date_to date NOT NULL,
length number(2) NOT NULL,
description varchar2(40),  
authorised_by_manager char(1) NOT NULL,
cover_needed char(1) NOT NULL,
half_day char(1) NOT NULL,

PRIMARY KEY (absences_id, manager_id, employee_id),

FOREIGN KEY (sickness_id)  REFERENCES sickness (sickness_id),
FOREIGN KEY (cover_needed) REFERENCES cover    (cover_needed)
);

Answer 1

这是您定义cover：

的方法

CREATE TABLE cover (
    . . .
    **PRIMARY KEY (cover_needed, employee_id)**
);

您有一个复合主键。外键引用需要引用两个键。。。并以相同的顺序。

所以：

FOREIGN KEY (cover_needed, employee_id)
    REFERENCES cover (cover_needed, employee_id)

如果您使用自动生成的数字主键，我认为您的数据结构和查询会更简单。这将简化外键关系并简化连接表的查询。

SQL ORA-02270：此列列表没有匹配的唯一键或主键

1 个答案: