我在尝试将数据库加载到MySQL时遇到问题,因为我的外键有一些错误。我试图解决这个问题的方法是: - 将外键放在主键之后 例如:
CREATE TABLE IF NOT EXISTS Passenger (
.......
PRIMARY KEY(tNum),
FOREIGN KEY (fNum) REFERENCES Flights(fNum),
FOREIGN KEY (fDate) REFERENCES Flights(fDate),
FOREIGN KEY (sCity) REFERENCES Flights(sCity),
FOREIGN KEY (eCity) REFERENCES Flights(eCity)
);
- 以格式聚合外键 例如:
ALTER TABLE Passenger ADD FOREIGN KEY (fNum, fDate, sCity, eCity) REFERENCES Flights(fNum, fDate, sCity, eCity);
我得到的错误是:
我的完整代码是:
DROP DATABASE IF EXISTS airline;
CREATE DATABASE IF NOT EXISTS airline;
USE airline;
CREATE TABLE IF NOT EXISTS Flights (
fNum char(6) not null,
pID char(4) not null,
fDate DATE not null,
eDate DATE not null,
sTime char(4) not null,
lTime char(4) not null,
sOStart char(4) null,
sOEnd char(4) null,
sCity varchar(30) not null,
eCity varchar(30) not null,
sOCity varchar(30),
sNum char(5) not null,
PRIMARY KEY (fNum)
);
CREATE TABLE IF NOT EXISTS Passenger (
tNum char(4) not null,
dPurch DATE not null,
pMethod varchar(30) not null,
fNum char(6) not null,
fDate DATE not null,
sCity varchar(30) not null,
eCity varchar(30) not null,
tType varchar(30) not null,
Price decimal(4,2) not null,
iType varchar(30) not null,
idNum char(8) not null,
fName varchar(30) not null,
lName varchar(30) not null,
Sex char(1) not null,
pAddress varchar(30) not null,
pPhone char(8) not null,
pEmail varchar(30) not null,
PRIMARY KEY(tNum)
);
CREATE TABLE IF NOT EXISTS Planes (
pID char(4) not null,
pType char(3) not null,
pDesc varchar(30) not null,
pRange char(4) not null,
Capacity char(3) not null,
mDate DATE not null,
pDate DATE not null,
sDate DATE not null,
PRIMARY KEY (pID)
);
CREATE TABLE IF NOT EXISTS Staff (
sNum char(5) not null,
sName varchar(30) not null,
sDOB DATE not null,
sAddress varchar(30) not null,
pCompany varchar(30) ,
pStart DATE ,
pEnd DATE ,
jID char(1) not null,
PRIMARY KEY (sNum)
);
CREATE TABLE IF NOT EXISTS Emergency (
eID char(5) not null,
sNum char(5) not null,
eName varchar(30) not null,
eAddress varchar(30) not null,
ePhone char(8) not null,
eEmail varchar(30) not null,
eRelationship varchar(30) not null,
PRIMARY KEY(eID)
);
CREATE TABLE IF NOT EXISTS Pilot (
sNum char(5) not null,
pID char(4) not null,
cDate DATE not null,
jID char(1) not null,
PRIMARY KEY(jID)
);
CREATE TABLE IF NOT EXISTS Attendant (
sNum char(5) not null,
tSDate Date not null,
tFDate Date not null,
tDesc Varchar(30) not null,
jID Char(1) not null,
PRIMARY KEY(jID)
);
ALTER TABLE Flights ADD FOREIGN KEY (pID) REFERENCES Planes(pID);
ALTER TABLE Flights ADD FOREIGN KEY (sNum) REFERENCES Staff(sNum);
ALTER TABLE Passenger ADD FOREIGN KEY (fNum) REFERENCES Flights(fNum);
ALTER TABLE Passenger ADD FOREIGN KEY (fDate) REFERENCES Flights(fDate);
ALTER TABLE Passenger ADD FOREIGN KEY (sCity) REFERENCES Flights(sCity);
ALTER TABLE Passenger ADD FOREIGN KEY (eCity) REFERENCES Flights(eCity);
ALTER TABLE Emergency ADD FOREIGN KEY (sNum) REFERENCES Staff(sNum);
ALTER TABLE Pilot ADD FOREIGN KEY (sNum) REFERENCES Staff(sNum);
ALTER TABLE Pilot ADD FOREIGN KEY (pID) REFERENCES Planes(pID);
ALTER TABLE Pilot ADD FOREIGN KEY (jID) REFERENCES Staff(jID);
ALTER TABLE Attendant ADD FOREIGN KEY (sNum) REFERENCES Staff(sNum);
ALTER TABLE Attendant ADD FOREIGN KEY (jID) REFERENCES Staff(jID);
答案 0 :(得分:1)
对我来说,这是第一次失败的那个
ALTER TABLE Passenger ADD FOREIGN KEY (fDate) REFERENCES Flights(fDate);
首先尝试在Flights.fdate上添加索引,然后执行外键并执行其他引用,直到它工作为止。如果这对您有用,请告诉我,它对我有用。
顺便说一下,您可能希望重新考虑您的架构。连接和关系应该只在整数上完成。随着模式的发展,这种模式会很快陷入困境。此外,也许这只是个人偏好,但我更喜欢first_name到fName。对于其他开发人员来说更容易阅读,这不是1986年,我们现在可以拥有人类可读的名字: - )