我在设置第一个大学数据库时遇到了麻烦。我将不得不将公司和员工的钥匙引用到工作中。在一种关系中,员工只能在一家公司工作。
我不断得到一些错误,一个在主键之后,而且引用也没有真正起作用。
仅供参考:我正在研究postgresql。
我希望有人可以帮助我。谢谢你的帮助
CREATE SCHEMA p10_1_employee;
Set search_path to p10_1_employee;
CREATE TABLE employee(
firstname varchar(20) NOT NULL,
lastname varchar(20) NOT NULL,
CONSTRAINT cPKfirstnamelastname PRIMARY KEY(firstname, lastname)
);
CREATE TABLE company(
companyname varchar(20) NOT NULL,
CONSTRAINT cPKcompanyname PRIMARY KEY (companyname)
);
CREATE TABLE works (
personenname varchar(40),
companyname varchar(20)
CONSTRAINT cPKpersonennamecompanyname PRIMARY KEY (personenname, companyname)
CONSTRAINT cFKfirstnamelastname FOREIGN KEY (personenname) REFERENCES employee(firstname, lastname),
CONSTRAINT cFKcompanyname FOREIGN KEY (companyname) REFERENCES company(companyname)
);
你在works
表中有几个错误(缺少逗号和错误的引用列数)。这是一个工作脚本
CREATE TABLE works (
personenname_firstname varchar(20),
personenname_lastname varchar(40),
companyname varchar(20),
CONSTRAINT cPKpersonennamecompanyname PRIMARY KEY (personenname_firstname, personenname_lastname, companyname),
CONSTRAINT cFKfirstnamelastname FOREIGN KEY (personenname_firstname, personenname_lastname) REFERENCES employee,
CONSTRAINT cFKcompanyname FOREIGN KEY (companyname) REFERENCES company
);