sql - 在 PostgreSql 中获取 "number of referencing and referenced columns for foreign key disagree"

Question

我在 pgAdmin 4 中创建了一些表，但由于某种原因我一直收到标题错误，你能找出原因吗？我没有看到任何问题，并且我已经查看了与我的代码示例相似的其他代码示例，这些示例编译得很好。它在 IDEone ( http://ideone.com/ZBn2Nr ) 中也运行正常。

谢谢!

Create table item
    (iname varchar(30) primary key,
    itype varchar(30));

Create table Cafe
    (license numeric(5,0) primary key,
    cname varchar(30),
    address varchar(30));

Create table Client
    (cid numeric(5,0) primary key,
    name varchar(30),
    phone numeric(9,0));

Create table Likes
    (cid numeric(5,0),
    iname varchar(30),
    primary key(cid,iname),
    foreign key(cid) references Client,
    foreign key(iname) references item);

Create table Sells
    (license numeric(5,0),
    iname varchar(30),
    price float check(price > 0),
    primary key(license,iname),
    foreign key(license) references Cafe,
    foreign key(iname) references item);

Create table Receipt
    (cid numeric(5,0),
    rno numeric(5,0),
    license numeric(5,0),
    rdate date,
    primary key(cid,rno),
    foreign key(cid) references Client,
    foreign key(license) references Cafe);

Create table Buys
    (cid numeric(5,0),
    rno numeric(5,0),
    iname varchar(30),
    amount int check(amount > 0),
    primary key(cid,rno,iname),
    foreign key(cid) references Client,
    foreign key(rno) references Receipt,
    foreign key(iname) references item);

Answer 1

当您未在引用子句中指定列列表时，它将扩展为引用表的主键。

例如:

foreign key(rno) references Receipt

扩展为

foreign key(rno) references Receipt(cid,rno)

所以列数不​​匹配