Question

我在插入与另一个表具有循环关系的表时遇到问题。在下面的模式中，每个表都有一个引用另一个的外键：

create table SUPPLIERS (
    SName varchar(60) primary key, 
    SAddress varchar(60) not null,
    PCategory varchar(60) unique references PRODUCTS deferrable initially deferred
);

create table PRODUCTS (
    Prodname varchar(60) primary key,  
    SName varchar(60) unique references SUPPLIERS deferrable initially deferred,
    PCategory varchar(60) not null,
    Price real not null
);

现在，当我执行这些陈述时：

insert into SUPPLIERS values
    ('Babolat', 'Topanga', 'Sports'),
    ('Infusium', 'Los Angeles', 'Beauty'),
    ('Market Pantry', 'San Jose', 'Food'),
    ('Staples', 'Burbank', 'Office')
;
insert into PRODUCTS values
    ('Tennis racket', 'Babolat', 'Sports', 100),
    ('Shampoo', 'Infusium', 'Beauty', 10),
    ('Water', 'Market Pantry', 'Food', 3),
    ('Paper', 'Staples', 'Office', 20)
;

抛出以下错误：

ERROR:  relation "products" does not exist

********** Error **********

ERROR: relation "products" does not exist
SQL state: 42P01

我尝试使用deferred关键字来让服务器执行插入操作并在事务完成后执行外键检查，但仍然会抛出错误。有什么想法吗？

Answer 1

像这样：

ALTER TABLE SUPPLIERS DROP CONSTRAINT SUPPLIERS_fkey;

insert into SUPPLIERS values
('Babolat', 'Topanga', 'Sports'),
('Infusium', 'Los Angeles', 'Beauty'),
('Market Pantry', 'San Jose', 'Food'),
('Staples', 'Burbank', 'Office');


insert into PRODUCTS values
('Tennis racket', 'Babolat', 'Sports', 100),
('Shampoo', 'Infusium', 'Beauty', 10),
('Water', 'Market Pantry', 'Food', 3),
('Paper', 'Staples', 'Office', 20);

ALTER TABLE SUPPLIERS
 ADD CONSTRAINT SUPPLIERS_fkey FOREIGN KEY (PCategory)
  REFERENCES products (PCategory) MATCH SIMPLE
  ON UPDATE NO ACTION ON DELETE NO ACTION DEFERRABLE INITIALLY DEFERRED;

无法插入到彼此引用的表中（PostgreSQL）

1 个答案: