postgresql中的可延迟初始延迟
我在两个表上有一个循环外键,所以我使用Delerable Initial deferred,如下所示:postgresql中的可延迟初始延迟,sql,foreign-keys,postgresql,deferrable-constraint,Sql,Foreign Keys,Postgresql,Deferrable Constraint,我在两个表上有一个循环外键,所以我使用Delerable Initial deferred,如下所示: uni=# create table vorlesungen (vnr integer primary key, gelesenvon integer); NOTICE: CREATE TABLE / PRIMARY KEY will create implicit index "vorlesungen_pkey" for table "vorlesungen" CREATE TABLE u
uni=# create table vorlesungen (vnr integer primary key, gelesenvon integer);
NOTICE: CREATE TABLE / PRIMARY KEY will create implicit index "vorlesungen_pkey" for table "vorlesungen"
CREATE TABLE
uni=# create table professoren (pnr integer primary key, lieblingsvo integer);
NOTICE: CREATE TABLE / PRIMARY KEY will create implicit index "professoren_pkey" for table "professoren"
CREATE TABLE
uni=# alter table professoren add constraint vfk foreign key (lieblingsvo) references vorlesungen (vnr) deferrable initially deferred;
ALTER TABLE
uni=# alter table vorlesungen add constraint pfk foreign key (gelesenvon) references professoren (pnr) deferrable initially deferred;
ALTER TABLE
到目前为止还不错。
但是现在,当我想插入到表中时,我会遇到外键冲突,尽管我指定了delferrable initially deferred:
uni=# insert into vorlesungen values (1, 1);
ERROR: insert or update on table "vorlesungen" violates foreign key constraint "pfk"
DETAIL: Key (gelesenvon)=(1) is not present in table "professoren".
uni=# insert into professoren values (1, 1);
ERROR: insert or update on table "professoren" violates foreign key constraint "vfk"
DETAIL: Key (lieblingsvo)=(1) is not present in table "vorlesungen".
有什么问题吗?您是否在 插页?如果不使用BEGIN,则每个insert都是一个独立的事务,因此在每个命令的末尾强制使用外键