Postgresql继承和外键引用父表
我已经记录了这一点,并阅读了其他用户关于这一点的帖子,但在我的例子中,引用应该可以正常工作:我有几个表扩展了一个“实体”表,一个“关联”表只引用了“实体”表。所以我只引用拥有其他所有表id的父表Postgresql继承和外键引用父表,postgresql,postgresql-9.1,Postgresql,Postgresql 9.1,我已经记录了这一点,并阅读了其他用户关于这一点的帖子,但在我的例子中,引用应该可以正常工作:我有几个表扩展了一个“实体”表,一个“关联”表只引用了“实体”表。所以我只引用拥有其他所有表id的父表 ERROR: insert or update on table "association" violates foreign key constraint "association_id1_fkey" DETAIL: Key (id1)=(1) is not present in table "e
ERROR: insert or update on table "association" violates foreign key constraint "association_id1_fkey"
DETAIL: Key (id1)=(1) is not present in table "entity".
这是我正在使用的模式
CREATE TABLE entity (
id serial primary key,
created_at int,
updated_at int,
deleted_at int
);
CREATE TABLE association (
id1 int references entity(id) on delete cascade on update cascade,
atype varchar,
id2 int references entity(id) on delete cascade on update cascade,
created_at int,
deleted_at int
);
CREATE TABLE "user" (
first_name varchar(255),
last_name varchar(255)
)INHERITS(entity);
CREATE TABLE "pet" (
name varchar(255)
)INHERITS(entity);
INSERT INTO "user" (first_name) VALUES ('damiano');
INSERT INTO "user" (first_name) VALUES ('francesco');
INSERT INTO "user" (first_name) VALUES ('romolo');
INSERT INTO "pet" (name) VALUES ('baloo');
INSERT INTO "pet" (name) VALUES ('micia');
INSERT INTO "pet" (name) VALUES ('ioria');
INSERT INTO "association" VALUES (1, 'pets', 4, 0, 0);
INSERT INTO "association" VALUES (1, 'pets', 5, 0, 0);
INSERT INTO "association" VALUES (2, 'pets', 4, 0, 0);
INSERT INTO "association" VALUES (2, 'pets', 5, 0, 0);
INSERT INTO "association" VALUES (3, 'pets', 6, 0, 0);
正确插入行:
testing=# select * from "entity";
id | created_at | updated_at | deleted_at
----+------------+------------+------------
1 | | |
2 | | |
3 | | |
4 | | |
5 | | |
6 | | |
(6 rows)
testing=# select * from "user";
id | created_at | updated_at | deleted_at | first_name | last_name
----+------------+------------+------------+------------+-----------
1 | | | | damiano |
2 | | | | francesco |
3 | | | | romolo |
(3 rows)
testing=# select * from "pet";
id | created_at | updated_at | deleted_at | name
----+------------+------------+------------+-------
4 | | | | baloo
5 | | | | micia
6 | | | | ioria
(3 rows)
testing=#
父表不包含继承表中的所有数据。从该表中选择实际上会对继承的表执行一个联合
比较这些:
SELECT * FROM "entity";
SELECT * FROM ONLY "entity";
这就是为什么继承没有被更多地使用。实体表有记录?是的,更新我的问题以包括select STATS您需要通过ops!那我就不能做我想做的事了对吗?我需要使用一些触发器来保持完整性?我只想完全避免继承,除非你(1)有时间完全理解它,(2)有令人信服的理由喜欢它而不是标准的关系实践。它可以有效地使用,但不经常使用。