我已经定义了我的表：
create table device (
id serial primary key,
manufacturerid integer references manufacturer(id) on delete restrict,
model text,
price real,
usagepros text,
usagecons text
);
create table robot (
numaxes integer,
capacity real,
reach real,
accuracy real,
installmethodid integer references installmethod(id) on delete restrict,
mass real
) inherits (device);
create table robotComplex(
id serial primary key,
name text
);
create table robotComplexDevice(
id serial primary key,
deviceId integer references device(id) on delete restrict,
robotcomplexid integer references robotcomplex(id) on delete cascade
);
etc...
运行 sql 命令时，我得到以下信息：
id | manufacturerid | model | price | usagepros | usagecons | numaxes | capacity | reach | accuracy | installmethodid | mass
-----+----------------+-------+-------+-----------+-----------+---------+----------+-------+----------+-----------------+-------
159 | 117 | Robot | 100.3 | OK | NoOK | 6 | 15.3 | 15.4 | 76.1234 | 45 | 100.1
> select * from device;
id | manufacturerid | model | price | usagepros | usagecons
-----+----------------+-------+-------+-----------+-----------
159 | 117 | Robot | 100.3 | OK | NoOK
> select * from robotcomplex;
id | name
----+--------------
27 | Complex
> insert into robotcomplexdevice (deviceid, robotcomplexid) values (159, 27);
ERROR: insert or update on table "robotcomplexdevice" violates foreign key constraint "robotcomplexdevice_deviceid_fkey"
DETAIL: Key (deviceid)=(159) is not present in table "device".
出于某种原因，即使我已经定义了“机器人”表来继承“设备”表，我也无法引用它。也许我没有正确获得对象关系数据库模型。但是，如果您不能引用这些表，那么对象关系模型的意义何在？