Question

我有四张桌子：

CREATE TABLE t_users (
user_id varchar PRIMARY KEY,
user_email varchar
);

CREATE TABLE t_items (
item_id varchar PRIMARY KEY,
owner_id varchar not null references t_users(user_id),
title varchar
);

CREATE TABLE t_access_gropes (
access_group_id varchar PRIMARY KEY,
user_id varchar not null references t_users(user_id)
);

CREATE TABLE t_access_sets (
access_set_id varchar PRIMARY KEY,
item_id varchar not null references t_items(item_id),
access_group_id varchar not null references t_access_gropes(access_group_id)
);

使用数据：

INSERT INTO t_users VALUES ('us123', 'us123@email.com');
INSERT INTO t_users VALUES ('us456', 'us456@email.com');
INSERT INTO t_users VALUES ('us789', 'us789@email.com');

INSERT INTO t_items VALUES ('it123', 'us123', 'title1');
INSERT INTO t_items VALUES ('it456', 'us456', 'title2');
INSERT INTO t_items VALUES ('it678', 'us789', 'title3');
INSERT INTO t_items VALUES ('it323', 'us123', 'title4');
INSERT INTO t_items VALUES ('it764', 'us456', 'title5');
INSERT INTO t_items VALUES ('it826', 'us789', 'title6');
INSERT INTO t_items VALUES ('it568', 'us123', 'title7');
INSERT INTO t_items VALUES ('it038', 'us456', 'title8');
INSERT INTO t_items VALUES ('it728', 'us789', 'title9');

INSERT INTO t_access_gropes VALUES ('ag123', 'us123');
INSERT INTO t_access_gropes VALUES ('ag456', 'us456');
INSERT INTO t_access_gropes VALUES ('ag789', 'us789');

INSERT INTO t_access_sets VALUES ('as123', 'it123', 'ag123');
INSERT INTO t_access_sets VALUES ('as456', 'it456', 'ag123');

t_access_gropes 形成用户组。 t_access_sets 形成安全套件。

如何为用户提供获取所有项的请求。类似的东西：

select *
from t_items
inner join t_users on t_items.owner_id = t_users.user_id
inner join t_access_gropes on t_users.user_id = t_access_gropes.user_id
inner join t_access_sets on t_items.item_id = t_access_sets.item_id
where t_access_gropes.user_id = 'us123';

谢谢。

Answer 1

select u.user_id, u.email, i.item_id, i.title
from t_users u
  join t_items i on i.owner_id = u.user_id
where u.user_id = 'us123'

我相信这是您想要的确切要求！

否则你所写的内容很好，但我没有看到你在一起连接你的用户表和项目表时加入的表中的相关性，这就是为什么你不需要加入其他两个表（组和组））。通常在某些情况下，您会在users和items表之间找到user_items表。

内部联接请求以获取用户可用的项目

1 个答案: