Question

我有三个表：clients，items和client_has_item。

CREATE TABLE clients (id_c serial primary key, name text);

CREATE TABLE items (id_i serial primary key, name text);

CREATE TABLE client_has_item 
  (id_c int references clients (id_c),
  id_i int references items (id_i));


INSERT INTO clients (name) values ('client a'), ('client b');
INSERT INTO items (name) values ('item a'), ('item a');

请注意，客户可以拥有多个项目，一个项目可以由多个客户拥有，而且名称不是唯一的。

如果我想为一个客户端插入一些项目（1，'客户端a'），那很简单：

WITH inserted_items as (
   INSERT INTO items (name) values ('item a'), ('item b')
   RETURNING id_i
)
INSERT INTO client_has_item (id_c, id_i) select 1, id_i from inserted_items

我的问题是如何为几个客户执行此操作。理想情况下我会这样做：

 WITH inserted_items as (
   INSERT INTO items (name) SELECT new_items.item_name from (values (1, 'item a'), (2, 'item b')) new_items (id_client, item_name)
   RETURNING items.id_i, new_items.id_client
)
INSERT INTO client_has_item (id_c, id_i) select id_client, id_i from inserted_items

但是我收到以下错误：

RETURNING items.id_i, new_items.id_client

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

ERROR: missing FROM-clause entry for table "new_items"

什么是最好的选择？当然我可以做一个循环，但我想避免这种情况。

插入关系表并返回

0 个答案: