PostgreSQL的“Deferrable Delete”仍然符合Delete的限制

我希望在SQL事务/数据库补丁中删除某些表中的条目’delete_from_me’.问题是,我想在松开链接本身之前根据第二个表’constraining_table’中的选择进行删除.

这是两个表的描述：

tab-quarantine=> d delete_from_me
       Table "public.delete_from_me"
  Column   |       Type        | Modifiers 
-----------+-------------------+-----------
 id        | character varying | not null
 extension | character varying | not null
Indexes:
    "delete_from_me_pkey" PRIMARY KEY,btree (id)

tab-quarantine=> d constraining_table 
   Table "public.constraining_table"
 Column |       Type        | Modifiers 
--------+-------------------+-----------
 image  | character varying | not null
 type   | character varying | not null
Foreign-key constraints:
    "constraining_table_image_fkey" FOREIGN KEY (image) REFERENCES delete_from_me(id)
         ON UPDATE CASCADE
         ON DELETE RESTRICT DEFERRABLE

这是我刚刚在那里抨击的一些示例数据：

tab-quarantine=> SELECT * FROM delete_from_me;
     id     | extension 
------------+-----------
 12345abcde | png
(1 row)

tab-quarantine=> SELECT * FROM constraining_table;
   image    |   type   
------------+----------
 12345abcde | select_me
(1 row)

这是我的交易：

BEGIN;
set ON_ERROR_STOP 1
SET CONSTRAINTS ALL DEFERRED;
DELETE FROM delete_from_me WHERE id IN (
    SELECT image FROM constraining_table WHERE type = 'select_me'
);
DELETE FROM constraining_table WHERE type = 'select_me';
COMMIT;

此交易失败.当我单步执行并手动执行此操作时,出现以下错误消息：

ERROR:  update or delete on table "delete_from_me" violates foreign key constraint "constraining_table_image_fkey" on table "constraining_table"
DETAIL:  Key (id)=(12345abcde) is still referenced from table "constraining_table".

这似乎是临时表的一个很好的候选者,但是我想知道为什么我不能按此顺序删除,因为约束在事务结束之前不应该有效？