尝试使用 SQL 从多个表中删除

Question

我的应用程序中有 4 个表：

• 用户
• 用途
• 上行列表
• 项目共享

最后三个表包含一个名为 的字段session_id。

在下面的代码中，括号中的部分用于session_id从usession用户“awpeople”的表中获取所有值。

问题是如何将这个结果集读入一个数组并从session_id数组结果中的所有三个表中删除。

代码：

DELETE FROM usession, 
            upklist, 
            projshar 
WHERE  session_id = (SELECT session_id 
                     FROM   usession 
                     WHERE  delete_session_id IS NULL 
                            AND user_id = (SELECT user_id 
                                           FROM   users 
                                           WHERE  REGEXP_LIKE(USER_NAME, 
                                                  'awpeople', 'i'))); 

Answer 1

delete 一次只能处理一张表，所以你需要三个语句：

DELETE FROM upklist 
WHERE  session_id = (SELECT session_id 
                     FROM   usession 
                     WHERE  delete_session_id IS NULL 
                            AND user_id = (SELECT user_id 
                                           FROM   users 
                                           WHERE  REGEXP_LIKE(USER_NAME, 
                                                  'awpeople', 'i'))); 

DELETE FROM projshar 
WHERE  session_id = (SELECT session_id 
                     FROM   usession 
                     WHERE  delete_session_id IS NULL 
                            AND user_id = (SELECT user_id 
                                           FROM   users 
                                           WHERE  REGEXP_LIKE(USER_NAME, 
                                                  'awpeople', 'i'))); 

DELETE FROM usession 
WHERE  session_id = (SELECT session_id 
                     FROM   usession 
                     WHERE  delete_session_id IS NULL 
                            AND user_id = (SELECT user_id 
                                           FROM   users 
                                           WHERE  REGEXP_LIKE(USER_NAME, 
                                                  'awpeople', 'i'))); 

请注意，由于内部查询依赖于usersession，您应该最后从中删除。