＆＃39; DROP＆＃39;表内触发器 - MySQL

Question

我有一张桌子＆＃39; chat_record＆＃39;其中有一列＆＃39; chat_id＆＃39;。对于每个聊天内容＆＃39;存在同名表。现在我想创建一个触发器，以便在删除chat_record的条目时删除该表。 这是我的代码 - **

create trigger drop_table before delete on chat_record
for each row
begin
declare chatid varchar(20);
set @chatid=(select chat_id from chat_record where chat_id=old.chat_id);
drop table chatid;
end;

** 错误1422：不允许显式或隐式提交存储函数或触发器。

Answer 1

create or replace trigger drop_table1 before delete on chat_record
for each row
declare
chatid1 varchar(20);
pragma autonomous_transaction;
begin
select 1 into chatid1 from chat_record where chat_id=:old.chat_id;
if chatid1 = 1
then
   EXECUTE IMMEDIATE 'drop table chatid';
end if;
end;