mysql事务（ddl隐式提交）

DDL为隐式提交若出如今begin与rollback之间，则会直接提交ddl以前的语句，以下：

begin;
select * from test;
update test set add='25-933-733-123444' where ID=1;#未提交
delete fromorder where orderID=2;#已提交
truncate test;#已提交
select * from test;#已提交
drop table dbshards.aly_test;#已提交
show tables from dbshards like 'test';#已提交
create table test (orderID int);#已提交
insert into dbshards.aly_test (orderID) values (1),(2),(3),(4);#已提交
select * from dbshards.aly_test;#已提交
rollback;#无效

在遇到第一句ddl语句执行以后，已commit，致使最后的rollback不起做用

 [即便设置 autocommit为false，依然没法回滚]

mysql> show variables like 'autocommit';
+---------------+-------+
| Variable_name | Value |
+---------------+-------+
| autocommit | OFF |
+---------------+-------+