Some statements cannot be rolled back. 某些语句无法回滚。In general, these include data definition language (DDL) statements, such as those that create or drop databases, those that create, drop, or alter tables or stored routines.通常，这些语句包括数据定义语言（DDL）语句，例如创建或删除数据库的语句，创建、删除或更改表或存储例程的语句。

You should design your transactions not to include such statements. 你应该设计你的交易不包括这样的陈述。If you issue a statement early in a transaction that cannot be rolled back, and then another statement later fails, the full effect of the transaction cannot be rolled back in such cases by issuing a ROLLBACK statement.如果您在事务的早期发出一条无法回滚的语句，随后另一条语句失败，则在这种情况下，无法通过发出ROLLBACK语句来回滚事务的全部效果。