DROP The DROP command removes a table from the database. All the tables' rows, indexes and privileges will also be removed. No DML triggers will be fired. The operation cannot be rolled back. TRUNCATE TRUNCATE removes all rows from a table. The operation cannot be rolled back and no triggers will be fired. As such, TRUNCATE is faster and doesn't use as much undo space as a DELETE. Table level lock will be added when Truncating. DELETE The DELETE command is used to remove rows from a table. A WHERE clause can be used to only remove some rows. If no WHERE condition is specified, all rows will be removed. After performing a DELETE operation you need to COMMIT or ROLLBACK the transaction to make the change permanent or to undo it. Note that this operation will cause all DELETE triggers on the table to fire. Row level lock will be added when deleting.

来自:http://www.orafaq.com/faq/difference_between_truncate_delete_and_drop_commands

对于SQL Server或MySQL，如果有一个带有自动递增的PK, truncate将重置计数器。

最大的区别是truncate是不记录日志的操作，而delete是。

简单地说，这意味着在数据库崩溃的情况下，不能通过截断恢复所操作的数据，但可以通过删除恢复。

详情请点击这里

我想对matthieu的帖子发表评论，但我还没有得到代表…

在MySQL中，自动递增计数器通过truncate重置，而不是通过delete重置。

SQL server中删除与截断的总结 完整文章请点击这个链接:http://codaffection.com/sql-server-article/delete-vs-truncate-in-sql-server/

摘自dotnet mob文章:删除Vs截断SQL Server

在这个例子中，Truncate也可以被rollback

begin Tran
delete from  Employee

select * from Employee
Rollback
select * from Employee