2013-08-04 13:48:22 760 [ERROR] InnoDB: Attempted to open a previously opened tablespace. Previous tablespace isaactest/wp_usermeta uses space ID: 2 at filepath: .isaactestwp_usermeta.ibd. Cannot open tablespace mysql/innodb_index_stats which uses space ID: 2 at filepath: .mysqlinnodb_index_stats.ibd
InnoDB: Error: could not open single-table tablespace file .mysqlinnodb_index_stats.ibd
InnoDB: We do not continue the crash recovery, because the table may become
InnoDB: corrupt if we cannot apply the log records in the InnoDB log to it.
InnoDB: To fix the problem and start mysqld:
InnoDB: 1) If there is a permission problem in the file and mysqld cannot
InnoDB: open the file, you should modify the permissions.
InnoDB: 2) If the table is not needed, or you can restore it from a backup,
InnoDB: then you can remove the .ibd file, and InnoDB will do a normal
InnoDB: crash recovery and ignore that table.
InnoDB: 3) If the file system or the disk is broken, and you cannot remove
InnoDB: the .ibd file, you can set innodb_force_recovery > 0 in my.cnf
InnoDB: and force InnoDB to continue crash recovery here.
出现这个问题好几次了，每次的解决问题都是重新弄下Mysql.
我用的是XAMPP 1.83,今天终于找到解决办法了
在D:xamppmysqlin下面的my.ini中添加
innodb_force_recovery = 1
OK,谢谢。