首先貼上實驗用各版本：
OS：CentOS 6.5
MySQL：
mysql> select version ();
+------------+
| version () |
+------------+
| 5.6.22 |
+------------+
1 row in set (0.00 sec)
事情是這樣的：本來是要在虛機上搭建一個wordpress做實驗，剛創建完數據庫，就在賦權額時候發生不在計劃的錯誤：
mysql>grant all on wordpress.* to wordpress@localhost identified by "wp123456";
ERROR 2013 (HY000): Lost connection to MySQL server during query
查看報錯日誌如下：tail -fn 30 /var/log/mysqld.log
2016-11-15 12:56:22 112085 [ERROR] Missing system table mysql.proxies_priv; please run mysql_upgrade to create it
2016-11-15 12:56:22 112085 [ERROR] Native table 'performance_schema'.'cond_instances' has the wrong structure
2016-11-15 12:56:22 112085 [ERROR] Native table 'performance_schema'.'events_waits_current' has the wrong structure
2016-11-15 12:56:22 112085 [ERROR] Native table 'performance_schema'.'events_waits_history' has the wrong structure
2016-11-15 12:56:22 112085 [ERROR] Native table 'performance_schema'.'events_waits_history_long' has the wrong structure
看報錯日誌一直在提示wrong structure（結構錯誤），通常結構錯誤是由升級MySQL版本導致的，我雖然沒有升級，但是在安裝MySQL5.6.22前，安裝的是5.1版本，可能是由於卸除的不乾淨(但是之前在賦權時並沒有此問題，疑惑？？)，看了網上N多方法，但是對於我的問題就是不感冒啊！突然在網上看到一個升級腳本修復的例子，就想着我的是不是也適用(因爲我之前裝過舊版本)，所以就試了一下果然OK啊！看到成功那一刻，一掃額頭陰霾O(∩_∩)O~
執行升級腳本命令：
/usr/local/mysql/bin/mysql_upgrade -u root -p
輸入密碼後回車，再次賦權成功啦，哇咔咔..........
mysql> grant all on wordpress.* to wordpress@localhost identified by "wp123456";
Query OK, 0 rows affected (0.00 sec)