MYSQL啟動失敗解決方法
在MYSQL安裝目錄下查詢.err型別的檔案，比如我的mysql安裝下是 mysqlServer5.5\data\JYF-PC.err。
開啟後可以看到：
181209 13:38:27 [Note] Plugin 'FEDERATED' is disabled.
181209 13:38:27 InnoDB: The InnoDB memory heap is disabled
181209 13:38:27 InnoDB: Mutexes and rw_locks use Windows interlocked functions
181209 13:38:27 InnoDB: Compressed tables use zlib 1.2.3
181209 13:38:28 InnoDB: Initializing buffer pool, size = 128.0M
181209 13:38:28 InnoDB: Completed initialization of buffer pool
181209 13:38:28 InnoDB: highest supported file format is Barracuda.
181209 13:38:28 InnoDB: Waiting for the background threads to start
181209 13:38:29 InnoDB: 1.1.8 started; log sequence number 1768474
181209 13:38:29 [ERROR] MySQL: unknown variable 'explicit_defaults_for_timestamp=true'
181209 13:38:29 [ERROR] Aborting
181209 13:38:29 InnoDB: Starting shutdown...
181209 13:38:30 InnoDB: Shutdown completed; log sequence number 1768474
181209 13:38:30 [Note] MySQL: Shutdown complete
通過日誌ERROR說明，結合自己修改了什麼配置，即可定位到錯誤配置項，修改後重啟mysql服務
停止服務:net stop mysql;
啟動服務:net start mysql;