前幾天幫同事解決一個案例，在主從復制環境下，從庫上的MySQL版本號是5.5.5，遇到下面的錯誤： ~~~ #其他非相關信息我都隱藏掉了 [(yejr@imysql.com)]> show slave status \G; Slave_IO_Running: Yes Slave_SQL_Running: No Last_Errno: 1064 Last_Error: Error 'You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '6e86db84_14847168f19__8000' at line 1' on query. Default database: 'act'. Query: 'SAVEPOINT 6e86db84_14847168f19__8000' Last_IO_Errno: 0 Last_IO_Error: Last_SQL_Errno: 1064 Last_SQL_Error: Error 'You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '6e86db84_14847168f19__8000' at line 1' on query. Default database: 'act_log'. Query: 'SAVEPOINT 6e86db84_14847168f19__8000' ~~~ 第一感覺是遇到保留關鍵字了，不過看到這么長的字符串，不應該是保留關鍵字才對。 經過嘗試，最后發現是字符串中的 “e” 這個字符如果存在就可能會報錯，看起來應該是bug才對了。 在MySQL的bug系統里確實找到了這個bug，不過看bug描述，在5.5版本中應該是已經修復了才對，看來太不靠譜了呀~~ 關于這個bug：[Savepoint identifier is occasionally considered as floating point numbers](http://bugs.mysql.com/bug.php?id=55962 "Savepoint identifier is occasionally considered as floating point numbers") 其實除了升級版本外，解決方法也很簡單，把savepoint后面的 identifier 字符串用反引號（波浪號的下檔鍵，英文叫做 backticks 鍵）引用起來就行。 例如： ~~~ savepoint `6e86db84_14847168f19__8000`; ~~~ 這樣就可以了。 這個案例也提示我們，在寫SQL時，涉及到數據庫、表、字段、identifier 等名稱時，最好是都能用反引號引用，確保可用。 曾經看到線上數據表有個字段名是?check?，這個名字在MySQL里很早就已經是保留關鍵字，幸好開發同學比較靠譜，都加上了反引號。 關于savepoint的2個bug： [Savepoint Identifier should be enclosed with backticks](http://bugs.mysql.com/bug.php?id=55961 "Savepoint Identifier should be enclosed with backticks") [Savepoint identifier is occasionally considered as floating point numbers](http://bugs.mysql.com/bug.php?id=55962 "Savepoint identifier is occasionally considered as floating point numbers")