[TYPO3] Warning: mysql_fetch_row(): supplied argument is not a valid MySQL result resource in /var/www/vhosts/typo3_src-4.0/t3lib/class.t3lib_db.php on line 814

[Nguyen Duc Hung]

I'm writing an extension so when i query wrong then it show this 
notice.If in this case you'll difficult to fix bug.
You can fix bug in the way .Miss the Ext last install . And try remove 
then check FE . When you find the Ext miss.You update this Ext ...