多關鍵模糊查詢，只需要改兩處：
$val='username like "%'.str_replace(' ','%" or username like "%',$keywords).'%"';
$sql="select * from fuzzyuser where {$val}";
高亮也不用重寫
多關鍵字的模糊查詢：
$val='username like %'.str_replace(' ','%, or username like %',$val).'%';
select * from user where username like {$val}';
