PHP mysql多关键字搜索

我在我的网站中使用ajax搜索。用户可以搜索房屋。我想让用户做一个精确的搜索与他想要的关键字。但我的问题是，我不知道用户输入了什么，我可以搜索多少个关键字。这是我的查询:

$query = "Select a.*,c.name as agent_name,d.country_name,e.state_name,g.city from #__osrs_properties as a"
                                ." inner join #__osrs_agents as c on c.id = a.agent_id"
                                ." inner join #__osrs_types as f on f.id = a.pro_type"
                                ." inner join #__osrs_categories as j on j.id = a.category_id"
                                ." inner join #__osrs_countries as d on d.id = a.country"
                                ." inner join #__osrs_states as e on e.id = a.state"
                                ." inner join #__osrs_cities as g on g.id = a.city"
                                ." where a.approved = '1' and a.published = '1' and a.category_id = '$category->id' and (";
                        //
                        $newKeyword = explode(" ",$keyword);    
                        $query1="j.category_name like '%$newKeyword[0]%' and f.type_name like '%$newKeyword[1]%' and  g.city like '%$newKeyword[2]%'";

它工作，但当用户只输入3个关键字，而不是更多。