项目里有用到meta_search与acts-as-taggable-on这两个gem，后台录入的MM需要有通过标签查询的功能meta_search的文档好像没有提到类似这种需求的解决方法，GOOGLE之：找到如下解决方法http://stackoverflow.com/questions/5766427/combining-meta-search-with-acts-as-taggable-onPost.metasearch({:title_or_tag_taggings_tag_name_contains => params[:search]})在我项目中，acts-as-taggable-on :times 相应改成

<%= f.select :time_taggings_tag_name_contains, [[“请选择”,””]]+Tag::TIMES %>在console中测试能达到效果，但是生成的SQL，有些复杂ruby-1.9.2-p180 :004 > Solution.metasearch({:time_taggings_tag_name_contains => “XXX”})

Solution Load (6.6ms) SELECT solutions.* FROM solutions LEFT OUTER JOIN taggings ON taggings.taggable_id = solutions.id AND taggings.tagger_id IS NULL AND taggings.context = ‘times’ AND taggings.taggable_type = ‘Solution’ LEFT OUTER JOIN tags ON tags.id = taggings.tag_id WHERE (tags.name LIKE ‘%XXX%’)

有个问题：我发布到服务器后测试报错：Mysql2::Error: Unknown column ‘tags.id’ in ‘on clause’: SELECT COUNT(DISTINCT solutions……….我比较了一下本机与服务器的MySQL版本：本机：

mysql5 Ver 14.14 Distrib 5.1.53, for apple-darwin10.5.0 (i386) using readline 6.1服务器：mysql Ver 14.14 Distrib 5.1.41, for debian-linux-gnu (x86_64) using readline 6.1不知道是不是因为服务器版本的差异导致的这个问题。