How to enable ActiveRecord to support CJK query?

I ask a question in stackoverflow:, There is no answer!

After runing rails console, I can execute the following query:

1.9.3-p551 :001 > ActivityObject.where(:title => “kiketurpis integer aliquet”)
And I got a unique answer existed in database. But if I enter:

1.9.3-p551 :002 > ActivityObject.where(:title => ‘第一个纵纹’)

(In double quotes there is a Chinese string.) I got all records in table activity_objects, which means I can not use Chinese string in predicate where.

Also, I can directly query this record using the Chinese string under psql:

vish_development=# select * from activity_objects where title = ‘第一个纵纹’;

So my question is that what should I do for enabling CJK string in ActiveRecord’s where or like this?

I'm not aware of any rails setting that controls this, however there are a few things that could come into play:

- what is the encoding of that string? Current versions of ruby default to Utf-8, but I don't think 1.9 did
- what are postgres' collation / encoding settings ? This will affect how strings are compared, which is super important in unicode, with different normalisation forms and so on.


hi, Fred
Thank you very much!

Now it works fine!

Because ruby 1.9 does not use utf-8 as default encode:

1.9.3-p551 :001 >


For UTF-8, I used the following commands:

bash-3.2$ export LANG=en_US.UTF-8

bash-3.2$ rails c

Loading development environment (Rails 3.2.22)

1.9.3-p551 :001 >

=> “UTF-8”

After that, I get the right record when I run the previous query:

1.9.3-p551 :002 > ActivityObject.where(:title => ‘第一个纵纹’)

ActivityObject Load (29.5ms) SELECT “activity_objects”.* FROM “activity_objects” WHERE “activity_objects”.“title” = ‘第一个纵纹’

=> [#<ActivityObject id: 648, created_at: “2015-06-21 14:41:19”, updated_at: “2015-06-21 14:41:19”, object_type: “Excursion”, like_count: 0, title: “第一个纵纹”, description: “整的行不?”, follower_count: 1, visit_count: 5, language: “independent”, age_min: 0, age_max: 0, notified_after_draft: false, comment_count: 0, popularity: 0, download_count: 0, qscore: 500000, reviewers_qscore: nil, users_qscore: nil, ranking: 0, title_length: 1, desc_length: 1, tags_length: 1, scope: 0, avatar_file_name: nil, avatar_content_type: nil, avatar_file_size: nil, avatar_updated_at: nil, teachers_qscore: nil>]