I've recently dusted off an old Ruby on Rails project of mine. In the past, I've never had any problems getting all the tests to pass, but now there is one test that gives me the following error:
ActiveRecord::StatementInvalid: Mysql::Error: #HY000Illegal mix of collations (latin1_swedish_ci,IMPLICIT) and (utf8_general_ci,COERCIBLE) for operation '=': SELECT * FROM cards WHERE (cards.l1_description = '是' AND cards.l2_word = '')
So I go to my test db and ask:
mysql> use flashcard_test
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A
Database changed
mysql> show full columns from cards;
+----------------+--------------+-------------------+------+-----+---------+----------------+---------------------------------+---------+
| Field | Type | Collation | Null | Key | Default | Extra | Privileges | Comment |
+----------------+--------------+-------------------+------+-----+---------+----------------+---------------------------------+---------+
| id | int(11) | NULL | NO | PRI | NULL | auto_increment | select,insert,update,references | |
| l2_word | varchar(255) | latin1_swedish_ci | YES | | NULL | | select,insert,update,references | |
| l1_description | text | latin1_swedish_ci | YES | | NULL | | select,insert,update,references | |
| l1_id | int(11) | NULL | YES | | NULL | | select,insert,update,references | |
| l2_id | int(11) | NULL | YES | | NULL | | select,insert,update,references | |
+----------------+--------------+-------------------+------+-----+---------+----------------+---------------------------------+---------+
5 rows in set (0.01 sec)
And as you can see, the collation is latin1_swedish_ci, and presumably if it were "utf8_general_ci", my problems would be solved. Thankfully, my development database is already okay, so I go and
rake db:test:clone_structure
and back to MySql and check again in the test db
mysql> show full columns from cards;
+----------------+--------------+-----------------+------+-----+---------+----------------+---------------------------------+---------+
| Field | Type | Collation | Null | Key | Default | Extra | Privileges | Comment |
+----------------+--------------+-----------------+------+-----+---------+----------------+---------------------------------+---------+
| id | int(11) | NULL | NO | PRI | NULL | auto_increment | select,insert,update,references | |
| l2_word | varchar(255) | utf8_general_ci | YES | | NULL | | select,insert,update,references | |
| l1_description | text | utf8_general_ci | YES | | NULL | | select,insert,update,references | |
| l1_id | int(11) | NULL | YES | | NULL | | select,insert,update,references | |
| l2_id | int(11) | NULL | YES | | NULL | | select,insert,update,references | |
+----------------+--------------+-----------------+------+-----+---------+----------------+---------------------------------+---------+
5 rows in set (0.00 sec)
Ah, so now everything is looking good, so once again I
rake test
But I get the same problem all over again, and when I check my test db, I find that the collation column has been reset to latin1_swedish_ci.
I do not understand very well how rake test works, but my working hypothesis is that it recreates the DB using schema.rb. Now, in one of my migrations, I've got
class CreateCards < ActiveRecord::Migration
def self.up
create_table :cards, :options => "DEFAULT CHARACTER SET=utf8 COLLATE=utf8_general_ci" do |t|
t.column :english_word, :string
t.column :chinese_description, :text
end
end
def self.down
drop_table :cards
end
end
And this apparently has taken care of the collate problem there. (I've got another migration which renames english_word and chinese_description to l2_word and l1_description, respectively.) But this information has not made it into schema.rb. And somehow, apparently, MySql has decided to assume that I want latin1_swedish_ci.
So, to summarize, what I think I need to do is somehow edit something so that I'll be using the utf8_general_ci collation, and then my problems will go away (right?). But I cannot figure out how to make the code that gets run when you "rake test" do this. Can anybody help?
For what it's worth, both the test and development databases were created as
create database flashcard_test default character set utf8 default collate utf8_general_ci;
and
create database flashcard_development default character set utf8 default collate utf8_general_ci;
And my database.yml has
development:
adapter: mysql
database: flashcard_development
username: root
password:
encoding: utf8
test:
adapter: mysql
database: flashcard_test
username: root
password:
encoding: utf8
collation: utf8_general_ci
http://nhw.pl/wp/2008/09/16/mysql-collate-setting-in-rails-application seems to suggest that this problem has something to do with the connection between RoR and MySql, but I haven't had any luck with the suggestions there.