Using Rails 3.1.1, I'm getting occasional errors in production where it seems like the bind parameters on a mysql query are not there for some reason. The error looks like this:
A ActiveRecord::StatementInvalid occurred in events#show:
Mysql::Error: : SELECT `events`.* FROM `events` WHERE `events`.`id` = ? LIMIT 1
activerecord (3.1.1) lib/active_record/connection_adapters/mysql_adapter.rb:890:in `execute
It's not consistent on any insert or select, so I'm having trouble tracking it down. Does anybody have any suggestions?
Edit: updated with simpler example.
#events_controller.rb
def show
#event = Event.find(params[:id])
...
end
#called with parameters: {"action"=>"show", "controller"=>"events", "id"=>"26"}
The probable reason
Check your database driver installation here.
This seems to have gone away after upgrading to the latest rails - uncertain as to what it was.
Related
I have SQLite and MySQL installed on my local and development machine respectively. Following is working fine on my local machine(with SQLite):
select_single = {'date': "strftime('%%Y-%%m-%%d',projectName_Modelname.created)"}
queryset.extra(select=select_single)
But since strftime doesn't work with MySQL(link), I tried using DATE_FORMAT() as suggested in given link and other places too.
Though now when I execute below:
select_single = {'date': "DATE_FORMAT(projectName_Modelname.created, '%%Y-%%m-%%d')"}
queryset.extra(select=select_single)
Following error comes:
DatabaseError: (1054, "Unknown column 'projectName_Modelname.created' in 'field list'")
where 'created' is Datetime field in Django model 'Modelname' of app 'projectName'
To debug when I replace projectName_Modelname.created with NOW() no error comes. I have also tried just Modelname.created instead of projectName_Modelname.created though with no benefit?
Note: I am using Django1.5.5
I think it should be something like:
date_raw_query = {'date': "date_format(created, '%%Y-%%m-%%d')"}
and then try
queryset.extra(select=date_raw_query)
Hope that works in your setup. I have tried this on Django 1.7 and MySQL and seems to be working.
Also remember that if SQL errors start coming up, you can always do a print queryset.extra(select=date_raw_query).query to see what might be going wrong.
And when it comes to writing compatible code between SQLite and MySQL like this one, writing a custom MySQL function has been suggested here
But I would suggest otherwise. It's better to have a similar dev environment with MySQL setup in local and also, upgrade Django as soon as possible. :P
i've looked into previous questions which look similar to my problem, nothing seems to be related.
After doing the following query:
Runner::Models::Job.where(:id => job_id)
I get an exception, it happens once in a while:
Mysql2::Error: MySQL server has gone away: SELECT jobs.* FROM jobs WHERE jobs.id = 7507 LIMIT 1
I use puma, and in config.ru i am using:
use ActiveRecord::ConnectionAdapters::ConnectionManagement
The thing is that this error always happens in the same place, and i cant figure out why is it happening, i've checked memory, cpu, etc'.., all seem normal.
Maybe someone will have an idea.
thanks !
Write your Resque task like this:
class MyTask
def self.perform
ActiveRecord::Base.verify_active_connections!
# rest of your code
end
end
see more details here: https://github.com/resque/resque/wiki/FAQ#how-do-you-work-around-the-mysql-server-has-gone-away-error-
I am upgrading my Rails app from Rails 2.3 to 3.2.
and I am getting this weird error
Mysql2::Error: Unknown column '6' in 'where clause':
above error is due to `(backtick) which is applied to data in the where clause along with the column names see the following query.
Mysql2::Error: Unknown column '6' in 'where clause': SELECT `users`.`username`,`users`.`password` FROM `users` WHERE `id` IN (`6`)
see the 6 even though it is data activerecord is applying backtick to it.because of that mysql is raising exception.
NOTE:This is usually seen while calling related object(one to one,many to many)
eg:
u = User.where(:active =>true).each{|u|
//some code
u.user_role #error will raise in this line
}
if I reinitiate the object it will work fine.
u = User.where(:active =>true).each{|u|
//some code
u.user_role #error will raise in this line
u1 = User.find(u.id)
u1.user_role #works fine.
}
This is happening throughout the application and with other models as well,above code snippet is just one instance.
Environment details:
OS: Ubuntu 13.10,Ruby 1.9.3-p545,Rails 3.2.17 mysql 5.5
Anyone knows what going on here ? is it because of gem incompatibility ?
Please let me know if you need some more details.
This issue is due to gem incompatibility.I was using 'slim_scrooge' gem to optimize queries in Rails 2.X doesn't gem well with Rails 3 or higher.
I am not sure why this may be coming, but I think you can avoid this and an extra query to sql while accessing user_role by using include in your query. This will eager load user_role in the first query itself and will not make extra query in each loop.
Code will be something like following:
u = User.where(:active =>true).includes(:user_roles).each{|u|
//some code
u.user_role #error will raise in this line
}
More details on include is here: http://apidock.com/rails/ActiveRecord/QueryMethods/includes
I'm trying to insert into a remote mysql database. I am able to connect correctly and can query 'select' no problem from it. However, I cannot perform inserts into the same table that I can select from. I suspect it has something to do with my binds, but this is nearly identical to what I was using to get sqlite3 working which I think uses the same Arel to insert.
#result = #db.query("insert into lead_to_processes (case_number, style_of_case) values (?,?)", [
self.case_number.to_blob.force_encoding("UTF-8"),
self.style_of_case.to_blob.force_encoding("UTF-8")
]
)
Ultimate goal is to be able query a remote database from inside of a model and insert data into it. I've tried using Octopus and that didn't quite work because the tables will be different from the databases.
I have full permissions with this user on the database.
So following guidance from comments i changed the syntax and am getting a different error
Mysql2::Error: You have an error in your SQL syntax;
However i'm doing the query like this now
#db = Mysql2::Client.new(connectionstring)
#case_number = #db.escape(self.case_number)
#style_of_case = #db.escape(self.style_of_case)
#db.query("insert into lead_to_processes (case_number, style_of_case) VALUES
(#{#case_number}, #{#style_of_case})
Any ideas or guidance? I've also tried this with '' encapsulating the variables that i'm inserting
I guess there were some weird characters in my code so I had to force UTF-8 encoding and then removed the characters using gsub below, everything is flowing now.
Thanks for the advice
#db.escape(self.style_of_case.force_encoding("UTF-8"))
#db.escape(self.case_number.gsub(/[\xC2]/,'').gsub(/[\xA0]/,'').force_encoding("UTF-8"))
Is it possible that you are missing an end quote?
this
#db.query("insert into lead_to_processes (case_number, style_of_case) VALUES
(#{#case_number}, #{#style_of_case})
should be
#db.query("insert into lead_to_processes (case_number, style_of_case) VALUES
(#{#case_number}, #{#style_of_case}") <== notice the quote at the end.
I have the following code that run on heroku inside a controller that intermittently fails. It's a no-brainer that it should work to me, but I must be missing something.
#artist = Artist.find(params[:artist_id])
The parameters hash looks like this:
{"utf8"=>"������",
"authenticity_token"=>"XXXXXXXXXXXXXXX",
"password"=>"[FILTERED]",
"commit"=>"Download",
"action"=>"show",
"controller"=>"albums",
"artist_id"=>"62",
"id"=>"157"}
The error I get looks like this:
ActiveRecord::StatementInvalid: Mysql::Error: : SELECT `artists`.* FROM `artists` WHERE `artists`.`id` = ? LIMIT 1
notice the WHEREartists.id= ? part of the statement? It's trying to find an ID of QUESTION MARK. Meaning Rails is not passing in the params[:artist_id] which is obviously in the params hash. I'm at complete loss.
I get the same error on different pages trying to select the record in a similar fashion.
My environment: Cedar Stack on Heroku (this only happens on Heroku), Ruby 1.9.3, Rails 3.2.8, files being hosted on Amazon S3 (though I doubt it matters), using the mysql gem (not mysql2, which doesn't work at all), ClearDB MySQL database.
Here's the full trace.
Any help would be tremendously appreciated.
try sql?
If it's just this one statement, and it's causing production problems, can you omit the query generator just for now? In other words, for very short term, just write the SQL yourself. This will buy you a bit of time.
# All on one line:
Artist.find_by_sql
"SELECT `artists`.* FROM `artists`
WHERE `artists`.`id` = #{params[:artist_id].to_i} LIMIT 1"
ARel/MySQL explain?
Rails can help explain what MySQL is trying to do:
Artist.find(params[:artist_id]).explain
http://weblog.rubyonrails.org/2011/12/6/what-s-new-in-edge-rails-explain/
Perhaps you can discover some kind of difference between the queries that are succeeding vs. failing, such as how the explain uses indexes or optimizations.
mysql2 gem?
Can you try changing from the mysql gem to the mysql2 gem? What failure do you get when you switch to the mysql2 gem?
volatility?
Perhaps there's something else changing the params hash on the fly, so you see it when you print it, but it's changed by the time the query runs?
Try assigning the variable as soon as you receive the params:
artist_id = params[:artist_id]
... whatever code here...
#artist = Artist.find(artist_id)
not the params hash?
You wrote "Meaning Rails is not passing in the params[:artist_id] which is obviously in the params hash." I don't think that's the problem-- I expect that you're seeing this because Rails is using the "?" as a placeholder for a prepared statement.
To find out, run the commands suggested by #Mori and compare them; they should be the same.
Article.find(42).to_sql
Article.find(params[:artist_id]).to_sql
prepared statements?
Could be a prepared statement cache problem, when the query is actually executed.
Here's the code that is failing-- and there's a big fat warning.
begin
stmt.execute(*binds.map { |col, val| type_cast(val, col) })
rescue Mysql::Error => e
# Older versions of MySQL leave the prepared statement in a bad
# place when an error occurs. To support older mysql versions, we
# need to close the statement and delete the statement from the
# cache.
stmt.close
#statements.delete sql
raise e
end
Try configuring your database to turn off prepared statements, to see if that makes a difference.
In your ./config/database.yml file:
production:
adapter: mysql
prepared_statements: false
...
bugs with prepared statements?
There may be a problem with Rails ignoring this setting. If you want to know a lot more about it, see this discussion and bug fix by Jeremey Cole and Aaron: https://github.com/rails/rails/pull/7042
Heroku may ignore the setting. Here's a way you can try overriding Heroku by patching the prepared_statements setup: https://github.com/rails/rails/issues/5297
remove the query cache?
Try removing the ActiveRecord QueryCache to see if that makes a difference:
config.middleware.delete ActiveRecord::QueryCache
http://edgeguides.rubyonrails.org/configuring.html#configuring-middle
try postgres?
If you can try Postgres, that could clear it up too. That may not be a long term solution for you, but it would isolate the problem to MySQL.
The MySQL statement is obviously wrong, but the Ruby code you mentioned would not produce it. Something is wrong here, either you use a different Ruby code (maybe one from a before_filter) or pass a different parameter (like params[:artist_id] = "?"). Looks like you use nested resources, something like Artist has_many :albums. Maybe the #artist variable is not initialized correctly in the previous action, so that params[:artist_id] has not the right value?