Question

I am trying to use the following bit of code to help in seeding my database. I need to add data continually over development and do not want to have to completely reseed data every time I add something new to the seeds.rb file. So I added the following function to insert the data if it doesn’t already exist.

def AddSetting(group, name, value, desc)
    Admin::Setting.create({group: group, name: name, value: value, description: desc}) unless Admin::Setting.find_by_sql("SELECT * FROM admin_settings WHERE group = '#{group}' AND name = '#{name}';").exists?
end

AddSetting('google', 'analytics_id', '', 'The ID of your Google Analytics account.')
AddSetting('general', 'page_title', '', '')
AddSetting('general', 'tag_line', '', '')

This function is included in the db/seeds.rb file. Is this the right way to do this?

However I am getting the following error when I try to run it through rake.

rake aborted!
Mysql2::Error: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'group = 'google' AND name = 'analytics_id'' at line 1: SELECT * FROM admin_settings WHERE group = 'google' AND name = 'analytics_id';

Tasks: TOP => db:seed
(See full trace by running task with --trace)

Process finished with exit code 1

What is confusing me is that I am generating correct SQL as far as I can tell. In fact my code generates the SQL and I pass that to the find_by_sql function for the model, Rails itself can’t be changing the SQL, or is it?

SELECT * FROM admin_settings WHERE group = 'google' AND name = 'analytics_id';

I’ve written a lot of SQL over the years and I’ve looked through similar questions here. Maybe I’ve missed something, but I cannot see it.

Answer 1

“group” is a keyword so you can’t use it as-is as an identifier, you have to quote it with backticks (for MySQL at least):

SELECT *
FROM admin_settings
WHERE `group` = 'google'
  AND name    = 'analytics_id'

Any SQL that Rails/ActiveRecord generates will use the quoted version of the column name so I’d guess that you’re generating some SQL (or just a snippet of SQL for the WHERE clause) and neglecting to quote the column names.

I’d recommend against using group as a column name, use something else so that you don’t have to worry about sprinkling backticks all over the place in your code.