Question

I’m learning ruby on rails by following Patrick Lenz’s book from Sitepoint. I know it’s a bit outdated, so I’m adapting as I go along.

I’ve gotten to a place where I’m in my rails console, ready to start creating/saving to my database, and when I create a class, then type story.save, I get this error:

1.9.3p194 :007 > story.save
   (0.1ms)  begin transaction
  SQL (0.5ms)  INSERT INTO "stories" ("link", "name") VALUES (?, ?)  [["link", nil], ["name", nil]]
SQLite3::ConstraintException: constraint failed: INSERT INTO "stories" ("link", "name") VALUES (?, ?)
   (0.1ms)  rollback transaction
ActiveRecord::StatementInvalid: SQLite3::ConstraintException: constraint failed: INSERT INTO "stories" ("link", "name") VALUES (?, ?)
    from /Users/ideogram/.rvm/gems/ruby-1.9.3-p194/gems/sqlite3-1.3.6/lib/sqlite3/statement.rb:108:in `step'
    from /Users/ideogram/.rvm/gems/ruby-1.9.3-p194/gems/sqlite3-1.3.6/lib/sqlite3/statement.rb:108:in `block in each'
    from /Users/ideogram/.rvm/gems/ruby-1.9.3-p194/gems/sqlite3-1.3.6/lib/sqlite3/statement.rb:107:in `loop'
    from /Users/ideogram/.rvm/gems/ruby-1.9.3-p194/gems/sqlite3-1.3.6/lib/sqlite3/statement.rb:107:in `each'
    from /Users/ideogram/.rvm/gems/ruby-1.9.3-p194/gems/activerecord-3.2.3/lib/active_record/connection_adapters/sqlite_adapter.rb:263:in `to_a'
    from /Users/ideogram/.rvm/gems/ruby-1.9.3-p194/gems/activerecord-3.2.3/lib/active_record/connection_adapters/sqlite_adapter.rb:263:in `block in exec_query'
    from /Users/ideogram/.rvm/gems/ruby-1.9.3-p194/gems/activerecord-3.2.3/lib/active_record/connection_adapters/abstract_adapter.rb:280:in `block in log'
    from /Users/ideogram/.rvm/gems/ruby-1.9.3-p194/gems/activesupport-3.2.3/lib/active_support/notifications/instrumenter.rb:20:in `instrument'
    from /Users/ideogram/.rvm/gems/ruby-1.9.3-p194/gems/activerecord-3.2.3/lib/active_record/connection_adapters/abstract_adapter.rb:275:in `log'
    from /Users/ideogram/.rvm/gems/ruby-1.9.3-p194/gems/activerecord-3.2.3/lib/active_record/connection_adapters/sqlite_adapter.rb:242:in `exec_query'
    from /Users/ideogram/.rvm/gems/ruby-1.9.3-p194/gems/activerecord-3.2.3/lib/active_record/connection_adapters/abstract/database_statements.rb:63:in `exec_insert'
    from /Users/ideogram/.rvm/gems/ruby-1.9.3-p194/gems/activerecord-3.2.3/lib/active_record/connection_adapters/abstract/database_statements.rb:90:in `insert'
    from /Users/ideogram/.rvm/gems/ruby-1.9.3-p194/gems/activerecord-3.2.3/lib/active_record/connection_adapters/abstract/query_cache.rb:14:in `insert'
    from /Users/ideogram/.rvm/gems/ruby-1.9.3-p194/gems/activerecord-3.2.3/lib/active_record/relation.rb:66:in `insert'
    from /Users/ideogram/.rvm/gems/ruby-1.9.3-p194/gems/activerecord-3.2.3/lib/active_record/persistence.rb:363:in `create'
    from /Users/ideogram/.rvm/gems/ruby-1.9.3-p194/gems/activerecord-3.2.3/lib/active_record/timestamp.rb:57:in `create'
... 14 levels...
    from /Users/ideogram/.rvm/gems/ruby-1.9.3-p194/gems/activerecord-3.2.3/lib/active_record/validations.rb:50:in `save'
    from /Users/ideogram/.rvm/gems/ruby-1.9.3-p194/gems/activerecord-3.2.3/lib/active_record/attribute_methods/dirty.rb:22:in `save'
    from /Users/ideogram/.rvm/gems/ruby-1.9.3-p194/gems/activerecord-3.2.3/lib/active_record/transactions.rb:241:in `block (2 levels) in save'
    from /Users/ideogram/.rvm/gems/ruby-1.9.3-p194/gems/activerecord-3.2.3/lib/active_record/transactions.rb:295:in `block in with_transaction_returning_status'
    from /Users/ideogram/.rvm/gems/ruby-1.9.3-p194/gems/activerecord-3.2.3/lib/active_record/connection_adapters/abstract/database_statements.rb:192:in `transaction'
    from /Users/ideogram/.rvm/gems/ruby-1.9.3-p194/gems/activerecord-3.2.3/lib/active_record/transactions.rb:208:in `transaction'
    from /Users/ideogram/.rvm/gems/ruby-1.9.3-p194/gems/activerecord-3.2.3/lib/active_record/transactions.rb:293:in `with_transaction_returning_status'
    from /Users/ideogram/.rvm/gems/ruby-1.9.3-p194/gems/activerecord-3.2.3/lib/active_record/transactions.rb:241:in `block in save'
    from /Users/ideogram/.rvm/gems/ruby-1.9.3-p194/gems/activerecord-3.2.3/lib/active_record/transactions.rb:252:in `rollback_active_record_state!'
    from /Users/ideogram/.rvm/gems/ruby-1.9.3-p194/gems/activerecord-3.2.3/lib/active_record/transactions.rb:240:in `save'
    from (irb):7
    from /Users/ideogram/.rvm/gems/ruby-1.9.3-p194/gems/railties-3.2.3/lib/rails/commands/console.rb:47:in `start'
    from /Users/ideogram/.rvm/gems/ruby-1.9.3-p194/gems/railties-3.2.3/lib/rails/commands/console.rb:8:in `start'
    from /Users/ideogram/.rvm/gems/ruby-1.9.3-p194/gems/railties-3.2.3/lib/rails/commands.rb:41:in `<top (required)>'
    from script/rails:6:in `require'
    from script/rails:6:in `<main>'1.9.3p194 :008 > 

I have no idea what this means. Any ideas? Help is much appreciated. 🙂

I’m running on a Macbook Pro OSX Lion 10.7.3, Ruby 1.9.3-194, Rails 3.2.3. Have installed homebrew, rvm, and then several packages including readlines, sqlite3, and git.

THANK YOU!

Addendum: here is my schema:

ActiveRecord::Schema.define(:version => 0) do

  create_table "stories", :force => true do |t|
    t.string "name"
    t.string "link"
  end

  add_index "stories", ["id"], :name => "sqlite_autoindex_stories_1", :unique => true

end

This is the sqlite command I used to create my table:

CREATE TABLE `stories` (
  `id` int(11) NOT NULL,
  `name` varchar(255) default NULL,
  `link` varchar(255) default NULL,
  PRIMARY KEY (`id`)
);

Answer 1

Thank you all very much for helping me out.

Between your comments, I figured out the issue. The issue was in my database — it wasn’t created correctly so once I had deleted the original file and then recompiled the file again (making sure all of my commas were in the correct place) then it finally worked!

I appreciate all your help, so thank you again. I learned quite a bit from your answers. 🙂