Issue with PostgreSQL adapter: ActiveRecord::StatementInvalid: PG::ProtocolViolation: ERROR

[bbonamin]

Hello!

Thank you for open sourcing this gem, think it's a brilliant idea. I've been able to give it a try with sqlite3, but I haven't had much luck making it work with PostgreSQL. (Latest Rails 4.2 and Ruby 2.2.3)

Given a User model, with a attribute of name, if one is present in the database; when I run Polo.explore(User, 1), I get the following stack trace:

irb(main):001:0> Polo.explore(User, 1)
  User Load (0.3ms)  SELECT "users".* FROM "users" WHERE "users"."id" = $1  [["id", 1]]
  User Load (0.7ms)  SELECT "users".* FROM "users" WHERE "users"."id" = 1
  User Load (1.0ms)  SELECT "users".* FROM "users" WHERE "users"."id" = $1
ActiveRecord::StatementInvalid: PG::ProtocolViolation: ERROR:  bind message supplies 0 parameters, but prepared statement "" requires 1
: SELECT "users".* FROM "users" WHERE "users"."id" = $1
    from /Users/bcb/.gem/ruby/2.2.3/gems/activerecord-4.2.5/lib/active_record/connection_adapters/postgresql_adapter.rb:592:in `async_exec'
    from /Users/bcb/.gem/ruby/2.2.3/gems/activerecord-4.2.5/lib/active_record/connection_adapters/postgresql_adapter.rb:592:in `block in exec_no_cache'
    from /Users/bcb/.gem/ruby/2.2.3/gems/activerecord-4.2.5/lib/active_record/connection_adapters/abstract_adapter.rb:472:in `block in log'
    from /Users/bcb/.gem/ruby/2.2.3/gems/activesupport-4.2.5/lib/active_support/notifications/instrumenter.rb:20:in `instrument'
    from /Users/bcb/.gem/ruby/2.2.3/gems/activerecord-4.2.5/lib/active_record/connection_adapters/abstract_adapter.rb:466:in `log'
    from /Users/bcb/.gem/ruby/2.2.3/gems/activerecord-4.2.5/lib/active_record/connection_adapters/postgresql_adapter.rb:592:in `exec_no_cache'
    from /Users/bcb/.gem/ruby/2.2.3/gems/activerecord-4.2.5/lib/active_record/connection_adapters/postgresql_adapter.rb:584:in `execute_and_clear'
    from /Users/bcb/.gem/ruby/2.2.3/gems/activerecord-4.2.5/lib/active_record/connection_adapters/postgresql/database_statements.rb:160:in `exec_query'
    from /Users/bcb/.gem/ruby/2.2.3/gems/activerecord-4.2.5/lib/active_record/connection_adapters/abstract/database_statements.rb:355:in `select'
    from /Users/bcb/.gem/ruby/2.2.3/gems/activerecord-4.2.5/lib/active_record/connection_adapters/abstract/database_statements.rb:32:in `select_all'
    from /Users/bcb/.gem/ruby/2.2.3/gems/activerecord-4.2.5/lib/active_record/connection_adapters/abstract/query_cache.rb:70:in `select_all'
    from /Users/bcb/.gem/ruby/2.2.3/gems/activerecord-4.2.5/lib/active_record/querying.rb:39:in `find_by_sql'
    from /Users/bcb/.gem/ruby/2.2.3/gems/polo-0.1.0/lib/polo/translator.rb:24:in `block in instances'
    from /Users/bcb/.gem/ruby/2.2.3/gems/polo-0.1.0/lib/polo/translator.rb:23:in `each'
    from /Users/bcb/.gem/ruby/2.2.3/gems/polo-0.1.0/lib/polo/translator.rb:23:in `flat_map'
    from /Users/bcb/.gem/ruby/2.2.3/gems/polo-0.1.0/lib/polo/translator.rb:23:in `instances'
... 5 levels...
    from /Users/bcb/.gem/ruby/2.2.3/gems/railties-4.2.5/lib/rails/commands/console.rb:9:in `start'
    from /Users/bcb/.gem/ruby/2.2.3/gems/railties-4.2.5/lib/rails/commands/commands_tasks.rb:68:in `console'
    from /Users/bcb/.gem/ruby/2.2.3/gems/railties-4.2.5/lib/rails/commands/commands_tasks.rb:39:in `run_command!'
    from /Users/bcb/.gem/ruby/2.2.3/gems/railties-4.2.5/lib/rails/commands.rb:17:in `<top (required)>'
    from /Users/bcb/.gem/ruby/2.2.3/gems/activesupport-4.2.5/lib/active_support/dependencies.rb:274:in `require'
    from /Users/bcb/.gem/ruby/2.2.3/gems/activesupport-4.2.5/lib/active_support/dependencies.rb:274:in `block in require'
    from /Users/bcb/.gem/ruby/2.2.3/gems/activesupport-4.2.5/lib/active_support/dependencies.rb:240:in `load_dependency'
    from /Users/bcb/.gem/ruby/2.2.3/gems/activesupport-4.2.5/lib/active_support/dependencies.rb:274:in `require'
    from /Users/bcb/code/polo_rails_test/bin/rails:9:in `<top (required)>'
    from /Users/bcb/.gem/ruby/2.2.3/gems/activesupport-4.2.5/lib/active_support/dependencies.rb:268:in `load'
    from /Users/bcb/.gem/ruby/2.2.3/gems/activesupport-4.2.5/lib/active_support/dependencies.rb:268:in `block in load'
    from /Users/bcb/.gem/ruby/2.2.3/gems/activesupport-4.2.5/lib/active_support/dependencies.rb:240:in `load_dependency'
    from /Users/bcb/.gem/ruby/2.2.3/gems/activesupport-4.2.5/lib/active_support/dependencies.rb:268:in `load'
    from /Users/bcb/.rubies/ruby-2.2.3/lib/ruby/2.2.0/rubygems/core_ext/kernel_require.rb:54:in `require'
    from /Users/bcb/.rubies/ruby-2.2.3/lib/ruby/2.2.0/rubygems/core_ext/kernel_require.rb:54:in `require'

Here's a sample application that exhibits this behavior: https://github.com/bbonamin/polo_rails_test

Let me know if I can be of any help :) To be honest I'm kind of lost on where to go an fix this, but apparently it's related to the fact that PostgreSQL validates prepared statements. rails/rails#20077

[nettofarah]

Hi, @bbonamin. Thank you for reporting this!
Tbh, PG support is something I haven't look into much. But I know some people are working on it.

@derencius is working on it though.
Maybe he'll be able to give us some insight.
https://github.com/derencius/polo/pull/1

[bbonamin]

This is great! Thanks. I didn't even think of checking the open pull requests 😖 !
I'll follow that PR with interest.

[jlerpscher]

Same issue here, I'll also follow that PR :)
Thanks

[nettofarah]

Here's the PR, folks!
#20

I'd love for y'all to provide some feedback.

[nettofarah]

solved!

[bbonamin]

Thanks @nettofarah and @derencius 💯 👍 💯 !

[nettofarah]

@bbonamin, @derencius, @jlerpscher mind helping us with the survey on #19?