Postgresql prepared statement in Rails : PG::Error: ERROR: bind message supplies 1 parameters, but prepared statement "a4" requires 0

Question

I have introduced a new field to a model file in my 4.0.0 Ruby on Rails application and added a validation to make sure it is unique using the following line:

validates_uniqueness_of :source_id

Immediately after that my RSpec/Capybara test suite started breaking with the following error message:

Failure/Error: let(:product) { FactoryGirl.create(:product) }
ActiveRecord::StatementInvalid:
       PG::Error: ERROR:  bind message supplies 1 parameters, but prepared statement "a4" requires 0
SELECT  1 AS one FROM "products"  WHERE "products"."source_id" = 'Product GUID6' LIMIT 1

I understand this has to do with Postgresql prepared statements, but am not sure as to what needs to be done exactly to resolve this issue.

As an additional piece of information, I have updated the DB table with index for field "source_id" with unique: true option.

Your input is greatly appreciated.

I am using FactoryGirl gem to handle the creation of my model object such as:

  let(:product) { FactoryGirl.create(:product) }

  subject { product_dimension }

  describe "method" do
     it { should respond_to(:product) }
  end  

and here is the snippet from the actual Factories.rb file:

factory :product do
    sequence(:source_id) { |n| "Product GUID#{n}" }
    sequence(:title) { |n| "Prodcut #{n}" }
    content "Lorem ipsum"
    channel_id 1
  end

Here is the exception stack trace:

1) ProductDimension method dimension 
     Failure/Error: let(:product) { FactoryGirl.create(:product) }
     ActiveRecord::StatementInvalid:
       PG::Error: ERROR:  bind message supplies 1 parameters, but prepared statement "a4" requires 0
       : SELECT  1 AS one FROM "products"  WHERE "products"."source_id" = 'Product GUID6' LIMIT 1
     # ./spec/models/product_dimension_spec.rb:4:in `block (2 levels) in <top (required)>'
     # ./spec/models/product_dimension_spec.rb:7:in `block (2 levels) in <top (required)>'
     # ./spec/models/product_dimension_spec.rb:9:in `block (2 levels) in <top (required)>'
     # ./spec/models/product_dimension_spec.rb:28:in `block (3 levels) in <top (required)>'

Here is a more detailed stack trace:

1) ProductDimension methods dimension 
     Failure/Error: let(:product) { FactoryGirl.create(:product) }
     ActiveRecord::StatementInvalid:
       PG::Error: ERROR:  bind message supplies 1 parameters, but prepared statement "a4" requires 0
       : SELECT  1 AS one FROM "products"  WHERE "products"."source_id" = 'GUID 6' LIMIT 1
     # /Users/kirillberlin/.rvm/gems/ruby-2.0.0-p247/gems/activerecord-4.0.0/lib/active_record/connection_adapters/postgresql_adapter.rb:780:in `get_last_result'
     # /Users/kirillberlin/.rvm/gems/ruby-2.0.0-p247/gems/activerecord-4.0.0/lib/active_record/connection_adapters/postgresql_adapter.rb:780:in `exec_cache'
     # /Users/kirillberlin/.rvm/gems/ruby-2.0.0-p247/gems/activerecord-4.0.0/lib/active_record/connection_adapters/postgresql/database_statements.rb:139:in `block in exec_query'
     # /Users/kirillberlin/.rvm/gems/ruby-2.0.0-p247/gems/activerecord-4.0.0/lib/active_record/connection_adapters/abstract_adapter.rb:425:in `block in log'
     # /Users/kirillberlin/.rvm/gems/ruby-2.0.0-p247/gems/activesupport-4.0.0/lib/active_support/notifications/instrumenter.rb:20:in `instrument'
     # /Users/kirillberlin/.rvm/gems/ruby-2.0.0-p247/gems/activerecord-4.0.0/lib/active_record/connection_adapters/abstract_adapter.rb:420:in `log'
     # /Users/kirillberlin/.rvm/gems/ruby-2.0.0-p247/gems/activerecord-4.0.0/lib/active_record/connection_adapters/postgresql/database_statements.rb:137:in `exec_query'
     # /Users/kirillberlin/.rvm/gems/ruby-2.0.0-p247/gems/activerecord-4.0.0/lib/active_record/connection_adapters/postgresql_adapter.rb:885:in `select'
     # /Users/kirillberlin/.rvm/gems/ruby-2.0.0-p247/gems/activerecord-4.0.0/lib/active_record/connection_adapters/abstract/database_statements.rb:24:in `select_all'
     # /Users/kirillberlin/.rvm/gems/ruby-2.0.0-p247/gems/activerecord-4.0.0/lib/active_record/connection_adapters/abstract/query_cache.rb:63:in `select_all'
     # /Users/kirillberlin/.rvm/gems/ruby-2.0.0-p247/gems/activerecord-4.0.0/lib/active_record/connection_adapters/abstract/database_statements.rb:30:in `select_one'
     # /Users/kirillberlin/.rvm/gems/ruby-2.0.0-p247/gems/activerecord-4.0.0/lib/active_record/connection_adapters/abstract/database_statements.rb:36:in `select_value'
     # /Users/kirillberlin/.rvm/gems/ruby-2.0.0-p247/gems/activerecord-4.0.0/lib/active_record/relation/finder_methods.rb:174:in `exists?'
     # /Users/kirillberlin/.rvm/gems/ruby-2.0.0-p247/gems/activerecord-4.0.0/lib/active_record/validations/uniqueness.rb:28:in `validate_each'
     # /Users/kirillberlin/.rvm/gems/ruby-2.0.0-p247/gems/activemodel-4.0.0/lib/active_model/validator.rb:153:in `block in validate'
     # /Users/kirillberlin/.rvm/gems/ruby-2.0.0-p247/gems/activemodel-4.0.0/lib/active_model/validator.rb:150:in `each'
     # /Users/kirillberlin/.rvm/gems/ruby-2.0.0-p247/gems/activemodel-4.0.0/lib/active_model/validator.rb:150:in `validate'
     # /Users/kirillberlin/.rvm/gems/ruby-2.0.0-p247/gems/activesupport-4.0.0/lib/active_support/callbacks.rb:283:in `_callback_before_17'
     # /Users/kirillberlin/.rvm/gems/ruby-2.0.0-p247/gems/activesupport-4.0.0/lib/active_support/callbacks.rb:467:in `_run__2082443422329982594__validate__callbacks'
     # /Users/kirillberlin/.rvm/gems/ruby-2.0.0-p247/gems/activesupport-4.0.0/lib/active_support/callbacks.rb:80:in `run_callbacks'
     # /Users/kirillberlin/.rvm/gems/ruby-2.0.0-p247/gems/activemodel-4.0.0/lib/active_model/validations.rb:373:in `run_validations!'
     # /Users/kirillberlin/.rvm/gems/ruby-2.0.0-p247/gems/activemodel-4.0.0/lib/active_model/validations/callbacks.rb:106:in `block in run_validations!'
     # /Users/kirillberlin/.rvm/gems/ruby-2.0.0-p247/gems/activesupport-4.0.0/lib/active_support/callbacks.rb:373:in `_run__2082443422329982594__validation__callbacks'
     # /Users/kirillberlin/.rvm/gems/ruby-2.0.0-p247/gems/activesupport-4.0.0/lib/active_support/callbacks.rb:80:in `run_callbacks'
     # /Users/kirillberlin/.rvm/gems/ruby-2.0.0-p247/gems/activemodel-4.0.0/lib/active_model/validations/callbacks.rb:106:in `run_validations!'
     # /Users/kirillberlin/.rvm/gems/ruby-2.0.0-p247/gems/activemodel-4.0.0/lib/active_model/validations.rb:314:in `valid?'
     # /Users/kirillberlin/.rvm/gems/ruby-2.0.0-p247/gems/activerecord-4.0.0/lib/active_record/validations.rb:70:in `valid?'
     # /Users/kirillberlin/.rvm/gems/ruby-2.0.0-p247/gems/activerecord-4.0.0/lib/active_record/validations.rb:77:in `perform_validations'
     # /Users/kirillberlin/.rvm/gems/ruby-2.0.0-p247/gems/activerecord-4.0.0/lib/active_record/validations.rb:57:in `save!'
     # /Users/kirillberlin/.rvm/gems/ruby-2.0.0-p247/gems/activerecord-4.0.0/lib/active_record/attribute_methods/dirty.rb:41:in `save!'
     # /Users/kirillberlin/.rvm/gems/ruby-2.0.0-p247/gems/activerecord-4.0.0/lib/active_record/transactions.rb:275:in `block in save!'
     # /Users/kirillberlin/.rvm/gems/ruby-2.0.0-p247/gems/activerecord-4.0.0/lib/active_record/transactions.rb:326:in `block in with_transaction_returning_status'
     # /Users/kirillberlin/.rvm/gems/ruby-2.0.0-p247/gems/activerecord-4.0.0/lib/active_record/connection_adapters/abstract/database_statements.rb:202:in `block in transaction'
     # /Users/kirillberlin/.rvm/gems/ruby-2.0.0-p247/gems/activerecord-4.0.0/lib/active_record/connection_adapters/abstract/database_statements.rb:210:in `within_new_transaction'
     # /Users/kirillberlin/.rvm/gems/ruby-2.0.0-p247/gems/activerecord-4.0.0/lib/active_record/connection_adapters/abstract/database_statements.rb:202:in `transaction'
     # /Users/kirillberlin/.rvm/gems/ruby-2.0.0-p247/gems/activerecord-4.0.0/lib/active_record/transactions.rb:209:in `transaction'
     # /Users/kirillberlin/.rvm/gems/ruby-2.0.0-p247/gems/activerecord-4.0.0/lib/active_record/transactions.rb:323:in `with_transaction_returning_status'
     # /Users/kirillberlin/.rvm/gems/ruby-2.0.0-p247/gems/activerecord-4.0.0/lib/active_record/transactions.rb:275:in `save!'
     # /Users/kirillberlin/.rvm/gems/ruby-2.0.0-p247/gems/factory_girl-4.2.0/lib/factory_girl/configuration.rb:14:in `block in initialize'
     # /Users/kirillberlin/.rvm/gems/ruby-2.0.0-p247/gems/factory_girl-4.2.0/lib/factory_girl/evaluation.rb:15:in `[]'
     # /Users/kirillberlin/.rvm/gems/ruby-2.0.0-p247/gems/factory_girl-4.2.0/lib/factory_girl/evaluation.rb:15:in `create'
     # /Users/kirillberlin/.rvm/gems/ruby-2.0.0-p247/gems/factory_girl-4.2.0/lib/factory_girl/strategy/create.rb:12:in `block in result'
     # /Users/kirillberlin/.rvm/gems/ruby-2.0.0-p247/gems/factory_girl-4.2.0/lib/factory_girl/strategy/create.rb:9:in `tap'
     # /Users/kirillberlin/.rvm/gems/ruby-2.0.0-p247/gems/factory_girl-4.2.0/lib/factory_girl/strategy/create.rb:9:in `result'
     # /Users/kirillberlin/.rvm/gems/ruby-2.0.0-p247/gems/factory_girl-4.2.0/lib/factory_girl/factory.rb:42:in `run'
     # /Users/kirillberlin/.rvm/gems/ruby-2.0.0-p247/gems/factory_girl-4.2.0/lib/factory_girl/factory_runner.rb:23:in `block in run'
     # /Users/kirillberlin/.rvm/gems/ruby-2.0.0-p247/gems/activesupport-4.0.0/lib/active_support/notifications.rb:161:in `instrument'
     # /Users/kirillberlin/.rvm/gems/ruby-2.0.0-p247/gems/factory_girl-4.2.0/lib/factory_girl/factory_runner.rb:22:in `run'
     # /Users/kirillberlin/.rvm/gems/ruby-2.0.0-p247/gems/factory_girl-4.2.0/lib/factory_girl/strategy_syntax_method_registrar.rb:19:in `block in define_singular_strategy_method'
     # ./spec/models/event_dimension_spec.rb:5:in `block (2 levels) in <top (required)>'
     # /Users/kirillberlin/.rvm/gems/ruby-2.0.0-p247/gems/rspec-core-2.14.4/lib/rspec/core/memoized_helpers.rb:199:in `block (2 levels) in let'
     # /Users/kirillberlin/.rvm/gems/ruby-2.0.0-p247/gems/rspec-core-2.14.4/lib/rspec/core/memoized_helpers.rb:199:in `fetch'
     # /Users/kirillberlin/.rvm/gems/ruby-2.0.0-p247/gems/rspec-core-2.14.4/lib/rspec/core/memoized_helpers.rb:199:in `block in let'
     # ./spec/models/event_dimension_spec.rb:8:in `block (2 levels) in <top (required)>'
     # /Users/kirillberlin/.rvm/gems/ruby-2.0.0-p247/gems/rspec-core-2.14.4/lib/rspec/core/memoized_helpers.rb:199:in `block (2 levels) in let'
     # /Users/kirillberlin/.rvm/gems/ruby-2.0.0-p247/gems/rspec-core-2.14.4/lib/rspec/core/memoized_helpers.rb:199:in `fetch'
     # /Users/kirillberlin/.rvm/gems/ruby-2.0.0-p247/gems/rspec-core-2.14.4/lib/rspec/core/memoized_helpers.rb:199:in `block in let'
     # ./spec/models/event_dimension_spec.rb:10:in `block (2 levels) in <top (required)>'
     # /Users/kirillberlin/.rvm/gems/ruby-2.0.0-p247/gems/rspec-core-2.14.4/lib/rspec/core/memoized_helpers.rb:199:in `block (2 levels) in let'
     # /Users/kirillberlin/.rvm/gems/ruby-2.0.0-p247/gems/rspec-core-2.14.4/lib/rspec/core/memoized_helpers.rb:199:in `fetch'
     # /Users/kirillberlin/.rvm/gems/ruby-2.0.0-p247/gems/rspec-core-2.14.4/lib/rspec/core/memoized_helpers.rb:199:in `block in let'
     # /Users/kirillberlin/.rvm/gems/ruby-2.0.0-p247/gems/rspec-core-2.14.4/lib/rspec/core/memoized_helpers.rb:433:in `block (2 levels) in its'
     # /Users/kirillberlin/.rvm/gems/ruby-2.0.0-p247/gems/rspec-core-2.14.4/lib/rspec/core/memoized_helpers.rb:199:in `block (2 levels) in let'
     # /Users/kirillberlin/.rvm/gems/ruby-2.0.0-p247/gems/rspec-core-2.14.4/lib/rspec/core/memoized_helpers.rb:199:in `fetch'
     # /Users/kirillberlin/.rvm/gems/ruby-2.0.0-p247/gems/rspec-core-2.14.4/lib/rspec/core/memoized_helpers.rb:199:in `block in let'
     # /Users/kirillberlin/.rvm/gems/ruby-2.0.0-p247/gems/rspec-core-2.14.4/lib/rspec/core/memoized_helpers.rb:440:in `should'
     # ./spec/models/event_dimension_spec.rb:32:in `block (3 levels) in <top (required)>'
     # /Users/kirillberlin/.rvm/gems/ruby-2.0.0-p247/gems/rspec-core-2.14.4/lib/rspec/core/example.rb:114:in `instance_eval'
     # /Users/kirillberlin/.rvm/gems/ruby-2.0.0-p247/gems/rspec-core-2.14.4/lib/rspec/core/example.rb:114:in `block in run'
     # /Users/kirillberlin/.rvm/gems/ruby-2.0.0-p247/gems/rspec-core-2.14.4/lib/rspec/core/example.rb:179:in `call'
     # /Users/kirillberlin/.rvm/gems/ruby-2.0.0-p247/gems/rspec-core-2.14.4/lib/rspec/core/example.rb:179:in `run'
     # /Users/kirillberlin/.rvm/gems/ruby-2.0.0-p247/gems/rspec-core-2.14.4/lib/rspec/core/extensions/instance_eval_with_args.rb:16:in `instance_exec'
     # /Users/kirillberlin/.rvm/gems/ruby-2.0.0-p247/gems/rspec-core-2.14.4/lib/rspec/core/extensions/instance_eval_with_args.rb:16:in `instance_eval_with_args'
     # /Users/kirillberlin/.rvm/gems/ruby-2.0.0-p247/gems/rspec-core-2.14.4/lib/rspec/core/example.rb:247:in `instance_eval_with_args'
     # /Users/kirillberlin/.rvm/gems/ruby-2.0.0-p247/gems/rspec-core-2.14.4/lib/rspec/core/hooks.rb:87:in `block (2 levels) in run'
     # /Users/kirillberlin/.rvm/gems/ruby-2.0.0-p247/gems/rspec-core-2.14.4/lib/rspec/core/hooks.rb:89:in `call'
     # /Users/kirillberlin/.rvm/gems/ruby-2.0.0-p247/gems/rspec-core-2.14.4/lib/rspec/core/hooks.rb:89:in `run'
     # /Users/kirillberlin/.rvm/gems/ruby-2.0.0-p247/gems/rspec-core-2.14.4/lib/rspec/core/hooks.rb:427:in `run_hook'
     # /Users/kirillberlin/.rvm/gems/ruby-2.0.0-p247/gems/rspec-core-2.14.4/lib/rspec/core/example_group.rb:339:in `run_around_each_hooks'
     # /Users/kirillberlin/.rvm/gems/ruby-2.0.0-p247/gems/rspec-core-2.14.4/lib/rspec/core/example.rb:256:in `with_around_each_hooks'
     # /Users/kirillberlin/.rvm/gems/ruby-2.0.0-p247/gems/rspec-core-2.14.4/lib/rspec/core/example.rb:111:in `run'
     # /Users/kirillberlin/.rvm/gems/ruby-2.0.0-p247/gems/rspec-core-2.14.4/lib/rspec/core/example_group.rb:400:in `block in run_examples'
     # /Users/kirillberlin/.rvm/gems/ruby-2.0.0-p247/gems/rspec-core-2.14.4/lib/rspec/core/example_group.rb:396:in `map'
     # /Users/kirillberlin/.rvm/gems/ruby-2.0.0-p247/gems/rspec-core-2.14.4/lib/rspec/core/example_group.rb:396:in `run_examples'
     # /Users/kirillberlin/.rvm/gems/ruby-2.0.0-p247/gems/rspec-core-2.14.4/lib/rspec/core/example_group.rb:381:in `run'
     # /Users/kirillberlin/.rvm/gems/ruby-2.0.0-p247/gems/rspec-core-2.14.4/lib/rspec/core/example_group.rb:382:in `block in run'
     # /Users/kirillberlin/.rvm/gems/ruby-2.0.0-p247/gems/rspec-core-2.14.4/lib/rspec/core/example_group.rb:382:in `map'
     # /Users/kirillberlin/.rvm/gems/ruby-2.0.0-p247/gems/rspec-core-2.14.4/lib/rspec/core/example_group.rb:382:in `run'
     # /Users/kirillberlin/.rvm/gems/ruby-2.0.0-p247/gems/rspec-core-2.14.4/lib/rspec/core/example_group.rb:382:in `block in run'
     # /Users/kirillberlin/.rvm/gems/ruby-2.0.0-p247/gems/rspec-core-2.14.4/lib/rspec/core/example_group.rb:382:in `map'
     # /Users/kirillberlin/.rvm/gems/ruby-2.0.0-p247/gems/rspec-core-2.14.4/lib/rspec/core/example_group.rb:382:in `run'
     # /Users/kirillberlin/.rvm/gems/ruby-2.0.0-p247/gems/rspec-core-2.14.4/lib/rspec/core/command_line.rb:28:in `block (2 levels) in run'
     # /Users/kirillberlin/.rvm/gems/ruby-2.0.0-p247/gems/rspec-core-2.14.4/lib/rspec/core/command_line.rb:28:in `map'
     # /Users/kirillberlin/.rvm/gems/ruby-2.0.0-p247/gems/rspec-core-2.14.4/lib/rspec/core/command_line.rb:28:in `block in run'
     # /Users/kirillberlin/.rvm/gems/ruby-2.0.0-p247/gems/rspec-core-2.14.4/lib/rspec/core/reporter.rb:58:in `report'
     # /Users/kirillberlin/.rvm/gems/ruby-2.0.0-p247/gems/rspec-core-2.14.4/lib/rspec/core/command_line.rb:25:in `run'
     # /Users/kirillberlin/.rvm/gems/ruby-2.0.0-p247/gems/rspec-core-2.14.4/lib/rspec/core/runner.rb:80:in `run'
     # /Users/kirillberlin/.rvm/gems/ruby-2.0.0-p247/gems/rspec-core-2.14.4/lib/rspec/core/runner.rb:17:in `block in autorun'

Answer 1

I came across this error while Upgrading Rails from 5.1.3 to 5.2 and I was able to fix it by updating cancancan gem to the latest version i.e 3.0.2.

Answer 2

This is a bug in ActiveRecord. It will be fixed in Rails 4.0.3.

Answer 3

I have figured it out. Thanks to @muistooshort for pointing me in the right direction with the last comment. There was an issue with the relationship between my models. It prompted me to revise the need for my ProductDimension model at which point I completely discarded it in favour of another approach.