Fail to select the record in rails 5 console - ruby-on-rails

Question

I have tested the new rails code on c9.io and it is working fine to select the record when the emailReceived field is false on Invitation table,
After I updated the new code into Heroku, it is failed to do it. And showing the error message.
ActiveRecord::StatementInvalid: PG::UndefinedColumn: ERROR: column
"emailreceived" does not exist
I used Invitation.column_names and can find the "emailReceived". Does the database corrupted? Here is the console information for your reference. Please help to advise how to fix it.
irb(main):005:0> Invitation.column_names
=> ["id", "church", "telephone1", "telephone2", "worshipTime", "contactName", "contactNumber", "priest", "preacher", "emailReceived", "acceptPromote", "promotionTime", "other", "created_at", "updated_at"]
irb(main):006:0> Invitation.where("emailReceived = false")
Invitation Load (3.0ms) SELECT "invitations".* FROM "invitations" WHERE (emailReceived = false)
ActiveRecord::StatementInvalid: PG::UndefinedColumn: ERROR: column "emailreceived" does not exist
LINE 1: SELECT "invitations".* FROM "invitations" WHERE (emailReceiv...
^
HINT: Perhaps you meant to reference the column "invitations.emailReceived".
: SELECT "invitations".* FROM "invitations" WHERE (emailReceived = false)
from /app/vendor/bundle/ruby/2.2.0/gems/activerecord-5.0.0.1/lib/active_record/connection_adapters/postgresql_adapter.rb:598:in async_exec'
from /app/vendor/bundle/ruby/2.2.0/gems/activerecord-5.0.0.1/lib/active_record/connection_adapters/postgresql_adapter.rb:598:inblock in exec_no_cache'
from /app/vendor/bundle/ruby/2.2.0/gems/activerecord-5.0.0.1/lib/active_record/connection_adapters/abstract_adapter.rb:566:in block in log'
from /app/vendor/bundle/ruby/2.2.0/gems/activesupport-5.0.0.1/lib/active_support/notifications/instrumenter.rb:21:ininstrument'
from /app/vendor/bundle/ruby/2.2.0/gems/activerecord-5.0.0.1/lib/active_record/connection_adapters/abstract_adapter.rb:560:in log'
from /app/vendor/bundle/ruby/2.2.0/gems/activerecord-5.0.0.1/lib/active_record/connection_adapters/postgresql_adapter.rb:598:inexec_no_cache'
from /app/vendor/bundle/ruby/2.2.0/gems/activerecord-5.0.0.1/lib/active_record/connection_adapters/postgresql_adapter.rb:585:in execute_and_clear'
from /app/vendor/bundle/ruby/2.2.0/gems/activerecord-5.0.0.1/lib/active_record/connection_adapters/postgresql/database_statements.rb:103:inexec_query'
from /app/vendor/bundle/ruby/2.2.0/gems/activerecord-5.0.0.1/lib/active_record/connection_adapters/abstract/database_statements.rb:373:in select'
from /app/vendor/bundle/ruby/2.2.0/gems/activerecord-5.0.0.1/lib/active_record/connection_adapters/abstract/database_statements.rb:41:inselect_all'
from /app/vendor/bundle/ruby/2.2.0/gems/activerecord-5.0.0.1/lib/active_record/connection_adapters/abstract/query_cache.rb:70:in select_all'
from /app/vendor/bundle/ruby/2.2.0/gems/activerecord-5.0.0.1/lib/active_record/querying.rb:39:infind_by_sql'
from /app/vendor/bundle/ruby/2.2.0/gems/activerecord-5.0.0.1/lib/active_record/relation.rb:699:in exec_queries'
from /app/vendor/bundle/ruby/2.2.0/gems/activerecord-5.0.0.1/lib/active_record/relation.rb:580:inload'
from /app/vendor/bundle/ruby/2.2.0/gems/activerecord-5.0.0.1/lib/active_record/relation.rb:260:in records'
from /app/vendor/bundle/ruby/2.2.0/gems/activerecord-5.0.0.1/lib/active_record/relation.rb:683:ininspect'
from /app/vendor/bundle/ruby/2.2.0/gems/railties-5.0.0.1/lib/rails/commands/console.rb:65:in start'
from /app/vendor/bundle/ruby/2.2.0/gems/railties-5.0.0.1/lib/rails/commands/console_helper.rb:9:instart'
from /app/vendor/bundle/ruby/2.2.0/gems/railties-5.0.0.1/lib/rails/commands/commands_tasks.rb:78:in console'
from /app/vendor/bundle/ruby/2.2.0/gems/railties-5.0.0.1/lib/rails/commands/commands_tasks.rb:49:inrun_command!'
from /app/vendor/bundle/ruby/2.2.0/gems/railties-5.0.0.1/lib/rails/commands.rb:18:in <top (required)>'
from bin/rails:8:inrequire'
from bin/rails:8:in `'irb(main):007:0>
One more information on this case, I run "heroku run rake --trace db:migrate VERSION=20161007083159" and get the below result. And it still doesn't work
heroku run rake --trace db:migrate VERSION=20161007083159
Running rake --trace db:migrate VERSION=20161007083159 on ⬢ shrouded-scrubland-30708... up, run.1694
** Invoke db:migrate (first_time)
** Invoke environment (first_time)
** Execute environment
** Invoke db:load_config (first_time)
** Execute db:load_config
** Execute db:migrate
ActiveRecord::SchemaMigration Load (0.6ms) SELECT "schema_migrations".* FROM "schema_migrations"
ActiveRecord::SchemaMigration Load (0.5ms) SELECT "schema_migrations".* FROM "schema_migrations"
(0.5ms) SELECT pg_try_advisory_lock(129277373589159705);
ActiveRecord::SchemaMigration Load (0.5ms) SELECT "schema_migrations".* FROM "schema_migrations"
ActiveRecord::InternalMetadata Load (0.8ms) SELECT "ar_internal_metadata".* FROM "ar_internal_metadata" WHERE "ar_internal_metadata"."key" = $1 LIMIT $2 [["key", :environment], ["LIMIT", 1]]
(0.5ms) BEGIN
(0.4ms) COMMIT
(0.5ms) SELECT pg_advisory_unlock(129277373589159705)
** Invoke db:_dump (first_time)
** Execute db:_dump
Thanks
Patrick Lee

Answer 1

Eventually, I found that the problem is occurred due to the case sensitive of postgresql. So I changed the code from Invitation.where("emailReceived is ? OR emailReceived = ?", nil,false) to Invitation.where("emailReceived" => nil) on model.
But one more question, how can use OR for Invitation.where("emailReceived" => nil) Invitation.where("emailReceived" => false)?
Thanks
Patrick Lee