ruby on rails - PG::DuplicateTable: ERROR: relation "posts" already exists

Question

When I run rake db:migrate I get following output:

== 20141219011612 CreatePost: migrating ======================================= -- create_table("posts") rake aborted! StandardError: An error has occurred, this and all later migrations canceled: == 20141219011612 Postposts: migrating ======================================= -- create_table("posts") rake aborted! StandardError: An error has occurred, this and all later migrations canceled:

PG::DuplicateTable: ERROR: relation "posts" already exists : CREATE TABLE "posts" ("id" serial primary key, "post" text, "release_date" timestamp, "created_at" timestamp, "updated_at" timestamp) /home/admin/.rvm/gems/ruby-2.1.5/gems/activerecord-4.1.8/lib/active_record/connection_adapters/postgresql/database_statements.rb:128:in async_exec' /home/admin/.rvm/gems/ruby-2.1.5/gems/activerecord-4.1.8/lib/active_record/connection_adapters/postgresql/database_statements.rb:128:in block in execute' /home/admin/.rvm/gems/ruby-2.1.5/gems/activerecord-4.1.8/lib/active_record/connection_adapters/abstract_adapter.rb:373:in block in log' /home/admin/.rvm/gems/ruby-2.1.5/gems/activesupport-4.1.8/lib/active_support/notifications/instrumenter.rb:20:in instrument' /home/admin/.rvm/gems/ruby-2.1.5/gems/activerecord-4.1.8/lib/active_record/connection_adapters/abstract_adapter.rb:367:in log' /home/admin/.rvm/gems/ruby-2.1.5/gems/activerecord-4.1.8/lib/active_record/connection_adapters/postgresql/database_statements.rb:127:in execute' /home/admin/.rvm/gems/ruby-2.1.5/gems/activerecord-4.1.8/lib/active_record/connection_adapters/abstract/schema_statements.rb:205:in create_table' /home/admin/.rvm/gems/ruby-2.1.5/gems/activerecord-4.1.8/lib/active_record/migration.rb:649:in block in method_missing' /home/admin/.rvm/gems/ruby-2.1.5/gems/activerecord-4.1.8/lib/active_record/migration.rb:621:in block in say_with_time' /home/admin/.rvm/gems/ruby-2.1.5/gems/activerecord-4.1.8/lib/active_record/migration.rb:621:in say_with_time' /home/admin/.rvm/gems/ruby-2.1.5/gems/activerecord-4.1.8/lib/active_record/migration.rb:641:in `method_missing'

...

migrate' /home/admin/.rvm/gems/ruby-2.1.5/gems/activerecord-4.1.8/lib/active_record/railties/databases.rake:34:in block (2 levels) in <top (required)>' Tasks: TOP => db:migrate (See full trace by running task with --trace)

I don't understund how this is possible, bescause In scheme file I don't have post table.

Answer 1

Somehow, you ended up with a table named 'posts' in your database. Perhaps from a prior migration that you deleted without rolling back? If you don't care about any of your data in the database, you can run

rake db:drop db:create db:migrate

to bring your development database inline with your current migrations.

If you have data in other tables you don't want to lose, open the database console and drop the posts table manually:

$ rails db

# drop table posts;

Then run db:migrate again.