i have problem with ‘rake db:migrate’
i use this tutorial =>
form first step to this step.
when i type ‘rake db:migrate’ in my terminal.
i get this error =>
== 20160127215334 Books: migrating
– create_table(:books)
rake aborted!
StandardError: An error has occurred, this and all later migrations
canceled:
PG::DuplicateTable: ERROR: relation “books” already exists
: CREATE TABLE “books” (“id” serial primary key, “title” character
varying(32) NOT NULL, “price” float, “subject_id” integer, “description”
text, “created_at” timestamp)
/var/lib/gems/2.1.0/gems/activerecord-4.2.5/lib/active_record/connection_adapters/postgresql/database_statements.rb:155:in
async_exec' /var/lib/gems/2.1.0/gems/activerecord-4.2.5/lib/active_record/connection_adapters/postgresql/database_statements.rb:155:in block in execute’
/var/lib/gems/2.1.0/gems/activerecord-4.2.5/lib/active_record/connection_adapters/abstract_adapter.rb:472:in
block in log' /var/lib/gems/2.1.0/gems/activesupport-4.2.5/lib/active_support/notifications/instrumenter.rb:20:in instrument’
/var/lib/gems/2.1.0/gems/activerecord-4.2.5/lib/active_record/connection_adapters/abstract_adapter.rb:466:in
log' /var/lib/gems/2.1.0/gems/activerecord-4.2.5/lib/active_record/connection_adapters/postgresql/database_statements.rb:154:in execute’
/var/lib/gems/2.1.0/gems/activerecord-4.2.5/lib/active_record/connection_adapters/abstract/schema_statements.rb:208:in
create_table' /var/lib/gems/2.1.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:665:in block in method_missing’
/var/lib/gems/2.1.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:634:in
block in say_with_time' /var/lib/gems/2.1.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:634:in say_with_time’
/var/lib/gems/2.1.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:654:in
method_missing' /var/lib/gems/2.1.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:416:in method_missing’
/root/Desktop/Rails/library/db/migrate/20160127215334_books.rb:4:in up' /var/lib/gems/2.1.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:571:in up’
/var/lib/gems/2.1.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:611:in
exec_migration' /var/lib/gems/2.1.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:592:in block (2 levels) in migrate’
/var/lib/gems/2.1.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:591:in
block in migrate' /var/lib/gems/2.1.0/gems/activerecord-4.2.5/lib/active_record/connection_adapters/abstract/connection_pool.rb:292:in with_connection’
/var/lib/gems/2.1.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:590:in
migrate' /var/lib/gems/2.1.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:768:in migrate’
/var/lib/gems/2.1.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:998:in
block in execute_migration_in_transaction' /var/lib/gems/2.1.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:1044:in block in ddl_transaction’
/var/lib/gems/2.1.0/gems/activerecord-4.2.5/lib/active_record/connection_adapters/abstract/database_statements.rb:213:in
block in transaction' /var/lib/gems/2.1.0/gems/activerecord-4.2.5/lib/active_record/connection_adapters/abstract/transaction.rb:184:in within_new_transaction’
/var/lib/gems/2.1.0/gems/activerecord-4.2.5/lib/active_record/connection_adapters/abstract/database_statements.rb:213:in
transaction' /var/lib/gems/2.1.0/gems/activerecord-4.2.5/lib/active_record/transactions.rb:220:in transaction’
/var/lib/gems/2.1.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:1044:in
ddl_transaction' /var/lib/gems/2.1.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:997:in execute_migration_in_transaction’
/var/lib/gems/2.1.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:959:in
block in migrate' /var/lib/gems/2.1.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:955:in each’
/var/lib/gems/2.1.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:955:in
migrate' /var/lib/gems/2.1.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:823:in up’
/var/lib/gems/2.1.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:801:in
migrate' /var/lib/gems/2.1.0/gems/activerecord-4.2.5/lib/active_record/tasks/database_tasks.rb:137:in migrate’
/var/lib/gems/2.1.0/gems/activerecord-4.2.5/lib/active_record/railties/databases.rake:44:in
block (2 levels) in <top (required)>' ActiveRecord::StatementInvalid: PG::DuplicateTable: ERROR: relation "books" already exists : CREATE TABLE "books" ("id" serial primary key, "title" character varying(32) NOT NULL, "price" float, "subject_id" integer, "description" text, "created_at" timestamp) /var/lib/gems/2.1.0/gems/activerecord-4.2.5/lib/active_record/connection_adapters/postgresql/database_statements.rb:155:in async_exec’
/var/lib/gems/2.1.0/gems/activerecord-4.2.5/lib/active_record/connection_adapters/postgresql/database_statements.rb:155:in
block in execute' /var/lib/gems/2.1.0/gems/activerecord-4.2.5/lib/active_record/connection_adapters/abstract_adapter.rb:472:in block in log’
/var/lib/gems/2.1.0/gems/activesupport-4.2.5/lib/active_support/notifications/instrumenter.rb:20:in
instrument' /var/lib/gems/2.1.0/gems/activerecord-4.2.5/lib/active_record/connection_adapters/abstract_adapter.rb:466:in log’
/var/lib/gems/2.1.0/gems/activerecord-4.2.5/lib/active_record/connection_adapters/postgresql/database_statements.rb:154:in
execute' /var/lib/gems/2.1.0/gems/activerecord-4.2.5/lib/active_record/connection_adapters/abstract/schema_statements.rb:208:in create_table’
/var/lib/gems/2.1.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:665:in
block in method_missing' /var/lib/gems/2.1.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:634:in block in say_with_time’
/var/lib/gems/2.1.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:634:in
say_with_time' /var/lib/gems/2.1.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:654:in method_missing’
/var/lib/gems/2.1.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:416:in
method_missing' /root/Desktop/Rails/library/db/migrate/20160127215334_books.rb:4:in up’
/var/lib/gems/2.1.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:571:in
up' /var/lib/gems/2.1.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:611:in exec_migration’
/var/lib/gems/2.1.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:592:in
block (2 levels) in migrate' /var/lib/gems/2.1.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:591:in block in migrate’
/var/lib/gems/2.1.0/gems/activerecord-4.2.5/lib/active_record/connection_adapters/abstract/connection_pool.rb:292:in
with_connection' /var/lib/gems/2.1.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:590:in migrate’
/var/lib/gems/2.1.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:768:in
migrate' /var/lib/gems/2.1.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:998:in block in execute_migration_in_transaction’
/var/lib/gems/2.1.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:1044:in
block in ddl_transaction' /var/lib/gems/2.1.0/gems/activerecord-4.2.5/lib/active_record/connection_adapters/abstract/database_statements.rb:213:in block in transaction’
/var/lib/gems/2.1.0/gems/activerecord-4.2.5/lib/active_record/connection_adapters/abstract/transaction.rb:184:in
within_new_transaction' /var/lib/gems/2.1.0/gems/activerecord-4.2.5/lib/active_record/connection_adapters/abstract/database_statements.rb:213:in transaction’
/var/lib/gems/2.1.0/gems/activerecord-4.2.5/lib/active_record/transactions.rb:220:in
transaction' /var/lib/gems/2.1.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:1044:in ddl_transaction’
/var/lib/gems/2.1.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:997:in
execute_migration_in_transaction' /var/lib/gems/2.1.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:959:in block in migrate’
/var/lib/gems/2.1.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:955:in
each' /var/lib/gems/2.1.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:955:in migrate’
/var/lib/gems/2.1.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:823:in
up' /var/lib/gems/2.1.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:801:in migrate’
/var/lib/gems/2.1.0/gems/activerecord-4.2.5/lib/active_record/tasks/database_tasks.rb:137:in
migrate' /var/lib/gems/2.1.0/gems/activerecord-4.2.5/lib/active_record/railties/databases.rake:44:in block (2 levels) in <top (required)>’
PG::DuplicateTable: ERROR: relation “books” already exists
/var/lib/gems/2.1.0/gems/activerecord-4.2.5/lib/active_record/connection_adapters/postgresql/database_statements.rb:155:in
async_exec' /var/lib/gems/2.1.0/gems/activerecord-4.2.5/lib/active_record/connection_adapters/postgresql/database_statements.rb:155:in block in execute’
/var/lib/gems/2.1.0/gems/activerecord-4.2.5/lib/active_record/connection_adapters/abstract_adapter.rb:472:in
block in log' /var/lib/gems/2.1.0/gems/activesupport-4.2.5/lib/active_support/notifications/instrumenter.rb:20:in instrument’
/var/lib/gems/2.1.0/gems/activerecord-4.2.5/lib/active_record/connection_adapters/abstract_adapter.rb:466:in
log' /var/lib/gems/2.1.0/gems/activerecord-4.2.5/lib/active_record/connection_adapters/postgresql/database_statements.rb:154:in execute’
/var/lib/gems/2.1.0/gems/activerecord-4.2.5/lib/active_record/connection_adapters/abstract/schema_statements.rb:208:in
create_table' /var/lib/gems/2.1.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:665:in block in method_missing’
/var/lib/gems/2.1.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:634:in
block in say_with_time' /var/lib/gems/2.1.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:634:in say_with_time’
/var/lib/gems/2.1.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:654:in
method_missing' /var/lib/gems/2.1.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:416:in method_missing’
/root/Desktop/Rails/library/db/migrate/20160127215334_books.rb:4:in up' /var/lib/gems/2.1.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:571:in up’
/var/lib/gems/2.1.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:611:in
exec_migration' /var/lib/gems/2.1.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:592:in block (2 levels) in migrate’
/var/lib/gems/2.1.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:591:in
block in migrate' /var/lib/gems/2.1.0/gems/activerecord-4.2.5/lib/active_record/connection_adapters/abstract/connection_pool.rb:292:in with_connection’
/var/lib/gems/2.1.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:590:in
migrate' /var/lib/gems/2.1.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:768:in migrate’
/var/lib/gems/2.1.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:998:in
block in execute_migration_in_transaction' /var/lib/gems/2.1.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:1044:in block in ddl_transaction’
/var/lib/gems/2.1.0/gems/activerecord-4.2.5/lib/active_record/connection_adapters/abstract/database_statements.rb:213:in
block in transaction' /var/lib/gems/2.1.0/gems/activerecord-4.2.5/lib/active_record/connection_adapters/abstract/transaction.rb:184:in within_new_transaction’
/var/lib/gems/2.1.0/gems/activerecord-4.2.5/lib/active_record/connection_adapters/abstract/database_statements.rb:213:in
transaction' /var/lib/gems/2.1.0/gems/activerecord-4.2.5/lib/active_record/transactions.rb:220:in transaction’
/var/lib/gems/2.1.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:1044:in
ddl_transaction' /var/lib/gems/2.1.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:997:in execute_migration_in_transaction’
/var/lib/gems/2.1.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:959:in
block in migrate' /var/lib/gems/2.1.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:955:in each’
/var/lib/gems/2.1.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:955:in
migrate' /var/lib/gems/2.1.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:823:in up’
/var/lib/gems/2.1.0/gems/activerecord-4.2.5/lib/active_record/migration.rb:801:in
migrate' /var/lib/gems/2.1.0/gems/activerecord-4.2.5/lib/active_record/tasks/database_tasks.rb:137:in migrate’
/var/lib/gems/2.1.0/gems/activerecord-4.2.5/lib/active_record/railties/databases.rake:44:in
`block (2 levels) in <top (required)>’
Tasks: TOP => db:migrate
(See full trace by running task with --trace)
what i have to do now?