Question

when I new a migration and run it,error occurred:

$ rake db:migrate
== CreateEReadings: migrating ================================================
— create_table(:e_readings) rake aborted! An error has occurred, this and all later migrations canceled:

SQLite3::SQLException: table “e_readings” already exists

while this e_readings is the last table I created using migration.

The migration file name is :20120508145115_create_e_readings.rb

and the version in db/schema.rb is :

:version => 20120508145115

Seems that rails forget that I already have run this migration and try to re-play it, so error occurred,but why is this happening and how can I solve this?

Answer 1

It seems like you may have run it before and it failed after creating the table for some reason. If you’re sure it has already run, you can manually add a record to the “schema_migrations” table with the 20120508145115 as the version.

If this is just a dev environment and you don’t mind blowing it away, you could also run rake db:reset and that would drop, create, load the schema and reseed it.