新手问题 Mysql2::Error: Specified key was too long; max key length is 767 bytes
fengfans@fengfans-PC:~/codes/rails-project/GoodRead$ rake db:migrate
(in /home/fengfans/codes/rails-project/GoodRead)
== DeviseCreateUsers: migrating ==============================================
-- create_table(:users)
-> 0.1092s
-- add_index(:users, :email, {:unique=>true, :limit=>5})
rake aborted!
An error has occurred, all later migrations canceled:
Mysql2::Error: Specified key was too long; max key length is 767 bytes: CREATE UNIQUE INDEX `index_users_on_email` ON `users` (`email`)
(See full trace by running task with --trace)
fengfans@fengfans-PC:~/codes/rails-project/GoodRead$
请各位高手指点小弟！