Use proper names while generating migrations.FixColumnName looks totally out of context.Please see  the documentation and sample examples for generating migrations here: http://guides.rubyonrails.org/migrations.html#creating-a-standalone-migration.

The migration name should give information about what changes have been made in the migration.Usually we add/remove/rename columns.

For e.g. consider we want to create a User model and want to add first_name and last_name columns.Then the migration generation step should look like:

$rails g migration AddFirstNameAndLastNameToUsers first_name:string last_name:string

For removal of those columns

$rails g migration RemoveFirstNameAndLastNameFromUsers first_name:string last_name:string

Using Add and Remove as the first word in migration name is treated specially by Rails generator.Those indicate adding the appropriate method add_column or remove_column to the generated migration file instead of we writing those.

For renaming of those columns

$rails g migration RenameFirstNameToFNameInUsers

Here adding the column names after migration name doesn't matter Rails generator doesn't take not of it and you have to manually write the rename column method call inside the generated migration.

Please go through the documentation for more details.