I changed the column name, but it said Undefined method for the column before the change.

version

・ Ruby 2.5.7 ・ Rails 5.2.4.3

Trying to save a new record with a different column name but an error

It is called Undefined method script_id.

However, when I look at schema.rb (before change: script_id → after change: joke_book_id), it has changed.

schema.rb

t.integer "joke_book_id"
t.integer "user_id"
t.text "introduction"

So where does this script_id come from?

Conclusion: I didn't change the model

After researching various things, I notice that the model is suspicious. Looking at the model, It was the same as before the change with validates: script_id, {presence: true}. Change here to a new column. validates :joke_book_id, {presence: true}

users_joke.rb

#validates :script_id, {presence: true} #Change before

validates :joke_book_id, {presence: true} #After change

It worked! !! !!