我在rails中有一个名为Users的现有表。它有一个名为gender的列。我有另一个名为GenderOptions的表。我想创建一个迁移，以便Users表中的gender列是引用GenderOptions表的外键。
第一次尝试迁移文件看起来像这样：

class ForeignKey < ActiveRecord::Migration[7.1]
  def change
    add_reference :users, :gender, foreign_key: {to_table: :GenderOptions}
  end
end

字符串
但我得到一个错误消息：

add_reference(:users, :gender, {:foreign_key=>{:to_table=>:GenderOptions}})
rake aborted!
StandardError: An error has occurred, all later migrations canceled: (StandardError)

Mysql2::Error: Duplicate column name 'gender_id'
...:in `change'

Caused by:
ActiveRecord::StatementInvalid: Mysql2::Error: Duplicate column name 'gender_id' (ActiveRecord::StatementInvalid)
...:in `change'

Caused by:
Mysql2::Error: Duplicate column name 'gender_id' (Mysql2::Error)
...:in `change'
Tasks: TOP => db:migrate
(See full trace by running task with --trace)

型
我也试过：

class ForeignKey < ActiveRecord::Migration[7.1]
  def change
    add_foreign_key :users, :GenderOptions, column: :gender_id, primary_key: :id

  end
end

型
但我也犯了同样的错误。
在Rails中，如何更新现有表中的现有列，使其成为引用另一个表的外键？