Rails迁移drop_users 编辑迁移

    class DropUsers < ActiveRecord::Migration
      def change
        drop_table :users do |t|
          t.string :name
          t.timestamps
        end
      end
    end

rake db: migrate

你能做的最好的办法就是

rails g migration Drop_table_Users

然后执行以下操作

rake db:migrate

我需要删除我们的迁移脚本以及表本身……

class Util::Table < ActiveRecord::Migration

 def self.clobber(table_name)   
    # drop the table
    if ActiveRecord::Base.connection.table_exists? table_name
      puts "\n== " + table_name.upcase.cyan + " ! " 
           << Time.now.strftime("%H:%M:%S").yellow
      drop_table table_name 
    end

    # locate any existing migrations for a table and delete them
    base_folder = File.join(Rails.root.to_s, 'db', 'migrate')
    Dir[File.join(base_folder, '**', '*.rb')].each do |file|
      if file =~ /create_#{table_name}.rb/
        puts "== deleting migration: " + file.cyan + " ! "
             << Time.now.strftime("%H:%M:%S").yellow
        FileUtils.rm_rf(file)
        break
      end
    end
  end

  def self.clobber_all
    # delete every table in the db, along with every corresponding migration 
    ActiveRecord::Base.connection.tables.each {|t| clobber t}
  end

end

从终端窗口运行:

$ rails runner "Util::Table.clobber 'your_table_name'"

or

$ rails runner "Util::Table.clobber_all"

删除表/迁移

运行: $ rails生成迁移DropTablename

$ rails生成迁移DropProducts

ActiveRecord:: Base.connection。drop_table: table_name

如果有人在寻找如何在SQL中做到这一点。

从终端输入rails dbconsole

输入密码

在控制台做

使用db_name;

DROP TABLE table_name;

exit

请不要忘记从模式中删除迁移文件和表结构