更改列轨示例
def change
change_column(:table_name, :column_name, :new_type)
end
如何创建迁移rails
rails g migration AddPartNumberToProducts
activerecord添加列
class AddPartNumberToProducts < ActiveRecord::Migration[6.0]
def change
add_column :products, :part_number, :string
end
end
ruby on rails db migrate
rails db:migrate
如何在ruby中创建SQL表
def self.create_table
sql = <<-SQL
CREATE TABLE IF NOT EXISTS IF NOT EXISTS students (
name TEXT,
grade TEXT
)
SQL
DB[:conn].execute(sql)
end