ruby-on-rails - 如何获取 Rails 4 activerecord 插入 sql？

Question

我想动态获取activerecord的sql语句。例如

pen = Pen.new
pen.description = "HB"
pen_sql = pen.insert_sql
puts pen_sql 
=> "Insert into pens (description) values ('HB')"

Answer 1

您创建自己的方法来获取类似这样的插入语句。

def get_insert_sql(from_dbmodel)
  insert_sql = from_dbmodel.class.arel_table.create_insert.tap do |im|
    im.insert(from_dbmodel.send(:arel_attributes_with_values_for_create, from_dbmodel.attribute_names))
  end.to_sql

  return insert_sql     
end

pen = Pen.new
pen.description = "HB"
pen_sql = get_insert_sql(pen)
puts pen_sql 
=> "Insert into pens (description) values ('HB')"

在 rails 4 中测试