我有一个model ProjectKeyword,在第:segemnted_data
列中使用jsonb数据类型
class ProjectKeyword < ApplicationRecord
belongs_to :project
belongs_to :keyword
has_many :project_keyword_dimensions
has_many :dimensions, through: :project_keyword_dimensions
validates :project_id, :keyword_id, presence: true
end
迁移
class AddSegemtnedDataToProjectKeywords < ActiveRecord::迁移[5.0]
def change
add_column :project_keywords, :segmented_data, :jsonb, default: '{}'
add_index :project_keywords, :segmented_data, using: :gin
end
end
我的问题是,当我创建新的project_keyword
实例时,segmented_data
的默认值是一个字符串而不是散列,我无法更新此字段或与另一个散列合并
[12] pry(#)> new_pr_keyword = ProjectKeyword.new(project_id: 1671333, keyword_id: 39155)
=> #<ProjectKeyword:0x007fd997641090 id: nil, project_id: 1671333, keyword_id: 39155, segmented_data: "{}">
[13] pry(#)> new_pr_keyword.save!
=> true
[14] pry(#)> new_pr_keyword.segmented_data.update({'new_data' => 'some_data'})
NoMethodError: undefined method `update' for "{}":String
from (pry):14:in `block (3 levels) in <top (required)>'
但是,当我在更新之前将hash
值赋给字段segmented_data
时,update
方法就可以了.
例如
[15] pry(#)> new_pr_keyword.segmented_data = {'new_data' => 'some_data'}
=> {"new_data"=>"some_data"}
[16] pry(#)> new_pr_keyword.save!
=> true
[17] pry(#)> new_pr_keyword.segmented_data.update({'new_data_2' => 'some_data_2'})
=> {"new_data"=>"some_data", "new_data_2"=>"some_data_2"}
[18] pry(#)> new_pr_keyword.save!
=> true
问题是,如何将分段_数据的默认值设置为哈希类而不是字符串,以便在刚刚创建对象之后,方法更新将直接在该字段上工作.