Rails 上的 Ruby：如何使用 JSON 路径访问（并保存到数据库）嵌套在 JSON 数组中的 objects/properties？
Ruby on Rails: How can I use JSONPath to access (and save to database) nested objects/properties within a JSON array?
我正在尝试从 JSON 对象数组向我的数据库播种数据。我有两个单独的数据库表 - 属性 和单位（属性 有很多单位）。我已经能够通过 API 请求 JSON 数据成功地为 属性 信息（属性 模型）执行此操作，然后将其播种到数据库但是 ValuationReport 属性在我的前端显示为字符串形式的 JSON 对象。
这是我正在使用的 JSON 数据的示例（出于演示目的，我将此示例限制为包含 3 个对象的数组）：
[
{
"PublicationDate": "17/09/2019",
"PropertyNumber": 2198231,
"County": "CAVAN",
"LocalAuthority": "CAVAN COUNTY COUNCIL",
"Valuation": 15090,
"Category": "OFFICE",
"Uses": "OFFICE (OVER THE SHOP), -",
"Address1": "77(1ST & 2ND FL) MAIN STREET",
"Address2": "CAVAN",
"Address3": "CO. CAVAN",
"Address4": "",
"Address5": "",
"CarPark": 0,
"Xitm": 641927.73,
"Yitm": 804638.3,
"ValuationReport": [
{
"Level": "1",
"FloorUse": "RESTAURANT",
"Area": 112.25,
"NavPerM2": 80,
"Nav": 8980
},
{
"Level": "2",
"FloorUse": "RESTAURANT",
"Area": 98.57,
"NavPerM2": 62,
"Nav": 6111.34
}
]
},
{
"PublicationDate": "17/09/2019",
"PropertyNumber": 1558322,
"County": "CAVAN",
"LocalAuthority": "CAVAN COUNTY COUNCIL",
"Valuation": 10200,
"Category": "OFFICE",
"Uses": "OFFICE (OWN DOOR), -",
"Address1": "23E MAIN STREET",
"Address2": "CAVAN",
"Address3": "CO. CAVAN",
"Address4": "",
"Address5": "",
"CarPark": 0,
"Xitm": 641941.19,
"Yitm": 804875.56,
"ValuationReport": [
{
"Level": "0",
"FloorUse": "OFFICE(S)",
"Area": 127.55,
"NavPerM2": 80,
"Nav": 10204
}
]
},
{
"PublicationDate": "17/09/2019",
"PropertyNumber": 2116802,
"County": "CAVAN",
"LocalAuthority": "CAVAN COUNTY COUNCIL",
"Valuation": 15140,
"Category": "OFFICE",
"Uses": "OFFICE (OWN DOOR), HERITAGE / INTERPRETATIVE CENTRE",
"Address1": "LOCAL NO/MAP REF: 7AB",
"Address2": "MULLAGH",
"Address3": "BAILIEBORO CO. CAVAN",
"Address4": "",
"Address5": "",
"CarPark": 0,
"Xitm": 668656.19,
"Yitm": 785281.05,
"ValuationReport": [
{
"Level": "0",
"FloorUse": "OFFICE(S)",
"Area": 252.49,
"NavPerM2": 60,
"Nav": 15149.4
property_id: unit[property.id]
}
]
}
]
我遇到的困难是 ValuationReport 属性，它是 JSON 属性数组中每个元素的大小不同的数组。因此，某些属性将具有仅包含一个对象的 ValuationReport 数组，而其他属性将包含具有多个对象的 ValuationReport 对象。我想将每个 ValuationReport 数组中的每个嵌套对象保存到我的数据库（单元模型）中的一个单独单元中。
我已经使用 JSON路径 Gem 尝试访问所需的元素，但我做错了什么。
当我 运行 '$ rails db:seed' 时，现在 运行ning 直到一个点，我收到以下错误：
Creating property 2198231
Creating unit.
rails aborted!
TypeError: no implicit conversion of String into Integer
/db/seeds.rb:62:in `[]'
/db/seeds.rb:62:in `block (2 levels) in properties'
/db/seeds.rb:58:in `each'
/db/seeds.rb:58:in `block in properties'
/db/seeds.rb:36:in `each'
/db/seeds.rb:36:in `properties'
/db/seeds.rb:207:in `<top (required)>'
bin/rails:4:in `require'
bin/rails:4:in `<main>'
Tasks: TOP => db:seed
(See full trace by running task with --trace)
这是我的 Gem 文件中的相关 Gem：
# REST Client for APIs
gem 'rest-client', '~> 2.1'
# JSONPath - for acessing values in nested JSON objects.
gem 'jsonpath', '~> 0.5.8'
我的数据库架构如下：
ActiveRecord::Schema.define(version: 2020_11_07_130018) do
# These are extensions that must be enabled in order to support this database
enable_extension "plpgsql"
create_table "properties", force: :cascade do |t|
t.date "publication_date"
t.string "property_number"
t.string "county"
t.string "local_authority"
t.decimal "valuation"
t.string "category"
t.string "uses"
t.string "address_1"
t.string "address_2"
t.string "address_3"
t.string "address_4"
t.string "address_5"
t.decimal "car_park"
t.decimal "xitm"
t.decimal "yitm"
t.datetime "created_at", precision: 6, null: false
t.datetime "updated_at", precision: 6, null: false
end
create_table "units", force: :cascade do |t|
t.string "level"
t.string "floor_use"
t.decimal "area"
t.decimal "nav_per_m2"
t.decimal "nav"
t.bigint "property_id"
t.datetime "created_at", precision: 6, null: false
t.datetime "updated_at", precision: 6, null: false
t.index ["property_id"], name: "index_units_on_property_id"
end
add_foreign_key "units", "properties"
end
我的 seeds.rb 文件如下。我尝试使用索引 (i) 来确保 ValuationReport 对象数组的循环为每个 属性 循环一次并创建每个 属性.[=19 中存在的所有单位=]
require 'rest-client'
require 'json'
require 'jsonpath'
# Define Method - API Request
def properties
response = RestClient.get('https://api.valoff.ie/api/Property/GetProperties?Fields=*&LocalAuthority=CAVAN%20COUNTY%20COUNCIL&CategorySelected=OFFICE&Format=csv&Download=false')
json = JSON.parse(response)
json.each do |property|
puts "Creating property #{property['PropertyNumber']}"
Property.create!(
publication_date: property['PublicationDate'],
property_number: property['PropertyNumber'],
county: property['County'],
local_authority: property['LocalAuthority'],
valuation: property['Valuation'],
category: property['Category'],
uses: property['Uses'],
address_1: property['Address1'],
address_2: property['Address2'],
address_3: property['Address3'],
address_4: property['Address4'],
address_5: property['Address5'],
car_park: property['CarPark'],
xitm: property['Xitm'],
yitm: property['Yitm'],
units:
JsonPath.new('$.ValuationReport').on(property).each do |unit|
puts "Creating unit."
Unit.create!(
level: unit['$.Level'],
floor_use: unit['$.FloorUse'],
area: unit['$.Area'],
nav_per_m2: unit['$.NavPerM2'],
nav: unit['$.Nav'],
property_id: unit['property.id']
)
end
)
end
end
# Call Method
properties
感谢您的宝贵时间和帮助！
在这种情况下，您不需要 JsonPath。我更新了你的脚本：
- 删除了 JsonPath 以支持使用
property['ValuationReport']
- 从 json 个键中删除了
$.
- 首先你应该创建一个 属性，然后在 Units 中使用它的 ID（或者你可以在模型中设置
accepts_nested_attributes）
require 'rest-client'
require 'json'
require 'jsonpath'
# Define Method - API Request
def properties
response = RestClient.get('https://api.valoff.ie/api/Property/GetProperties?Fields=*&LocalAuthority=CAVAN%20COUNTY%20COUNCIL&CategorySelected=OFFICE&Format=csv&Download=false')
json = JSON.parse(response)
json.each do |property|
puts "Creating property #{property['PropertyNumber']}"
property_model = Property.create!(
publication_date: property['PublicationDate'],
property_number: property['PropertyNumber'],
county: property['County'],
local_authority: property['LocalAuthority'],
valuation: property['Valuation'],
category: property['Category'],
uses: property['Uses'],
address_1: property['Address1'],
address_2: property['Address2'],
address_3: property['Address3'],
address_4: property['Address4'],
address_5: property['Address5'],
car_park: property['CarPark'],
xitm: property['Xitm'],
yitm: property['Yitm']
)
property['ValuationReport'].each do |unit|
puts "Creating unit."
property_model.units.create!(
level: unit['Level'],
floor_use: unit['FloorUse'],
area: unit['Area'],
nav_per_m2: unit['NavPerM2'],
nav: unit['Nav']
)
end
end
end
# Call Method
properties
我正在尝试从 JSON 对象数组向我的数据库播种数据。我有两个单独的数据库表 - 属性 和单位（属性 有很多单位）。我已经能够通过 API 请求 JSON 数据成功地为 属性 信息（属性 模型）执行此操作，然后将其播种到数据库但是 ValuationReport 属性在我的前端显示为字符串形式的 JSON 对象。
这是我正在使用的 JSON 数据的示例（出于演示目的，我将此示例限制为包含 3 个对象的数组）：
[
{
"PublicationDate": "17/09/2019",
"PropertyNumber": 2198231,
"County": "CAVAN",
"LocalAuthority": "CAVAN COUNTY COUNCIL",
"Valuation": 15090,
"Category": "OFFICE",
"Uses": "OFFICE (OVER THE SHOP), -",
"Address1": "77(1ST & 2ND FL) MAIN STREET",
"Address2": "CAVAN",
"Address3": "CO. CAVAN",
"Address4": "",
"Address5": "",
"CarPark": 0,
"Xitm": 641927.73,
"Yitm": 804638.3,
"ValuationReport": [
{
"Level": "1",
"FloorUse": "RESTAURANT",
"Area": 112.25,
"NavPerM2": 80,
"Nav": 8980
},
{
"Level": "2",
"FloorUse": "RESTAURANT",
"Area": 98.57,
"NavPerM2": 62,
"Nav": 6111.34
}
]
},
{
"PublicationDate": "17/09/2019",
"PropertyNumber": 1558322,
"County": "CAVAN",
"LocalAuthority": "CAVAN COUNTY COUNCIL",
"Valuation": 10200,
"Category": "OFFICE",
"Uses": "OFFICE (OWN DOOR), -",
"Address1": "23E MAIN STREET",
"Address2": "CAVAN",
"Address3": "CO. CAVAN",
"Address4": "",
"Address5": "",
"CarPark": 0,
"Xitm": 641941.19,
"Yitm": 804875.56,
"ValuationReport": [
{
"Level": "0",
"FloorUse": "OFFICE(S)",
"Area": 127.55,
"NavPerM2": 80,
"Nav": 10204
}
]
},
{
"PublicationDate": "17/09/2019",
"PropertyNumber": 2116802,
"County": "CAVAN",
"LocalAuthority": "CAVAN COUNTY COUNCIL",
"Valuation": 15140,
"Category": "OFFICE",
"Uses": "OFFICE (OWN DOOR), HERITAGE / INTERPRETATIVE CENTRE",
"Address1": "LOCAL NO/MAP REF: 7AB",
"Address2": "MULLAGH",
"Address3": "BAILIEBORO CO. CAVAN",
"Address4": "",
"Address5": "",
"CarPark": 0,
"Xitm": 668656.19,
"Yitm": 785281.05,
"ValuationReport": [
{
"Level": "0",
"FloorUse": "OFFICE(S)",
"Area": 252.49,
"NavPerM2": 60,
"Nav": 15149.4
property_id: unit[property.id]
}
]
}
]
我遇到的困难是 ValuationReport 属性，它是 JSON 属性数组中每个元素的大小不同的数组。因此，某些属性将具有仅包含一个对象的 ValuationReport 数组，而其他属性将包含具有多个对象的 ValuationReport 对象。我想将每个 ValuationReport 数组中的每个嵌套对象保存到我的数据库（单元模型）中的一个单独单元中。
我已经使用 JSON路径 Gem 尝试访问所需的元素，但我做错了什么。
当我 运行 '$ rails db:seed' 时，现在 运行ning 直到一个点，我收到以下错误：
Creating property 2198231
Creating unit.
rails aborted!
TypeError: no implicit conversion of String into Integer
/db/seeds.rb:62:in `[]'
/db/seeds.rb:62:in `block (2 levels) in properties'
/db/seeds.rb:58:in `each'
/db/seeds.rb:58:in `block in properties'
/db/seeds.rb:36:in `each'
/db/seeds.rb:36:in `properties'
/db/seeds.rb:207:in `<top (required)>'
bin/rails:4:in `require'
bin/rails:4:in `<main>'
Tasks: TOP => db:seed
(See full trace by running task with --trace)
这是我的 Gem 文件中的相关 Gem：
# REST Client for APIs
gem 'rest-client', '~> 2.1'
# JSONPath - for acessing values in nested JSON objects.
gem 'jsonpath', '~> 0.5.8'
我的数据库架构如下：
ActiveRecord::Schema.define(version: 2020_11_07_130018) do
# These are extensions that must be enabled in order to support this database
enable_extension "plpgsql"
create_table "properties", force: :cascade do |t|
t.date "publication_date"
t.string "property_number"
t.string "county"
t.string "local_authority"
t.decimal "valuation"
t.string "category"
t.string "uses"
t.string "address_1"
t.string "address_2"
t.string "address_3"
t.string "address_4"
t.string "address_5"
t.decimal "car_park"
t.decimal "xitm"
t.decimal "yitm"
t.datetime "created_at", precision: 6, null: false
t.datetime "updated_at", precision: 6, null: false
end
create_table "units", force: :cascade do |t|
t.string "level"
t.string "floor_use"
t.decimal "area"
t.decimal "nav_per_m2"
t.decimal "nav"
t.bigint "property_id"
t.datetime "created_at", precision: 6, null: false
t.datetime "updated_at", precision: 6, null: false
t.index ["property_id"], name: "index_units_on_property_id"
end
add_foreign_key "units", "properties"
end
我的 seeds.rb 文件如下。我尝试使用索引 (i) 来确保 ValuationReport 对象数组的循环为每个 属性 循环一次并创建每个 属性.[=19 中存在的所有单位=]
require 'rest-client'
require 'json'
require 'jsonpath'
# Define Method - API Request
def properties
response = RestClient.get('https://api.valoff.ie/api/Property/GetProperties?Fields=*&LocalAuthority=CAVAN%20COUNTY%20COUNCIL&CategorySelected=OFFICE&Format=csv&Download=false')
json = JSON.parse(response)
json.each do |property|
puts "Creating property #{property['PropertyNumber']}"
Property.create!(
publication_date: property['PublicationDate'],
property_number: property['PropertyNumber'],
county: property['County'],
local_authority: property['LocalAuthority'],
valuation: property['Valuation'],
category: property['Category'],
uses: property['Uses'],
address_1: property['Address1'],
address_2: property['Address2'],
address_3: property['Address3'],
address_4: property['Address4'],
address_5: property['Address5'],
car_park: property['CarPark'],
xitm: property['Xitm'],
yitm: property['Yitm'],
units:
JsonPath.new('$.ValuationReport').on(property).each do |unit|
puts "Creating unit."
Unit.create!(
level: unit['$.Level'],
floor_use: unit['$.FloorUse'],
area: unit['$.Area'],
nav_per_m2: unit['$.NavPerM2'],
nav: unit['$.Nav'],
property_id: unit['property.id']
)
end
)
end
end
# Call Method
properties
感谢您的宝贵时间和帮助！
在这种情况下，您不需要 JsonPath。我更新了你的脚本：
- 删除了 JsonPath 以支持使用
property['ValuationReport'] - 从 json 个键中删除了
$. - 首先你应该创建一个 属性，然后在 Units 中使用它的 ID（或者你可以在模型中设置
accepts_nested_attributes）
require 'rest-client'
require 'json'
require 'jsonpath'
# Define Method - API Request
def properties
response = RestClient.get('https://api.valoff.ie/api/Property/GetProperties?Fields=*&LocalAuthority=CAVAN%20COUNTY%20COUNCIL&CategorySelected=OFFICE&Format=csv&Download=false')
json = JSON.parse(response)
json.each do |property|
puts "Creating property #{property['PropertyNumber']}"
property_model = Property.create!(
publication_date: property['PublicationDate'],
property_number: property['PropertyNumber'],
county: property['County'],
local_authority: property['LocalAuthority'],
valuation: property['Valuation'],
category: property['Category'],
uses: property['Uses'],
address_1: property['Address1'],
address_2: property['Address2'],
address_3: property['Address3'],
address_4: property['Address4'],
address_5: property['Address5'],
car_park: property['CarPark'],
xitm: property['Xitm'],
yitm: property['Yitm']
)
property['ValuationReport'].each do |unit|
puts "Creating unit."
property_model.units.create!(
level: unit['Level'],
floor_use: unit['FloorUse'],
area: unit['Area'],
nav_per_m2: unit['NavPerM2'],
nav: unit['Nav']
)
end
end
end
# Call Method
properties