Postgres JSON数据类型Rails查询

一尘不染

Postgres JSON数据类型Rails查询

json

我正在使用Postgres的json数据类型，但想对嵌套在json中的数据进行查询/排序。

我想订购或查询json数据类型上的.where。例如，我要查询关注者计数> 500的用户，或者要按关注者或关注计数进行订购。

谢谢！

例：

model User

data: {
     "photos"=>[
       {"type"=>"facebook", "type_id"=>"facebook", "type_name"=>"Facebook", "url"=>"facebook.com"}
      ], 
     "social_profiles"=>[
         {"type"=>"vimeo", "type_id"=>"vimeo", "type_name"=>"Vimeo", "url"=>"http://vimeo.com/", "username"=>"v", "id"=>"1"},
         {"bio"=>"I am not a person, but a series of plants", "followers"=>1500, "following"=>240, "type"=>"twitter", "type_id"=>"twitter", "type_name"=>"Twitter", "url"=>"http://www.twitter.com/", "username"=>"123", "id"=>"123"}
     ]
}

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2020-07-27

共1个答案

一尘不染

对于任何偶然发现的人。我想出了一个使用ActiveRecord和Postgres的JSON数据类型的查询列表。随时对其进行编辑以使其更加清晰。

以下使用的JSON运算符的文档：https : //www.postgresql.org/docs/current/functions-
json.html。

# Sort based on the Hstore data:
Post.order("data->'hello' DESC")
=> #<ActiveRecord::Relation [
    #<Post id: 4, data: {"hi"=>"23", "hello"=>"22"}>, 
    #<Post id: 3, data: {"hi"=>"13", "hello"=>"21"}>, 
    #<Post id: 2, data: {"hi"=>"3", "hello"=>"2"}>, 
    #<Post id: 1, data: {"hi"=>"2", "hello"=>"1"}>]>

# Where inside a JSON object:
Record.where("data ->> 'likelihood' = '0.89'")

# Example json object:
r.column_data
=> {"data1"=>[1, 2, 3], 
    "data2"=>"data2-3", 
    "array"=>[{"hello"=>1}, {"hi"=>2}], 
    "nest"=>{"nest1"=>"yes"}}

# Nested search:
Record.where("column_data -> 'nest' ->> 'nest1' = 'yes' ")

# Search within array:
Record.where("column_data #>> '{data1,1}' = '2' ")

# Search within a value that's an array:
Record.where("column_data #> '{array,0}' ->> 'hello' = '1' ")
# this only find for one element of the array.

# All elements:
Record.where("column_data ->> 'array' LIKE '%hello%' ") # bad
Record.where("column_data ->> 'array' LIKE ?", "%hello%") # good

2020-07-27