ruby on rails - How to compare if a record exist with json data type field? -

i want check if record exist on database, have 1 json data type field , need compare too. when try check using exists? got following error:

select  1 one "arrangements" "arrangements"."deleted_at" null , "arrangements"."account_id" = 1 , "arrangements"."receiver_id" = 19 , "config"."hardware" = '--- category: mobile serial: ''00000013'' vehicle:  ' , "arrangements"."recorded" = 't' limit 1  pg::undefinedtable: error:  missing from-clause entry table "config" line 1: ...id" = 1 , "arrangements"."receiver_id" = 19 , "config"."...                                                          ^ 

code using check if exists:

@arrangement = arrangement.new({account_id: receiver.account.id, receiver_id: receiver.id, config: params[:config], recorded: true})  if arrangement.exists?(account_id: @arrangement.account_id, receiver_id: @arrangement.receiver_id, config: @arrangement.config, recorded: @arrangement.recorded)     puts 'true' end 

i tried:

if arrangement.exists?(@arrangement)    puts 'true' end 

but return false

table:

create_table :arrangements |t|   t.references :account,    index:   true   t.references :receiver,   index:   true   t.json       :config,     null:    false   t.boolean    :recorded,   default: false   t.datetime   :deleted_at, index:   true   t.integer    :created_by   t.timestamps end 

you cannot compare jsons. try compare jsons values

where("arrangements.config->>'category' = ?", params[:config][:category])

look in postgresql docs other json functions , operators