How to remove “id” from json string in ruby on rails?

Question

I have got data without "id" field from database. But when I parse the data to json string and show it on screen, I saw an "id" field on json string. How to remove this "id" field?

Here is my code:

-report_logic.rb

def fetch_data ()
@datalist=WorkEarlyOverTime
@datalist = @datalist.joins("INNER JOIN `works` ON `work_early_over_times`.`work_id` = `works`.`id`")
  @datalist = @datalist.select('`work_early_over_times`.work_id AS 1次協力会社名','`work_early_over_times`.working_temp_person AS 職種名','`work_early_over_times`.working_temp_hour AS 作業場所','`work_early_over_times`.at_time_overtime_start AS 作業内容','`works`.`contents`')
@datalist = @datalist.where(work_id: $work_id)
return @datalist
end

- report_controller.rb

def work_late
report_logic = ReportLogic.new(params)
@work_late = report_logic.fetch_data()
render action: :work_late
end

- work_late.json.jbuilder

json.一覧 @work_late

When I show the string I expected the output is:

{"一覧":[
    {"1次協力会社名":1,
    "職種名":"0",
    "作業場所":"0.00 ",
    "作業内容":"2000-01-01T19:00:00.000+00:00",
    "contents":"作業内容1"}
    ]}

but the actual output is:

{"一覧":[
    {"id":null,
    "1次協力会社名":1,
    "職種名":"0",
    "作業場所":"0.00 ",
    "作業内容":"2000-01-01T19:00:00.000+00:00",
    "contents":"作業内容1"}
    ]}

Answer 1

If id is always null then just ignore all nils:

json.ignore_nil!
json.一覧 @work_late

If that's not the case then you have to filter out the id before serializing it. One way would be:

json.一覧 @work_late.serializable_hash.except("id")

Answer 2

As your desired output is a JSON , you could try .as_json by excepting the id field as follows:

@datalist.select('`work_early_over_times`.work_id AS 1次協力会社名','`work_early_over_times`.working_temp_person AS 職種名','`work_early_over_times`.working_temp_hour AS 作業場所','`work_early_over_times`.at_time_overtime_start AS 作業内容','`works`.`contents`').as_json(:except => :id)

Your detailed fetch_data function will be like this:

def fetch_data ()
    @datalist=WorkEarlyOverTime
    @datalist = @datalist.joins("INNER JOIN `works` ON `work_early_over_times`.`work_id` = `works`.`id`")
      @datalist = @datalist.select('`work_early_over_times`.work_id AS 1次協力会社名','`work_early_over_times`.working_temp_person AS 職種名','`work_early_over_times`.working_temp_hour AS 作業場所','`work_early_over_times`.at_time_overtime_start AS 作業内容','`works`.`contents`').as_json(:except => :id)
    @datalist = @datalist.where(work_id: $work_id)
    return @datalist
end