如何生成受数据精度限制的模型，在Rails上按比例缩放红宝石

Question

I am trying to generate the following a model named PriceUsdOneMinIntervals , but unable to apply the format for precision and scale correctly, can someone please advise how to correct the syntax in the following:

rails generate model PriceUsdOneMinInterval unix_timestamp:integer usd_high:decimal :precision[20] :scale[8] usd_low:decimal :precision[20] :scale[8] usd_open:decimal :precision[20] :scale[8] usd_close:decimal :precision[20] scale[8]

I have referred to this api while making the above statement.

Answer 1

TRy this

rails generate model PriceUsdOneMinInterval :unix_timestamp, :integer, 
:usd_high, :decimal, precision: 20, scale: 8, :usd_low, :decimal, precision: 20, 
scale: 8, :usd_open, :decimal, precision: 20, scale: 8, 
:usd_close, :decimal, precision: 20, scale: 8

OR

generate migration with just field names and data_types and then change you can change the values in migration

def change
    add_column :price_usd_one_min_intervals, :unix_timestamp, :integer
    add_column :price_usd_one_min_intervals, :usd_high, :decimal, precision: 20, :scale: 8
    add_column :price_usd_one_min_intervals, :usd_low, :decimal, precision: 20, scale: 8
    add_column :price_usd_one_min_intervals, :usd_open, :decimal, precision: 20, scale: 8
    add_column :price_usd_one_min_intervals, :usd_close, :decimal, precision: 20, scale: 8
end 

Answer 2

rails g model PriceUsdOneMinInterval \
unix_timestamp:integer \
'usd_high:decimal{20,8}' \
'usd_low:decimal{20,8}' \
'usd_open:decimal{20,8}' \
'usd_close:decimal{20,8}'