Can't divide on the filtered count distinct measure

[natahha]

Hello,

I am new to Looker and I may be on a wrong track but I created a query which is made up of 3 columns: product_id, number_of_sales, number_of_promo_days, number_of_non_promo_days.

What I need to do is create measures that would give me an average number of sales on promo and non_promo days

What I have is:

measure: number_of_sale_days {

type: count_distinct

sql: ${order_date} ;;

filters: [promo: “yes”]
}

measure: number_of_non_sale_days {

type: count_distinct

sql: ${order_date} ;;

filters: [promo: “no”]

}

But when I try to create a table calculation of ${number_of_sales} / ${number_of_sale_days}. I can’t set it up because i’m getting this error:

The second argument for "/" must be a Number, but a String was given

Count of _Order Date number_of_sale_days

Type: String

I managed to work around it by creating measures of type number that are referencing initial measures like:

measure: number_of_sale_days_2 {

type: number

sql: ${number_of_sale_days} ;;
}

I wonder if there is a better way of doing this? I planned to create custom measures for that but they are not working at all.

Thanks!