Clickhouse: Clickhouse: Percent to Total

[calgs]

We have to port our script which calculates "Percent to total".

Product,Sales
P1, 100
P2, 200
P3, 150
P4, 50

We are looking at writing a script which can populate
Product, Sales, PercenttoTotal
P1, 100, 20%
P2, 200, 40%
P3, 150, 30%
P4, 50, 10%

Is there a quick way via various functions in Clickhouse using which we can accomplish this. Thanks in advance

[filimonov]

You need something like that:

SELECT 
   productid,
   count() as per_product_count,
   ( SELECT count() from prod_sales ) as total_count,
   per_product_count * 100 /total_count as percent_to_total
FROM prod_sales
GROUP BY productid

or the same without extra column:

SELECT 
   productid,
   count() as per_product_count,
   per_product_count * 100 / ( SELECT count() from prod_sales ) as percent_to_total
FROM prod_sales
GROUP BY productid

P.S. Google group or stackoverflow is better place for those type of questions.