Count per week per column PostgreSQL

Question

Let's say I have a PostgreSQL table with 10 columns and 2 weeks (w1 w2) with 5 countries. Something that would look like this :

What I would like to do is a count per week and per column like this :

Answer 1

As count() counts only the non-NULL values, this is a simple GROUP BY query:

SELECT week, count(col1), ..., count(col10)
  FROM your_table
 GROUP BY week;

Answer 2

You can get through below query:

SELECT  week, 
        SUM(Col1), SUM(Col2), SUM(Col3),  SUM(Col4),  SUM(Col5), 
        SUM(Col6), SUM(Col7), SUM(Col8),  SUM(Col9),  SUM(Col10) 
FROM <table name> 
GROUP BY 1