How to compute the sum of multiple columns in PostgreSQL

Question

I would like to know if there's a way to compute the sum of multiple columns in PostgreSQL.

I have a table with more than 80 columns and I have to write a query that adds each value from each column.

I tried with SUM(col1, col2, col3 etc) but it didn't work.

Answer 1

SELECT COALESCE(col1,0) + COALESCE(col2,0)
FROM yourtable