how to count null values in a column in sql code example

Example 1: how to count null values in sql

SELECT COUNT(1) FROM my_table WHERE my_column IS NULL;

Example 2: sql count null values in all columns

SELECT sum(CASE WHEN column_A IS NULL THEN 1 ELSE 0 END) A,
       sum(CASE WHEN column_B IS NULL THEN 1 ELSE 0 END) B
FROM my_table;