COUNT CASE and WHEN statement in MySQL
Use:
SELECT SUM(CASE WHEN t.your_column IS NULL THEN 1 ELSE 0 END) AS numNull, SUM(CASE WHEN t.your_column IS NOT NULL THEN 1 ELSE 0 END) AS numNotNull FROM YOUR_TABLE tThat will sum up the column NULL & not NULL for the entire table. It's likely you need a GROUP BY clause, depending on needs.
You can exploit the fact that COUNT only counts non-null values:
SELECT COUNT(IFNULL(t.your_column, 1)) AS numNull, COUNT(t.your_column) AS numNotNull FROM YOUR_TABLE tAnother approach is to use the fact that logical conditions get evaluated to numeric 0 and 1, so this will also work:
SELECT IFNULL(SUM(t.your_column IS NULL), 0) AS numNull, IFNULL(SUM(t.your_column IS NOT NULL), 0) AS numNotNull FROM YOUR_TABLE tPlease note that SUM will return NULL if there are no rows selected (i.e. the table is empty or a where condition excludes all rows), this is the reason for the IFNULL statements.