How can one optimize a query to filter out empty fields within a dataset directly in the SQL query itself, rather than using PHP to filter them afterwards?

When querying a dataset in SQL, you can use the WHERE clause to filter out empty fields by specifying a condition that checks for non-empty values. This can be done by using the IS NOT NULL condition to exclude rows where a specific field is empty. By including this condition directly in the SQL query, you can optimize the query to only retrieve the desired non-empty data.

SELECT * 
FROM table_name
WHERE column_name IS NOT NULL;