Question

I am trying to create a query which will check how many entries I have in my database for the last 7 days, it works, but it only returns the dates where records exist. I would like it to return a 0 for days where there is no data as I am producing a 7 day report.

Any help gratefully received!

SELECT DATE(created_date) AS date, 
    (SELECT COUNT(id) 
    FROM records 
    WHERE DATE(created_date) = date AND method = 'tw') AS total_records 
FROM records 
WHERE created_date > DATE_SUB(NOW(), INTERVAL 7 day) 
GROUP BY date

Answer 1

SELECT DATE(NOW() + INTERVAL num.i DAY) AS date, 
       COUNT(r.id) AS total_records 
FROM 
        ( SELECT 0 AS i UNION ALL               -- where 0 means today
          SELECT -1 UNION ALL                   -- and -1 is yesterday
          ...
          SELECT -6
        ) AS num
    LEFT JOIN
        records AS r
            ON  r.created_date >= DATE(NOW() + INTERVAL num.i DAY)
            AND r.created_date < DATE(NOW() + INTERVAL 1+num.i DAY)
            AND r.method = 'tw'
GROUP BY num.i ;

An index on (method, created_date) will help efficiency.