Question

How would you group a range of dates into days (with PHP, no 5.3 available at the moment for use of DateTime by the way)? I’ve read out all data entries via MySQL for a month and now want to calculate how many data entries have been created in each day of the month, timestamp is default like 2011-11-05 23:42:03.

Answer 1

Assuming timstamp is the name of your column, use DATE() to extract only the date part. Group by the extracted date to form your aggregate:

SELECT 
  DATE(`timestamp`) AS day, 
  COUNT(*) as numentries
FROM tbl
GROUP BY day
ORDER BY day ASC