Calculating weekly data from a range of dates

Question

I have a date range lets say from 2012-12-01 and 2013-01-09 . I want to fetch weekly data for number of records, it should be 7 days from the start date for each week.So 2012-12-01 to 2012-12-07 is week1 and so on...

The table is as below,

+-ID-+--items---+---dated---+
+----+----------+-----------+
| 1  | 10       |2012-12-01 |
| 2  | 2        |2012-12-02 |
| .  | .        |   .       |
| .  | .        |   .       |
| .  | .        |   .       |
+----+----------+-----------+

Initial query Select count(items),week(date) from item_data

Answer 1

Try this ...

SELECT `id`, `items`, `dated`
FROM `table` 
GROUP BY WEEK(`dated`) 

Answer 2

SELECT SUM(items) AS total_items, CONCAT(dated, ' - ', dated + INTERVAL 6 DAY) AS week
    FROM tablename
    GROUP BY WEEK(dated)
    ORDER BY WEEK(dated);

Answer 3

Try this:

SELECT CEILING(DATEDIFF(dated, '2012-12-01')) AS weekNo, SUM(items) AS NoOfItems
FROM table
WHERE dated BETWEEN '2012-12-01' AND '2013-01-09'
GROUP BY weekNo