Question

I have a table in MySQL that contains min and max date values for each key:

key |   minDate   |   maxDate
 1     2011-01-01   2011-01-10 
 2     2011-02-13   2011-02-15
 3     2011-10-19   2011-12-10

How can I create a new table that contains one row for each date between minDate and maxDate for each of the keys:

key |     Date   
 1     2011-01-01
 1     2011-01-02
 ...     ...
 1     2011-01-10
 2     2011-02-13
 2     2011-02-14
 2     2011-02-15
 3     2011-10-19
 ...     ...

Answer 1

Using an integers table, you can do this:

    SELECT "key", minDate + INTERVAL i DAY
      FROM mytable
INNER JOIN integers
           ON i <= DATEDIFF(maxDate, minDate)

That assumes the “integers” table has its column named “i”, of course.

From there you can populate your new table with INSERT INTO ... SELECT.