Question

I have a database full of dates that are in the format: MM/dd/yy. For example, today’s date (November 4, 2011) is saved in the database as: 11/04/11. I’m having trouble with date ranges since my dates aren’t formatted as yyyy/MM/dd (example: 2011/11/04). I don’t have a way to change the way the database is populated, so I need to account for the date formatting differences within my MYSQL queries (via VB.NET). Here is my query (it doesn’t work well because the dates are in the incorrect format):

SELECT CMP_DATE FROM my_data WHERE OBJ_DATE >= '1994/01/01' AND CMP_DATE <= '2011/11/04' 

Is there anyway to reformat the dates within the query? Thank you.

Answer 1

The function you need is STR_TO_DATE:

SELECT CMP_DATE
FROM my_data
WHERE STR_TO_DATE(OBJ_DATE, '%d/%m/%y') >= '1994-01-01'
AND STR_TO_DATE(CMP_DATE, '%d/%m/%y') <= '2011-11-04'

@Piskvor has a good point, too, you should consider interpreting the 2-digit year yourself, instead of letting mysql perform some arbitrary conversion.