Question

I have starting dates and ending dates in my database (MySQL).
How can I get the answer, how many weeks(or days) are inside of those 2 dates? (mysql or php)

For example I have this kind of database:

Started and | will_end
2009-12-17 | 2009-12-24
2009-12-12 | 2009-12-26
…

Update to the question:
How to use DATEDIFF?
How can I make this to work? or should I use DATEDIFF completly differently?

SELECT DATEDIFF(‘Started ‘,’will_end’) AS ‘Duration’ FROM my_table WHERE id = ‘110’;

Answer 1

MySQL has datediff which returns the difference in days between two dates, since MySQL 4.1.1.

Do note that, as per the manual, DATEDIFF(expr1,expr2) returns expr1 – expr2 expressed as a value in days from one date to the other. expr1 and expr2 are date or date-and-time expressions. Only the date parts of the values are used in the calculation.