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';

I try to get answer, how many days are inside of two dates.

I would like to get an aswer like:
Duration = 7 days;

I have this kind of database:

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

Answer 1

Put will_end first, started second:

SELECT  DATEDIFF('2009-12-24', '2009-12-17') 

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  7

Also, remove the single quotes from your field names:

SELECT  DATEDIFF(will_end, started) AS Duration
FROM    my_table
WHERE   id = 110

, or replace them with the backticks:

SELECT  DATEDIFF(`will_end`, `started`) AS `Duration`
FROM    `my_table`
WHERE   `id` = 110