按日期订购特定ID - 只输出一个（队列系统）

Question

Okey, I need to order an specific ID by date.

Let's say that I have:

Id 50 = 2015-01-22 14.00

Id 51 = 2015-01-23 14.00

I need to order this and get out just one with WHERE? (I guess)

So If I have $_GET['51'] I need to know which place it has. In this case: Number 2

And I will also need an list of it all, so:

Number 1 = Id 50 = 2015-01-22 14.00

Number 2 = Id 51 = 2015-01-23 14.00

So basic, I want to know how to change the date to numbers and order them by the date.

Answer 1

Is this what you want?

select count(*) as therank
from table t
where t.date <= (select t2.date from table t2 where t2.id = 51);

It returns the rank of id = 51, based on the date.