MySQL date comparison issue

I have the date in 开发者_Go百科this format in mySQL databse:

2011-02-21 14:40:03

But i have to compare only datepart of this dateandtime i.e:

2011-02-21

How???

A better solution is to use WHERE col >= '2011-02-21' AND col < '2011-02-22', so MySql can use a index if there is one present.

... where date(datetime_column) = '2011-02-21'

Here is the documentation