I've got a trouble with creating mysql Query.

My PHP script executes this query on each run: INSERT INTO Executes SET UserIp='%s' (%s is user IP)

Executes table is:

ExecuteId UNSIGNED BIGINT AI PRIMARY 
Date TIMESTAMP DEFAULT CURRENT_TIMESTAMP INDEX 
UserIp CHAR(24) ... | Some Columns

I want to retrive number of Executes in each hour. The most obvious solution would be:

SELECT COUNT(*) as ExecutesNum, DATE(Date) as D, HOUR(Date) as H GROUP BY D, H

And it works, BUT it does not create rows for hours where there were no executes.

What should I modify to get result like:

  1 | 2012-09-01 | 14

**0 | 2012-09-01 | 15**

 11 | 2012-09-01 | 16

  1 | 2012-09-01 | 17