SQL Server Server query - Count distinct DateTime field

Question

Supposing we have the following records in an SQL Server table.

Date
19/5/2009 12:00:00 pm
19/5/2009 12:15:22 pm
20/5/2009 11:38:00 am

What is the SQL syntax for getting something like this one?

Date Count
19/5/2009 2
20/5/2009 1

Answer 1

You need to do any grouping on a Date only version of your datefield, such as this.

SELECT
    CONVERT(VARCHAR(10), YourDateColumn, 101),
    COUNT(*)
FROM
    YourTable
GROUP BY
    CONVERT(VARCHAR(10), YourDateColumn, 101)

I usually do this though, as it avoids conversion to varchar.

SELECT
    DATEPART(yy, YourDateColumn),
    DATEPART(mm, YourDateColumn),
    DATEPART(dd, YourDateColumn),
    COUNT(*)
FROM
    YourTable
GROUP BY
    DATEPART(yy, YourDateColumn),
    DATEPART(mm, YourDateColumn),
    DATEPART(dd, YourDateColumn)

EDIT: Another way to get just the date part of a datetime

DATEADD(d, 0, DATEDIFF(d, 0, YourDateColumn))

Answer 2

That would depend on your database engine. For SQL Server 2008 (and future versions), you can use the date type to do this.

select
    convert(date, date_column_name) as Date,
    count(1) as Count

from table_name

group by convert(date, date_column_name)