将值转换为组的日期类型。

GROUP BY CAST(myDateTime AS DATE)

GROUP BY DATEADD(day, DATEDIFF(day, 0, MyDateTimeColumn), 0)

或者在SQL Server 2008以后，你可以像@Oded建议的那样简单地转换为Date:

GROUP BY CAST(orderDate AS DATE)

CAST datetime字段到日期

select  CAST(datetime_field as DATE), count(*) as count from table group by CAST(datetime_field as DATE);

GROUP BY DATE(date_time_column)

下面的例子在oracle中工作得很好

select to_char(columnname, 'DD/MON/yyyy'), count(*) from table_name group by to_char(createddate, 'DD/MON/yyyy');

将值转换为组的日期类型。

GROUP BY CAST(myDateTime AS DATE)