SQL Tips GROUP by datetime Type field, take only the date part

Often encountered in the work, in order to query the SQL report, query results are required by date to list, or by day, or by month, year.

This time we are often distressed, datetime is accurate to milliseconds, if the simple group by datetime will result in incorrect results.

This is what we can do with the CONVERT function:

SELECT CONVERT (varchar), createdate,120, var1, Var2from tablegroup by convert (varchar), createdate,120) ASC

The first parameter is the type of conversion, 10 is the length, and the need to eradicate it is adjusted.

The second parameter is a datetime-type field.

The third parameter is a date format. (Detailed format parameters can be consulted: http://www.w3school.com.cn/sql/func_convert.asp)

SQL Tips GROUP by datetime Type field, take only the date part