Datetime Conversion Change

Dan Guzman notes a change in behavior in how datetime fields are upconverted:

SQL Server 2016 and Azure SQL Database V12 use the raw datetime internal value without rounding during conversion to another temporal type. The value is rounded only once during conversion, to the target type precision. The end result will be the same as before SQL Server 2016 when the target type precision is 3 or less. However, the converted value will be different when the target type precision is greater than 3 and the internal time unit interval is not evenly divisible by 3 (i.e. rounded source datetime millisecond value is 3 or 7). Note the non-zero microseconds and nanoseconds in the script results below and that rounding is based on the target type precision rather than the source.

This is a good thing on net, but be aware of this if you try to compare datetime versus datetime2 values.

Related Posts

Upgrading That Expired Evaluation Copy Of SQL Server

Cody Konior finds a way to extricate the poor souls who need to upgrade expired evaluation copies of SQL Server from their mess: Common advice here is to set the clock backwards. My problem with that is that you’re probably doing this on an unsupported unknown black-box flaming garbage can of a system set up […]

Read More

When AT TIME ZONE Is Too Slow

Robert Davis troubleshoots a performance problem relating to time zones: Time Zones were definitely being a drag today. I got an email from one of the developers at work asking about the performance difference between 2 queries. The only difference between the 2 queries is that one of them uses the AT TIME ZONE clause that was […]

Read More

Categories

October 2016
MTWTFSS
« Sep Nov »
 12
3456789
10111213141516
17181920212223
24252627282930
31