But let’s say you don’t need that kind of accuracy and are happy with a granularity to the nearest minute. Maybe you’re storing time cards and don’t think it’s necessary to store seconds. As discussed in the Fundamentals series, you really want to choose the most appropriate datatype for your data.
SMALLDATETIME, which rounds up or down to the nearest minute. The seconds value for any
SMALLDATETIMEis 00. Values of 29.999 seconds or higher are automatically rounded up to the nearest minute, while values of 29.998 seconds or lower are rounded down.
Read on to see Randolph’s explanation of why he recommends against using SMALLDATETIME.