Summary of SQL Server usage issues

1.datetime,smalldatetime,date difference

1) datetime

Date and time data from January 1, 1753 to December 31, 9999, with an accuracy of 3% seconds (equal to 3.33 milliseconds or 0.00333 seconds). Adjust the values to. 000,. 003, or. 007 seconds increments as shown in the following table.

The date and Time section, which can represent the date range from January 1, 1753 A.D. 00:00:00.000 to December 31, 9999 23:59:59.997, is accurate to 3.33 milliseconds, which requires 8 bytes of storage space.

2)smalldatetime

Date and time data from January 1, 1900 to June 6, 2079 are accurate to minutes. The smalldatetime value of 29.998 seconds or less is rounded down to the nearest minute, the smalldatetime value of 29.999 seconds or higher is rounded up to the nearest minute. Requires 4 bytes of storage space.

3) Date

New data types introduced in SQL Server 2008. It represents a day, and does not contain a time part, which can be expressed from January 1 to December 31, 9999 of the year of the A.D.. Only 3 bytes of storage space is required.

The data is read regardless of whether your field is datetime or smalldatetime read out in the same format (for example: 1900-01-01). DateTime does not show his milliseconds, but he will appear in milliseconds when the time comparison is made, so that two time periods cannot be equal.

Summary of SQL Server usage issues