What\'s the Difference Between Timestamp and Datetime in SQL Server?

Timestamp vs. Datetime in SQL Server

In SQL Server, both timestamp and datetime are data types designed to store date and time information. However, there are critical differences between the two:

Timestamp: Synonym for Rowversion

Contrary to the assumption that timestamps store date and time, a timestamp in SQL Server is a synonym for rowversion. This means that it's automatically generated and guaranteed to be unique for each record in a table. Its primary purpose is for concurrency control and to track row changes.

Datetime: Stores Actual Date and Time

Datetime, on the other hand, is a true date and time data type. It allows users to store the specific date and time, including seconds and microseconds. It can be client-specified during insert or update operations, meaning the value is provided by the application using the database.

Key Differences Summary:

Feature	Timestamp	Datetime
Primary Purpose	Concurrency control and uniqueness	Storing specific date and time
Generation	Automatically generated as rowversion	Can be specified by the client
Uniqueness	Guaranteed to be unique	Not guaranteed to be unique
Data Type	Synonym for rowversion	True date and time data type

Therefore, while both timestamp and datetime can be used to store date time information, their primary function and implementation differ significantly. Timestamps provide unique identifiers for record versions, while datetimes offer flexibility in storing and managing precise date and time values.

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