How Can I Achieve Millisecond Precision in MySQL Timestamps?

Creating Timestamps with Millisecond Precision in MySQL

In MySQL, precision for timestamps can be a crucial aspect when dealing with values representing specific points in time. If the application demands millisecond precision, the timestamp declaration requires consideration.

The issue arises when timestamps are stored in the 'timestamp' data type, which sets all values to '0000-00-00 00:00:00' when working with millisecond precision. To address this problem, users must ensure their MySQL version is 5.6.4 or later, as it introduces support for fractional-second time datatypes.

To enable millisecond precision, columns can be declared using 'DATETIME(3)' or 'TIMESTAMP(6)'. These data types provide millisecond or microsecond precision, respectively.

Retrieving the current time with millisecond precision is possible using 'NOW(3)', which returns the current time from the server's operating system with the specified precision.

In case of timestamps represented as milliseconds since the Unix epoch, the conversion to a 'DATETIME(3)' value can be achieved using 'FROM_UNIXTIME(ms * 0.001)'. This conversion formula applies to JavaScript timestamps and ensures their correct representation.

If upgrading to a MySQL version supporting fractional-second time datatypes is not feasible, alternative methods can be considered. These methods involve storing timestamps as numbers in 'BIGINT' or 'DOUBLE' columns, utilizing the formula 'FROM_UNIXTIME(col 0.001)' for conversion, and using 'UNIX_TIMESTAMP() 1000' to obtain the current time for storage in such columns.

Remember, precision plays a vital role when dealing with timestamps. By understanding the capabilities and limitations of MySQL's timestamp data types and leveraging appropriate techniques, developers can ensure accurate and precise time tracking within their applications.

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