Is java.sql.Timestamp's Time Zone Behavior Consistent Across Databases and Drivers?

Is java.sql.Timestamp Impacted by Time Zone?

Introduction:

When storing date and time values in a database, it's essential to consider whether these values are impacted by the time zone. Java provides the java.sql.Timestamp class for handling timestamps, and this article will address whether it is influenced by time zones.

Understanding Timestamp Conversion and Storage:

To store UTC timestamps in a database, it's necessary to convert specific time zone timestamps into UTC. In your example, you converted a timestamp in the "Asia/Calcutta" time zone to UTC using Date and TimeZone classes.

Timestamp Storage Behavior:

Despite converting the timestamp to UTC before storing it in the Oracle database, the database stored it in the original "Asia/Calcutta" time zone instead of UTC. This is because JDBC drivers typically use the time zone of the server's virtual machine when setting timestamps unless a Calendar object is specified.

Impact of Time Zones:

The default time zone of the virtual machine running your application influences how Timestamp values are stored in the database. If you do not explicitly specify a Calendar object with a different time zone, the Timestamp is stored in the server's time zone.

Alternative Approach:

To store Timestamp values in a specific time zone, it's recommended to use the setTimestamp(int parameterIndex, Timestamp x, Calendar cal) method. This method allows you to specify a custom Calendar object, ensuring that the timestamp is stored in the desired time zone. In your case, you would use:

This approach ensures that the Timestamp is stored in GMT time zone.

timeStamp.toString() Behavior:

Whether timeStamp.toString() prints the timestamp in local time or UTC depends on the JDBC driver implementation. Some drivers may respect the time zone of the Calendar object used when setting the Timestamp, while others may always use the time zone of the virtual machine. It's always advisable to use the getObject(.., LocalDateTime.class) method to retrieve Timestamp values, as it returns a java.time.LocalDateTime object, which is not impacted by time zones.

The above is the detailed content of Is java.sql.Timestamp's Time Zone Behavior Consistent Across Databases and Drivers?. For more information, please follow other related articles on the PHP Chinese website!