![]() The MySQL TIMESTAMP is the only data type designed to store instant points on the time-line using the implied time zone conversion. More details are given below, but first let’s define what exactly we mean when talking about “instant date-time classes” and “instant MySQL types”. connectionTimeZone=user_defined & preserveInstants=true – helps to overcome the situation when the server time zone cannot be recognized by the connector because it is set as a generic abbreviation like CET/CEST.connectionTimeZone=SERVER & preserveInstants=true – corresponds to the previous Connector/J 8.0 behavior and Connector/J 5.1 behavior with useLegacyDatetimeCode=false.connectionTimeZone=LOCAL & forceConnectionTimeZoneToSession=true – the new mode which provides the most natural way for handling date-time values.connectionTimeZone=LOCAL & forceConnectionTimeZoneToSession=false – corresponds with the Connector/J 5.1 behavior with useLegacyDatetimeCode=true.preserveInstants= true|false turns on|off the conversion of instant values between JVM and ‘connectionTimeZone’.forceConnectionTimeZoneToSession=true| false controls whether the session time_zone variable is to be set to the value specified in ‘connectionTimeZone’. ![]() connectionTimeZone= LOCAL|SERVER|user-defined time zone (previously known as ‘serverTimezone’, now with additional fixed values) defines how the server’s session time zone is to be determined by Connector/J.The following connection properties define the time zone handling: Both ways are now possible with Connector/J 8.0.23. But you might want to store the instant point on the time-line, like for a Zoom meeting start time, in other cases. You probably don’t care about the real internal TIMESTAMP value if you don’t do any server-side calculations with it. When retrieved, a value is constructed after converting the on-wire value from session time zone to the local one, so it still represents the same instant, but the visual representation is different in different client time zones.Īctually both approaches are valid use cases. But the internal UTC value of a TIMESTAMP could be different from an expected instant value.Ĭonnector/J 8.0.22 and before converts the original value to the session time zone before sending, thus the internal UTC value of a TIMESTAMP matches the expected instant value. Thus, the visual representation remains the same in any client time zone and on the server. The result will be “ 12:00:00” with Connector/J 5.1 but “ 13:00:00” with Connector/J 8.0.īy default, Connector/J 5.1 sends values as they are rendered locally and, on retrieval, constructs values using the client’s local time zone. If the client is running in the UTC+2 time zone and server is running in UTC+1 the internal value of the TIMESTAMP field will be “ 11:00:00Z” with Connector/J 5.1 but “ 10:00:00Z” with Connector/J 8.0.Īnother client in the UTC+3 time zone is reading this value: ResultSet rs = st.executeQuery("SELECT * FROM t1") PreparedStatement ps = conn.prepareStatement("INSERT INTO t1 VALUES (?)") ![]() St.executeUpdate("CREATE TABLE t1 (ts TIMESTAMP)") Problems with migration from Connector/J 5.1 to Connector/J 8.0 were caused by the early decision that Connector/J 8.0 should always try to preserve an instant point on the time-line while Connector/J 5.1 does it optionally and, by default, preserves the original visual representation.įor example, the following code will store different results with Connector/J 5.1 and Connector/J 8.0 in case the client and server time zones are different: Statement st = conn.createStatement() They provide more flexibility for configuring time zone handling and allow migration from Connector/J 5.1 with much less effort. Connector/J version 8.0.23 came out with several bug fixes related to date-time types support.
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