For Mysql, we have a limitation.In the driver Mysql doc, we have :
The following are some known issues and limitations for MySQL Connector/J: When Connector/J retrieves timestamps for a daylight saving time (DST) switch day using the getTimeStamp() method on the result set, some of the returned values might be wrong. The errors can be avoided by using the following connection options when connecting to a database:
useTimezone=trueuseLegacyDatetimeCode=falseserverTimezone=UTCSo, when we do not use this parameters and we call setTimestamp or getTimestamp with calendar or without calendar, we have the timestamp in the jvm timezone.
Example :
The jvm timezone is GMT+2.In the database, we have a timestamp : 1461100256 = 19/04/16 21:10:56,000000000 GMT
Properties props = new Properties();props.setProperty("user", "root");props.setProperty("password", "");props.setProperty("useTimezone", "true");props.setProperty("useLegacyDatetimeCode", "false");props.setProperty("serverTimezone", "UTC");Connection con = DriverManager.getConnection(conString, props);......Calendar nowGMT = Calendar.getInstance(TimeZone.getTimeZone("GMT"));Calendar nowGMTPlus4 = Calendar.getInstance(TimeZone.getTimeZone("GMT+4"));......rs.getTimestamp("timestampColumn");//Oracle driver convert date to jvm timezone and Mysql convert date to GMT (specified in the parameter)rs.getTimestamp("timestampColumn", nowGMT);//convert date to GMT rs.getTimestamp("timestampColumn", nowGMTPlus4);//convert date to GMT+4 timezoneThe first method returns : 1461100256000 = 19/04/2016 - 21:10:56 GMT
The second method returns : 1461100256000 = 19/04/2016 - 21:10:56 GMT
The third method returns : 1461085856000 = 19/04/2016 - 17:10:56 GMT
Instead of Oracle, when we use the same calls, we have :
The first method returns : 1461093056000 = 19/04/2016 - 19:10:56 GMT
The second method returns : 1461100256000 = 19/04/2016 - 21:10:56 GMT
The third method returns : 1461085856000 = 19/04/2016 - 17:10:56 GMT
NB :It is not necessary to specify the parameters for Oracle.
