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shift in mysql between sql timestamp and the hour I put

I am using intellij for a javaee project and I get problems with time storage : there is a shift of 2 hours between what I put and the hour really stored in mysql.
some searches on internet gave nothing at the moment.
here is the java statement in which I set the hour of 15:30
Bien bien = new Bien(0, "mon super bien #2", 320, 5, 3, true,
520000, "4 impasse des bleuets",
LocalDateTime.of(2019, Month.MAY,1,15,30),
false, bien0.getTypeChauffage(), bien0.getOptions(), bien0.getVille());
and you can see on the picture at the right that the stored hour is 13:30!! 2 hours were lost.
some informations :
I live in France, which is UTC+2 on summer hour; so I put this line in mysql' my.ini:
default-time-zone='+02:00'
and in phpmyadmin, if I type
select now();
I get the correct hour.
The wrong time is got from both intellij and phpmyadmin.
The wrong time was got even before changing the default-time-zone in mysql.(but when I changed the timezone the previously entered datetime were shifted).
the conection string is very usual,without any extra parameter(only database, port,user,password).
I will continue to search, but if someone can help me it would be kind.
here is an output from phpMyAdmin:

The timezone in the database is always stored in UTC. I suppose you did not change the timezone in your phpmyadmin or intellj configuration, so you get to see the raw data.
If you haven't found this yet, check How do I set the time zone of MySQL?.

Why querying a date BC is changed to AD in Java?

My program in Java connects to a Database (Oracle XE 11g) which contains many dates (date format of OracleXE is set to syyyy/mm/dd).
Doing a query in the database with negative dates (before Christ) works fine. When I do it in Java, they are all changed to AD (Anno Domini). How can I retrieve dates in Java respecting AD/BC?
My Java code here does the query to the DB and puts the result in a table.
try {
Object item=cbPD.getSelectedItem();
String dacercare=item.toString();
query = "SELECT DISTINCT PD.Titolo,PD.Inizio,(Select E.nome From Evento E WHERE PD.Inizio_Evento=E.CODE),
PD.Fine, (Select E.nome From Evento E WHERE PD.Fine_Evento=E.CODE ) FROM Periododelimitato PD WHERE PD.Titolo=?";
PreparedStatement stAccess = Login.connessione.prepareStatement(query, ResultSet.TYPE_SCROLL_INSENSITIVE, ResultSet.CONCUR_READ_ONLY);
stAccess.setString(1,dacercare);
rset = stAccess.executeQuery();
j = modelPD.getRowCount();
for (i=0; i<j; i++) modelPD.removeRow(0);
Date data;
while (rset.next()) {
data = rset.getDate(2);
modelPD.addRow(new Object[]{rset.getString(1),data, rset.getString(3), rset.getString(4), rset.getString(5)});
}
}
Here an Example using a specific Query:
try {
query = "SELECT PD.Inizio FROM PeriodoDelimitato PD WHERE PD.CodP=?";
String dacercare="8"; //look for record with this specific Primary key
PreparedStatement stAccess = Login.connessione.prepareStatement(query,
ResultSet.TYPE_SCROLL_INSENSITIVE, ResultSet.CONCUR_READ_ONLY);
stAccess.setString(1, dacercare);
rset = stAccess.executeQuery();
while(rset.next()) {
Date dateBC = rset.getDate(1);
modelPD.addRow(new Object[]{null, dateBC, null, null, null});
}
Output in Java is:
0509-01-01
Output using the same query (substituing ? with the primary key specified) in Sql developer:
-0509/01/01
Note on the query: the column selected in this example is in Oracle a DATE type.
Adding information: DBMS is Oracle (XE 11g), DB has been built on IDE (SQL developer). The program is written in Java through Netbeans 8.2. I connect to the database in Netbeans adding the Library "ojdbc6.jar".

First, it’s not immediately clear how you should handle historic and not least prehistoric dates and how you should expect them to behave. It’s not something I know, but I doubt that any calendar in common use today was used in the 6th century BCE (before the common era, “BC”). Maybe you were already aware, I just wanted to mention it for anyone else reading this answer.
With thanks to Basil Bourque’s (now deleted) answer, what you have observed seems to be the intended behaviour with java.sql.Date. I tried printing dates from year 2 CE (common era, “AD”) and then year 2 BCE and compared. First 2 CE:
LocalDate ld = LocalDate.of(2, 1, 1);
java.sql.Date sqlDate = java.sql.Date.valueOf(ld);
System.out.println("java.sql.Date " + sqlDate + " millis " + sqlDate.getTime());
java.sql.Date 0002-01-01 millis -62104237200000
This is as expected. For 2 BCE we need to supply -1 to LocalDate since 0 means 1 BCE, and -1 means 2 BCE. Insert LocalDate.of(-1, 1, 1) in the above code, and the output is
java.sql.Date 0002-01-01 millis -62198931600000
We note that the date is printed the same. 0002 is hardly downright incorrect, but it doesn’t tell us whether it’s year 2 CE or BCE. I believe that this explains the behaviour you observed. Next we note that the millisecond values are different, so the dates are different as they should be. The diffirence is 94694400000 milliseconds, which equals 1096 days or 3 years if one of them is a leap year. The leap year may surprise, but otherwise I think it’s correct.
There is something fishy, though. When I converted the sql date back into a LocalDate, the era was lost, I always got a date in the common era. Since you don’t need this conversion, you probably don’t need to care.
I believe the good solution will be to drop the outdated Date class completely and use the modern LocalDate throughout. You should be aware that this follows the so-called proleptic Gregorian calendar, which may not always give the exact same dates as Date. Also this requires JDBC 4.2 compliant driver, so your ojdbc6.jar won’t do. Even though this may mean you’re prevented, I am letting the suggestion stand for anyone else reading along. I have not tested, but I think the following should work:
LocalDate dateBC = rset.getObject(1, LocalDate.class);

A solution using the old Date type to query SQL dates BC and AC that is working is to declare into my class a SimpleDataFormat with the format specified below
public SimpleDateFormat sdf= new SimpleDateFormat("yyyy-MM-dd G");
Then I declared a Date dataOUT invoking the format method of SimpleDataFormat giving as input the Date BC queried from the Database
dataOUT=sdf.format(rset.getDate(2));
Thank you all for the time dedicated to my question!

DateTime withTimeAtStartOfDay with timezone

could somebody help or give me some hint with following problem. I have trouble with creating Timestamp in Java. In my db i have timestamp stored in UTC time for example 2016-10-20 23:30:00.000000 and my timezone is Europe/Prague so time is +1 Hour. And if i want to select records from 2016-10-21 i have to select also records from 2016-10-20 23:00:00.000000 if i want to have correct results. I am using Postgresql and JOOQ.
public DateTime getDateTimeWithZone() {
return new DateTime().withZone(MyFormatter.getDateTimeZone());
}
This code is in service class Localization service.
Then in controller i create joda time Interval.
Interval range = new Interval(localizationService.getDateTimeWithZone().withTimeAtStartOfDay(), localizationService.getDateTimeWithZone().withTimeAtStartOfDay().plusDays(1));
This gives me
2016-10-21T00:00:00.000+01:00/2016-10-22T00:00:00.000+01:00
and then in method for selecting records from db via JOOQ i use this construction
Timestamp start = new Timestamp(dtRange.getStartMillis());
Timestamp end = new Timestamp(dtRange.getEndMillis());
and result is
start = 2016-10-21 00:00:00.0
end = 2016-10-22 00:00:00.0
but i need to have start and end one hour back
Also i tried to modify method getDateTimeWithZone() with UTC time
public DateTime getDateTimeWithZone() {
return new DateTime().withZone(DateTimeZone.UTC);
}
range is the same. I think problem is with .withTimeAtStartOfDay() but in this case i need to have .withTimeAtStartOfDay() return 2016-10-20 23:00:00.0000. Is there any way how to do it with joda time or new java.time or write some own implementation od DateTime and override .withTimeAtStartOfDay() to return shifted DateTime. I will appreciate any help.

Orientdb reads out wrong time

I am using Orientdb with Eclipse and the orientdb-client jar. I use the following statement to read out Messages:
List<ODocument> result = connection.command(
new OSQLSynchQuery<ODocument>(
"SELECT * FROM Message"))
.execute();
At first glance the results looks right, but then i realized that the time i read out from a DATTIME field is wrong.
When i run the query "select * from Message ", the locahost version gives me the following results (just a part of it):
When i run the java snippet from above, the results looks like :
For the formating i use a SimpleDateFormat:
DateFormat formatter = new SimpleDateFormat("HH:mm:ss a");
String time = formatter.format(each.field("Time"));
So why is the hour of the date different ( 2 hours) ? Could it be a Timezone issue?

It because database returns results in database's timezone.
You can see it from studio in section Db->configuration.
Command to update timezone looks like
alter database timezone GMT+6

java.sql.timestamp versus date

I am using Derby database with Java and Eclipse. I have a table which has a TIMESTAMP field and I use a model to populate a JTable from it. I am finding timestamp and data and java.sql and java.utils very confusing. The following line of code errors with cannot cast date to timestamp. mod is the model interfacing Derby table and JTable.
int rowcount = mod.getRowCount();
java.sql.Timestamp ts = (java.sql.Timestamp) mod.getValueAt(rowcount-1,1);
My objective is to get the date of the most recent record and subtract 30 days then run an sql query on the same database to find all the records more recent than that date. How do I recover the first timestamp, subtract the 30 days, then construct a query with the result of the subtraction as the condition in a WHERE clause. Sounds simple but I am having such difficulty that I feel I must be missing some fundamental principal. I thought conversion to long and back again might be the route but came up against the same cast problem.

Timestamp is declared as
public class Timestamp extends java.util.Date { ... }
Therefore you can't cast date to timstamp, you could create a timestamp from a date.
Timstamp ts = new Timestamp( date.getTime() );
To subtract 30 days this sequence might be helpful:
Calendar cal = new GregorianCalendar();
cal.setTime( date.getTime() );
cal.add( Calendar.DAY_OF_MONTH, -30 );
Date d30 = cal.getTime();
Anyway I would try to perform this using only SQL.