Part of java.util.Date milliseconds is trimmed when saving to database

Question

MySQL

In general, such a problem: there is hibernate, a mysql database, there is a certain class with a java.util.Date field. There is something like this test:

assertEquals(objectService.findById(object.getId()), object);

The test fails.
The hashCode and equals methods are overloaded.

I began to understand why and what is wrong. As a result, before saving to the database, the date field returns 1357721424351 milliseconds, and after the object is pulled out of the database, the same field returns 135721424000. the last 3 digits are cut off

Actually, maybe there are ideas who is to blame and what to do?

Answer 1

Probably the database is to blame. In the SQL standard (http://www.contrib.andrew.cmu.edu/~shadow/sql/sql1992.txt):

There are three classes of datetime data types defined within this
International Standard:
— DATE — contains the <datetime field>s YEAR, MONTH, and DAY;
- TIME - contains the <datetime field>s HOUR, MINUTE, and SECOND;
and
- TIMESTAMP - contains the <datetime field>s YEAR, MONTH, DAY,
HOUR, MINUTE, and SECOND.

Those. milliseconds are not stored.

Answer 2

You say that the hashcode and equals methods are overloaded, so you need to overload them more and compare dates with an accuracy of seconds