HHH-11773 - Add support for JDBC 4.2 type names

[vladmihalcea]

https://hibernate.atlassian.net/browse/HHH-11773

[marschall]

Regarding database support in general you need up to date database drivers. To my knowledge the current situation is like this:

• HSQLDB 2.4.0 supports it but has issues with literal parsing, this is fixed in 2.4.1 (not yet released)
• Oracle needs ojdbc8-12.2.0.1
• SQL Server as of 6.1.0.jre8 only supports #setObject(int, Object) but not #getObject(int, Class), however you can use proprietary APIs
• H2 needs 1.4.194 (1.4.193 works in theory as well)
• Postgres needs pgjdbc 9.4.1208 or later

This all comes from marschall/threeten-jpa#41 in this project.

To be fair I only use #setObject(int, Object) and not #setObject(int, Object, int) there, I believe that's where at least the H2 failures stem from.

[marschall]

I created h2database/h2database#536 to fix the issue in H2.

[marschall]

pgjdbc should definitively support it https://github.com/pgjdbc/pgjdbc/blob/master/pgjdbc/src/main/java/org/postgresql/jdbc/PgPreparedStatement.java#L637

[vladmihalcea]

We use the following drivers:

• PostgreSQL 42.1.1 > 9.4.1208
• H2 1.4.196 > 1.4.194
• SQL Server 6.1.0.jre8, I added the datetime specific logic using Reflection
• Oracle ojdbc7 12.1.0.2, I should upgrade to ojdbc8-12.2.0.1

I'll also try with #setObject(int, Object) as you suggested.

[vladmihalcea]

I tried with #setObject(int, Object), but it only works better for PostgreSQL, and just for handling Timestamp, not Time.

I'll leave this PR open for a while hoping that JDBC drivers will better handle the new JDBC 4.2 timestamp and time with timezone types.

[marschall]

I understand this decision. There exist work arounds for people who want to experiment.

Probably in time for the JPA 2.1 service release that's part of Java EE 8 this will have to be revisited, let's hope the situation improves until then. Speaking of which right now Hibernate implements support for LocalDateTime and LocalTime by converting through java.sql types. This is not optimal for two reasons

1. LocalTime has nanosecond resolution java.sql.Time has millisecond resolution, converting results in silent data truncation.
2. java.sql.Timestamp due to implementation details is affected by daylight savings time even though it shouldn't be. If you run your JVM in a time zone that has daylight savings time the following value can not be stored or loaded correctly when a conversion through java.sql.Timestamp happens. It can only be stored and loaded correctly when driver support for JSR-310 is used.

  private static LocalDateTime getUnstorableValue() {
    ZoneId systemTimezone = ZoneId.systemDefault();
    Instant now = Instant.now();

    ZoneRules rules = systemTimezone.getRules();
    ZoneOffsetTransition transition = rules.nextTransition(now);
    assertNotNull(transition);
    if (!transition.getDateTimeBefore().isBefore(transition.getDateTimeAfter())) {
      transition = rules.nextTransition(transition.getInstant().plusSeconds(1L));
      assertNotNull(transition);
    }

    Duration gap = Duration.between(transition.getDateTimeBefore(), transition.getDateTimeAfter());
    return transition.getDateTimeBefore().plus(gap.dividedBy(2L));
  }

Ultimately somebody has to make the first move, if drivers are waiting for frameworks to move first and frameworks are waiting for drivers to move first we end up in a chicken and egg situation see pgjdbc/pgjdbc#695

Yes OffsetTime support has not yet been implemented in pgjdbc.

[vladmihalcea]

@dreab8 Andrea, check out the comment above about LocalTime and Timestamp. I guess we should open a Jira issue about it, right?

[dreab8]

Hi @vladmihalcea,
I have not a great experience on this topic, better to ask @sebersole for an opinion.

[vladmihalcea]

@dreab8 @sebersole I created HHH-11835 for those findings.

[abcfy2]

Any update for this pull request ? I think support Types.TIMESTAMP_WITH_TIMEZONE is very useful when I use OffsetDateTime and ZonedDateTime, but I find this pull request is still not merge.

Is hibernate still plan to support JDBC 4.2 type names ?

[marschall]

@abcfy2 until fully supported you may find the threeten-jpa-jdbc42-hibernate subproject of https://github.com/marschall/threeten-jpa to be helpful. Pleas note that:

• this requires driver support
• this does not add support for DDL
• ZonedDateTime only really works with Oracle

[marschall]

Was fixed in 2c80250 in 6.0.0. Can be closed.