I'm storing a simple java.util.date in an Oracle XE database via hibernate.
When testing with JUnit if I can retrieve the correct value, I get an error like this:
junit.framework.AssertionFailedError:
expected:<Sun Dec 28 11:20:27 CET 2008>
but was:<2008-12-28 11:20:27.0>
The value is stored in an Oracle Date column (which should have a second-precision) which looks okay to me. Also, I'm surprised that 11:20:27 is not equal to 11:20:27.0. Or does this have to do with timezones?
Any help is welcome.
Thorsten
Okay, worked some more on it ...
Oracle Date columns only store values with an accuracy of a second.
Java Dates do contain milliseconds, but they are typically not printed. So
expected:
was actually created by a date like 11:20:27,345, which is of course not equal to 11:20:27.0
Solution:
either only use full second dates to store and retrieve
or
get hibernate to create the correct Oracle Datatype (TIMESTAMP) - this is very dependent on the dialect specified in the hibernate config (OracleDialect and Oracle10gDialect create different types).
If you compare a java.util.Date to a java.sql.Date that both represent the same instant in time, equals(Object) will return false (it considers two objects of different classes to never be equal).
Your tests need to account for that. The easiest way to do this is to convert the dates to UNIX time (e.g. java.util.Date.getTime()) and compare those values.
Related
I have a situation where a table in the database has a date field defined as date where time also is important (for sorting later).
At first, all times for the date where coming as 000000 but I updated the code to use timestamp and when inserting new records, it's working fine.
Update on the other hand will not change the database if the date is the same (but different time). Apparently, while inserting, hibernate doesn't take into consideration the time and the record is not change (or at least this is what I discovered from my testing).
I can't change the database structure to use timestamp or add a time field.
Any help is really appreciated :)
Thanks
For few columns from the source i.e .csv file, we are having values like 1:52:00, 14:45:00.
I am supposed to load to the Oracle table.
Which data type should I choose in Target as well as source?
Should i be doing any thing in the expression transformation?
Use SQLLDR to load the data into database with the format described as in the link
http://docs.oracle.com/cd/B19306_01/server.102/b14200/sql_elements004.htm
ie.'HH24:MI:SS'
Oracle does not support time-only values, it supports dates (with a time component).
You have a few options:
Store the value as a string, perhaps providing a leading zero for
the hour.
Store the value as the number of seconds (or minutes) past midnight.
Store the value as the time component of some arbitrarily defined date, for
example 0001-JAN-01 01:52:00 and 0001-Jan-01 14:45:00. Tell your report writers to ignore the date portion of the value.
Your source datatype will be string(8). Use LPAD to add leading zeroes.
Does hibernate have any mapping for this oracle data type:(10G)
TIMESTAMP(6) WITH TIME ZONE
I am getting:
No Dialect mapping for JDBC type: -101
My manager does not want to do the: registerHibernateType(-101, Hibernate.getText().getname())
He thinks it is too much.:)
What alternative can I have?
The answer you provide to yourself is more like a workaround than a proper solution. For the sake of the visitors looking for an answer, I'll provide my view on this:
1) Database date-based fields should be always set to UTC, never with a specific timezone. Date calculation with timezone information is an unneeded complexity. Remember that timezones usually changes twice a year for a lot of countries in the world ("daylight saving time"). There's a reason why only a few RDMBS' supports this, and there's a reason why Hibernate developers refuse to support this data-type. The patch for Hibernate is simple enough (one line of code), the implications aren't.
2) Converting your "timestamp with timezone" to a String will only cause problems later. Once you retrieve it as String, you'll need to convert it again to a Date/Calendar object, an unneeded overhead. Not to mention the risks associated with this operation.
3) If you need to know in which timezone is some user, just store the String representing the timezone offset (like "Europe/Prague"). You can use this in Java to build a Calendar with date/time and timezone, as it'll take care of DST for you.
For now, I solved the problem by:
`select TO_CHAR(TRUNC(field)) from table` //field is the one having type= timestamp with timezone
This ensures that when the query returns, the field has datatype 'String'
We have an NHibernate app that we are migrating from SQL Server to Oracle. Our optimistic concurrency is implemented via a <timestamp name="Version"> mapping element.
The data type of the corresponding Version column in Oracle is DATE. After we save an object, the in-memory C# object is left with a timestamp value in milliseconds (e.g. 12:34:56.789) while the value in the database is precise only to the second (e.g. 12:34:56). Thus, if we attempt to save the object a 2nd time, we get a StaleStateException because the two values do not match.
I attempted to fix this by altering the data type of the Version column to TIMESTAMP(3). Unfortunately, the C# object and the DB value are still off by one millisecond (e.g. 12:34:56.789 vs 12:34:56.788), so the 2nd attempt to save the object still causes a StaleStateException.
What can I do to create a working <timestamp> mapping to an Oracle column of type DATE or TIMESTAMP so that the same object can be saved multiple times?
Thanks.
-- Brian
TIMESTAMP(7) has the correct precision to match the .NET DateTime class and fixed the problem.
I have Informix database with timestamp field defined as YEAR TO SECOND.
When I show this field using JDBC rs.getString(column) it uses format with miliseconds so this field looks like:
2008-12-18 13:58:14.0
I would like it to use only YEAR TO SECOND fields. I set environment variable:
GL_DATETIME=%Y-%m-%D %H:%M:%S
but even then I got miliseconds. Programs using ODBC do not show milisecond. How can I receive TIMESTAMP string "YEAR TO SECOND" only? In my program I can check metadata if field is TIMESTAMP and then cut ".0", but I think there should be simplier way.
Server version:
IBM Informix Dynamic Server Version 11.50.TC2DE
Client version:
IBM Informix JDBC Driver for IBM Informix Dynamic Server 3.50.JC3DE
EDIT
It looks that all other JDBC drivers I tested (Oracle and PostgreSQL) shows Timestamp columns with miliseconds if I use getString(). So I used solution proposed by Todd. I check metatdata and if column is Timestamp then I use getTimestamp() and format it.
If you are using JDBC, you can use the rs.getDate(column) or rs.getTimestamp(column) methods, which return Date and Timestamp objects respectively. Then you have an object representing time, rather than a String expressing it directly. With Date or Timestamp, you can use a date formatter to format it to whatever String representation of that time you choose.
Update (after reading comments below):
If you use getDate(), it will still work for Timestamp columns. It will just reduce the precision down to the second. That way you don't have to check the metadata, you just have to know that the column is some kind of timestamp or date.