Mapping util.Date to Oracle timestamp

Question

Tuesday, March 22, 2005
I am currently experiencing difficulty in mapping a java.util.Date
field to an Oracle TIMESTAMP column.
Here's what I see. By default, Kodo maps the date field to a DATE
column. I suppose this makes sense since Oracle's date columns
have time information that resolves to the second. In this case,
the client has a business case to store subsecond resolution,
hence the desire to store the date field in an Oracle TIMESTAMP
column.
First question: how should this be done?
Here's what I've tried. I tried setting the jdbc-type extension
for the date field to "timestamp". This setting makes no
difference, and I suspect the reason is that OracleDBDictionary
has made the mapping from TIMESTAMP to DATE.
I tried setting the jdbc-sql-type extension for the date field to
"timestamp". This makes a difference only when I drop the table.
Then the schematool's refresh action creates a table with date's
field mapped to a TIMESTAMP column. I have also gone ahead and
manually altered the table to achieve the same effect.
Once the mapping is created, I see the following behavior. Kodo
has no problem reading the TIMESTAMP column and putting the info
into the date field. It also has no problem saving non-null date
values into the TIMESTAMP column. But it does have a problem
storing a null in the date field.
Second question: what is the workaround to this problem?
The the stack dump (obtained by using the JDO Tools Library
example) follows.
Thanks in advance,
David Ezzio
enter command:
--> return book
Select the book to return:
1. book [com.ysoft.jdo.book.library.Book-354] "Gone to War" checked out:
Tue Mar 22 10:38:01 EST 2005
2. book [com.ysoft.jdo.book.library.Book-356] "Gone to Work" checked
out: Tue Mar 22 10:33:58 EST 2005
3. book [com.ysoft.jdo.book.library.Book-357] "Gone Fishing" checked
out: Tue Mar 22 10:33:58 EST 2005
4. book [com.ysoft.jdo.book.library.Book-360] "Gone Sailing" checked
out: Tue Mar 22 10:33:58 EST 2005
5. book [com.ysoft.jdo.book.library.Book-355] "Gone Hunting" checked
out: Tue Mar 22 10:33:58 EST 2005
Enter selection:
--> 2
okay
enter command:
--> commit
exception caught in command
kodo.util.FatalDataStoreException: The transaction has been rolled back.
See the nested exceptions for details on the errors that occu
rred.
at
kodo.runtime.PersistenceManagerImpl.throwFlushException(PersistenceManagerImpl.java:1262)
at
kodo.runtime.PersistenceManagerImpl.flush(PersistenceManagerImpl.java:1122)
at
kodo.runtime.PersistenceManagerImpl.flushSafe(PersistenceManagerImpl.java:1005)
at
kodo.runtime.PersistenceManagerImpl.beforeCompletion(PersistenceManagerImpl.java:932)
at
kodo.runtime.LocalManagedRuntime.commit(LocalManagedRuntime.java:69)
at
kodo.runtime.PersistenceManagerImpl.commit(PersistenceManagerImpl.java:592)
at
com.ysoft.jdo.book.library.LibraryHandler.commitTransaction(LibraryHandler.java:175)
at
com.ysoft.jdo.book.library.client.CommitTransaction.execute(Library.java:279)
at
com.ysoft.jdo.book.common.console.UserInterface.execute(UserInterface.java:196)
at
com.ysoft.jdo.book.common.console.UserInterface.pumpCommands(UserInterface.java:186)
at com.ysoft.jdo.book.library.client.Library.run(Library.java:139)
at com.ysoft.jdo.book.library.client.Library.main(Library.java:104)
NestedThrowablesStackTrace:
kodo.util.DataStoreException: Invalid column type
at
kodo.jdbc.sql.DBDictionary.newDataStoreException(DBDictionary.java:3081)
at kodo.jdbc.sql.SQLExceptions.getDataStore(SQLExceptions.java:77)
at kodo.jdbc.sql.SQLExceptions.getDataStore(SQLExceptions.java:63)
at kodo.jdbc.sql.SQLExceptions.getDataStore(SQLExceptions.java:43)
at
kodo.jdbc.runtime.PreparedStatementManager.flush(PreparedStatementManager.java:89)
at
kodo.jdbc.runtime.UpdateManagerImpl.flush(UpdateManagerImpl.java:445)
at
kodo.jdbc.runtime.UpdateManagerImpl.flush(UpdateManagerImpl.java:193)
at
kodo.jdbc.runtime.UpdateManagerImpl.flush(UpdateManagerImpl.java:95)
at
kodo.jdbc.runtime.JDBCStoreManager.flush(JDBCStoreManager.java:609)
at
kodo.runtime.DelegatingStoreManager.flush(DelegatingStoreManager.java:153)
at
kodo.runtime.PersistenceManagerImpl.flush(PersistenceManagerImpl.java:1122)
at
kodo.runtime.PersistenceManagerImpl.flushSafe(PersistenceManagerImpl.java:1005)
at
kodo.runtime.PersistenceManagerImpl.beforeCompletion(PersistenceManagerImpl.java:932)
at
kodo.runtime.LocalManagedRuntime.commit(LocalManagedRuntime.java:69)
at
kodo.runtime.PersistenceManagerImpl.commit(PersistenceManagerImpl.java:592)
at
com.ysoft.jdo.book.library.LibraryHandler.commitTransaction(LibraryHandler.java:175)
at
com.ysoft.jdo.book.library.client.CommitTransaction.execute(Library.java:279)
at
com.ysoft.jdo.book.common.console.UserInterface.execute(UserInterface.java:196)
at
com.ysoft.jdo.book.common.console.UserInterface.pumpCommands(UserInterface.java:186)
at com.ysoft.jdo.book.library.client.Library.run(Library.java:139)
at com.ysoft.jdo.book.library.client.Library.main(Library.java:104)
NestedThrowablesStackTrace:
java.sql.SQLException: Invalid column type
at oracle.jdbc.dbaccess.DBError.throwSqlException(DBError.java:134)
at oracle.jdbc.dbaccess.DBError.throwSqlException(DBError.java:179)
at oracle.jdbc.dbaccess.DBError.throwSqlException(DBError.java:269)
at
oracle.jdbc.driver.OracleStatement.get_internal_type(OracleStatement.java:6164)
at
oracle.jdbc.driver.OraclePreparedStatement.setNull(OraclePreparedStatement.java:1316)
at
com.solarmetric.jdbc.DelegatingPreparedStatement.setNull(DelegatingPreparedStatement.java:369)
at
com.solarmetric.jdbc.PoolConnection$PoolPreparedStatement.setNull(PoolConnection.java:406)
at
com.solarmetric.jdbc.DelegatingPreparedStatement.setNull(DelegatingPreparedStatement.java:369)
at
com.solarmetric.jdbc.DelegatingPreparedStatement.setNull(DelegatingPreparedStatement.java:369)
at
com.solarmetric.jdbc.DelegatingPreparedStatement.setNull(DelegatingPreparedStatement.java:369)
at
com.solarmetric.jdbc.LoggingConnectionDecorator$LoggingConnection$LoggingPreparedStatement.setNull(LoggingConnectionDecorato
r.java:792)
at
com.solarmetric.jdbc.DelegatingPreparedStatement.setNull(DelegatingPreparedStatement.java:369)
at kodo.jdbc.sql.DBDictionary.setNull(DBDictionary.java:950)
at
kodo.jdbc.sql.OracleDictionary.setNull(OracleDictionary.java:450)
at kodo.jdbc.sql.RowImpl.toSQL(RowImpl.java:828)
at kodo.jdbc.sql.RowImpl.flush(RowImpl.java:1039)
at kodo.jdbc.sql.RowImpl.flush(RowImpl.java:975)
at
kodo.jdbc.runtime.PreparedStatementManager.flushInternal(PreparedStatementManager.java:160)
at
kodo.jdbc.runtime.PreparedStatementManager.flush(PreparedStatementManager.java:84)
at
kodo.jdbc.runtime.UpdateManagerImpl.flush(UpdateManagerImpl.java:445)
at
kodo.jdbc.runtime.UpdateManagerImpl.flush(UpdateManagerImpl.java:193)
at
kodo.jdbc.runtime.UpdateManagerImpl.flush(UpdateManagerImpl.java:95)
at
kodo.jdbc.runtime.JDBCStoreManager.flush(JDBCStoreManager.java:609)
at
kodo.runtime.DelegatingStoreManager.flush(DelegatingStoreManager.java:153)
at
kodo.runtime.PersistenceManagerImpl.flush(PersistenceManagerImpl.java:1122)
at
kodo.runtime.PersistenceManagerImpl.flushSafe(PersistenceManagerImpl.java:1005)
at
kodo.runtime.PersistenceManagerImpl.beforeCompletion(PersistenceManagerImpl.java:932)
at
kodo.runtime.LocalManagedRuntime.commit(LocalManagedRuntime.java:69)
at
kodo.runtime.PersistenceManagerImpl.commit(PersistenceManagerImpl.java:592)
at
com.ysoft.jdo.book.library.LibraryHandler.commitTransaction(LibraryHandler.java:175)
at
com.ysoft.jdo.book.library.client.CommitTransaction.execute(Library.java:279)
at
com.ysoft.jdo.book.common.console.UserInterface.execute(UserInterface.java:196)
at
com.ysoft.jdo.book.common.console.UserInterface.pumpCommands(UserInterface.java:186)
at com.ysoft.jdo.book.library.client.Library.run(Library.java:139)
at com.ysoft.jdo.book.library.client.Library.main(Library.java:104)
enter command:
-->

Answer 1

Hi Stephen,
There are two related issues that are addressed. One, some Oracle
drivers return the wrong type (Type.OTHER) for the TIMESTAMP field.
This is true for the
9.2.0.1.0 driver that ships with 9iR2. This causes an exception when
attempting to assign a null to the date field that has been mapped to a
TIMESTAMP column. Two, all of the 9i drivers (and 10g drivers) return a
type name of "TIMESTAMP(x)" where x is the precision. This confuses
Kodo's OracleDictionary which is looking for a string without the
precision characters.
Following your suggestion, the following code fixes it just fine. It is
harmless, in that all it does is do what OracleDictionary intended but
failed to do. To use it, you must add the following property
configuration to the kodo.properties file.
kodo.jdbc.DBDictionary: xxx.jdo.FixedOracleDictionary
Without the fix, Kodo does not reassign the TIMESTAMP columns to a type
of DATE. So far as I can tell, as long as the driver returns a
Types.TIMESTAMP this does not cause a failure.
This fix will be moot as soon as the bug in OracleDictionary is fixed.
What I wonder about is why does Kodo reassign type TIMESTAMP to DATE?
Why don't you treat TIMESTAMP types as TIMESTAMP types? Curious minds
want to know.
Best wishes,
David
---- code follows
package xxx.jdo;
import java.sql.*;
import kodo.jdbc.schema.*;
import kodo.jdbc.sql.*;
* Some Oracle drivers do not return the correct type for the TIMESTAMP
field.
* This class fixes this issue for Kodo 3.3. The problem (an exception
complaining
* about an invalid column type) appears when mapping a Java field
(Date for example) to
* an Oracle timestamp field, and only when attempting to set null on
the Java field.
public class FixedOracleDictionary
extends OracleDictionary
public Column[] getColumns (DatabaseMetaData meta, String catalog,
String schemaName, String tableName,
String columnName, Connection conn)
throws SQLException
// Let Kodo's OracleDictionary do its thing
Column[] cols = super.getColumns (meta, catalog, schemaName,
tableName,
columnName, conn);
// Catch the columns with a name of "TIMESTAMP(n)" and mark them
as DATE types.
// This is what the OracleDictionary intended to do, but was
foiled by the
// name which now has a precision.
for (int i = 0; cols != null && i < cols.length; i++)
String tName = cols.getTypeName();
if (tName != null && tName.startsWith("TIMESTAMP"))
cols[i].setType(Types.DATE);
return cols;
---- code ends
Stephen Kim wrote:
This is a bug (1111)with regards to specific combinations of Oracle 10
driver and db.
To work around the issue until the next relase, getColumns (...) in
OracleDictionary needs to be extended/modified to instead of doing a
strict equals () comparison to "TIMESTAMP", to instead do a startsWith
("TIMESTAMP")
David Ezzio wrote:
Tuesday, March 22, 2005
I am currently experiencing difficulty in mapping a java.util.Date
field to an Oracle TIMESTAMP column.
Here's what I see. By default, Kodo maps the date field to a DATE
column. I suppose this makes sense since Oracle's date columns
have time information that resolves to the second. In this case,
the client has a business case to store subsecond resolution,
hence the desire to store the date field in an Oracle TIMESTAMP
column.
First question: how should this be done?
Here's what I've tried. I tried setting the jdbc-type extension
for the date field to "timestamp". This setting makes no
difference, and I suspect the reason is that OracleDBDictionary
has made the mapping from TIMESTAMP to DATE.
I tried setting the jdbc-sql-type extension for the date field to
"timestamp". This makes a difference only when I drop the table.
Then the schematool's refresh action creates a table with date's
field mapped to a TIMESTAMP column. I have also gone ahead and
manually altered the table to achieve the same effect.
Once the mapping is created, I see the following behavior. Kodo
has no problem reading the TIMESTAMP column and putting the info
into the date field. It also has no problem saving non-null date
values into the TIMESTAMP column. But it does have a problem
storing a null in the date field.
Second question: what is the workaround to this problem?
The the stack dump (obtained by using the JDO Tools Library
example) follows.
Thanks in advance,
David Ezzio
enter command:
--> return book
Select the book to return:
1. book [com.ysoft.jdo.book.library.Book-354] "Gone to War" checked
out:
Tue Mar 22 10:38:01 EST 2005
2. book [com.ysoft.jdo.book.library.Book-356] "Gone to Work" checked
out: Tue Mar 22 10:33:58 EST 2005
3. book [com.ysoft.jdo.book.library.Book-357] "Gone Fishing" checked
out: Tue Mar 22 10:33:58 EST 2005
4. book [com.ysoft.jdo.book.library.Book-360] "Gone Sailing" checked
out: Tue Mar 22 10:33:58 EST 2005
5. book [com.ysoft.jdo.book.library.Book-355] "Gone Hunting" checked
out: Tue Mar 22 10:33:58 EST 2005
Enter selection:
--> 2
okay
enter command:
--> commit
exception caught in command
kodo.util.FatalDataStoreException: The transaction has been rolled
back. See the nested exceptions for details on the errors that occu
rred.
at
kodo.runtime.PersistenceManagerImpl.throwFlushException(PersistenceManagerImpl.java:1262)
at
kodo.runtime.PersistenceManagerImpl.flush(PersistenceManagerImpl.java:1122)
at
kodo.runtime.PersistenceManagerImpl.flushSafe(PersistenceManagerImpl.java:1005)
at
kodo.runtime.PersistenceManagerImpl.beforeCompletion(PersistenceManagerImpl.java:932)
at
kodo.runtime.LocalManagedRuntime.commit(LocalManagedRuntime.java:69)
at
kodo.runtime.PersistenceManagerImpl.commit(PersistenceManagerImpl.java:592)
at
com.ysoft.jdo.book.library.LibraryHandler.commitTransaction(LibraryHandler.java:175)
at
com.ysoft.jdo.book.library.client.CommitTransaction.execute(Library.java:279)
at
com.ysoft.jdo.book.common.console.UserInterface.execute(UserInterface.java:196)
at
com.ysoft.jdo.book.common.console.UserInterface.pumpCommands(UserInterface.java:186)
at
com.ysoft.jdo.book.library.client.Library.run(Library.java:139)
at
com.ysoft.jdo.book.library.client.Library.main(Library.java:104)
NestedThrowablesStackTrace:
kodo.util.DataStoreException: Invalid column type
at
kodo.jdbc.sql.DBDictionary.newDataStoreException(DBDictionary.java:3081)
at
kodo.jdbc.sql.SQLExceptions.getDataStore(SQLExceptions.java:77)
at
kodo.jdbc.sql.SQLExceptions.getDataStore(SQLExceptions.java:63)
at
kodo.jdbc.sql.SQLExceptions.getDataStore(SQLExceptions.java:43)
at
kodo.jdbc.runtime.PreparedStatementManager.flush(PreparedStatementManager.java:89)
at
kodo.jdbc.runtime.UpdateManagerImpl.flush(UpdateManagerImpl.java:445)
at
kodo.jdbc.runtime.UpdateManagerImpl.flush(UpdateManagerImpl.java:193)
at
kodo.jdbc.runtime.UpdateManagerImpl.flush(UpdateManagerImpl.java:95)
at
kodo.jdbc.runtime.JDBCStoreManager.flush(JDBCStoreManager.java:609)
at
kodo.runtime.DelegatingStoreManager.flush(DelegatingStoreManager.java:153)
at
kodo.runtime.PersistenceManagerImpl.flush(PersistenceManagerImpl.java:1122)
at
kodo.runtime.PersistenceManagerImpl.flushSafe(PersistenceManagerImpl.java:1005)
at
kodo.runtime.PersistenceManagerImpl.beforeCompletion(PersistenceManagerImpl.java:932)
at
kodo.runtime.LocalManagedRuntime.commit(LocalManagedRuntime.java:69)
at
kodo.runtime.PersistenceManagerImpl.commit(PersistenceManagerImpl.java:592)
at
com.ysoft.jdo.book.library.LibraryHandler.commitTransaction(LibraryHandler.java:175)
at
com.ysoft.jdo.book.library.client.CommitTransaction.execute(Library.java:279)
at
com.ysoft.jdo.book.common.console.UserInterface.execute(UserInterface.java:196)
at
com.ysoft.jdo.book.common.console.UserInterface.pumpCommands(UserInterface.java:186)
at
com.ysoft.jdo.book.library.client.Library.run(Library.java:139)
at
com.ysoft.jdo.book.library.client.Library.main(Library.java:104)
NestedThrowablesStackTrace:
java.sql.SQLException: Invalid column type
at
oracle.jdbc.dbaccess.DBError.throwSqlException(DBError.java:134)
at
oracle.jdbc.dbaccess.DBError.throwSqlException(DBError.java:179)
at
oracle.jdbc.dbaccess.DBError.throwSqlException(DBError.java:269)
at
oracle.jdbc.driver.OracleStatement.get_internal_type(OracleStatement.java:6164)
at
oracle.jdbc.driver.OraclePreparedStatement.setNull(OraclePreparedStatement.java:1316)
at
com.solarmetric.jdbc.DelegatingPreparedStatement.setNull(DelegatingPreparedStatement.java:369)
at
com.solarmetric.jdbc.PoolConnection$PoolPreparedStatement.setNull(PoolConnection.java:406)
at
com.solarmetric.jdbc.DelegatingPreparedStatement.setNull(DelegatingPreparedStatement.java:369)
at
com.solarmetric.jdbc.DelegatingPreparedStatement.setNull(DelegatingPreparedStatement.java:369)
at
com.solarmetric.jdbc.DelegatingPreparedStatement.setNull(DelegatingPreparedStatement.java:369)
at
com.solarmetric.jdbc.LoggingConnectionDecorator$LoggingConnection$LoggingPreparedStatement.setNull(LoggingConnectionDecorato
r.java:792)
at
com.solarmetric.jdbc.DelegatingPreparedStatement.setNull(DelegatingPreparedStatement.java:369)
at kodo.jdbc.sql.DBDictionary.setNull(DBDictionary.java:950)
at
kodo.jdbc.sql.OracleDictionary.setNull(OracleDictionary.java:450)
at kodo.jdbc.sql.RowImpl.toSQL(RowImpl.java:828)
at kodo.jdbc.sql.RowImpl.flush(RowImpl.java:1039)
at kodo.jdbc.sql.RowImpl.flush(RowImpl.java:975)
at
kodo.jdbc.runtime.PreparedStatementManager.flushInternal(PreparedStatementManager.java:160)
at
kodo.jdbc.runtime.PreparedStatementManager.flush(PreparedStatementManager.java:84)
at
kodo.jdbc.runtime.UpdateManagerImpl.flush(UpdateManagerImpl.java:445)
at
kodo.jdbc.runtime.UpdateManagerImpl.flush(UpdateManagerImpl.java:193)
at
kodo.jdbc.runtime.UpdateManagerImpl.flush(UpdateManagerImpl.java:95)
at
kodo.jdbc.runtime.JDBCStoreManager.flush(JDBCStoreManager.java:609)
at
kodo.runtime.DelegatingStoreManager.flush(DelegatingStoreManager.java:153)
at
kodo.runtime.PersistenceManagerImpl.flush(PersistenceManagerImpl.java:1122)
at
kodo.runtime.PersistenceManagerImpl.flushSafe(PersistenceManagerImpl.java:1005)
at
kodo.runtime.PersistenceManagerImpl.beforeCompletion(PersistenceManagerImpl.java:932)
at
kodo.runtime.LocalManagedRuntime.commit(LocalManagedRuntime.java:69)
at
kodo.runtime.PersistenceManagerImpl.commit(PersistenceManagerImpl.java:592)
at
com.ysoft.jdo.book.library.LibraryHandler.commitTransaction(LibraryHandler.java:175)
at
com.ysoft.jdo.book.library.client.CommitTransaction.execute(Library.java:279)
at
com.ysoft.jdo.book.common.console.UserInterface.execute(UserInterface.java:196)
at
com.ysoft.jdo.book.common.console.UserInterface.pumpCommands(UserInterface.java:186)
at
com.ysoft.jdo.book.library.client.Library.run(Library.java:139)
at
com.ysoft.jdo.book.library.client.Library.main(Library.java:104)
enter command:
-->