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From Apache Wiki <wikidi...@apache.org>
Subject [Db-torque Wiki] Update of "OracleFAQ" by dkreutz
Date Mon, 05 Dec 2005 09:45:24 GMT
Dear Wiki user,

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The following page has been changed by dkreutz:
http://wiki.apache.org/db-torque/OracleFAQ

------------------------------------------------------------------------------
  
  See also http://db.apache.org/torque/runtime/oracle-howto.html
  
- == What should i know when using Oracle's data type DATE and TIMESTAMP ==
+ == What should i know when using Oracle's datatype  DATE and TIMESTAMP ==
  
- Oracles data type DATE support date and time with an accuracy up to seconds, which is fine
for many applications. 
+ Oracle datatype DATE supports date and time with an accuracy up to seconds, which is fine
for many applications. 
- Since Version 9i Oracle introduced additional data type TIMESTAMP that supports additional
accuracy within fractions of seconds.
+ Since Version 9i Oracle introduced additional datatype TIMESTAMP that supports additional
accuracy within fractions of seconds.
+ So far so good, but:
+ 
- So far so good, but unfortunately the village library used by Torque to read/write data
from/into databases truncates dates by setting hours, minutes and seconds all to zero. So
although oracle has a better precision in its Date datatype, you can not use the better precision
in Torque.  
+  1. The village library used by Torque to read/write data from/into databases truncates
dates by setting hours, minutes and seconds all to zero. So although oracle has a better precision
in its DATE datatype, you can not use the better precision in Torque.  
+ 
+  2. In Version 9.2 of the JDBC-driver Oracle changed the mapping of datatype DATE from java.sql.Timestamp
(prior 9.2) to java.sql.Date (since 9.2) leading to a loss of time information.
+ 
+ See also http://www.oracle.com/technology/tech/java/sqlj_jdbc/htdocs/jdbc_faq.htm#08_01
  
  === So what if I need exact date and time?  ===
  
-  1. When generating your Torque-classes specify all columns as type="TIMESTAMP" in the schema.xml
for Torque-Generator, regardless if they are data type DATE or TIMESTAMP in your Oracle-schema.
+  1. When generating your Torque-classes specify all columns as type="TIMESTAMP" in the schema.xml
for Torque-Generator, regardless if they are datatype DATE or TIMESTAMP in your Oracle-schema.
  
-  1. In your Oracle schema use data type TIMESTAMP for all columns where you need full date
and time. This is recommended when creating a new database schema. You can easily convert
DATE-columns to TIMESTAMP as Oracle casts these data types automatically (UPDATE mytable set
newTimestampColumn=oldDateColumn). For existing database (especially in production environment)
this may not be feasible:
+  1. In your Oracle schema use datatype TIMESTAMP for all columns where you need full date
and time. This is recommended when creating a new database schema. You can easily convert
DATE-columns to TIMESTAMP as Oracle casts these datatype automatically (UPDATE mytable set
newTimestampColumn=oldDateColumn). For existing database (especially in production environment)
this may not be feasible:
  
-  1. You may still use Oracles data type DATE. If you want correct time portion of the data
you must specify Java-VM parameter "-Doracle.jdbc.V8Compatible=true" that causes the JDBC-driver
to use old behaviour of JDBC-driver prior to Oracle 9i (returning full date and time for data
type DATE)
+  1. You may still use Oracles datatype DATE. If you want correct time portion of the data
you must specify Java-VM parameter "-Doracle.jdbc.V8Compatible=true" that causes the JDBC-driver
to use old behaviour of JDBC-driver prior to Oracle 9i (returning full date and time for data
type DATE)
  

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