Comments on: Using the unsaved-value attribute to prevent TransientObjectExceptions in Hibernate http://blog.xebia.com/2006/08/09/using-the-unsaved-value-attribute-to-prevent-transientobjectexceptions-in-hibernate/ Software development done right! Wed, 08 Feb 2012 14:41:38 +0000 hourly 1 http://wordpress.org/?v=3.3.1 By: Age Mooy http://blog.xebia.com/2006/08/09/using-the-unsaved-value-attribute-to-prevent-transientobjectexceptions-in-hibernate/#comment-94907 Age Mooy Fri, 21 May 2010 14:00:45 +0000 http://blog.xebia.com/2006/08/09/using-the-unsaved-value-attribute-to-prevent-transientobjectexceptions-in-hibernate/#comment-94907 Dude, this was way back in 2006 and I haven't used Hibernate in years. Your problem description is way to vague to determine any specific cause. I suggest Google and/or the manual. Dude, this was way back in 2006 and I haven’t used Hibernate in years. Your problem description is way to vague to determine any specific cause. I suggest Google and/or the manual.

]]> By: Yashashree http://blog.xebia.com/2006/08/09/using-the-unsaved-value-attribute-to-prevent-transientobjectexceptions-in-hibernate/#comment-94883 Yashashree Thu, 20 May 2010 09:09:39 +0000 http://blog.xebia.com/2006/08/09/using-the-unsaved-value-attribute-to-prevent-transientobjectexceptions-in-hibernate/#comment-94883 I am getting exception as "PersistenceException: Unable to add new object to the datastore", when i am adding new values in one of my tables using hibernate pojo class having unsaved-value=null. Can you people tell me whether this exception is related to that unsaved-value attribute??. I am getting exception as “PersistenceException: Unable to add new object to the datastore”, when i am adding new values in one of my tables using hibernate pojo class having unsaved-value=null. Can you people tell me whether this exception is related to that unsaved-value attribute??.

]]> By: Maarten Winkels http://blog.xebia.com/2006/08/09/using-the-unsaved-value-attribute-to-prevent-transientobjectexceptions-in-hibernate/#comment-315 Maarten Winkels Tue, 29 Aug 2006 06:33:05 +0000 http://blog.xebia.com/2006/08/09/using-the-unsaved-value-attribute-to-prevent-transientobjectexceptions-in-hibernate/#comment-315 Casper, you're probably right about using sequence numbers that start at 1 when using them for valus in a column. The tricky thing is, that when using Hibernates HiLoSequenceGenerator (too decrease load on the database when inserting a lot of records in a table with a PK based on a sequence), it uses the sequence to generate a range of numbers. The transformation maps the value of 0 to the range [ 1 - range_size+1], thus when range_size = 999, a sequnce that starts at 0 will produce the numbers [1 - 1000] first and then [1001 - 2000]. A sequence that starts at 1 will first returns numbers in the range [1001 - 2000], thus leaving a gap at the start. In our case we mix IdGenerators, since some objects are persisted more often than others, we use simple SequenceGenerators for these types. These should be used with sequences that start at 1. Casper, you’re probably right about using sequence numbers that start at 1 when using them for valus in a column. The tricky thing is, that when using Hibernates HiLoSequenceGenerator (too decrease load on the database when inserting a lot of records in a table with a PK based on a sequence), it uses the sequence to generate a range of numbers. The transformation maps the value of 0 to the range [ 1 - range_size+1], thus when range_size = 999, a sequnce that starts at 0 will produce the numbers [1 - 1000] first and then [1001 - 2000]. A sequence that starts at 1 will first returns numbers in the range [1001 - 2000], thus leaving a gap at the start.
In our case we mix IdGenerators, since some objects are persisted more often than others, we use simple SequenceGenerators for these types. These should be used with sequences that start at 1.

]]> By: Casper Groenen http://blog.xebia.com/2006/08/09/using-the-unsaved-value-attribute-to-prevent-transientobjectexceptions-in-hibernate/#comment-313 Casper Groenen Mon, 28 Aug 2006 15:05:12 +0000 http://blog.xebia.com/2006/08/09/using-the-unsaved-value-attribute-to-prevent-transientobjectexceptions-in-hibernate/#comment-313 Maybe, you should let your sequences start at 1 (which most DBMSes do anyway). Maybe, you should let your sequences start at 1 (which most DBMSes do anyway).

]]> By: Serge Beaumont http://blog.xebia.com/2006/08/09/using-the-unsaved-value-attribute-to-prevent-transientobjectexceptions-in-hibernate/#comment-172 Serge Beaumont Sat, 12 Aug 2006 18:50:07 +0000 http://blog.xebia.com/2006/08/09/using-the-unsaved-value-attribute-to-prevent-transientobjectexceptions-in-hibernate/#comment-172 IMHO it is a bug. I don't know Hibernate 3, but in 2 the unsaved value was essentially the same as whatever Java initializes an instance variable to when you don't provide an initializer: String blah; would mean a null value. int initializes to 0, etcetera. A Long initialized to 0 at least breaks backwards compaltibility. IMHO it is a bug. I don’t know Hibernate 3, but in 2 the unsaved value was essentially the same as whatever Java initializes an instance variable to when you don’t provide an initializer:

String blah;

would mean a null value. int initializes to 0, etcetera. A Long initialized to 0 at least breaks backwards compaltibility.

]]> By: Lars Vonk http://blog.xebia.com/2006/08/09/using-the-unsaved-value-attribute-to-prevent-transientobjectexceptions-in-hibernate/#comment-157 Lars Vonk Fri, 11 Aug 2006 21:02:08 +0000 http://blog.xebia.com/2006/08/09/using-the-unsaved-value-attribute-to-prevent-transientobjectexceptions-in-hibernate/#comment-157 This is probably an undocumented feature.The hibernate doc says: "unsaved-value (optional - defaults to a "sensible" value)" and "The unsaved-value attribute is almost never needed in Hibernate3.". Well indeed almost... This is probably an undocumented feature.The hibernate doc says:
“unsaved-value (optional – defaults to a “sensible” value)” and “The unsaved-value attribute is almost never needed in Hibernate3.”. Well indeed almost…

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