Re: [OJB-developers] Optimistic locking

[Thomas M. <tho...@ho...>]

Hi Jakob,

Thanks for your latest contribution. I hope to get it worked into the 
next release!


Thomas



Jakob Braeuchi wrote:

> hi,
> 
> the attached zip contains some code based on version 0.7.310 to support
> optimistic locking for int, long and timestamp fields.
> 
> <FieldDescriptor id="6">
> <field.name>test</field.name>
> <column.name>test</column.name>
> <jdbc_type>INTEGER</jdbc_type>
> <locking>true</locking>
> </FieldDescriptor>
> <FieldDescriptor id="8">
> <field.name>lastModified</field.name>
> <column.name>entryDate</column.name>
> <jdbc_type>TIMESTAMP</jdbc_type>
> <locking>true</locking>
> </FieldDescriptor>
> 
> the locking fields are used in the where-clause for update and delete. if
> the rowcount of the update is 0, an exception is thrown
> (JdbcAccess::executeUpdate()) :
> ...
> broker.getStatementManager().bindUpdate(stmt, mif, obj);
> if (stmt.executeUpdate() == 0 && mif.isLocking()) //BRJ
> {
>     throw new PersistenceBrokerException("Object has been modified by
> someone else");
> }
> ...
> 
> hth
> jakob
>