Jasper Neve wrote:
> I am trying to let MMBase talk with SQL Server and had same warning
> message, when loading the example myNews app. Later I got Java
> exception when trying to insert a new mag or newsitem. 
> With hssqldb I had no such warning and no such problem, so I guessed
> problem and warning are related. 

Normall, a builder maintains a list of 'known' fields.
This contains fields that are stored in the database (persistent 
fields), but also fields that hold data that is calculated, or that are 
used to store temporary data (such as status information).
The warning message is caused because the temporary field "_exists" does 
not occur in this list (it should be 'registered', but the code doesn't).
While this causes the warning messages, it does not really affect 
behavior of the system, with one exception: because it is not known, the 
_exists field is treated as being of type 'TYPE_UNKNOWN', rather than 
'TYPE_VIRTUAL'.
In most cases, TYPE_UNKNOWN is treated the same way as TYPE_VIRTUAL 
(i.e. it is not stored in the database).However, if you wrote your own 
database support class, you migth have code that treats it differently.

Note that, afaik, this bug was also present in the older versions of 
MMBase - the main difference is that now the 'bad' behavior is logged.

In 1.6, the _exists field is registered beforehand (when the builder 
starts up).

-- 
Pierre van Rooden
Mediapark, C 107 tel. +31 (0)35 6772815
"So long, and thanks for all the fish"


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