[Opensource] DBObject.clear() does not "clear" boolean fields - bug or feature

[larry hamel]

hi Milen,

good bug description.

it seems to me that DBObject.clear() is the culprit here.  A DBObject is "born" with nulls in the underlying hashtable, so I propose the following change to DBObject.clear() to reset that hash to all nulls.  I assume that the resulting object would behave then just as a newly created DBObject.  (BTW, the short-term workaround  would be to create a new DBObject rather than using clear() for now.)

does anyone see problems with this?  

hmm, I guess for one thing is the "log update" logic that is present in setField().  that seems easy to add (and deserves a separate method in DBObject).

larry
-------------------------------

    public synchronized void clear()
                            throws DBException {
        DBField oneField = null;

        for (Iterator i = getAllFieldsIterator(); i.hasNext();) {
            oneField = (DBField)i.next();

            if (!oneField.isVirtual()) {
                // avoid use of setField() here
                //setField(oneField.getName(), "");

                if (getDef().isLoggingEnabled()) {
                   // make this new method
                   logChange( oneField, null );
                }

                // reset underlying hash
                 setFieldData(oneField.getName(), null);
            }
        }
    }
----------------------------

At 08:01 AM 6/12/2002, you wrote:
>Hi,
>
>We are having some problems with boolean fields in Expresso v4.1.
>When we execute SQL query using new instance of a particular DBObject,
>(for example:
>DBObj myDBObj=new DBObj();
>myDBObj.setField("id","1");
>Vector v=myDBObj.searchAndRetrieve();
>)
>the query result set contains all the records we expect.
>But if we want to reuse the same DBObject and just execute .clear()
>- result set contains only the records that have boolean fields set to "false".
>(
>myDBObj.clear();
>myDBObj.setField("id","1");
>Vector v=myDBObj.searchAndRetrieve();
>)
>
>In Expresso DBObject, when DBObject.clear() is invoked the following fragment is executed:
>setField(oneField.getName(), "");
>
>and later in setField(String,String) we have:
>....
>if (oneField.getTypeString().equalsIgnoreCase("boolean")) {
>                   if (fieldValue.equalsIgnoreCase("Y") || fieldValue.equalsIgnoreCase("t")
>                               || fieldValue.equalsIgnoreCase("true")) {
>                       fieldValue = getBooleanFieldValue(true);
>                   } else {
>                       fieldValue = getBooleanFieldValue(false);
>                   }
>               }
>....
>The outcome is that the boolean fields will be set to "false".
>Hence when one does searchAndRetrieve() only the records with  "false" value will be returned.
>At least we think this is causing the trouble - but this is what we encounter.
>Do you have any solution for that problem?
>Or this is the way that method DBObject.clear() is supposed to work?
>Thank you in advance!
>Milen
>
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