Re: Objects stored in DB despite optimistic locking

From: Mike Kienenberger (mkienen..mail.com)
Date: Thu Jul 27 2006 - 14:17:06 EDT

  • Next message: Nikolai Raitsev: "Re: Objects stored in DB despite optimistic locking"

    Nikolai,

    I'm not completely following what you're asking for.

    Perhaps you're asking how you can make an empty string into a null
    automatically? Put this method into a BaseDataObject class (add this
    class between CayenneDataObject and your generated classes).

        public void writeProperty(String propName, Object value)
        {
            // Oracle can't handle empty strings, so convert them into
    nulls automatically.
            // We'll never use an empty string as a database value.
            if ( (value instanceof String) && (0 == ((String)value).length()) )
            {
                value = null;
            }

            super.writeProperty(propName, value);
        }

    On 7/27/06, Nikolai Raitsev <nikolai.raitse..mail.com> wrote:
    > Escuse me, that is my and SQL Server problem, not from cayenne...
    >
    > a blank in SQL Server is no blank...
    >
    > best regards,
    >
    > Nikolai
    >
    > ps. but, is it possibility to build the examination that ' '== '' (blank
    > equals not blank) into cayenne?
    >
    > 2006/7/27, Nikolai Raitsev <nikolai.raitse..mail.com>:
    > >
    > > I found the problem and probably a bug in cayenne...
    > >
    > > here is a part of my log:
    > >
    > > on first run, insert:
    > >
    > > INFO QueryLogger: INSERT INTO WPTAB (WPTAB_AENKZ, WPTAB_ISIN,
    > > WPTAB_LOEKZ) VALUES (?, ?, ?)
    > > INFO QueryLogger: [bind: ' ', 'DE0000044444', ' ']
    > >
    > > Attention, in ' ' is one blank!!!!
    > >
    > > on second run, update:
    > >
    > > INFO QueryLogger: UPDATE WPTAB SET WPTAB_AENKZ = ?, WPTAB_LOEKZ = ? WHERE
    > > WPTAB_ISIN = ?
    > > INFO QueryLogger: [bind: ' ', ' ', 'DE0000044444']
    > >
    > > Attention, and here in ' ' is one blank!!!!
    > > The Fields WPTAB_AENKZ and WPTAB_LOEKZ has not changed, why cayenne does
    > > those update?
    > >
    > > Have everybody a tip for me, what can I do?
    > >
    > > thanks and best regards,
    > >
    > > Nikolai
    > >
    > >
    > >
    > > 2006/7/27, Nikolai Raitsev <nikolai.raitse..mail.com>:
    > >
    > > > Hello
    > > >
    > > > How works optimistic locking?
    > > >
    > > > I understand it such (see
    > > > http://cwiki.apache.org/CAY/optimistic-locking-explained.html):
    > > >
    > > > if no data changed in the dataset, is this data record not updated in
    > > > the database.
    > > >
    > > > i have following problem:
    > > > first run:
    > > > i have 20000 datarecords in a table 1. This dataset I copy with cayenne
    > > > into another table 2.
    > > > I use setProperty method, like this:
    > > >
    > > > attrListParameter =
    > > > p_dataObjectInt.getObjEntity().getAttributes().toArray();
    > > >
    > > > int nSizeAttrListParameter = attrListParameter.length;
    > > > ObjAttribute attr;
    > > > String sAttrName;
    > > >
    > > > for(int i = 0; i<nSizeAttrListParameter; i++)
    > > > {
    > > > attr = (ObjAttribute) attrListParameter[i];
    > > > sAttrName = attr.getName();
    > > > p_dataObject.writeProperty(sAttrName,
    > > > p_dataObjectInt.readProperty(sAttrName));
    > > > }
    > > >
    > > > I make commit to the end, commit duratation is 11 sec.
    > > >
    > > > second run:
    > > > i have 20000 datarecords in a table 1 and in table 2.
    > > > I copy this 20000 records once again into table 2 (the data is not
    > > > changed!) with code from above and commit changes, but commit duratation is
    > > > also 11 sec.!!!! No data has changed!, optimistic locking is set in my
    > > > XXX.map.xml for class from p_dataObject and for all attributes.
    > > >
    > > > in the second run is to be sent nevertheless update for all 20000
    > > > datarecords, or?
    > > >
    > > > what i do wrong???
    > > >
    > > > with thanks, nikolai
    > > >
    > > >
    > > >
    > >
    >
    >



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