RE: Select by PK

From: Gentry, Michael (michael_gentr..anniemae.com)
Date: Wed Jan 07 2004 - 10:15:20 EST

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    Here is what I used a while back which seemed to work:

    Map map = new HashMap();
    map.put("identifier",
    HexCoder.decode(PSCollection.QUEUE_PURCHASE_MONTHLY));

    ObjectId oid = new ObjectId(PSCollection.class, map);
    PSCollection collection = (PSCollection) dataContext.refetchObject(oid);

    if (collection != null)
    {
      // Do stuff here ...
    }

    A few notes ... The "identifier" is the primary key column. The
    HexCoder stuff makes a binary data type out of a large hexadecimal value
    (we don't have simple integers in our existing legacy database). One of
    the other ObjectId constructors might work better for you, though. From
    what I understand, making an ObjectId like this essentially makes a
    fault object, and then you can ask your DataContext object to refetch
    it. I believe if the object is already in memory, it is refetched
    (updated from the DB) due to object uniquing.

    Hope that helps!

    /dev/mrg

    -----Original Message-----
    From: Leonardo Queiroz Antunes [mailto:Leonardo.Antune..r-tcs.com]
    Sent: Wednesday, January 07, 2004 7:30 AM
    To: cayenne-use..bjectstyle.org
    Subject: Select by PK

    Hi everybody,
     
    how can we select an object by its pk value?
     
    thanks
     
    Leonardo



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