Get PK value of a previously generated object

From: mr.abanjo (mr.abanj..mail.com)
Date: Mon Aug 09 2010 - 16:11:52 UTC

  • Next message: Mike Kienenberger: "Re: Get PK value of a previously generated object"

    Hi,
    my application need to generate a "parent" object and then create a "child"
    object that contains the PK value of the parent.
    I'm using MySQL and the colum "id" is "autoincrement". ( both tables )

    So first i create the main object (it extends DataObject ):

    MainObject mainObj = new MainObject();
    //setting properties... without id.. it's generated by mysql
    mainObj.set......
    ....
    ...
    DataContext...registerNewObject(MainObject);
    DataContext...commitChanges();

    The record is succesfully inserted in the database!

    Then i need to get the PK... in this case a single column ( Long ).

    If i insepct the corresponding filed it is empty, so i see in the
    documentation that there are two ways to perform this task:
    http://cayenne.apache.org/doc30/accessing-pk-and-fk-values.html
    public Long getMainObjectId() {
    return (getObjectId() != null && !getObjectId().isTemporary()) ? (Long)
    getObjectId().getIdSnapshot().get(ID) : null;
    }

    http://cayenne.apache.org/doc30/dataobjectutils.html
    long myId = (Long)DataObjectUtils.pkForObject(MainObject);

    but, with both techniques the value returned is "null"!

    What is wrong?

    Thansk for support.

    Davide

    This archive was generated by hypermail 2.0.0 : Mon Aug 09 2010 - 16:12:23 UTC