RE: Querying based on 1/2 the compound key

From: Fredrik Liden (flide..ranslate.com)
Date: Tue May 24 2005 - 19:50:39 EDT

  • Next message: Joshua Pyle: "Re: Querying based on 1/2 the compound key"

    Thanks Joshua!! I forgot about the DB methods (never used them so far)

    Do you know if there are any pros and cons when it comes to using the 2
    different types of ExpressionFactory methods such as matchExp vs
    matchDbExp? (Besides that fact that the regular ones doesn't seem to
    support including the PKs as a search field like the db ones do).

    Also it seems more convenient to use ExpressionFactory.matchDbExp to get
    an object based on a pk (compound or not) compared to using the
    DataObjectUtils which would require one to create a map with the PKs?

    Fredrik

    -----Original Message-----
    From: Joshua Pyle [mailto:joshua.t.pyl..mail.com]
    Sent: Tuesday, May 24, 2005 4:34 PM
    To: cayenne-use..bjectstyle.org
    Subject: Re: Querying based on 1/2 the compound key

    What is the exception ?

    Most likely you will need to create a "db" epression if the 2 primary
    key fields do not have accessors defined in the modeler/xml.

    I also notice that in your expression you note KEY and not KEY1 or KEY2.

    An example expression might be...
    Expression exp = ExpressionFactory.matchDbExp(TEST.KEY2,"1111");

    This is assuming that the variable TEST.KEY2 contains the database field
    name for that part of the primary key.

    -- 
    Joshua T. Pyle
    Go has always existed.
    

    On 5/24/05, Fredrik Liden <flide..ranslate.com> wrote: > I have one table with a compound key (key1,key2). > > Now I'm trying to retreive all the entries from this table/object TEST

    > where say key2="1111". > > If I use an expression like this: > Expression exp = ExpressionFactory.matchExp(TEST.KEY,"1111"); > SelectQuery query = new SelectQuery(TEST.class,exp); > I get an exception. > > Using the DataObjectUtils object I could probably get 1 unique object > if I populate it with a key map. But how can I get a list if I just > want to match one part of the compound key? > > Thanks, > > Fredrik >



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