Re: Cayenne chain-chank problem

From: Andrus Adamchik (andru..bjectstyle.org)
Date: Fri May 21 2010 - 09:33:01 UTC

  • Next message: ςΡΒΙΓΛΙΚ εΧΗΕΞΙΚ: "RE: Cayenne chain-chank problem"

    Ok I got it now.

    That's how Velocity works. This code is not Cayenne specific. I would
    suggest defining extra variables for conditions, or writing a Velocity
    expression to match your expectations. E.g. "#chunk($id || $id == 0).
    Not sure if you can redefine thsi behavior on the Velocity end.

    I am not entirely happy with Velocity as a SQLTemplate engine myself,
    but unless and until we write a substitution, we are stuck with that I
    guess.

    Andrus

    On May 21, 2010, at 12:11 PM, ςΡΒΙΓΛΙΚ εΧΗΕΞΙΚ wrote:

    > I took example from http://cayenne.apache.org/doc20/scripting-sqltemplate.html
    > and extend it so it use Boolean fields to show my problem.
    >
    > For me problematic that when I am going to filter ARTISTS with id ==
    > 1 or id == 10 it is all ok I will got query:
    >
    > SELECT * from ARTIST t0 WHERE id = ? [bind: 1 ]
    >
    > But if I am filtering with id == 0 (that is absolute valid column
    > value) I got:
    >
    > SELECT * from ARTIST t0
    >
    > But I was expecting:
    >
    > SELECT * from ARTIST t0 WHERE id = ? [bind: 0 ]
    >
    > That is my problem.... Same for Boolean values, I just want simple
    > filtering by only passed column values.
    >
    >
    > Evgeny.
    >
    >
    >
    > -----Original Message-----
    > From: Andrus Adamchik [mailto:andru..bjectstyle.org]
    > Sent: Friday, May 21, 2010 12:12 PM
    > To: de..ayenne.apache.org
    > Subject: Re: Cayenne chain-chank problem
    >
    > Hi Evgeny,
    >
    > Where did you find this example?
    >
    > I am checking #chunk directive example here: http://cayenne.apache.org/doc20/scripting-sqltemplate.html
    > and everything seems correct to me. IIRC "0 == null" is how Velocity
    > evaluates expressions (C-style), so this has to be taken into account
    > when building SQLtemplates.
    >
    > So I don't understand which parts you find problematic?
    >
    > Cheers,
    > Andrus
    >
    >
    > On May 21, 2010, at 10:36 AM, ςΡΒΙΓΛΙΚ εΧΗΕΞΙΚ wrote:
    >
    >> Hello, here is example from tutorial for 2.0:
    >>
    >> String sql = "SELECT DISTINCT"
    >> + " #result('ARTIST_ID' 'int'),"
    >> + " #result('ARTIST_NAME' 'String'),"
    >> + " #result('DATE_OF_BIRTH' 'java.util.Date')"
    >> + " #result('IS_DEAD' 'java.util.Boolean')"
    >> + " FROM ARTIST t0"
    >> + " #chain('OR' 'WHERE') // start
    >> chain prefixed by WHERE,
    >> // and joined
    >> by OR
    >> + " #chunk($name) ARTIST_NAME LIKE #bind($name) #end" //
    >> ARTIST_NAMEchunk"
    >> + " #chunk($id) ARTIST_ID > #bind($id) #end" // ARTIST_ID
    >> chunk"
    >> + " #chunk($isDead) IS_DEAD = #bind($isDead) #end" // IS_DEAD
    >> chunk"
    >> + " #end"; // end of chain
    >> SQLTemplate select = new SQLTemplate(Artist.class, sql, true);
    >>
    >>
    >> If I put in isDead true - everything is ok, but if I put false I got
    >> chat this condition is skipper because #chunk is actually checking
    >> condition of $isDead.
    >>
    >> Same thing if I put 0 in $id it will be false.
    >>
    >> So this example of tutorial is bad for Dead Artists or Artists with
    >> id == 0.
    >> Maybe it's a bug of #chunk directive and it should do only null
    >> check??
    >>
    >> Evgeny.
    >>
    >
    >



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