Re: Queries

From: Ted Moens (tmoen..elus.net)
Date: Mon Mar 03 2008 - 17:15:10 EST

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    Hi Mike:

    Thanks and I understand the need for details. The relationship is a
    simple one. A "Game" belongs to a "Grouping" and there are many games
    in a grouping. My model is full of similar relationships.

    When I use the XML encoder to dump all the games in a grouping to the
    client, there is no problem. Or, when I use the XML encoder to show
    attributes of the grouping associated with a particular game, it also
    works fine.

    Here are two expressions I use in the code the first is based on a test
    against a simple attribute:
                    expressionList.add(ExpressionFactory.matchExp("gameState", new
    ExpressionParameter("gameState")));

    No problem, queries work. Here is the one for comparing to a Game's
    Grouping's name:
             
    expressionList.add(ExpressionFactory.matchExp("toGrouping.groupingName",
    new ExpressionParameter("groupingId")));

    This is where I get the runtime error:

    Can't resolve path component: [Grouping.groupingName]

    Here is the data model for my "Game" class minus a lot of noise
    attributes...
    ---------------- db part ---------------------
            <db-entity name="game" catalog="ultiscore">
    sMandatory="true" length="10"/>
                    <db-attribute name="gameState" type="CHAR" isMandatory="true"
    length="11"/>
                    <db-attribute name="groupingId" type="INTEGER" isMandatory="true"
    length="10"/>
            </db-entity>
    -------------------- db relationship part ------------------
            <db-relationship name="toGrouping" source="game" target="grouping"
    toMany="false">
                    <db-attribute-pair source="groupingId" target="groupingId"/>
            </db-relationship>
    ------------------ object part --------------------
            <obj-entity name="Game" className="org.tsw.ultiserver.Game"
    dbEntityName="game">
                    <obj-attribute name="gameState" type="java.lang.String"
    db-attribute-path="gameState"/>
            </obj-entity>
    ------------------ object relationship part --------------------
            <obj-relationship name="toGrouping" source="Game" target="Grouping"
    db-relationship-path="toGrouping"/>

    And here is the Grouping Class again minus the junk:
    --------------------------------------
            <db-entity name="grouping" catalog="ultiscore">
                    <db-attribute name="groupingName" type="VARCHAR" isMandatory="true"
    length="50"/>
            </db-entity>
    --------------------------------------
            <db-relationship name="gameArray" source="grouping" target="game"
    toMany="true">
                    <db-attribute-pair source="groupingId" target="groupingId"/>
            </db-relationship>
    --------------------------------------
            <obj-entity name="Grouping" className="org.tsw.ultiserver.Grouping"
    dbEntityName="grouping">
                    <obj-attribute name="groupingName" type="java.lang.String"
    db-attribute-path="groupingName"/>
            </obj-entity>
    --------------------------------------
            <obj-relationship name="gameArray" source="Grouping" target="Game"
    db-relationship-path="gameArray"/>

    ============================

    Ted

    Mike Kienenberger wrote:
    > The first thing I would check is to verify that you have an
    > ObjRelationship named "Artist" from your root entity. Note that the
    > name is "toArtist" in the analogous code.
    >
    > It's somewhat difficult to comment on the cause of a concrete error
    > given only theoretical environment information :-)
    >
    > The relevant sections of your DataMap + the actual code would be helpful.
    >
    > On 3/3/08, Ted Moens <tmoen..elus.net> wrote:
    >> Greetings:
    >>
    >> I am trying to do a parameterized select query. My situation is
    >> directly analogous to the example:
    >>
    >> list.add(ExpressionFactory.matchExp("paintingTitle",
    >> new ExpressionParameter("pname")));
    >> list.add(ExpressionFactory.matchExp("toArtist.artistName",
    >> new ExpressionParameter("aname")));
    >>
    >> I follow this pattern but I run into troubles with when the first
    >> argument to the matchExp is an attribute of an object other than the
    >> target class itself. So in the above example, the first expression
    >> works fine but the second would fail with the following:
    >>
    >> Can't resolve path component: [Artist.artistName])
    >>
    >> I've very carefully checked that in other situations the attribute
    >> analogous to Artist.artistName is in fact accessible.
    >>
    >> Is there a common error made in these situations?
    >>
    >> Thanks in advance for any help.
    >>
    >> Ted
    >>
    >> FYI...
    >>
    >>
    >> at org.apache.cayenne.map.Entity$PathIterator.next(Entity.java:375)
    >> at
    >> org.apache.cayenne.access.trans.QueryAssemblerHelper.appendObjPath(QueryAssemblerHelper.java:90)
    >> at
    >> org.apache.cayenne.access.trans.QualifierTranslator.objectNode(QualifierTranslator.java:338)
    >> at org.apache.cayenne.exp.Expression.traverse(Expression.java:455)
    >> at org.apache.cayenne.exp.Expression.traverse(Expression.java:452)
    >> at org.apache.cayenne.exp.Expression.traverse(Expression.java:432)
    >> at
    >> org.apache.cayenne.access.trans.QualifierTranslator.doTranslation(QualifierTranslator.java:74)
    >> at
    >> org.apache.cayenne.access.trans.SelectTranslator.createSqlString(SelectTranslator.java:123)
    >> at
    >> org.apache.cayenne.dba.mysql.MySQLSelectTranslator.createSqlString(MySQLSelectTranslator.java:31)
    >> at
    >> org.apache.cayenne.access.trans.QueryAssembler.createStatement(QueryAssembler.java:95)
    >> at
    >> org.apache.cayenne.access.jdbc.SelectAction.performAction(SelectAction.java:71)
    >> at
    >> org.apache.cayenne.access.DataNodeQueryAction.runQuery(DataNodeQueryAction.java:57)
    >> at org.apache.cayenne.access.DataNode.performQueries(DataNode.java:236)
    >> at
    >> org.apache.cayenne.access.DataDomainQueryAction.runQuery(DataDomainQueryAction.java:446)
    >> at
    >> org.apache.cayenne.access.DataDomainQueryAction.access$000(DataDomainQueryAction.java:67)
    >> at
    >> org.apache.cayenne.access.DataDomainQueryAction$2.transform(DataDomainQueryAction.java:418)
    >> at
    >> org.apache.cayenne.access.DataDomain.runInTransaction(DataDomain.java:853)
    >> at
    >> org.apache.cayenne.access.DataDomainQueryAction.runQueryInTransaction(DataDomainQueryAction.java:415)
    >> at
    >> org.apache.cayenne.access.DataDomainQueryAction.execute(DataDomainQueryAction.java:119)
    >> at org.apache.cayenne.access.DataDomain.onQuery(DataDomain.java:746)
    >> at
    >> org.apache.cayenne.util.ObjectContextQueryAction.runQuery(ObjectContextQueryAction.java:282)
    >> at
    >> org.apache.cayenne.access.DataContextQueryAction.execute(DataContextQueryAction.java:59)
    >> at org.apache.cayenne.access.DataContext.onQuery(DataContext.java:1323)
    >> at
    >> org.apache.cayenne.access.DataContext.performQuery(DataContext.java:1312)
    >> at org.tsw.ultiserver.getXMLData.processRequest(getXMLData.java:138)
    >> at org.tsw.ultiserver.getXMLData.doGet(getXMLData.java:159)
    >> at javax.servlet.http.HttpServlet.service(HttpServlet.java:690)
    >> at javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
    >> at
    >> org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:269)
    >> at
    >> org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:188)
    >> at
    >> org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:213)
    >> at
    >> org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:174)
    >> at
    >> org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
    >> at
    >> org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:117)
    >> at
    >> org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:108)
    >> at
    >> org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:151)
    >> at
    >> org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:874)
    >> at
    >> org.apache.coyote.http11.Http11BaseProtocol$Http11ConnectionHandler.processConnection(Http11BaseProtocol.java:665)
    >> at
    >> org.apache.tomcat.util.net.PoolTcpEndpoint.processSocket(PoolTcpEndpoint.java:528)
    >> at
    >> org.apache.tomcat.util.net.LeaderFollowerWorkerThread.runIt(LeaderFollowerWorkerThread.java:81)
    >> at
    >> org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:689)
    >> at java.lang.Thread.run(Unknown Source)
    >>
    >>
    >
    >



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