Hello,
> I'm wondering about the message "Can not access DB data". Do you write > this message in case you do not retrieve any data? Or is someone else > printing it which might indicate that you cannot access the database at > all. I'm just guessing here.
Yes I use try and catch to display that msg. SO I should change the
method back to:
public List<lightingspecreimp.Lampent> allLightingpro(){List <Lampent>results=emp.createNamedQuery("getAlldetails").getResultList(); return results;
But that means I am still back to sqaure one.
Any more ideas. please, anyone.
Thanks
eve
> Date: Wed, 5 Dec 2007 20:51:28 +0100> From: mbo.tech@spree.de> To: persistence@glassfish.dev.java.net> Subject: Re: question on entity relationships> > Hi Eve,> > > Hello,> > > > Yes, same msg:> > > > [#|2007-12-05T19:00:44.843+0000|INFO|sun-appserver9.1|javax.enterprise.system.stream.out|_ThreadID=17;_ThreadName=httpSSLWorkerThread-8080-1;|> > Can not access DB data|#]> > [#|2007-12-05T19:00:53.609+0000|INFO|sun-appserver9.1|javax.enterprise.system.stream.out|_ThreadID=17;_ThreadName=httpSSLWorkerThread-8080-1;|> > Can not access DB data|#]> I'm wondering about the message "Can not access DB data". Do you write > this message in case you do not retrieve any data? Or is someone else > printing it which might indicate that you cannot access the database at > all. I'm just guessing here.> > > > > > here is the change code:> > > > *public List<lightingspecreimp.Lampent> allLightingpro(){> > List results=emp.createNamedQuery("getAlldetails").getResultList();> > return results;> > > > }*> The method would run into a ClassCastException in case getResultList > returns any data. Method getResultList returns a List<Object[]> which > cannot be cast to List<lightingspecreimp.Lampent>.**> > > ** > > Could it be that I need to make changes to my toString method of my > > Lampent:> > > > public String toString()> > {String s= pnumb + " " + catergory + " " + lwoltage + " " + > > lamManufacturerent ;> > return s;}> >> I think the implementation of the toString method does not effect the > result of the query execution.> > Regards Michael> > > > or even, the get and set methods in Lampent relating to > > lamManufacturerent :> > > > *public LamManufacturerent getLamManufacturerent()> > {return lamManufacturerent;}*> > ** > > * public void setLamManufacturerent(LamManufacturerent lamManufacturerent)> > {this.lamManufacturerent=lamManufacturerent;}*> > ** > > The above get method means it will return an object of > > *lamManufacturerent *not fields.> > So how do I get fields of *lamManufacturerent *from* Lampent?*> > ** > > Thanks> > ** > > *eve*> >> > * *> > > > > > > >> >> > > >> > ------------------------------------------------------------------------> > Date: Tue, 4 Dec 2007 15:07:54 -0800> > From: Craig.Russell@Sun.COM> > To: persistence@glassfish.dev.java.net> > Subject: Re: question on entity relationships> >> > Hi eve,> >> > The return type of the query should not be List<Lampent> since> > you're not returning Lampent instances, just a bunch of fields.> >> > Do you get the same exception if you do:> > List results=emp.createNamedQuery("getAlldetails").getResultList();> >> > Craig> >> > On Dec 4, 2007, at 3:01 PM, Eve Pokua wrote:> >> > Hello,> >> > I have checked this and made changes to this:> >> > @NamedQuery(name ="getAlldetails", query=" SELECT l.pnumb,> > l.catergory, l.lwoltage, lm.manuname FROM Lampent l LEFT OUTER> > JOIN l.lamManufacturerent lm")> >> > I am still not able to retreive data. error msg:> >> > [#|2007-12-04T22:51:10.754+0000|INFO|sun-appserver9.1|oracle.toplink.essentials.session.file:/C:/Sun/SDK2/domains/domain1/applications/j2ee-apps/LIGHTINGSPEC/LIGHTINGSPEC-ejb_jar/-LIGHTINGSPEC-ejbPU3|_ThreadID=19;_ThreadName=httpSSLWorkerThread-8080-1;|file:/C:/Sun/SDK2/domains/domain1/applications/j2ee-apps/LIGHTINGSPEC/LIGHTINGSPEC-ejb_jar/-LIGHTINGSPEC-ejbPU3> > login successful|#]> >> > [#|2007-12-04T22:51:11.234+0000|INFO|sun-appserver9.1|javax.enterprise.system.stream.out|_ThreadID=19;_ThreadName=httpSSLWorkerThread-8080-1;|> > Can not access DB data|#]> >> >> >> > here is the cde from my implementation:> >> > public List<lightingspecreimp.Lampent> allLightingpro(){> > List<Lampent>> > results=emp.createNamedQuery("getAlldetails").getResultList();> > return results;> > > > }> >> > apprecaite your everything. thanks> >> > eve> >> >> >> > > From: gordon.yorke@oracle.com <mailto:gordon.yorke@oracle.com>> > > To: persistence@glassfish.dev.java.net> > <mailto:persistence@glassfish.dev.java.net>> > > Date: Mon, 3 Dec 2007 16:32:03 -0500> > > Subject: RE: question on entity relationships> > > > > > Hello eve,> > > Did you cut and paste that query or type it in? There is a> > typo in the FROM clause.> > > > > > @NamedQuery(name ="getAlldetails", query=" SELECT l.pnumb,> > l.catergory, l.lwoltage, lm.manuname FROM Lampent l LEFT OUTER> > JOIN *l*.LamManufacturerent lm")> > > > > > --Gordon> > > > > > -----Original Message-----> > > From: Eve Pokua [mailto:gorgeous65@msn.com]> > > Sent: Monday, December 03, 2007 4:28 PM> > > To: persistence@glassfish.dev.java.net> > <mailto:persistence@glassfish.dev.java.net>> > > Subject: RE: question on entity relationships> > > > > > > > > > > > > > > Thanking you for your reply.> > > > > > James,> > > > > > LamManufacturerents is the foreign key in Lampent.> > LamManufacturerents exists in Lampent. So the query should be> > like this:> > > > > > > > > @NamedQuery(name ="getAlldetails", query=" SELECT l.pnumb,> > l.catergory, l.lwoltage, lm.manuname FROM Lampent l LEFT OUTER> > JOIN lm.LamManufacturerent lm")> > > > > > But i get the following errors:> > > > > > [#|2007-12-03T21:18:31.671+0000|INFO|sun-appserver9.1|oracle.toplink.essentials.session.file:/C:/Sun/SDK/domains/domain1/applications/j2ee-apps/LIGHTINGSPEC/LIGHTINGSPEC-ejb_jar/-LIGHTINGSPEC-ejbPU3|_ThreadID=34;_ThreadName=Thread-185;|file:/C:/Sun/SDK/domains/domain1/applications/j2ee-apps/LIGHTINGSPEC/LIGHTINGSPEC-ejb_jar/-LIGHTINGSPEC-ejbPU3> > logout successful|#]> > > > > > [#|2007-12-03T21:18:31.687+0000|SEVERE|sun-appserver9.1|javax.enterprise.system.tools.deployment|_ThreadID=34;_ThreadName=Thread-185;_RequestID=3961ec6a-8774-47c5-876a-b986184d7369;|Exception> > occured in J2EEC Phase> > > java.lang.StackOverflowError> > > at java.util.HashMap.get(HashMap.java:300)> > > at> > oracle.toplink.essentials.internal.parsing.ParseTreeContext.pathForVariable(ParseTreeContext.java:198)> > > at> > oracle.toplink.essentials.internal.parsing.VariableNode.resolveClass(VariableNode.java:282)> > > at> > oracle.toplink.essentials.internal.parsing.DotNode.resolveClass(DotNode.java:262)> > > at> > oracle.toplink.essentials.internal.parsing.VariableNode.resolveClass(VariableNode.java:287)> > > at> > oracle.toplink.essentials.internal.parsing.DotNode.resolveClass(DotNode.java:262)> > > at> > oracle.toplink.essentials.internal.parsing.VariableNode.resolveClass(VariableNode.java:287)> > > at> > oracle.toplink.essentials.internal.parsing.DotNode.resolveClass(DotNode.java:262)> > > at> > oracle.toplink.essentials.internal.parsing.VariableNode.resolveClass(VariableNode.java:287)> > > > > > > > > .............................> > > > > > > > > it gos on.> > > > > > Thankings everyone> > > > > > eve> > > > > > ----------------------------------------> > > > Date: Mon, 3 Dec 2007 07:08:22 -0800> > > > From: jamesssss@yahoo.com <mailto:jamesssss@yahoo.com>> > > > To: persistence@glassfish.dev.java.net> > <mailto:persistence@glassfish.dev.java.net>> > > > Subject: RE: question on entity relationships> > > > > > > > > > > > Do you have any LamManufacturerent that have Lampent? This> > query will filter> > > > out the none case, i.e. you will only get back> > LamManufacturerents that have> > > > 1 or more Lampent.> > > > > > > > You could use an outerjoin if you do not wish to filter the> > none case.> > > > > > > > i.e.> > > > SELECT l.pnumb, l.catergory, l.lwoltage, lm.manuname FROM> > LamManufacturerent> > > > lm left outer join lm.lampent l> > > > > > > > > > > > Eve Pokua wrote:> > > > > > > > > > > > > > > Hello James/Everyone, I have finally tried your> > suggestion but I'm> > > > > having problems retrieving data. Below are my to related> > entities with> > > > > their relationships: @Entity@Table(name="LAMPS") @Named> > Queries({> > > > > @Named Query(name ="getAlldetails", query=" SELECT> > l.pnumb, l.catergory,> > > > > l.lwoltage, lm.manuname FROM LamManufacturerent lm,> > in(lm.lampent) l")}> > > > > public class Lampent implements Serializable{> > ......................... > > > > > @ManyToOne private LamManufacturerent> > > > > lamManufacturerent;................... }> > @Entity@Table(name="LAMPMANU")> > > > > public class LamManufacturerent implements> > > > > Serializable{............................> > @OneToMany(mappedBy => > > > > "lamManufacturerent") private List<Lampent> lampent;> > .............> > > > > } Here is the JPQL: @Named Query(name ="getAlldetails",> > query=" SELECT> > > > > l.pnumb, l.catergory, l.lwoltage, lm.manuname FROM> > LamManufacturerent lm,> > > > > in(lm.lampent) l") Did I get it wrong because it is not> > working and not> > > > > retrieving any data. It however works, if I do some thing> > like this:> > > > > "Select l FROM Lampent l" It brings all data plus all the> > data from the> > > > > related entity LamManufacturerent. But i only want> > manuname from> > > > > LamManufacturerent. Im probably making just a little> > mistake. Please,> > > > > help. Thankseve ________________________________> From:> > > > > gorgeous65@msn.com <mailto:gorgeous65@msn.com>> To:> > persistence@glassfish.dev.java.net> > <mailto:persistence@glassfish.dev.java.net>> Date: Wed, 14> > > > > Nov 2007 15:07:03 +0000> Subject: RE: question on entity> > relationships> >> > > > > Thanks James> > I will try it and let you know.> > eve>> > >> Date: Wed, 14> > > > > Nov 2007 06:20:25 -0800>> From: jamesssss@yahoo.com> > <mailto:jamesssss@yahoo.com>>> To:> > > > > persistence@glassfish.dev.java.net> > <mailto:persistence@glassfish.dev.java.net>>> Subject: Re:> > question on entity> > > > > relationships>>>>>> The JPQL would be,>>>> "Select i.id,> > i.name,> > > > > i.description, i.colour, i.size, o.oid, o.date,>>> > o.quantity from Order o,> > > > > in(o.items) i">>>> You could also just select the Order> > and fetch join the> > > > > items, if you wanted>> the objects back. Or just select> > the Orders can> > > > > access the items from them>> in Java.>>>> "Select o from> > Order o join> > > > > fetch o.items">>>> "Select o from Order o">>>>>> Eve> > Pokua wrote:>>>>>>>>>> > > > > Hello everyone,>>>>>> I would like to know how to> > retrieve certain data> > > > > from the DB with respect>>> to entity relationship.> > Consider the following> > > > > SQL statement.>>>>>> "Select i.id, i.name, i.description,> > i.colour,> > > > > i.size, o.oid, o.date,>>> o.quantity from Item i, Order> > o">>>>>> Or a very> > > > > complex SQL statement using JOIN in tables.>>>>>> The> > Order entity is a 1> > > > > to many relation to Item - an order can have many>>>> > items. But when> > > > > retrieving the details from order, I want to see> > certain>>> data from the> > > > > Order table as stated above, but not all the data from>>>> > Order. How do I> > > > > achieve this in EJB3 query?>>>>>> Thanks>>>>>>> > eve>>>>>>>>> ----->> --->>> > > > > http://wiki.eclipse.org/User:James.sutherland.oracle.com> > James> > > > > Sutherland>>> > http://www.oracle.com/technology/products/ias/toplink/ Oracle> > > > > TopLink ,>> http://www.eclipse.org/eclipselink/>>> > EclipseLink ,> > > > > https://glassfish.dev.java.net/javaee5/persistence/> > TopLink>> Essentials>>> > > > > Wiki: http://en.wikibooks.org/wiki/Java_Persistence Java> > Persistence ,>>> > > > > http://wiki.eclipse.org/EclipseLink EclipseLink>> Forums:> > > > > http://forums.oracle.com/forums/forum.jspa?forumID=48> > TopLink ,>>> > > > > http://www.nabble.com/EclipseLink-f26430.html EclipseLink ,>>> > > > >> > http://www.nabble.com/java.net---glassfish-persistence-f13455.html> > > > > Glassfish>> Persistence>> -->> View this message in context:> > > > >> > http://www.nabble.com/question-on-entity-relationships-tf4804935.html#a13747259>>> > > > > Sent from the java.net - glassfish persistence mailing> > list archive at> > > > > Nabble.com.> > ________________________________> Get free> > emoticon packs> > > > > and customisation from Windows Live. Pimp My> > > > > Live!<http://www.pimpmylive.co.uk> > <http://www.pimpmylive.co.uk/>>> > > > >> > _________________________________________________________________> > > > > Get free emoticon packs and customisation from Windows Live. > > > > > http://www.pimpmylive.co.uk <http://www.pimpmylive.co.uk/>> > > > > > > > > > > > > > > > > -----> > > > ---> > > > http://wiki.eclipse.org/User:James.sutherland.oracle.com> > James Sutherland > > > > http://www.oracle.com/technology/products/ias/toplink/> > Oracle TopLink , > > > > http://www.eclipse.org/eclipselink/> > > > EclipseLink ,> > https://glassfish.dev.java.net/javaee5/persistence/ TopLink> > > > Essentials > > > > Wiki: http://en.wikibooks.org/wiki/Java_Persistence Java> > Persistence , > > > > http://wiki.eclipse.org/EclipseLink EclipseLink > > > > Forums:> > http://forums.oracle.com/forums/forum.jspa?forumID=48 TopLink , > > > > http://www.nabble.com/EclipseLink-f26430.html EclipseLink , > > > >> > http://www.nabble.com/java.net---glassfish-persistence-f13455.html> > Glassfish> > > > Persistence > > > > -- > > > > View this message in context:> > http://www.nabble.com/RE%3A-question-on-entity-relationships-tf4930046.html#a14131601> > <http://www.nabble.com/RE:-question-on-entity-relationships-tf4930046.html#a14131601>> > > > Sent from the java.net - glassfish persistence mailing list> > archive at Nabble.com.> > > > > > _________________________________________________________________> > > The next generation of MSN Hotmail has arrived - Windows Live> > Hotmail> > > http://www.newhotmail.co.uk <http://www.newhotmail.co.uk/>> >> > ------------------------------------------------------------------------> > The next generation of MSN Hotmail has arrived - Windows Live> > Hotmail <http://www.newhotmail.co.uk/>> >> >> > Craig Russell> > Architect, Sun Java Enterprise System http://java.sun.com/products/jdo> > 408 276-5638 mailto:Craig.Russell@sun.com> > P.S. A good JDO? O, Gasp!> >> >> > ------------------------------------------------------------------------> > Are you the Quizmaster? Play BrainBattle with a friend now! > > <http://specials.uk.msn.com/brainbattle>> > > -- > Tech@Spree Engineering GmbH Tel.: +49/(0)30/235 520-33> Buelowstr. 66 Fax.: +49/(0)30/217 520-12> 10783 Berlin mailto:mbo.tech@spree.de > > Geschaeftsfuehrung: Anna-Kristin Proefrock> Sitz Berlin, Amtsgericht Charlottenburg, HRB 564 52
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