I think you should forget these RDBMS tech.
On Sat, Apr 24, 2010 at 11:00 AM, aXqd <axqd...@gmail.com> wrote: > On Sat, Apr 24, 2010 at 1:36 AM, Ned Wolpert <ned.wolp...@imemories.com> > wrote: > > There is nothing wrong with what you are asking. Some work has been done > to > > get an ORM layer ontop of cassandra, for example, with a RubyOnRails > > project. I'm trying to simplify cassandra integration with grails with > the > > plugin I'm writing. > > The problem is ORM solutions to date are wrapping a relational database. > > (The 'R' in ORM) Cassandra isn't a relational database so it does not map > > cleanly. > > Thanks. I noticed this problem before. I just want to know, in the > first place, what exactly is the right way to model relations in > Cassandra(a no-relational database). > So far, I still have those entities, and, without foreign keys, I use > relational entities, which contains the IDs of both sides of > relations. > In some other cases, I just duplicate data, and maintain the relations > manually by updating all the data in the same time. > > Is this the right way to go? Or what I am doing is still trying to > convert Cassandra to a RDBMS? > > > > > On Fri, Apr 23, 2010 at 1:29 AM, aXqd <axqd...@gmail.com> wrote: > >> > >> On Fri, Apr 23, 2010 at 3:03 PM, Benoit Perroud <ben...@noisette.ch> > >> wrote: > >> > I understand the question more like : Is there already a lib which > >> > help to get rid of writing hardcoded and hard to maintain lines like : > >> > > >> > MyClass data; > >> > String[] myFields = {"name", "label", ...} > >> > List<Column> columns; > >> > for (String field : myFields) { > >> > if (field == "name") { > >> > columns.add(new Column(field, data.getName())) > >> > } else if (field == "label") { > >> > columns.add(new Column(field, data.getLabel())) > >> > } else ... > >> > } > >> > (same for loading (instanciating) automagically the object). > >> > >> Yes, I am talking about this question. > >> > >> > > >> > Kind regards, > >> > > >> > Benoit. > >> > > >> > 2010/4/23 dir dir <sikerasa...@gmail.com>: > >> >>>So maybe it's weird to combine ORM and Cassandra, right? Is there > >> >>>anything we can take from ORM? > >> >> > >> >> Honestly I do not understand what is your question. It is clear that > >> >> you can not combine ORM such as Hibernate or iBATIS with Cassandra. > >> >> Cassandra it self is not a RDBMS, so you will not map the table into > >> >> the object. > >> >> > >> >> Dir. > >> > >> Sorry, English is not my mother tongue. > >> > >> I do understand I cannot combine ORM with Cassandra, because they are > >> totally different ways for building our data model. But I think there > >> are still something can be learnt from ORM to make Cassandra easier to > >> use, just as what ORM did to RDBMS before. > >> > >> IMHO, domain model is still intact when we design our software, hence > >> we need another way to map them to Cassandra's entity model. Relation > >> does not just go away in this case, hence we need another way to > >> express those relations and have a tool to set up Keyspace / > >> ColumnFamily automatically as what django's SYNCDB does. > >> > >> According to my limited experience with Cassandra, now, we do more > >> when we write, and less when we read/query. Hence I think the problem > >> lies exactly in how we duplicate our data to do queries. > >> > >> Please correct me if I got these all wrong. > >> > >> >> > >> >> On Fri, Apr 23, 2010 at 12:12 PM, aXqd <axqd...@gmail.com> wrote: > >> >>> > >> >>> Hi, all: > >> >>> > >> >>> I know many people regard O/R Mapping as rubbish. However it is > >> >>> undeniable that ORM is quite easy to use in most simple cases, > >> >>> Meanwhile Cassandra is well known as No-SQL solution, a.k.a. > >> >>> No-Relational solution. > >> >>> So maybe it's weird to combine ORM and Cassandra, right? Is there > >> >>> anything we can take from ORM? > >> >>> I just hate to write CRUD functions/Data layer for each object in > even > >> >>> a disposable prototype program. > >> >>> > >> >>> Regards. > >> >>> -Tian > >> >> > >> >> > >> > > > > > > > > > -- > > Virtually, Ned Wolpert > > > > "Settle thy studies, Faustus, and begin..." --Marlowe > > >