What do u want to optimize in Query...
It will be a simple query...
first time when you load you run query like select * from table where
parentid==null/0/or even remove where clause
then when user click on any node on UI tree then u make RPC call to bring
its child.. and load them to tree
and if you really want to bring whole data in one trip in ur admin panel...
then bring everything as simple list of objects...
and for each object create a node and add to tree as par parent key
On Sat, May 7, 2011 at 7:30 PM, RH richkh...@gmail.com wrote:
h, I think you're right.
Any ideas on how to optimize the datastore query for a sub branch of
the tree?
With this approach I either need to
a) bring in all items in the app (possibly filtered by owner) across
the RPC boundary and then structure them in the GWT client
b) continue to look for child nodes in the tree via parentkey, until
no children remain (will require a query on each node for the
children).
I was hoping to avoid a long, drawn out query...
RH
On May 4, 2:37 am, Ravi Sharma ping2r...@gmail.com wrote:
I will advise you to use unowned relation in this scnerio. Instead of
Directory entity having childrens...i will put parent information in the
Directory entity.. this way you can make sure one Directiry can have
millions of Child directory...as you will not max out the maximum entity
size.
class Directory {
public String name;
public ArrayListDirectory children = new
ArrayListDirectory();//Delete this
public Key parentKey;
// could have any other properties or attributes here as well
Directory(String n){
name = n;
public void Display() {
System.out.println( name: + name);
for(Directory d : children)
Display();
}
}
You can write one GWT RPC function like this
Directory[] getMyChildren(String parentKeyParam){
//On the server you can query like this
Select * from Directory where parentKey = parentKeyParam
and return it back to GWT.
}
On Wed, May 4, 2011 at 3:47 AM, RH richkh...@gmail.com wrote:
here would be an example using the heap:
class Directory {
public String name;
public ArrayListDirectory children = new
ArrayListDirectory();
// could have any other properties or attributes here as well
Directory(String n){
name = n;
public void Display() {
System.out.println( name: + name);
for(Directory d : children)
Display();
}
}
You should be able to add or remove any object in the tree:
...
directoryObject.children.Add(new Directory(new child));
...
and you can display the node and any child nodes:
...
directoryObject.Display();
I want to use the GAE datastore to persist these POJOs (easy enough in
JDO) but also maintain their structural relationship to each other
(hard, at least that I can see) - That is, I am trying to persist the
object instances *and* their relations to each other.
RH
On May 2, 11:37 am, Todd Vierling t...@duh.org wrote:
On Saturday, April 30, 2011 9:06:45 PM UTC-4, RH wrote:
I'm looking for a simple way to persist a set of dynamic Composite
Design Pattern objects (as described in Design Patterns by Gamma,
Helm, Johnson, and Vlissides) with either Google's native
datastore,
JDO, or JPA, as well as send to and from the client via RPC.
Design patterns mean pretty much zero in real-world discussions, so
example
code would be a lot more helpful. (Or in other words, what does the
class
you're trying to persist look like?)
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