Greetings,

Is there a generic way of converting an Entity collection to a DataSet. I thought this to be a trivial task but then I realized that an object (in an EntityCollection) could have one more child collections as properties. In this case the object graph should be converted to a collection of related data tables that are contained in the data set.

It would be nice if FRANS builds a (.ToDataSet) method in the entity collection to expose this functionality...

OMAR

And how should m:1 and 1:1 related entities be represented, also in a separate datatable?

That would be a good way to do it.

There is a problem then

Datasets are set-based containers. This means that if you have an entity collection of Orders and each order has a loaded customer object, the only way to store this is to create two datatables, one for orders and one for customers and 1 datarelation. This is perhaps nice, but you then lose the obvious a-contained-in-b hierarchy you had with the order - customer hierarchy in the orders collection.

It's not that bad though, but it's a different way of looking at the data.

I wrote it, and the main problem is not m:1 or 1:1 relations but m:n relations. Yes it'll be usefull I think but also time consuming. The schemas creation take most of the time. It's why it can be usefull to make a : - public DataSet ToDataSet() : generate the schema and fill with data - public void FillDataSet(DataSet ds) : only fill the dataset (suppose that the schema is allready made) So that we can create dataset first time, store the schemas in the project so that we can onli use the FillDataSet method to take less time.

But why would you fill a dataset? There is already a way to fill a datatable with entity data (like fetching a list of entities into a datatable).

Frans... how would do that.. by looping through a collection and filling a data table or is there another way I don't know about

omar wrote:

Frans... how would do that.. by looping through a collection and filling a data table or is there another way I don't know about

Directly from the database?

Adapter:

// get all customers in a datatable. If you need a filter, just specify it as a 3rd parameter
// to FetchTypedList
CustomerEntity c = new CustomerEntity();
DataTable customers = new DataTable();
adapter.FetchTypedList(c.Fields, customers, null);

SelfServicing:

DataTable customers = CustomerCollection.GetMultiAsDataTable(null, 0, null);

Thanks Frans.. this is exactly what I was looking for.

I thought that TypedLists are only created from Views

LLBL rules

omar wrote:

Thanks Frans.. this is exactly what I was looking for.

I thought that TypedLists are only created from Views

Heh, no those are typed views! . Typed Lists are multi-entity views based on entities, which you can design in the designer. The routine to fetch them can also be used to fetch data based on a set of fields into a datatable

LLBL rules

Otis wrote:

But why would you fill a dataset? There is already a way to fill a datatable with entity data (like fetching a list of entities into a datatable).

Well but what about if your entity is linked to several other entities ? you have to fill a dataset with several tables, not a datatable. And the final touch is that you have to put primary keys and foreign keys.

Ok, good point, my only question is then: why would you need that dataset setup if you have entity collections? (just to understand where functionality is lacking in the generated code). Design time support is now covert with the new design time support code now in release candidate phase

I work througth webservices, and I dont use entities because : - dataset generate much more compact xml than llblgen entity serialization (yes we allready spoke about that ) - I don't want to install llblgen libraries on the client side (update problem to synchronize client and server version etc).

PS : Well, if the feature is only for me it's useless

Ok good point. I'll see what I can do.