Devart Forums

Hi,

I need to work with custom entities and I do not wish to have loads of tables. So I have come up with an idea of having one generic "Class" table with is then link to a "Group" table with custom column of string type.
ie C1, C2, C3.

It seems to me that there could be 2 methods to create the specific entities via ED.

1) Create a DB View for each "Group" and create an entity for each view by editing the "Mapping Details". Incidentally, although it says <Add a Table or View>, I can only see my tables? Is this a bug or am I missing something. The View definitely exists.

2) Use the Query View facility in the "Mapping Details" option and write the appropriate Entity-SQL. With this approach, one would not need to write specific DB Views. Would these be updatable like DB Views as long as I accessed just one table?

Thanks.

I may be moving forward on this.

I have added a View in my Model by choosing "New Defining Query". I then wrote my SQL which was something like "Select * from vwProduct". I then name my View "vwProduct" and then created a class from it. I could then "retrieve data" from this Class and all is fine. However how can I test that it will accept data, ie how do I do an insert and edit?

Please also comment on whether there are other approaches to my aim of creating custom entities against generic tables.

Thanks.

We recommend you to implement the following approach:
1. In Model.Store (Model Explorer) right click on the Tables/Views node > Add > New Defining Query > set Entity Name and specify SQL Query (select all needed columns from one or several tables/views).
2. In Model.Store (Model Explorer) right click on the Stored Procedures node > Add > New Command Text - create three insert/update/delete procedures in this way with the needed DML statement in each of them.
3. Drag&drop entity to the conceptual part of the model (within Model Explorer or on a diagram surface).
4. Right click on the class > Stored Procedure Mapping and map Insert/Update/Delete commands to insert/update/delete procedures.

A similar approach (but for a different task) was applied at http://forums.devart.com/viewtopic.php? ... 510#p86947.

Ok, Thanks for this. Will take a look.

Ed