I need to generate a user interface for entering a sales document (eg invoice). I’m trying to use components of “developer express” specifically the QuantumGrid component (TcxGrid). I’ve seen the demos of master-detail components and search in the devexpress support center, but none has helped me because all use 2 grids to handle the master-detail relation, and edit multiple records at once.
I just need to edit a record (document) at a time and using a pair of objects dataware components (eg TDBEdit) in the header and a grid to handle the detail.
something like this
Where can I find a basic example of using these components in this way?
Tthe Master/Child properties in the QuantumGrid are mainly designed to nest multiple items in the grid. If you setup the relationship in the data components you can simply hook the controls up to the correct DataSource and everything will work.
So if you have two DataSets Customer and Invoice. The Invoice Master Datasource is the Customer DataSource. Then on your edit controls you point to the Customer DataSource and you point the Grid to the Invoice DataSource.
If you think about what the Master/Detail relationship is doing it really just filters the records on the Detail DataSet to match the current record on the Master DataSet. Individual Edit controls will always display the “current” record in the DataSet they are connected to. Grids will show all visible records in the DataSet they are connected to.
I have a tendency to not use Master/Detail relationships in an edit form like you show here. I’m assuming there is some way on a different screen to pick the invoice to edit. I usually create a copy of the needed DataSets with only the records needed for this edit. If I am editing a existing invoice I copy the current records. If it is a new invoice I can start off with an empty recordset. It is more work – I have some generic library functions that will copy a DataSet Structure and then copy one or more records into that Dataset. Depending on your setup you can also requery your Database to just get the records you are interested in. Obviously that should not be done in all cases. Another issue with this approach is you need a way to update any other Datasets you may have with this data – i.e. your main search screen.
However, once I get on the edit screen I find it makes things eaiser. Now I don’t need to worry about the master detail relationship at the top level. If the invoice has internal Master/Detail relationships you can just deal with those, but you know that the DataSets only have the data for this one invoice – not everything in the Database.
In the case of your form if you limit the Data in the DataSets you can just hook everything up directly and it should work as you expect. You would only have one record in the Customer DataSet and the invoice would just have the records for this Invoice.