Windows Forms FAQ resources

5. Windows Forms Datagrid

5.30 How can I bind two datagrids in a Master-Detail relationship?

Please download this sample before reading the rest of this FAQ. Looking through the sample will help follow the description.

simpledata2.zip

What this boils down to is this:
1) Load both Master and Details queries in a dataset.

// I am using the SQL server NorthWind database

this.dataAdapterMaster.Fill(this.dataSet, "Customers");

this.dataAdapterDetails.Fill(this.dataSet, "Orders");

2) Bind the master data grid to the Master dataset table.

// The master view

grid.DataSource = this.dataSet;

grid.DataMember = "Customers";

3) Create a relationship that describes how the two tables relate to each other. A primary key foriegn key relationship is defined by two attributes.
The primary key column in the master table
The foreign key coumn in the details table
The created relationship is added to the dataset.

this.dataSet.Relations.Add("CustomersToOrders",

dataSet.Tables["Customers"].Columns["CustomerID"],

dataSet.Tables["Orders"].Columns["CustomerID"]);

4) Set the data member for the details table to be the name of relationship that was added to the dataset.

// The name of the relation is to be used as the DataMember for the

// details view

details.DataSource = this.dataSet;

// use the relationship called "CustomersToOrders in the Customers table.

// Remember that we called the relationship "CustomersToOrders".

details.DataMember = "Customers.CustomersToOrders";