Windows Forms FAQ resources

5. Windows Forms Datagrid

5.89 How can I display master-details-details in three separate grids?

Here is a sample (both VB and C#) that illustrates how to have a parent table whcih has a related child table, which also has a related grandchild table.

Below are some code snippets. The trick is to always make the main parent table be the DataSource for all the grid, and then set the DataMember to be the relation name where teh relation starts at the parent table. This means the DisplayMember for the Child table is "ParentToChild", the name of that relation. And, the DisplayMember for the grandchild grid is "ParentToChild.ChildToGrandChild" whcih defines the relation starting at the parent grid through the child grid.

Dim dSet As New DataSet()

'get the tables

Dim parentTable As DataTable = GetParentTable()

Dim childTable As DataTable = GetChildTable()

Dim grandChildTable As DataTable = GetGrandChildTable()

dSet.Tables.AddRange(New DataTable() {parentTable, childTable, grandChildTable})

'setup the relations

Dim parentColumn As DataColumn = parentTable.Columns("parentID")

Dim childColumn As DataColumn = childTable.Columns("ParentID")

dSet.Relations.Add("ParentToChild", parentColumn, childColumn)

parentColumn = childTable.Columns("childID")

childColumn = grandChildTable.Columns("ChildID")

dSet.Relations.Add("ChildToGrandChild", parentColumn, childColumn)

'set the grids

Me.dataGrid1.DataSource = parentTable

Me.dataGrid2.DataSource = parentTable

Me.dataGrid2.DataMember = "ParentToChild"

Me.dataGrid3.DataSource = parentTable

Me.dataGrid3.DataMember = "ParentToChild.ChildToGrandChild"

Me.dataGrid1.AllowNavigation = False

Me.dataGrid2.AllowNavigation = False

Me.dataGrid3.AllowNavigation = False