Question

How do you take a couple of data tables and put them in a dataset and relate (that doesn’t even sound like correct English) them?

I know how to create datatables.

Answer 1

Here is an example from one of my classes

// create the relationship between Booking and Booking_MNI
DataRelation relBookingMNI;                         
relBookingMNI = new DataRelation("BookingToBookingMNI",dsBooking.Tables["Booking"].Columns["Record_Id"],dsBooking.Tables["Booking_MNI"].Columns["booking_record_id"]);
dsBooking.Relations.Add(relBookingMNI);

dsBooking is my main dataset that contains 2 tables Booking and Booking_MNI
Where the Record_Id is the primary key and booking_record_id is the foreign key

I changed the code below to match my first example. But I think this is what you are looking for. In our production code this will produce the plus “+” symbol to the left of the row which would allow you to drill into the related table. Again I took production code and made it look like the first example so I don’t know if it will compile but it should get you going in the right direction.

DataTable dtBooking = ds.Tables[0];
DataTable dtBooking_MNI = ds.Tables[1];

dtBooking.PrimaryKey = new DataColumn[] {dtBooking.Columns["Record_Id"]};
dtBooking_MNI.PrimaryKey = new DataColumn[] {dtBooking_MNI.Columns["booking_Record_Id"]};

/* Setup DataRelation between the DataTables */
DataColumn[] dcBookingColsArray = new DataColumn[1] {dtBooking.Columns["Record_Id"]};
DataColumn[] dcBookingMNIColsArray = new DataColumn[1] {dtBooking_MNI.Columns["booking_record_Id"]};

DataRelation relBooking_To_MNI = new DataRelation("Booking_To_MNI",dcBookingColsArray,dcBookingMNIColsArray);
ds.Relations.Add(relBooking_To_MNI_Units);

// grid where you want to display the relationship
grdBooking.DataSource = ds;