How to insert into parent and child tables with relation

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I have 2 tables, Parent and Child.
There is a one-to-one DataRelationship between the tables.

I have set up a windows form with detail text boxes for all the fields of both tables. (since the relationship is one-to-one I didn't need a gridvie for the child records).

I have everything set up so that I can move through the ParentBindingSource and all the child fields adjust appropriately to display according to context.

The problem is that I want to Add new Parent AND Child records at the same time.

I have an ADDButton which calls "ParentBindingSource.AddNew()"
When I do this, my autoincrement ParentID field shows a value of -1;
The Child fields go blank;

I have a SAVEButton which calls "ParentTableAdapter.Update()"
This works to save the new Parent record.

PROBLEM: I cannot figure out the sequence of events to add a NEW child record at the same time!

What am I missing???

Thanks

Posted 12-Sep-11 21:24pm

Terry Pascal

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[no name] 13-Sep-11 3:31am

post what have you done before

2 solutions

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Terry Pascal · Answer 1 · 2011-09-13T15:44:00

Below is my code.
My test is very basic.
The user presses the "New" button and I try to create both a Parent and Child record.
I enter the data on the Form.
I click the "Save" button and try to save the data.

I recognize the need to get the new KeyID to save to the child, but the problem is that when I try to get the child row back that I added, nothing is there...

I believe I must be missing something when I click the New button... When I add the record to the ChildBindingSource perhaps it doesn't get linked to the parent record? Is there a programmatic way to "AddChildRecord"?

private void New_Click(object sender, EventArgs e)
{
ParentBindingSource.AddNew();
ChildBindingSource.AddNew();
}

private void SaveBTN_click( object sender, EventArgs e)
{
ParentBindingSource.EndEdit();
ChildBindingSource.EndEdit();
foreach (DataSet1.ParentRow cr in dataSet11.ParentTable)
{
if (cr.RowState == DataRowState.Added)
{

/*
The call to GetChildRows doesn't return any values!!! ???
*/
DataRow[] childRows = cr.GetChildRows(dataSet11.Relations["Parent_ChildRelation"]);
ParentTableAdapter.Update(cr);
ChildTableRow childRow = (ChildTableRow)childRows[0];
childRow.KeyID = cr.KeyID;
ChildTableAdapter.Update(childRow);

}
}

Herman<T>.Instance · Answer 2 · 2011-09-12T21:35:00

Solution 1

When you INSERT data into a datatable the PrimaryKey Value is not set. This value is needed in the child table as a reference to the parent table. So first add data to parent table. Find the newest PK value and use that value in your insert in your child table.

Posted 12-Sep-11 21:35pm

Herman<T>.Instance