ForeignKeyConstraint problem with insert

[Mika M]

Hello!

I'm using a dataset to manage SQL db. I created two tables into DataSet
(Headers and Items), I fill them with data, and I make relation between them
like (Headers-table column ID (AutoNumber) (int) to Items-table column
HeaderID (int)) ...

ds.Relations.Add(New DataRelation("Items",
ds.Tables("Headers").Columns("ID"), ds.Tables("Items").Columns("HeaderID")))

.... then I have bound Headers DataTable into TextBoxes and Items DataTable
into Grid.

So far application I working well, but when I add a new record (this only
happends when trying to add new records) after clicking 'New'-button ...

..EndCurrentEdit()
..AddNew()

.... I fill TextBoxes bound to parent DataTable, and then try to insert a new
row to the grid, I'll get the following error...

"ForeignKeyConstraint Items requires the child key values (2) to exist in
the parent table."

I know I don't have a datarow in parent DataTable with a primary key value
of 2 yet, but I think it must be possible to fill both TextBoxes and Grid
before saving (insert) these into database.

I hope to have explained well the problem.

 

[Frans Bouma [C# MVP]]

Hello!

I'm using a dataset to manage SQL db. I created two tables into DataSet
(Headers and Items), I fill them with data, and I make relation between them
like (Headers-table column ID (AutoNumber) (int) to Items-table column
HeaderID (int)) ...

ds.Relations.Add(New DataRelation("Items",
ds.Tables("Headers").Columns("ID"), ds.Tables("Items").Columns("HeaderID")))

... then I have bound Headers DataTable into TextBoxes and Items DataTable
into Grid.

So far application I working well, but when I add a new record (this only
happends when trying to add new records) after clicking 'New'-button ...

.EndCurrentEdit()
.AddNew()

... I fill TextBoxes bound to parent DataTable, and then try to insert a new
row to the grid, I'll get the following error...

"ForeignKeyConstraint Items requires the child key values (2) to exist in
the parent table."

I know I don't have a datarow in parent DataTable with a primary key value
of 2 yet, but I think it must be possible to fill both TextBoxes and Grid
before saving (insert) these into database.

I hope to have explained well the problem.

The relation you defined is in fact an FK constraint. So the dataset's logic
will verify if the values specified in child rows are present in the parent
rows, thus will verify the relation. If you don't want that, remove the
relation or supply the parent data first.

FB

 

[Andy Gaskell]

You might also be interested in the EnforceConstraints property.
http://msdn.microsoft.com/library/d...emdatadatasetclassenforceconstraintstopic.asp