While updating to the Database, it seems there is an extran empty row and it contradicts the nonnull constraint. Thanks. Here is the code:
Dim Obj_NewRowAs DataRow
You should not add a DataRow but an obj_DSFournisseur.Tables("fournisseurs").NewRow
https://docs.microsoft.com/en-us/dotnet/api/system.data.datatable.newrow?view=netcore-3.1
Success
Cor