"ConstraintException" error while filling dataset?

Hi,

I always get a "ConstraintException" error when trying, at beginning of application, to run following statement (within "Form1_Load" routine called by "this->Load" EventHandler):

"this->TauxTaxeTableAdapter->FillByPays(this->TauxTaxeDataSet->TauxTaxe,Cur_GrdView_SlPays);"

Also curiously if, while application is still running, I invoke again that same statement by means of a pushbutton clickevent, everything is running smootly without error... Looks to me that it is bugging only when running the first time...

Within Dataset, I tried to see what constraint could give me such trouble. Here is the only constraint I could find:

"this->Constraints->Add((gcnew System::Data::UniqueConstraint(L"Constraint1", gcnew cli::array< System::Data::DataColumn^ >(2) {this->columnPays, this->columnProvince_Etat}, true)));"

I then tried to find within "TauxTaxe" table if there could be any trace of records where "Pays" and "Province_Etat" columns would show any null value as well as any duplicate key values but there wasn't any...

Any place I should start to look for? BTW, I'm using a SQL Express database.

Thanks for your help,

Stphane

Here is the detailed error log I got:

System.Data.ConstraintException: Impossible d'activer les contraintes. Une ou plusieurs lignes contiennent des valeurs qui violent les contraintes de type non null, unique ou de cl externe.
à System.Data.DataSet.FailedEnableConstraints()
à System.Data.DataSet.EnableConstraints()
à System.Data.DataSet.set_EnforceConstraints(Boolean value)
à System.Data.Common.DataAdapter.Fill(DataTable[] dataTables, IDataReader dataReader, Int32 startRecord, Int32 maxRecords)
à System.Data.Common.DbDataAdapter.FillInternal(DataSet dataset, DataTable[] datatables, Int32 startRecord, Int32 maxRecords, String srcTable, IDbCommand command, CommandBehavior behavior)
à System.Data.Common.DbDataAdapter.Fill(DataTable[] dataTables, Int32 startRecord, Int32 maxRecords, IDbCommand command, CommandBehavior behavior)
à System.Data.Common.DbDataAdapter.Fill(DataTable dataTable)
à Test_ADO.DS_TauxTaxeTableAdapters.TA_TauxTaxe.FillByPays(TauxTaxeDataTable dataTable, String Pays) dans d:\projet\visual c++ 2005\projets c++cli\test_ado\ds_tauxtaxe.h:ligne 1247
à Test_ADO.Form1.Sel_Pays_NewSel(Object sender, EventArgs e) dans d:\projet\visual c++ 2005\projets c++cli\test_ado\form1.h:ligne 1887
à System.Windows.Forms.RadioButton.OnCheckedChanged(EventArgs e)
à System.Windows.Forms.RadioButton.set_Checked(Boolean value)
à Test_ADO.Form1.Init_Form1() dans d:\projet\visual c++ 2005\projets c++cli\test_ado\form1.h:ligne 1480
à Test_ADO.Form1.Form1_Load(Object sender, EventArgs e) dans d:\projet\visual c++ 2005\projets c++cli\test_ado\form1.h:ligne 1446
à System.Windows.Forms.Form.OnLoad(EventArgs e)
à System.Windows.Forms.Form.OnCreateControl()
à System.Windows.Forms.Control.CreateControl(Boolean fIgnoreVisible)
à System.Windows.Forms.Control.CreateControl()
à System.Windows.Forms.Control.WmShowWindow(Message& m)
à System.Windows.Forms.Control.WndProc(Message& m)
à System.Windows.Forms.ScrollableControl.WndProc(Message& m)
à System.Windows.Forms.ContainerControl.WndProc(Message& m)
à System.Windows.Forms.Form.WmShowWindow(Message& m)
à System.Windows.Forms.Form.WndProc(Message& m)
à System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m)
à System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)
à System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)

Finally, SQL Statement for "TA_TauxTaxe::FillByPays" is the following:

SELECT Pays, Province_Etat, Taxe1_Appl, Taxe1_Dsc, Taxe1_Taux, Taxe2_Appl, Taxe2_Dsc, Taxe2_Taux
FROM TauxTaxe
WHERE (Pays = @.Pays)

In debug mode, I double-checked and could verify that @.Pays didn't have any null value but a valid string value at time "Fill" routine was invoked. Any clue?

Hi again,

Seems that I found myself the solution to my problem. Let me explain. I first deleted all records in SQL table the error message was targetting. I then added a few records, in fact all states of U.S. and provinces of Canada and double-checked step by step how the SQL database was reacting. While entering a quite long province name, I finally discovered the problem which seemed to be a field length problem. I checked in Server Explorer the length of corresponding field but everything was OK. I then suspected that maybe the Dataset used by application didn't get updated. Bingo! It was effectively the case. In DataSet, the corresponding field still had the original length value and didn't get updated when I modified field length within Server Explorer. I think I learned a new thing... Any tricks you guys would maybe share on this issue? Must I absolutely make this "double" step each time I modify any table layout within Server Explorer?

Stphane