Hi All,
I'm trying to figure out what is wrong with my code for days now.... I just started to learn about the databases, so please excuse me if I make stupid mistakes.
So here is the problem:
I use MS Access database to store data in several tables. Occasionally, I want to update records in tblRequest table in my DB:
public void ModifyRecordInDataTable(ref DataTable dtable, ArrayList col, ArrayList val, string key)
{
//Set UPDATE Command of the DataAdapter
if (dtable.TableName == "NodeDataTable")
{ }
if (dtable.TableName == "RequestDataTable")
{
UPDATE_RequestQueryDataTable("tblRequests");
}
if (dtable.TableName == "QueryDataTable")
{
}
DataRow editDataRow = dtable.Rows.Find(key);
//Change DataColumn values of the DataRow
editDataRow.BeginEdit();
for (int i = 0; i < col.Count; i++)
{
editDataRow[col[i].ToString()] = val[i].ToString();
}
editDataRow.EndEdit();
}
int numrows = myDBAdapter.Update(dtable);
dtable.AcceptChanges();
}
private void UPDATE_RequestQueryDataTable(string dtable)
{
OleDbCommand myUpdateCommand = myDBConnection.CreateCommand();
myUpdateCommand.CommandText = "UPDATE " + dtable + " SET TimeReq = @TimeReq, AThold = @AThold, DThold = @DThold," +
" Period = @Period, F1 = @F1, B1 = @B1 " +
" WHERE NodeID = @NodeID";
myUpdateCommand.Parameters.Add("NodeID", OleDbType.Char, 2, "NodeID").SourceVersion = DataRowVersion.Original;
myUpdateCommand.Parameters.Add("TimeReq", OleDbType.Char, 21, "TimeReq");
myUpdateCommand.Parameters.Add("AThold", OleDbType.Char, 2, "AThold");
myUpdateCommand.Parameters.Add("DThold", OleDbType.Char, 3, "DThold");
myUpdateCommand.Parameters.Add("Period", OleDbType.Char, 3, "Period");
myUpdateCommand.Parameters.Add("F1", OleDbType.Char, 5, "F1");
myUpdateCommand.Parameters.Add("B1", OleDbType.Char, 5, "B1");
myDBAdapter.UpdateCommand = myUpdateCommand;
}Before that, I use OleDBAdapter.Fill() to fill the DataRequestTable with data from tblRequest (stored in myDB)
However, on line:
int numrows = myDBAdapter.Update(dtable);
I'm getting error "Concurrency violation: the UpdateCommand affected 0 of the expected 1 records."
I already searched web about this error and I still cannot figure it out why it is happening. I am the only who is updating the database, there are no other users. The DataRequestTable has primary key defined (NodeID). I have UPDATE statement defined for myDBAdapter. I have no clue why is this happening...
Please help!
