Primary key modification and Update

I want to be able to modify and correct a primary key : [CODE] string CommandText = "UPDATE " + nameTable + " SET IDObj=@IDObj , NameParent=@NameParent,TypeObj=@TypeObj"+ " WHERE IDObj=@IDObjOrig"; //IDObj : Primary key //NameParent,TypeObj : the two other columns. //comdUPDATE : is my Command. //declaration of parameters comdUPDATE.Parameters.Add(new OleDbParameter("@IDObjOrig", OleDbType.VarChar, 50)); comdUPDATE.Parameters.Add(new OleDbParameter("@IDObj", OleDbType.VarChar,50)); comdUPDATE.Parameters.Add(new OleDbParameter("@NameParent", OleDbType.VarChar,50)); comdUPDATE.Parameters.Add(new OleDbParameter("@TypeObj",OleDbType.VarChar, 50)); comdUPDATE.Parameters["@IDObjOrig"].SourceVersion =DataRowVersion.Original; comdUPDATE.Parameters["@IDObj"].SourceVersion = DataRowVersion.Current; comdUPDATE.Parameters["@NameParent"].SourceVersion= DataRowVersion.Current; comdUPDATE.Parameters["@TypeObj"].SourceVersion= DataRowVersion.Current; comdUPDATE.Parameters["@IDObjOrig"].SourceColumn = "IDObj"; comdUPDATE.Parameters["@IDObj"].SourceColumn = "IDObj"; comdUPDATE.Parameters["@NameParent"].SourceColumn = "NameParent"; comdUPDATE.Parameters["@TypeObj"].SourceColumn = "TypeObj"; con.Open(); // con is my OLE connection DAdp.Update(DS.Tables[nameTable]); //DAdp is my DataAdapter //DS is My dataSet //nameTable : a string containing the name of my Table. con.Close(); [CODE] I have this exception : (Concurrency violation : the update command affected 0 of the expected 1 records). ???? But i did not introduced two similar "IDObj" how is it possible to modify a primary key witch is the reference of that modified row? HELP!!!!