RowState case (Solved)

May be someone knows, what's happend: I use DataTable dtPotr with Serial column on MSSQL (string - because of I use it with many databases): dtPotr.Columns.Add("nrrek",typeof(String)); Next, I add some rows to it (serial is temporary 0): dPotr.Rows.Add(new object[]{ "0",.... }); Next, I set serial values (properValue is int) in loop: foreach(DataRow dr in dtPotr.Rows) dr["nrrek"]=properValue; Some of records (about half) have RowState changed from Inserted to Modified after it ... SORRY. It's my error. I found AcceptChanges() before loop in some cases.