private DataTable Join(DataTable first, DataTable second, DataColumn[] FJC, DataColumn[] SJC) { //将两个表根据某列关联生成一个表 DataTable table = new DataTable("Join"); try { DataSet ds = new DataSet(); DataTable[] dt ={ first.Copy(), second.Copy() }; //将两个表存入到Dataset中
ds.Tables.AddRange(dt);
DataColumn[] parentcolumns = new DataColumn[FJC.Length]; for (int i = 0; i < parentcolumns.Length; i++) { parentcolumns[i] = ds.Tables[0].Columns[FJC[i].ColumnName];
} DataColumn[] childcolumns = new DataColumn[SJC.Length];
for (int i = 0; i < childcolumns.Length; i++) { childcolumns[i] = ds.Tables[1].Columns[SJC[i].ColumnName]; } //设置两表中的关系．
DataRelation r = new DataRelation(string.Empty, parentcolumns, childcolumns, false); ds.Relations.Add(r); for (int i = 0; i < first.Columns.Count; i++) { table.Columns.Add(first.Columns[i].ColumnName, first.Columns[i].DataType); } for (int i = 0; i < second.Columns.Count; i++) { if (!table.Columns.Contains(second.Columns[i].ColumnName)) { table.Columns.Add(second.Columns[i].ColumnName, second.Columns[i].DataType); } else { table.Columns.Add(second.Columns[i].ColumnName + "_Second", second.Columns[i].DataType);
} } table.BeginLoadData(); foreach (DataRow firstrow in ds.Tables[0].Rows) { DataRow[] childrows = firstrow.GetChildRows(r); if (childrows != null && childrows.Length > 0) { object[] parentarray = firstrow.ItemArray; foreach (DataRow secondrow in childrows) { object[] secondarray = secondrow.ItemArray; object[] joinarray = new object[parentarray.Length + secondarray.Length]; Array.Copy(parentarray, 0, joinarray, 0, parentarray.Length); Array.Copy(secondarray, 0, joinarray, parentarray.Length, secondarray.Length); table.LoadDataRow(joinarray, true); } } else { object[] parentarray = firstrow.ItemArray; DataRow secondrow=second.NewRow(); object[] secondarray = secondrow.ItemArray; object[] joinarray = new object[parentarray.Length + secondarray.Length]; Array.Copy(parentarray, 0, joinarray, 0, parentarray.Length); Array.Copy(secondarray, 0, joinarray, parentarray.Length, secondarray.Length); table.LoadDataRow(joinarray, true); } } table.EndLoadData(); } catch (Exception e) { Response.Write(e.ToString()); } return table; } private DataTable Join(DataTable first, DataTable second, DataColumn FJC, DataColumn SJC) { return Join(first, second, new DataColumn[] { FJC }, new DataColumn[] { SJC }); } private DataTable Join(DataTable first, DataTable second, string FJC, string SJC) { return Join(first, second, new DataColumn[] { first.Columns[FJC] }, new DataColumn[] { first.Columns[SJC] }); }
