public static DataTable DatableInnerJoin(DataTable FirstTB, DataTable SecondTB, DataColumn[] FJC, DataColumn[] SJC)

    {

        if (FirstTB == null || SecondTB == null)

            return null;

        if (FJC == null || FJC.Length <= )

            return null;

        if (SJC == null || SJC.Length <= )

            return null;

        DataTable table = new DataTable("Join");

        using (DataSet ds = new DataSet())

        {

            ds.Tables.AddRange(new DataTable[] { FirstTB.Copy(), SecondTB.Copy() });

            DataColumn[] parentcolumns = new DataColumn[FJC.Length];

            for (int i = ; i < parentcolumns.Length; i++)

            {

                parentcolumns[i] = ds.Tables[].Columns[FJC[i].ColumnName];

            }

            DataColumn[] childcolumns = new DataColumn[SJC.Length];

            for (int i = ; i < childcolumns.Length; i++)

            {

                childcolumns[i] = ds.Tables[].Columns[SJC[i].ColumnName];

            }

            DataRelation relation = new DataRelation("Relation_Table", parentcolumns, childcolumns, false);

            ds.Relations.Add(relation);

            for (int i = ; i < FirstTB.Columns.Count; i++)

            {

                table.Columns.Add(FirstTB.Columns[i].ColumnName, FirstTB.Columns[i].DataType);

            }

            for (int i = ; i < SecondTB.Columns.Count; i++)

            {

                if (!table.Columns.Contains(SecondTB.Columns[i].ColumnName))

                    table.Columns.Add(SecondTB.Columns[i].ColumnName, SecondTB.Columns[i].DataType);

                else

                    table.Columns.Add(SecondTB.Columns[i].ColumnName + "_Second", SecondTB.Columns[i].DataType);

            }

            table.BeginLoadData();

            foreach (DataRow firstrow in ds.Tables[].Rows)

            {

                DataRow[] childrows = firstrow.GetChildRows(relation);

                if (childrows != null && childrows.Length > )

                {

                    object[] parentarray = firstrow.ItemArray;

                    foreach (DataRow secondrow in childrows)

                    {

                        object[] secondarray = secondrow.ItemArray;

                        object[] joinarray = new object[parentarray.Length + secondarray.Length];

                        Array.Copy(parentarray, , joinarray, , parentarray.Length);

                        Array.Copy(secondarray, , joinarray, parentarray.Length, secondarray.Length);

                        table.LoadDataRow(joinarray, true);

                    }

                }

            }

            table.EndLoadData();

        }

        return table;

    }