Question

I have two datatable , first contain

 DataTable  dtMaterialStatement = new DataTable();
                    dtMaterialStatement.Columns.Add(new DataColumn("MaterialNo", Type.GetType("System.String")));
                    dtMaterialStatement.Columns.Add(new DataColumn("MaterialId", Type.GetType("System.String")));
                    dtMaterialStatement.Columns.Add(new DataColumn("Qty", Type.GetType("System.Double")));
                    dtMaterialStatement.Columns.Add(new DataColumn("Unit", Type.GetType("System.String")));
                    dtMaterialStatement.Columns.Add(new DataColumn("SinglePrice", Type.GetType("System.Decimal")));
                    dtMaterialStatement.Columns.Add(new DataColumn("PricePerPack", Type.GetType("System.Decimal")));
                    dtMaterialStatement.Columns.Add(new DataColumn("UnitsPerPack", Type.GetType("System.String")));
                    dtMaterialStatement.Columns.Add(new DataColumn("Discount1", Type.GetType("System.Decimal")));
                    dtMaterialStatement.Columns.Add(new DataColumn("Discount2", Type.GetType("System.Decimal")));
                    dtMaterialStatement.Columns.Add(new DataColumn("Discount3", Type.GetType("System.Decimal")));
                    dtMaterialStatement.Columns.Add(new DataColumn("SalesPrice", Type.GetType("System.Decimal")));
                    dtMaterialStatement.Columns.Add(new DataColumn("Exist", Type.GetType("System.Boolean")));

Second contain:-

"MaterialNo"
  Qty
 "Unit"
 "SinglePrice"
 "PricePerPack"
 "UnitsPerPack"
 "Discount1"
  "Discount2"
 "Discount3"
 "SalesPrice"

and come extra column ,

I want to merge both table , if MaterialNo of first tabel is same with second table MaterialNo column , then take common column field value from second table to update value of first value corresponding columns.
else insert a new row in first table with using column of table first but taking value from second table.

Answer 1

1. Use this one to extract a new datatables that only contains differences http://kodesharp.blogspot.com/2007/12/c-compare-2-datatables-and-return-3rd.html

2. Then use foreach or for loop to manually extract the differenes into array. Then have it repumped into the datatable

Something like this:

DataTable dt = CompareDataTables(dt1, dt2);

ArrayList Errors = new ArrayList();

for (int i = 0; i < d.Columns.Count; i++)
{
    for (int j = 0; j < d.Rows.Count; j++)
    {
        if (dt1.Rows[j][i].ToString() != dt2.Rows[j][i].ToString())
            {
                Errors.Add(j);
                Errors.Add(i);
                Errors.Add(dt1.Rows[j][i].ToString());
                Errors.Add(dt2.Rows[j][i].ToString());
            }
     }
 }

DataTable dtFinal = dt;

for (int i = 0; i < Errors.Count; i += 4)
{
    int ak = Int32.Parse(Errors[i].ToString());
    int bk = Int32.Parse(Errors[i + 1].ToString());
    dtFinal.Rows[ak][bk] = Errors[i + 2].ToString() + "/" + Errors[i + 3].ToString();
}