How to fill Dataset with multiple tables?

Question

I'm trying to fill DataSet which contains 2 tables with one to many relationship. I'm using DataReader to achieve this :

    public DataSet SelectOne(int id)
    {
        DataSet result = new DataSet();
        using (DbCommand command = Connection.CreateCommand())
        {
            command.CommandText = "select * from table1";

            var param = ParametersBuilder.CreateByKey(command, "ID", id, null);
            command.Parameters.Add(param);

            Connection.Open();
            using (DbDataReader reader = command.ExecuteReader())
            {
                result.MainTable.Load(reader);
            }
            Connection.Close();
        }
        return result;
    }

But I've got only one table filled up. How do I achieve my goal - fill both tables?

I would like to use DataReader instead DataAdapter, if it possible.

Answer 1

public DataSet GetDataSet()
    {
        try
        {
            DataSet dsReturn = new DataSet();
            using (SqlConnection myConnection = new SqlConnection(Core.con))
            {
                string query = "select * from table1;  select* from table2";
                SqlCommand cmd = new SqlCommand(query, myConnection);
                myConnection.Open();
                SqlDataReader reader = cmd.ExecuteReader();
                dsReturn.Load(reader, LoadOption.PreserveChanges, new string[] { "tableOne", "tableTwo" });
                return dsReturn;
            }
        }
        catch (Exception)
        {
            throw;
        }
    }

Answer 2

protected void Page_Load(object sender, EventArgs e)
{
    SqlConnection con = new SqlConnection("data source=.;uid=sa;pwd=123;database=shop");
    //SqlCommand cmd = new SqlCommand("select * from tblemployees", con);
    //SqlCommand cmd1 = new SqlCommand("select * from tblproducts", con);
    //SqlDataAdapter da = new SqlDataAdapter();

    //DataSet ds = new DataSet();
    //ds.Tables.Add("emp");
    //ds.Tables.Add("products");
    //da.SelectCommand = cmd;
    //da.Fill(ds.Tables["emp"]);
    //da.SelectCommand = cmd1;

    //da.Fill(ds.Tables["products"]);
    SqlDataAdapter da = new SqlDataAdapter("select * from tblemployees", con);
    DataSet ds = new DataSet();
    da.Fill(ds, "em");
    da = new SqlDataAdapter("select * from tblproducts", con);
    da.Fill(ds, "prod");

    GridView1.DataSource = ds.Tables["em"];
    GridView1.DataBind();
    GridView2.DataSource = ds.Tables["prod"];
    GridView2.DataBind();
}

Answer 3

If you are issuing a single command with several select statements, you might use NextResult method to move to next resultset within the datareader: http://msdn.microsoft.com/en-us/library/system.data.idatareader.nextresult.aspx

I show how it could look bellow:

public DataSet SelectOne(int id)
{
    DataSet result = new DataSet();
    using (DbCommand command = Connection.CreateCommand())
    {
        command.CommandText = @"
select * from table1
select * from table2
        ";

        var param = ParametersBuilder.CreateByKey(command, "ID", id, null);
        command.Parameters.Add(param);

        Connection.Open();
        using (DbDataReader reader = command.ExecuteReader())
        {
            result.MainTable.Load(reader);
            reader.NextResult();
            result.SecondTable.Load(reader);
            // ...
        }
        Connection.Close();
    }
    return result;
}

Answer 4

Method Load of DataTable executes NextResult on the DataReader, so you shouldn't call NextResult explicetly when using Load, otherwise even tables might be lost.

Here is a generic solution to load multiple tables using a DataReader.

// your command initialization code here
// ...
DataSet ds = new DataSet();
DataTable t;
using (DbDataReader reader = command.ExecuteReader())
{
  while (!reader.IsClosed)
  {
    t = new DataTable();
    t.Load(rs);
    ds.Tables.Add(t);
  }
}

Answer 5

Here is very good answer of your question

see the example mentioned on above MSDN page :-

Answer 6

         string connetionString = null;
        SqlConnection connection ;
        SqlCommand command ;
        SqlDataAdapter adapter = new SqlDataAdapter();
        DataSet ds = new DataSet();
        int i = 0;
        string firstSql = null;
        string secondSql = null;

        connetionString = "Data Source=ServerName;Initial Catalog=DatabaseName;User ID=UserName;Password=Password";
        firstSql = "Your First SQL Statement Here";
        secondSql = "Your Second SQL Statement Here";
        connection = new SqlConnection(connetionString);

        try
        {
            connection.Open();

            command = new SqlCommand(firstSql, connection);
            adapter.SelectCommand = command;
            adapter.Fill(ds, "First Table");

            adapter.SelectCommand.CommandText = secondSql;
            adapter.Fill(ds, "Second Table");

            adapter.Dispose();
            command.Dispose();
            connection.Close();

            //retrieve first table data 
            for (i = 0; i <= ds.Tables[0].Rows.Count - 1; i++)
            {
                MessageBox.Show(ds.Tables[0].Rows[i].ItemArray[0] + " -- " + ds.Tables[0].Rows[i].ItemArray[1]);
            }
            //retrieve second table data 
            for (i = 0; i <= ds.Tables[1].Rows.Count - 1; i++)
            {
                MessageBox.Show(ds.Tables[1].Rows[i].ItemArray[0] + " -- " + ds.Tables[1].Rows[i].ItemArray[1]);

            }
        }
        catch (Exception ex)
        {
            MessageBox.Show("Can not open connection ! ");
        }