Steps to fill data in to a Dataset object - ablealias/asp.net GitHub Wiki

• First define a String variable to store database Connection String and get the connection string which configured on WebConfig file.

private string connectionString;
this.connectionString = System.Configuration.ConfigurationManager.ConnectionStrings["sqlDatabase"].ConnectionString;

• Create a SqlConnection object which is used to connect to the Database, provide the connection string as parameter.

SqlConnection connection = new SqlConnection(connetionString); 
connection.Open();

• Create an SqlDataAdapter object to execute your SQL statements either SELECT query or a Stored Procedure

SqlDataAdapter adapter = new SqlDataAdapter("Your SQL Statement Here", connection);

• Create a DataSet object to fill the SQL Data which is stored on the SqlDataAdapter

DataSet ds = new DataSet(); 
adapter.Fill(ds); 
connection.Close(); 

• if you want to go through the dataset data, just put foreach loop through the dataset table rows,

foreach (DataRow dr in ds.Tables[0].Rows)
{
    
}

Example with Stored Procedure

SqlDataAdapter adapter = new SqlDataAdapter("Procedure_Name",connection);
            adapter.SelectCommand.CommandType = CommandType.StoredProcedure;
            adapter.SelectCommand.Parameters.Add("@Contactid", SqlDbType.Int).Value = 123;
            DataSet ds = new DataSet();
            adapter.Fill(ds);