please give me Data Mapping example from sql database in C#

Entity Framework is a data mapper example. Using a framework like this saves you a lot of time and many headaches.

Just to show you the kind of fun you're in for without a mapping framework, this is a simple read-only data mapping example (without using entity framework):

public class MyTableEntryObject
{
    public int Id { get; set; }
    public string Name { get; set; }
...
}

var thisIsMapped = new List<MyTableEntryObject>();
using(var conn = new SqlConnection("MyServerName"))
{
    using(var command = new SqlCommand("SELECT * FROM tbl.myTable",conn))
    {
        using(var reader = SqlCommand.ExecuteReader())
        {
            if(read.HasRows)
            {
                while(reader.Read())
                {
                    var mappedObject = new MyTableEntryObject();
                    mappedObject.Id= reader.GetInt32(0);
                    mappedObject.Name = reader.GetString(1);
                    // other fields
                    ...
                }
            }
        }
    }
}    
</pre>