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c#asp.net.netlinqdatatable

How to convert DataTable to class Object?


I have already developed an application which returns DataTable everywhere.

Now my client wants to convert (use some part using service stack), so I need to return DTO (objects) in my application.

I don't want to change my existing stored procedures or even not want to use LINQ as much as possible (I am not too much aware with LINQ).

For small functionality, I can use Linq no issue.

My question is: how can I change my DataTable to objects of that class?

The sample code is below:

string s = DateTime.Now.ToString();
DataTable dt = new DataTable();

dt.Columns.Add("id");
dt.Columns.Add("name");

for (int i = 0; i < 5000000; i++)
{
    DataRow dr = dt.NewRow();
    dr["id"] = i.ToString();
    dr["name"] = "name" + i.ToString();
    dt.Rows.Add(dr);

    dt.AcceptChanges();
}

List<Class1> clslist = new List<Class1>();

for (int i = 0; i < dt.Rows.Count; i++)
{
    Class1 cls = new Class1();
    cls.id = dt.Rows[i]["id"].ToString();
    cls.name = dt.Rows[i]["name"].ToString();
    clslist.Add(cls);
}

Response.Write(s);
Response.Write("<br>");
Response.Write(DateTime.Now.ToString());

I know, the above method is time-consuming, and I am trying to find an alternate solution.

Is there any alternative way (I guess, LINQ to DataTable) by which it directly converts the rows of tables to List<Class1>?

So that I can return objects in my service stack and go ahead.


Solution

  • Initialize DataTable:

    DataTable dt = new DataTable(); 
    dt.Columns.Add("id", typeof(String)); 
    dt.Columns.Add("name", typeof(String)); 
    for (int i = 0; i < 5; i++)
    {
        string index = i.ToString();
        dt.Rows.Add(new object[] { index, "name" + index });
    }
    

    Query itself:

    IList<Class1> items = dt.AsEnumerable().Select(row => 
        new Class1
            {
                id = row.Field<string>("id"),
                name = row.Field<string>("name")
            }).ToList();