dataset to List<T>using linq - linq

Question

I have a DataSet and I want to convert the DataSet into List<T>
T - type object
How convert my DataSet? It has 10 columns, with all 10 properties my object has and it's returning over 15000 rows. I want to return that dataset into List<obj> and loop it how do I do that?

Answer 1

This is pretty much the same as the other answers, but introduces strongly-typed columns.
var myData = ds.Tables[0].AsEnumerable().Select(r => new {
column1 = r.Field<string>("column1"),
column2 = r.Field<int>("column2"),
column3 = r.Field<decimal?>("column3")
});
var list = myData.ToList(); // For if you really need a List and not IEnumerable

Answer 2

I think this should do it.
var output = yourDataSet.Tables[0].Rows.Cast<DataRow>().Select(r => new
{
Column1 = r["Column1"].ToString(),
Column2 = r["Column2"].ToString(),
Column3 = r["Column3"].ToString(),
Column4 = r["Column4"].ToString(),
Column5 = r["Column5"].ToString(),
Column6 = r["Column6"].ToString(),
Column7 = r["Column7"].ToString(),
Column8 = r["Column8"].ToString(),
Column9 = r["Column9"].ToString(),
Column10 = r["Column10"].ToString()
}).ToList();

Answer 3

First of all, you're on the right track, but you should be thinking in terms of IEnumerable<T> rather than List<T>. And here is how you would do that:
var myData = ds.Tables[0].AsEnumerable()
.Select(r => new {column1 = r[0].ToString(),
column2 = r[1].ToString()
/*etc*/
});
Never convert an IEnumerable to a List before you absolutely need to.

Answer 4

I know #bharat asked for a solution using LINQ, but mainly for myself I wanted to compare #Kelsey's solution to the old fashioned way of doing this:
List<Obj> list = new List<Obj>();
foreach (DataRow r in yourDataSet.Tables[0].Rows)
{
Obj obj = new Obj();
obj.Column1 = r["Column1"];
obj.Column2 = r["Column2"];
obj.Column3 = r["Column3"];
obj.Column4 = r["Column4"];
obj.Column5 = r["Column5"];
obj.Column6 = r["Column6"];
obj.Column7 = r["Column7"];
obj.Column8 = r["Column8"];
obj.Column9 = r["Column9"];
obj.Column10 = r["Column10"];
list.Add(obj);
}
Or via constructor:
List<Obj> list = new List<Obj>();
foreach (DataRow r in yourDataSet.Tables[0].Rows)
{
Obj obj = new Obj(r["Column1"], r["Column2"], r["Column3"], r["Column4"], r["Column5"],r["Column6"], r["Column7"], r["Column8"], r["Column9"],r["Column10"]);
list.Add(obj);
}
I intentionally left off .ToString() because I think using it depends on the situation.

Answer 5

Thanks for all the above posts...
I have done it with using Linq Query, for detail visit the link
http://codenicely.blogspot.com/2012/02/converting-your-datatable-into-list.html

Answer 6

A very simple approach that I use is following:
List<Obj> objList = new List<Obj>();
foreach (DataRow _dataRow in dataSet.Tables[0].Rows)
{
Obj obj = new Obj();
obj.Col1 = Convert.ToInt32(_dataRow["Col1"]);
obj.Col2 = Convert.ToInt32(_dataRow["Col2"]);
obj.Col3 = Convert.ToString(_dataRow["Col3"]);
objList.Add(obj);
}