Fastest way to convert datatable to generic list

Question

I have a data tier select method that returns a datatable. It\'s called from a business tier method that should then return a strongly typed generic List.

What I wa

Answer 1

Do you know the structure of the DataTable and the typed object ahead of time? You could use a delegate to do the mapping. If you don't (i.e. all you know is a Type and properties) there are ways of accelerating dynamic member access (such as HyperDescriptor).

Either way, consider an iterator block; that way you don't have to buffer the objects an entire second time; of course, if you are only dealing with smallish rowcounts this isn't an issue.

Can you clarify any of those points? I can add a lot more detail...

At the simplest, what is wrong with:

DataTable table = new DataTable {
    Columns = {
        {"Foo", typeof(int)},
        {"Bar", typeof(string)}
     }
};
for (int i = 0; i < 5000; i++) {
    table.Rows.Add(i, "Row " + i);
}

List data = new List(table.Rows.Count);
foreach (DataRow row in table.Rows) {
    data.Add(new MyType((int)row[0], (string)row[1]));
}

(the problems in the above might steer the right approach...)