LINQ provides many query operators and custom operators with which we can query DataSets. When we say querying DataSets, we actually mean querying DataTables inside DataSets. We cannot directly query DataTables, as it returns DataRow objects. To be a part of LINQ queries, DataTables should be enumerable and the source for the LINQ query should be IEnumerable<T>. Querying can be done on enumeration of DataRow objects so that we will have all DataColumns available for the query expressions.
var categories = dataSetDeserts.Tables[0].AsEnumerable();
var items = dataSetDeserts.Tables[1].AsEnumerable();
var rowCategories = from p in categories
where p.Field<int>("CategoryID") == 1
select p;
foreach (var cat in rowCategories)
{
Console.WriteLine(cat[0] + " " + cat[1] + " " + cat[2]);
}
In the above example, dataSetDeserts has two tables which have details of different categories and items for each category. To query these details, we need to get the enumeration of...