LINQ to DataSet需要使用System.Core.dll、System.Data.dll和System.Data.DataSetExtensions.dll，在项目中添加引用System.Data和System.Data.DataSetExtensions。

1. DataTable读取列表

DataSet ds = new DataSet();// 省略ds的Fill代码DataTable products = ds.Tables["Product"];IEnumerable
     
       rows = from p in products.AsEnumerable()                            select p;foreach (DataRow row in rows){    Console.WriteLine(row.Field
      
       ("ProductName"));}
      
     

DataSet ds = new DataSet();// 省略ds的Fill代码DataTable products = ds.Tables["Product"];var rows = products.AsEnumerable()    .Select(p => new    {        ProductID = p.Field
     
      ("ProductID"),        ProductName = p.Field
      
       ("ProductName"),        UnitPrice = p.Field
       
        ("UnitPrice")    });foreach (var row in rows){    Console.WriteLine(row.ProductName);}
       
      
     

var products = ds.Tables["Product"].AsEnumerable();var query = from p in products            select p.Field
     
      ("ProductName");
     

2. DataTable查询

var rows = products.AsEnumerable()    .Where(p => p.Field
     
      ("UnitPrice") > 10m)    .Select(p => new    {        ProductID = p.Field
      
       ("ProductID"),        ProductName = p.Field
       
        ("ProductName"),        UnitPrice = p.Field
        
         ("UnitPrice")    });
        
       
      
     

3. DataTable数据排序

var rows = products.AsEnumerable()    .Where(p => p.Field
     
      ("UnitPrice") > 10m)    .OrderBy(p => p.Field
      
       ("SortOrder"))    .Select(p => new    {        ProductID = p.Field
       
        ("ProductID"),        ProductName = p.Field
        
         ("ProductName"),        UnitPrice = p.Field
         
          ("UnitPrice")    });
         
        
       
      
     

var expr = from p in products.AsEnumerable()            orderby p.Field
     
      ("SortOrder")            select p;IEnumerable
      
        rows = expr.ToArray();foreach (var row in rows){    Console.WriteLine(row.Field
       
        ("ProductName"));}
       
      
     

var expr = from p in ds.Tables["Product"].AsEnumerable()           orderby p.Field
     
      ("SortOrder"), p.Field
      
       ("ProductName") descending           select p;
      
     

4. 多个DataTable查询

var query = from p in ds.Tables["Product"].AsEnumerable()            from c in ds.Tables["Category"].AsEnumerable()            where p.Field
     
      ("CategoryID") == c.Field
      
       ("CategoryID")                && p.Field
       
        ("UnitPrice") > 10m            select new            {                ProductID = p.Field
        
         ("ProductID"),                ProductName = p.Field
         
          ("ProductName"),                CategoryName = c.Field
          
           ("CategoryName") };
          
         
        
       
      
     

5. DataTable分组

var query = from p in ds.Tables["Product"].AsEnumerable()            group p by p.Field
     
      ("CategoryID") into g            select new            {                CategoryID = g.Key,                Products = g            };foreach (var item in query){    Console.WriteLine(item.CategoryID);    foreach (var p in item.Products)    {        Console.WriteLine(p.Field
      
       ("ProductName"));    }}
      
     

　　查询Product中每个CategoryID的数目：

var expr = from p in ds.Tables["Product"].AsEnumerable()           group p by p.Field
     
      ("CategoryID") into g           select new           {               CategoryID = g.Key,               ProductsCount = g.Count()           };