Question

我如何result到EnumerableRowCollection<DataRow>或DataView？

DataTable table1 = /*something*/ ;
DataTable table2 = /*something*/ ;
DataTable table3 = /*something*/ ;

IEnumerable<DataRow> result = (from t1 in table1.AsEnumerable() join 
                                    t2 in table2.AsEnumerable() on t1.Field<int>("id") equals t2.Field<int>("t1id") join
                                    t3 in table3.AsEnumerable() on t2.Field<int>("t3id") equals t3.Field<int>("id")
                               where 666.Equals(t3.Field<int>("id"))
                              select t1);

感谢

Answer 1

来自.NET文档here

DataTable orders = dataSet.Tables["SalesOrderHeader"];

EnumerableRowCollection<DataRow> query =
    from order in orders.AsEnumerable()
    where order.Field<bool>("OnlineOrderFlag") == true
    orderby order.Field<decimal>("TotalDue")
    select order;

DataView view = query.AsDataView();

bindingSource1.DataSource = view;

Answer 2

正如Jon Skeet所说：

DataTable table1 = /*something*/ ;
DataTable table2 = /*something*/ ;
DataTable table3 = /*something*/ ;

DataTable result = (from t1 in table1.AsEnumerable() join 
                                    t2 in table2.AsEnumerable() on t1.Field<int>("id") equals t2.Field<int>("t1id") join
                                    t3 in table3.AsEnumerable() on t2.Field<int>("t3id") equals t3.Field<int>("id")
                               where 666.Equals(t3.Field<int>("id"))
                              select t1).CopyToDataTable<DataRow>();

如果你想要一个DataView：

DataTable table1 = /*something*/ ;
DataTable table2 = /*something*/ ;
DataTable table3 = /*something*/ ;

DataView result = (from t1 in table1.AsEnumerable() join 
                                    t2 in table2.AsEnumerable() on t1.Field<int>("id") equals t2.Field<int>("t1id") join
                                    t3 in table3.AsEnumerable() on t2.Field<int>("t3id") equals t3.Field<int>("id")
                               where 666.Equals(t3.Field<int>("id"))
                              select t1).CopyToDataTable<DataRow>().AsDataView();

将IEnumerable <datarow>转换为EnumerableRowCollection <datarow>或DataView

2 个答案: