将Linq中的列连接到SQL选择

Question

我想根据一列的条件连接两个列值。

我正在尝试这样

select
{
     Orders=r.ordercode.length==0?r.order1:r.ordercode.length==3?r.order1+r.order2+r.order3
}

Answer 1

Orders = r.ordercode.length == 0？r.order1：r.ordercode.length == 3？string.concat（r.order1，“，”，r.order2，“，”，r.order3 ）： “”

Answer 2

试试这个

select
{
     Orders = (
                (r.ordercode.length == 0 || r.ordercode.length == 3) ? 
                    String.Format("{0}, {1}, {2}", r.order1, r.order2, r.order3) : 
                    String.Empty
              )
}