vb.net - 如何联合两个 LINQ 查询（WhereSelectEnumerableIterator）错误

Question

我正在尝试构建一个 Kendo 条形图。我需要打开的票数和关闭的票数。我需要按月分组的结果。这是我的 LINQ

Dim openTickets = (From t In queue _
                   Where _
                   (t.CreateDate.Year = Convert.ToDateTime(DateTime.Now).Year)
                   Group t By _
                   ID = CType(t.CreateDate.Month, Integer), _
                   Month = CType(t.CreateDate.ToString("MMMM"), String) _
                   Into g = Group _
                   Select New With _
                   {.Month = Month.Substring(0, 3), .Opened = g.Where(Function(t) t.CreateDate.Month = ID).Count(Function(t) t.Id)})

Dim closedTickets = (From t In queue _
                   Where _
                   (t.CloseDate.Year = Convert.ToDateTime(DateTime.Now).Year)
                   Group t By _
                   ID = CType(t.CloseDate.Month, Integer), _
                   Month = CType(t.CloseDate.ToString("MMMM"), String) _
                   Into g = Group _
                   Select New With _
                   {.Month = Month.Substring(0, 3), .Closed = g.Where(Function(t) t.CloseDate.Month = ID).Count(Function(t) t.Id)})

Dim ticketCount = openTickets.Union(closedTickets)

当我尝试这个时，我得到“WhereSelectEnumerableIterator”。如果我将第二个查询更改为名称为“.Opened”而不是“.Closed”，则它可以工作，但我不知道“已关闭”的计数。

最终我试图得到一个数组的输出来提供图表......类似于这个：

[{"Month":"Apr","Opened":138,"Closed":150}

INSTEAD OF

[{"Month":"Apr","Opened":138,"Closed":0},{"Month":"Apr","Opened":0,"Closed":150}

Answer 1

您需要使用Join语句来合并两者并保持值不同。像这样的东西：

Dim tickets = From open In openTickets _
              Join closed In closedTickets _
              On open.Month Equals closed.Month _
              Select New With _
              {.Month = open.Month, .Opened = open.Opened, .Closed = closed.Closed}