从 SQL 表创建饼图答案

【问题标题】：Creating Pie Chart from SQL Table从 SQL 表创建饼图
【发布时间】：2016-10-05 01:13:05
【问题描述】：

我正在尝试使用 SQL 表提供的数据构建饼图。我的查询结果如下：

Total  A    B    C     D     E     F
11005  0  1485  3667  2665  2579  609

问题是我有很多“系列”，每个系列只包含一个数据。我认为我只需要构建一个“系列”就可以显示饼图。我的代码是：

 Dim RequeteByTpe As String = "SELECT COUNT(*) as Total,
Sum(CASE
  WHEN [Type] = 'A' THEN 1
   ELSE 0
    END) A,
  Sum(CASE
   WHEN [Type] = 'B' THEN 1
    ELSE 0
     END) B,
  Sum(CASE
  WHEN [Type] = 'C' THEN 1
   ELSE 0
    END) C, 
  Sum(CASE
  WHEN [Type] = 'D' THEN 1
   ELSE 0
    END) D,
 Sum(CASE
  WHEN [Constructeur] = 'E' THEN 1
   ELSE 0
    END) E, 
 Sum(CASE
  WHEN [Constructeur] = 'F' THEN 1
   ELSE 0
    END) F          
 From DBase.dbo.MyTable"  

    Dim DA As New SqlDataAdapter(RequeteByType, ConnexionMyBase)
    Dim DS As New DataSet()
    DAConstC.Fill(DS, "ByType")

    Dim ChartType As New Chart

    Dim ChartArea2 As New ChartArea()

    ChartConstC.ChartAreas.Add("ChartArea2")

    ChartConstC.ChartAreas(0).Area3DStyle.Enable3D = True

    Dim Series21 As Series = New Series("A")
    Dim Series22 As Series = New Series("B")
    Dim Series23 As Series = New Series("C")
    Dim Series24 As Series = New Series("D")
    Dim Series25 As Series = New Series("E")
    Dim Series26 As Series = New Series("F")

    Series21.ChartArea = "ChartArea2"
    Series22.ChartArea = "ChartArea2"
    Series23.ChartArea = "ChartArea2"
    Series24.ChartArea = "ChartArea2"
    Series25.ChartArea = "ChartArea2"
    Series26.ChartArea = "ChartArea2"

    ChartByType.DataSource = DS.Tables("ByType")

    ChartByType.Series.Add(Series21)
    ChartByType.Series.Add(Series22)
    ChartByType.Series.Add(Series23)
    ChartByType.Series.Add(Series24)
    ChartByType.Series.Add(Series25)
    ChartByType.Series.Add(Series26)

    ChartByType.Series(0).YValueMembers = "A"
    ChartByType.Series(1).YValueMembers = "B"
    ChartByType.Series(2).YValueMembers = "C"
    ChartByType.Series(3).YValueMembers = "D"
    ChartByType.Series(4).YValueMembers = "E"
    ChartByType.Series(4).YValueMembers = "F"

    ChartByType.Titles.Add("Type proportions")
    ChartByType.Titles(0).Font = New Font("Arial", 12, FontStyle.Regular)

    ChartByType.Titles(0).Alignment = System.Drawing.ContentAlignment.TopCenter

    ChartByType.Location = New System.Drawing.Point(15, 45)

    ChartByType.Size = New System.Drawing.Size(760, 260)

    Me.Controls.Add(ChartByType)

我不知道我是否必须更改我的 sql 查询以获取其他类型的数据，或者是否有可能通过某些数据归属方法或其他方法来解决此问题。有人可以帮忙吗？

【问题讨论】：

你得到什么结果，你想得到什么结果？
@TabAlleman ，我目前只能显示一个条形图，我想显示一个饼图，其中包含 A、B、C、D、E、F 值的比例。

标签： sql-server vb.net charts

【解决方案1】：

你需要行而不是列...

而不是将A、B、C放在自己的列中，
逐行合计

示例 sql...

select [Type], count(*) as Total From DBase.dbo.MyTable group by [Type]

我注意到case 语句中有两列，
如果需要，您可以union 将结果放在一起...

select [Type] as Label, count(*) as Total From DBase.dbo.MyTable group by [Type]
union all
select [Constructeur] as Label, count(*) as Total From DBase.dbo.MyTable group by [Constructeur]

【讨论】：