多线图

我一直在尝试制作一个从数据库中提取数据的多线图。 为了做到这一点，我编写了以下代码来填充图表：

SqlConnection con1 = new SqlConnection(); con1.ConnectionString = ConfigurationManager.ConnectionStrings["Removed"].ToString(); SqlCommand cmd1 = new SqlCommand("SELECT YEAR(Start_Date) AS Year, Month(Start_Date) As Month, Cost, Utility_Type FROM import_Utilities WHERE YEAR(Start_Date) = 2011 AND Utility_Type = 'Water'"); cmd1.Connection = con1; con1.Open(); SqlDataAdapter da1 = new SqlDataAdapter(cmd1); DataTable dt1 = new DataTable(); da1.Fill(dt1); Chart1.DataSource = dt1; Chart1.Series["Series2"].XValueMember = "Month"; Chart1.Series["Series2"].YValueMembers = "Cost"; Chart1.Legends.Add(new Legend("Default") { Docking = Docking.Right }); Chart1.DataBind(); con1.Close(); SqlConnection con = new SqlConnection(); con.ConnectionString = ConfigurationManager.ConnectionStrings["Removed"].ToString(); con.Open(); SqlCommand cmd = new SqlCommand("SELECT YEAR(Start_Date) AS Year, Month(Start_Date) As Month, Cost, Utility_Type FROM import_Utilities WHERE YEAR(Start_Date) = 2012 AND Utility_Type = 'Water'"); cmd.Connection = con; SqlDataAdapter da = new SqlDataAdapter(cmd); DataTable dt = new DataTable(); da.Fill(dt); Chart1.DataSource = dt; Chart1.Series["2010"].XValueMember = "Month"; Chart1.Series["2010"].YValueMembers = "Cost"; Chart1.DataBind(); con.Close(); 

此代码有效，但它有两个数据源，因此只有底部的sqlconnection填充到图表中。 我迷失了如何解决这个问题，我想他们是一个更好的方法来做这件事，但我不知所措。

更新：

使用示例下面我最后使用pivot sql来制作一个表（见图）。 然后我更新了我的代码如下：

  SqlCommand cmd = new SqlCommand("SELECT * FROM ( SELECT YEAR(Start_Date), CASE MONTH(Start_Date) WHEN 1 THEN 'January' WHEN 2 THEN 'February' WHEN 3 THEN 'March' WHEN 4 THEN 'April' WHEN 5 THEN 'May' WHEN 6 THEN 'June' WHEN 7 THEN 'July' WHEN 8 THEN 'August' WHEN 9 THEN 'September'WHEN 10 THEN 'October' WHEN 11 THEN 'November' WHEN 12 THEN 'December' END as [Month], [Cost] FROM [HousingAccountingReports].[dbo].[import_Utilities] Where [Building] = 'Building B' AND [Utility_Type] = 'Electric') TableDate PIVOT (SUM([Cost]) FOR [Month] IN ([January],[February],[March],[April],[May],[June],[July],[August],[September],[October],[November],[December] )) PivotTable"); cmd.Connection = con; SqlDataAdapter da = new SqlDataAdapter(cmd); DataTable dt = new DataTable(); da.Fill(dt); Chart3.DataSource = dt; Chart3.Series["Series1"].XValueMember = "Month"; Chart3.Series["Series1"].YValueMembers = "2010"; Chart3.Series["Series2"].XValueMember = "Month"; Chart3.Series["Series2"].YValueMembers = "2011"; Chart3.Series["Series3"].XValueMember = "Month"; Chart3.Series["Series3"].YValueMembers = "2012"; Chart3.DataBind();` 

当我运行页面时，它出错，找不到列Month。 如果我添加：
dt.Columns.Add（ “月”）; dt.Columns.Add（“Year”）;`它找不到2010，如何让我的图表正确驾驶; 我的pivot sql有问题吗？

Answer 1

我昨天回答了类似的问题。 分离图表系列

您不能像在上面的代码中那样更改图表数据源而不重置数据。

就像昨天的问题一样，我建议您先创建一个数据表，然后在数据表中引用您特定系列的列

从昨天回答

所以作为清理代码的建议，我会在下面做

1. 获取2个数据表
2. 合并具有“Month”的数据表作为主键
3. 将每列添加到图表中作为新系列

或者你可以手动绘制系列

所以下降

 Chart1.DataSource = dt Chart1.Series["2010"].XValueMember = "Month"; Chart1.Series["2010"].YValueMembers = "Cost"; 

并替换它

 For Each row As DataRow In dt1.Rows Chart1.Series("Series2").Points.AddXY(row.Item("Month"), row.Item("Cost")) Next For Each row As DataRow In dt.Rows Chart1.Series("2010").Points.AddXY(row.Item("Month"), row.Item("Cost")) Next 

如果您设法将所有数据放入一个Datatable并创建一个包含两个系列的图表，那么您可以执行以下操作

  Dim dt As New DataTable dt.Columns.Add("Month", GetType(String)) dt.Columns.Add("2010", GetType(Integer)) dt.Columns.Add("2011", GetType(Integer)) dt.Rows.Add("January", 15, 25) dt.Rows.Add("February", 18, 32) dt.Rows.Add("March", 12, 34) dt.Rows.Add("April", 12, 34) Chart1.DataSource = dt Chart1.Series(0).XValueMember = "Month" Chart1.Series(0).YValueMembers = "2010" Chart1.Series(1).XValueMember = "Month" Chart1.Series(1).YValueMembers = "2011" Chart1.DataBind() 

根据您的代码，这应该符合我的理解：

 SqlConnection con = new SqlConnection(); con.ConnectionString = ConfigurationManager.ConnectionStrings["removed"].ToString(); con.Open(); SqlCommand cmd = new SqlCommand("SELECT YEAR(Start_Date) AS Year, Month(Start_Date) As Month, Cost, Utility_Type, Building FROM import_Utilities WHERE YEAR(Start_Date) = 2012 AND YEAR(Start_Date) = 2011 AND Utility_Type = 'Water'"); cmd.Connection = con; SqlDataAdapter da = new SqlDataAdapter(cmd); DataTable dt = new DataTable(); da.Fill(dt); Chart1.DataSource = dt; Chart1.Series(0).XValueMember = "Month"; Chart1.Series(0).YValueMembers = "2010"; Chart1.Series(1).XValueMember = "Month"; Chart1.Series(1).YValueMembers = "2011" Chart1.DataBind() 

数据表dt应该包含所有数据{因为我正在考虑这两年）（如何将其绑定到表以便我可以validation）

现在它的抱怨系列不能用作方法。

我是一个非常新的程序员，只能在我的空闲时间这样做，所以请原谅我的简单错误。

我是否需要像在此处一样设置数据表：Chart1.DataSource = dt; Chart1.Series（0）.XValueMember =“Month”; Chart1.Series（0）.YValueMembers =“2010”;

  Chart1.Series(1).XValueMember = "Month"; Chart1.Series(1).YValueMembers = "2011" Chart1.DataBind() 

或者它是基于sql表吗？