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我的 Access 数据库中有一个名为的表，Historical_Stock_Prices其中包含各种公司的历史股票价格。我需要运行一个查询，将原始数据（股票价格）转换为季度增长率，并以DataGridView.

我已经在我的 Access 数据库的 SQL 视图中编写了以下查询，它在 Access 中工作。

SELECT MinMaxYrQtrDates.YrQtr, MinMaxYrQtrDates.Ticker, MinMaxYrQtrDates.MaxDate, [Historical Prices].Close, MinMaxYrQtrDates.MinDate, [Historical Prices_1].Open, ([Historical Prices].[Close]/[Historical Prices_1].[Open]-1)*100 AS GrowthRate FROM [Historical Prices] AS [Historical Prices_1] INNER JOIN ([Historical Prices] INNER JOIN [SELECT Year([Date]) & "-" & DatePart("q",[Date]) AS YrQtr, [Historical Prices].Ticker, Max([Historical Prices].Date) AS MaxDate, Min([Historical Prices].Date) AS MinDate FROM [Historical Prices] GROUP BY Year([Date]) & "-" & DatePart("q",[Date]), [Historical Prices].Ticker]. AS MinMaxYrQtrDates ON ([Historical Prices].Date = MinMaxYrQtrDates.MaxDate) AND ([Historical Prices].Ticker = MinMaxYrQtrDates.Ticker)) ON ([Historical Prices_1].Ticker = MinMaxYrQtrDates.Ticker) AND ([Historical Prices_1].Date = MinMaxYrQtrDates.MinDate);

我需要能够从我的程序中调用它并将结果显示在DataGridView. 我试图从 Access 复制 SQL 语句并将其用作我的代码中的 SQL 语句，但它不起作用。我没有收到任何错误，DataGridView只是空白。到目前为止，这是我的代码：

Imports System.IO
Imports System.Data.OleDb

Public Class Historical_Growth_Rates_Annual

Public tblName As String = "Historical_Stock_Prices"

Private Sub Historical_Growth_Rates_Annual_Load(sender As Object, e As EventArgs) Handles MyBase.Load
    If (File.Exists(Nordeen_Investing_3.databaseName)) Then
        Nordeen_Investing_3.con.Open()
        Dim restrictions(3) As String
        restrictions(2) = tblName
        Dim dbTbl As DataTable = Nordeen_Investing_3.con.GetSchema("Tables", restrictions)
        If dbTbl.Rows.Count = 0 Then
            MessageBox.Show("Historical Stock Prices tables does not exist in the database.  Please Update")
        Else
            Dim da As OleDbDataAdapter = New OleDbDataAdapter("SELECT MinMaxYrQtrDates.YrQtr, MinMaxYrQtrDates.Ticker, MinMaxYrQtrDates.MaxDate, [Historical_Stock_Prices].Close1, MinMaxYrQtrDates.MinDate, [Historical_Stock_Prices_1].Open1, ([Historical_Stock_Prices].[Close1]/[Historical_Stock_Prices_1].[Open1]-1)*100 AS GrowthRate FROM [Historical_Stock_Prices] AS [Historical_Stock_Prices_1] INNER JOIN ([Historical_Stock_Prices] INNER JOIN [SELECT Year([Date1]) & " - " & DatePart('q',[Date1]) AS YrQtr, [Historical_Stock_Prices].Ticker, Max([Historical_Stock_Prices].Date) AS MaxDate, Min([Historical_Stock_Prices].Date) AS MinDate FROM [Historical_Stock_Prices] GROUP BY Year([Date1]) & " - " & DatePart('q',[Date1]), [Historical_Stock_Prices].Ticker]. AS MinMaxYrQtrDates ON ([Historical_Stock_Prices].Date = MinMaxYrQtrDates.MaxDate) AND ([Historical_Stock_Prices].Ticker = MinMaxYrQtrDates.Ticker)) ON ([Historical_Stock_Prices_1].Ticker = MinMaxYrQtrDates.Ticker) AND ([Historical_Stock_Prices_1].Date = MinMaxYrQtrDates.MinDate);", Nordeen_Investing_3.con)
            'create a new dataset
            Dim ds As New DataSet()
            'fill the datset
            da.Fill(ds)
            'attach dataset to the datagrid
            DataGridView1.DataSource = ds.Tables(0)
            ds = Nothing
            da = Nothing
            Nordeen_Investing_3.con.Close()
        End If
    Else
        MessageBox.Show("Database does not exist.  Please update.")
    End If
End Sub
End Class

我真的被困住了，可以使用一些帮助！谢谢！

数据库示例

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1 回答 1

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您希望 VB.Net 代码重新创建SELECT在 Access 中工作的相同语句。然而，看看 Vim 的语法高亮显示，我认为你实际上可能正在创建其他东西。（这可能就像创建一个字符串作为其他 2 个字符串的区别：）"string 1" - "string 2"。

但无论我猜对与否，请使用字符串变量来保存您的SELECT语句。然后将该字符串打印到控制台或将其写入文本文件，以便您可以检查您提供给数据库引擎的实际语句。

或者将 Access 中的工作查询保存为命名查询对象，并使用 VB.Net 代码中的查询名称 --- 这绝对保证使用已确认在 Access 中工作的相同 SQL。

于 2013-08-23T18:55:02.360 回答