如何将DataSet转换为DataTable [英] How to convert DataSet to DataTable

问题描述

我从SQL表中检索数据，以便可以将结果作为HTML表格显示在页面上。后来我需要能够将该表格保存为CSV文件。

到目前为止，我已经想出了如何检索数据并将其填充到数据集中以用于显示目的（这是完美的）...

  string selectQuery =SELECT Name，ProductNumber，ListPrice FROM Poduction.Product; 
 
 //建立与SQL数据库的连接
 SqlConnection conn = ConnectionManager.GetConnection（）; 
 conn.Open（）; 
 
 //使用上述查询连接到SQL数据库以获取表中的所有数据。 
 SqlDataAdapter myCommand = new SqlDataAdapter（selectQuery，conn）; 
 
 //创建并填充一个DataSet。 
 DataSet ds = new DataSet（）; 
 myCommand.Fill（ds）; 
  

以及如何借助以下代码将它们保存在CSV文件中： http://www.evontech.com/login/topic/1983.html

  private void exportDataTableToCsv（DataTable formattedDataTable，string filename）
 {
 DataTable toExcel = formattedDataTable.Copy（）; 
 HttpContext context = HttpContext.Current; 
 context.Response.Clear（）; 
 
 foreach（toExcel.Columns中的DataColumn列）
 {
 context.Response.Write（column.ColumnName +，）; 
} 
 
 context.Response.Write（Environment.NewLine）; 
 foreach（在toExcel.Rows中的DataRow行）
 {
 for（int i = 0; i< toExcel.Columns.Count; i ++）
 {
 context .Response.Write（row.ToString（）。Replace（，，string.Empty）+，）; 
} 
 
 context.Response.Write（Environment.NewLine）; 
} 
 
 context.Response.ContentType =text / csv; 
 context.Response.AppendHeader（Content-Disposition，attachment; filename =+ filename +.csv）; 
 context.Response.End（）; 
 
 $ / code> 

现在我的问题是如何转换这个 DataSet 到 DataTable ？我已经尝试过 NO 运气： http://www.ezineasp.net/post/ASP-Net-C-sharp-Convert-DataSet-to-DataTable.aspx

任何人都可以帮助我吗？

解决方案 DataSet already 包含 DataTables 。您可以使用：

  DataTable firstTable = dataSet.Tables [0]; 
  

或名称：

  DataTable customerTable = dataSet.Tables [Customer]; 
  

请注意，您应该使用语句为你的SQL代码，以确保连接正确处置：

$ p $ 使用（SqlConnection conn = ...）
{
//此处的代码...
}





I am retrieving data from a SQL table so I can display the result on the page as a HTML table. Later I need to be able to save that table as a CSV file.

So far I have figured out how to retrieve the data and fill them in a dataset for display purpose (which is working perfectly)...

        string selectQuery = "SELECT Name, ProductNumber, ListPrice FROM Poduction.Product";

        // Establish the connection to the SQL database 
        SqlConnection conn = ConnectionManager.GetConnection();
        conn.Open();

        // Connect to the SQL database using the above query to get all the data from table.
        SqlDataAdapter myCommand = new SqlDataAdapter(selectQuery, conn);

        // Create and fill a DataSet.
        DataSet ds = new DataSet();
        myCommand.Fill(ds);

and how to save them in a CSV file with the help of following code from: http://www.evontech.com/login/topic/1983.html

    private void exportDataTableToCsv(DataTable formattedDataTable, string filename)
    {
       DataTable toExcel = formattedDataTable.Copy();
       HttpContext context = HttpContext.Current;
       context.Response.Clear();

       foreach (DataColumn column in toExcel.Columns)
       {
          context.Response.Write(column.ColumnName + ",");
       }

       context.Response.Write(Environment.NewLine);
       foreach (DataRow row in toExcel.Rows)
       {
          for (int i = 0; i < toExcel.Columns.Count; i++)
          {
             context.Response.Write(row.ToString().Replace(",", string.Empty) + ",");
          }

          context.Response.Write(Environment.NewLine);
       }

       context.Response.ContentType = "text/csv";
       context.Response.AppendHeader("Content-Disposition", "attachment; filename=" + filename + ".csv");
       context.Response.End();
    }

Now my problem is how do I convert this DataSet to DataTable? I have tried the way described here with NO luck: http://www.ezineasp.net/post/ASP-Net-C-sharp-Convert-DataSet-to-DataTable.aspx

Can anyone help me?

解决方案

A DataSet already contains DataTables. You can just use:

DataTable firstTable = dataSet.Tables[0];

or by name:

DataTable customerTable = dataSet.Tables["Customer"];

Note that you should have using statements for your SQL code, to ensure the connection is disposed properly:

using (SqlConnection conn = ...)
{
    // Code here...
}

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