C# 如何将数据集转换为数据表
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How to convert DataSet to DataTable
提问by AlwaysANovice
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.
我正在从 SQL 表中检索数据，以便可以将结果作为 HTML 表显示在页面上。稍后我需要能够将该表保存为 CSV 文件。
So far I have figured out how to retrieve the data and fill them in a dataset for display purpose (which is working perfectly)...
到目前为止，我已经想出了如何检索数据并将它们填充到数据集中用于显示目的（工作完美）...
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
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 (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 DataSetto DataTable? I have tried the way described here with NOluck: http://www.ezineasp.net/post/ASP-Net-C-sharp-Convert-DataSet-to-DataTable.aspx
现在我的问题是如何将其转换DataSet为DataTable？我尝试过这里描述的方法，但没有运气：http: //www.ezineasp.net/post/ASP-Net-C-sharp-Convert-DataSet-to-DataTable.aspx
Can anyone help me?
谁能帮我？
采纳答案by Jon Skeet
A DataSetalready containsDataTables. You can just use:
ADataSet已经包含DataTables. 你可以只使用：
DataTable firstTable = dataSet.Tables[0];
or by name:
或按名称：
DataTable customerTable = dataSet.Tables["Customer"];
Note that you should have usingstatements for your SQL code, to ensure the connection is disposed properly:
请注意，您应该using为 SQL 代码编写语句，以确保正确处理连接：
using (SqlConnection conn = ...)
{
// Code here...
}
回答by Pranay Rana
DataSet is collection of DataTables.... you can get the datatable from DataSet as below.
DataSet 是 DataTables 的集合....您可以从 DataSet 中获取数据表，如下所示。
//here ds is dataset
DatTable dt = ds.Table[0]; /// table of dataset
回答by MORFEE89
Here is my solution:
这是我的解决方案：
DataTable datatable = (DataTable)dataset.datatablename;
