Question

我在stackoverflow上寻找类似的线程并尝试调整我的代码，但它仍然不起作用所以我不妨在这里问。

他告诉我，对象引用没有设置为：

DataRow[] result = tablez.Select("Release = 1");

以下是整个代码：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Data.OleDb;
using System.IO;
using System.Data;
namespace TestExcelSelect
{
class Program
{
    static void Main(string[] args)
    {
        string physicalPath = Path.Combine(Environment.CurrentDirectory, "Mapping.xlsx");
        OleDbCommand cmd = new OleDbCommand();
        OleDbDataAdapter da = new OleDbDataAdapter();
        DataSet ds = new DataSet();

        String connString = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=" + physicalPath + ";Extended Properties=\"Excel 12.0;HDR=Yes;IMEX=2\"";
        String query = "SELECT Release, StructuralElement FROM Mapping"; // You can use any different queries to get the data from the excel sheet
        OleDbConnection conn = new OleDbConnection(connString);
        if (conn.State == ConnectionState.Closed) conn.Open();
        try
        {
            cmd = new OleDbCommand(query, conn);
            da = new OleDbDataAdapter(cmd);
            da.Fill(ds, "Mapping");

        }
        catch
        {
            // Exception Msg 

        }
        finally
        {
            da.Dispose();
            conn.Close();
        }
        if (ds == null)
        {
            Console.WriteLine("Mapping not found");
            return;
        }
        DataTable tablez = ds.Tables["Mapping"];
        DataRow[] result = table.Select("Release = 1"); // this will return one row for above data 
        foreach (DataRow row in tablez.Rows)
        {
            Console.WriteLine("{0}, {1}", row[0], row[1]);
            Console.WriteLine(row["Column1"].ToString());
        }

        //DataTable data = ds.Tables["data"];
        //string key = data.Rows[0].Field<string>("Release");
        //string value = data.Rows[0].Field<string>("StructuralElement");

    }
}
}

我基本上想要通过一个对象列表，将该对象列表与我的Release行进行比较，如果匹配，则将StructuralElement行写入某处。

编辑：也许我的名字失败了？

我的xslx称为Mapping 里面的工作表叫做Mapping2
这些列称为Release，StructuralElement

c＃dataset对象引用未设置为对象的实例

0 个答案: