asp.net-mvc - 使用 C# (ASP.NET MVC) 上传 csv 文件

Question

我有一个 CSV 文件，其中包含以下内容:

ProductName,EmployeeID,EmployeeName,ContactNo,Adddress
iPad,1233,Tom,89897898,34 Pitt st
iPad,1573,Jack,8978 9689,50 George st
iPad,1893,Peter,8878 8989,32 Martin st 

以下代码将插入到一个表中。我想要实现的是插入到 2 个表中:

Product table (parent table)ProductId(Pk), ProductNameEmployee Table (child table)EmployeeId(Pk), ProductId(fk), EmployeeName, ContactNo, Address

So I need to basically insert the record first into Product table and then into Employee table from the CSV file.

Controller.cs

[HttpPost]
public ActionResult Index(HttpPostedFileBase FileUpload)
{
    // Set up DataTable place holder 

    Guid ProductId= Guid.NewGuid();
    using (SqlConnection conn = new SqlConnection(connString))
    {
        conn.Open();

        using (SqlCommand cmd = new SqlCommand(
               "INSERT INTO Product VALUES(" + "@ReferralListID,  @ProductName)", conn))
        {
            //Note product name need to read from csv file
            cmd.Parameters.AddWithValue("@ProductId", ProductId);
            cmd.Parameters.AddWithValue("@ProductName", ProductName); 

            int rows = cmd.ExecuteNonQuery();

            //rows number of record got inserted
        }
    }

    DataTable dt = new DataTable();

    //check we have a file 
    if (FileUpload.ContentLength > 0)
    {
        //Workout our file path
        string fileName = Path.GetFileName(FileUpload.FileName);
        string path = Path.Combine(Server.MapPath("~/App_Data/uploads"), fileName);

        //Try and upload
        try
        {
            FileUpload.SaveAs(path);
            //Process the CSV file and capture the results to our DataTable place holder
            dt = ProcessCSV(path);

            //Process the DataTable and capture the results to our SQL Bulk copy
            ViewData["Feedback"] = ProcessBulkCopy(dt);
        }
        catch (Exception ex)
        {
            //Catch errors
            ViewData["Feedback"] = ex.Message;
        }
    }
    else
    {
        //Catch errors
        ViewData["Feedback"] = "Please select a file";
    }

    //Tidy up
    dt.Dispose();

    return View("Index", ViewData["Feedback"]);
}

/// <summary>
/// Process the file supplied and process the CSV to a dynamic datatable
/// </summary>
/// <param name="fileName">String</param>
/// <returns>DataTable</returns>
private static DataTable ProcessCSV(string fileName)
{
    //Set up our variables 
    string Feedback = string.Empty;
    string line = string.Empty;
    string[] strArray;  
    DataTable dt = new DataTable();
    DataRow row;

    // work out where we should split on comma, but not in a sentance
    Regex r = new Regex(",(?=(?:[^\"]*\"[^\"]*\")*(?![^\"]*\"))");

    //Set the filename in to our stream
    StreamReader sr = new StreamReader(fileName);

    //Read the first line and split the string at , with our regular express in to an array
    line = sr.ReadLine();
    strArray = r.Split(line);

    //For each item in the new split array, dynamically builds our Data columns. Save us having to worry about it.
    Array.ForEach(strArray, s => dt.Columns.Add(new DataColumn()));


    //Read each line in the CVS file until it's empty
    while ((line = sr.ReadLine()) != null)
    {
        row = dt.NewRow();

        //add our current value to our data row
        row.ItemArray = r.Split(line);
        dt.Rows.Add(row);
    }

    //Tidy Streameader up
    sr.Dispose();

    //return a the new DataTable
    return dt;


}

/// <summary>
/// Take the DataTable and using WriteToServer(DataTable) send it all to the database table "BulkImportDetails" in one go
/// </summary>
/// <param name="dt">DataTable</param>
/// <returns>String</returns>
private static String ProcessBulkCopy(DataTable dt)
{
    string Feedback = string.Empty;
    string connString = ConfigurationManager.ConnectionStrings["DataBaseConnectionString"].ConnectionString;

    //make our connection and dispose at the end    
    using(  SqlConnection conn = new SqlConnection(connString))
    {
        //make our command and dispose at the end
        using (var copy = new SqlBulkCopy(conn))
        {
            //Open our connection
            conn.Open();

            //Set target table and tell the number of rows
            copy.DestinationTableName = "Employee";
            copy.BatchSize = dt.Rows.Count;
            try
            {
                //Send it to the server
                copy.WriteToServer(dt);
                Feedback = "Upload complete";
            }
            catch (Exception ex)
            {
                Feedback = ex.Message;
            }
        }
    }

    return Feedback;
}

View.aspx

<asp:Content ID="Content1" ContentPlaceHolderID="TitleContent" runat="server">
    Home Page
</asp:Content>

<asp:Content ID="Content2" ContentPlaceHolderID="MainContent" runat="server">

    <h2>CSV Bulk Upload</h2> 

    <% using (Html.BeginForm("","",FormMethod.Post, new {enctype="multipart/form-data"})){ %>

        <input type="file" name="FileUpload" />
        <input type="submit" name="Submit" id="Submit" value="Upload" />
    <% } %>

    <p><%= Html.Encode(ViewData["Feedback"]) %></p> 
</asp:Content>

存储过程

USE [BULkDatabase]
GO


SET ANSI_NULLS ON
GO

SET QUOTED_IDENTIFIER OFF
GO



CREATE PROCEDURE [dbo].[InsertProdutInfo] 
(
   @ProductName varchar (50),  
   @EmployeeName varchar (50),
   @EmployeeAddress varchar (50)
)

AS


BEGIN TRAN

   update [dbo.Product] 
   set    [ProductName] = @ProductName
   where  [ProductName] = @ProductName;

   -- get product id
   select ProductId = [ProductId] 
   from   [dbo.Product]
   where  [ProductName] = @ProductName;  

   if @@rowcount = 0
   BEGIN TRAN

      DECLARE @ProductId uniqueidentifier
      -- there's no such product, let's create it
      insert into [dbo.Product]
      values (NEWID(),@ProductName);

      select @ProductId = SCOPE_IDENTITY()
   end

   -- now that we know we have added the product and have the id, let's add the rest
   insert into [dbo.Employees]
   values (NEWID(), @EmployeeName, @EmployeeAddress, @ProductId);

COMMIT TRAN

Answer 1

首先，您应该将 Controller 与数据库代码分离，只需创建一个新的类项目并在那里托管所有数据库访问，这样您就可以在 Controller 中拥有如下内容:

[HttpPost]
public ActionResult UploadFile(HttpPostedFileBase FileUpload)
{
    if (FileUpload.ContentLength > 0) {
        // there's a file that needs our attention
        var success = db.UploadProductFile(FileUpload);

        // was everything ok?
        if (success)
            return View("UploadSuccess");
        else
            return View("UploadFail");
    }

    return RedirectToAction("Index", new { error = "Please upload a file..." });
}

public ActionResult Index(string error)
{
    ...
}

这样， Controller 并不真正关心您如何处理上传的文件，因为 Controller 不关心知道这样的事情，它的任务是知道它需要委派该工作并处理结果，仅此而已。

请注意操作方法名为 UploadFile 而不是 Index。发布到同一操作并不是一个好习惯，以避免在用户刷新页面时再次发布。

我还建议你使用ADO.NET实体模型，那里有很多视频，在ASP.NET网站上也是如此，它将极大地帮助你更简单地使用数据库和干净的方式。

回到你的问题...在你的Database类中，方法UploadProductFile应该是类似的，假设你没有超过200条记录来处理，最好使用memory to deal with the file而不是花时间再次保存和读取(更多信息，您应该保存文件并处理它，就像您已经做的那样):

private bool UploadProductFile(HttpPostedFileBase FileUpload)
{
    // get the file stream in a readable way
    StreamReader reader = new StreamReader(FileUpload.InputStream);

    // get a DataTable representing the passed string
    System.Data.DataTable dt = ProcessCSV(reader.ReadToEnd()); 

    // for each row, compose the statement
    bool success = true;
    foreach (System.Data.DataRow row in dt.Rows)
        success = db.InsertProdutInfo(row);

    return success;
}

方法InsertProdutInfo会触发一个store procedure，类似于:

declare @product_key int

begin tran

   update [tbl_products] 
   set    [name] = @product_name, [last_update] = getdate()
   where  [name] = @product_name;

   -- get product id
   select @product_key = [id] 
   from   [tbl_products]
   where  [name] = @product_name;  

   if @@rowcount = 0
   begin
      -- there's no such product, let's create it
      insert into [tbl_products] (name, last_update)
      values (@product_name, getdate());

      select @product_key = SCOPE_IDENTITY()
   end

   -- now that we know we have added the product and have the id, let's add the rest
   insert into [tbl_Employees] (id, product_id, name, contact, address)
   values (@employee_id, @product_key, @employee_name,
           @employee_contact, @employee_address);

commit tran

这样你就会拥有你需要的一切。