如何在MySQL数据库中插入图像并使用vb.net进行检索？

Question

我使用longblob数据类型插入图像，但它给出了错误。

我想从图片框插入图像到MySQL数据库。

Answer 1

我这里有一个C＃实现，但你可以使用a c# to VB.Net converter

在aspx文件：

<asp:FileUpload runat="server" ID="fuPersonPicture" /> 
<asp:Button runat="server" ID="btnPhotoUpload" Text="Upload" OnClick="btnPhotoUpload_Click" /> 

在后台代码：

定义的

protected void btnPhotoUpload_Click(object sender, EventArgs e) 
{ 
    byte[] rawData = new byte[fuPersonPicture.FileBytes.Length]; 
    int fileSize = fuPersonPicture.FileBytes.Length; 
    fuPersonPicture.FileContent.Read(rawData, 0, fileSize); 

    string extension = Path.GetExtension(fuPersonPicture.PostedFile.FileName); 
    switch (extension.ToLower()) 
    { 
     // Only allow uploads that look like images. 
     case ".jpg": 
     case ".jpeg": 
     case ".gif": 
     case ".png": 
     case ".bmp": 
      System.Drawing.Image myImage = System.Drawing.Image.FromStream(fuPersonPicture.PostedFile.InputStream); 

      fuPersonPicture.FileContent.Close(); 

      PersonPictureManager.Insert(fuPersonPicture.FileName, fileSize, rawData, myImage.Height, myImage.Width); 

      //lbUploadMessage.Text = string.Empty; 
      break; 

     default: 
      //lbUploadMessage.Text = "<br>File is not a valid image file (JPG, JPEG, GIF, BMP, PNG)."; 
      break; 
    } 
    fuPersonPicture.FileContent.Close(); 
} 

PersonPictureManager.Insert()

public static void Insert(string FileName, int FileSize, byte[] RawData, int ImageHeight, int ImageWidth) 
{ 
     string strSQL = "insert into person_picture (file_id, file_name, file_size, file, width, height) values (NULL, @file_name, @file_size, ?file, @width, @height)"; 
     using (MySqlCommand cmd = new MySqlCommand(strSQL)) 
     { 
      cmd.Parameters.Add(new MySqlParameter("@file_name", FileName)); 
      cmd.Parameters.Add(new MySqlParameter("@file_size", FileSize)); 
      cmd.Parameters.Add(new MySqlParameter("@height", ImageHeight)); 
      cmd.Parameters.Add(new MySqlParameter("@width", ImageWidth)); 
      cmd.Parameters.Add(new MySqlParameter("?file", RawData)); 
      DatabaseConnection.ExecuteNonQuery(cmd); // Just a DB helper class 
     } 
}