Develop Reference

Updating and retrieving images (Asp.net c#)

protected void upimg_about_Click(object sender, EventArgs e)
{
con.Open();
string sqlQuery = " UPDATE [dbo].[tbldetails] SET [image]=#image,[image2]=#image2 WHERE id=#id";
SqlCommand cmd2 = new SqlCommand(sqlQuery, con);
cmd2.Parameters.AddWithValue("#id", Session["email"].ToString());
int img = Image1.PostedFile.ContentLength;
int img2 = Image2.PostedFile.ContentLength;
byte[] msdata = new byte[img];
byte[] msdata2 = new byte[img2];
Image1.PostedFile.InputStream.Read(msdata, 0, img);
Image2.PostedFile.InputStream.Read(msdata2, 0, img2);
cmd2.Parameters.AddWithValue("#image", msdata);
cmd2.Parameters.AddWithValue("#image2", msdata2);
if (con.State == ConnectionState.Closed)
{
con.Open();
}
cmd2.ExecuteNonQuery();
con.Close();
data1.Text="Image Updated Successfully";
}
This is the code I am using to update the images in the database.
The user when required can update the images (eg: in the firstpage.aspx) and can retrieve it in the next page (nextpage.aspx).
But the problem is: suppose a user wants to update just a single image and he/she upload's the image and clicks the update button and when retrieving images in the next page the image that was updated is visible but the one which is already present in the database is not. I am not sure but during the updation the other fileupload is empty is this why this is happening? Is there other way to do it?
PS: I have textboxes in the firstpage.aspx in which i am retrieving the text he/she has already put in the database and hence when the user wants to make changes it can be done easily.
TextBox1.Text = dr["name"].ToString();
TextBox2.Text = dr["address"].ToString();
So, is it possible to retrieve the image path which the user has previously submitted? Or any way in which the user can update a single image and during retrieval both the images can be retrieved?
Thank You! :)

Break your code up so that you can send 1 image at a time to the DB. Then pass the corresponding FileUpload and SQL Column name to your function. Conditionally send the new file to the database depending on whether the FileUpload contains a file. You can check this by looking at the HasFile property.
protected void upimg_about_Click(object sender, EventArgs e)
{
// make sure at least 1 file
if (!Image1.HasFile && !Image2.HasFile)
{
data1.Text="No Images Uploaded";
return;
}
con.Open();
UploadImage(Image1, "[image]");
UploadImage(Image2, "[image2]");
con.Close();
data1.Text = "Image Updated Successfully";
}
void UploadImage(FileUpload fileUpload, string columnName)
{
if (!fileUpload.HasFile)
{
return;
}
string sqlQuery = "UPDATE [dbo].[tbldetails] SET " + columnName + "=#image WHERE id=#id";
SqlCommand cmd = new SqlCommand(sqlQuery, con);
cmd.Parameters.AddWithValue("#id", Session["email"].ToString());
int img = fileUpload.PostedFile.ContentLength;
byte[] msdata = new byte[img];
fileUpload.PostedFile.InputStream.Read(msdata, 0, img);
cmd.Parameters.AddWithValue("#image", msdata);
cmd.ExecuteNonQuery();
}

Saving multiple Images at once to the database with a FileUpload Control

I am working on a company Blog site, and when a user is making a post, they can add an image from their computer to the post. I used a FileUpload control to do this, and it works great. However, I am trying to change the functionality to allow the user to select and upload multiple images in one post, and I am running into some issues. I have set the 'allow multiple' property to 'true', however once multiple images are selected into the control (Image URLs get separated by a comma) and the post button is clicked, only one of the images is inserted into the database, but it is inserted as many times as images there are, and only that one image is displayed on the blog post. So if I try to add three different images, it inserts three instances of the first image into the database. The code corresponding to the the FileUpload in my onClick function is below:
if (imageUpload.HasFile == true)
{
SqlCommand maxMessId = new SqlCommand("SELECT Max(MessageID) FROM BlogMessages", conn);
lastMessageID = Convert.ToInt32(maxMessId.ExecuteScalar());
foreach (var uploadedFile in imageUpload.PostedFiles)
{
SqlCommand cmdInsertImage = new SqlCommand("INSERT INTO BlogImages(Image, MessageID) VALUES (#Image, #MessageID)", conn);
cmdInsertImage.Parameters.AddWithValue("#Image", SqlDbType.Image).Value = imageUpload.FileBytes;
cmdInsertImage.Parameters.AddWithValue("#MessageID", lastMessageID);
cmdInsertImage.ExecuteNonQuery();
}
}
I am thinking the issue could be with:
cmdInsertImage.Parameters.AddWithValue("#Image", SqlDbType.Image).Value = imageUpload.FileBytes;
If that is getting the file bytes for only one image.. I am not sure how to get the filebytes for both files. The image column in my BlogImages table is of the type Image.
Any suggestions are much appreciated!

Are you sure that you're working on the right way ?????PostesFiles are the list of file and each one has it own properties you need to read from there.....nothing else
Here a simples examples
For Each xx In fp.PostedFiles
xx.InputStream
xx.ContentLength
xx.FileName
Next
Where those properties upon expose Inputstrem a stream of the image,ContenteLenght it lenght, Filename the filename of the images.So when you pass the imageupload.FileBytes is not the correct way to achive your goal.You have to read the stream and return a bytearray to save the data withing your sql server.Nothing else i hope it could help you to solve your issue.
UPDATE*
Assume that you're into the foreach loop for each single file you have to setup its own bytearray
MemoryStream ms = new MemoryStream();
file.PostedFile.InputStream.CopyTo(ms);
var byts = ms.ToArray();
ms.Dispose();
then
change your insert statement like this
cmdInsertImage.Parameters.AddWithValue("#Image", SqlDbType.Image).Value = byts;
not tested but it should solve the issue.
UPDATE 2
if (test.HasFiles) {
StringBuilder sb = new StringBuilder();
foreach (void el_loopVariable in test.PostedFiles) {
el = el_loopVariable;
sb.AppendLine("FILENAME:<B>" + el.FileName.ToString + "</B><BR/>");
MemoryStream ms = new MemoryStream();
el.InputStream.CopyTo(ms);
byte[] byts = ms.ToArray;
ms.Dispose();
sb.AppendLine(string.Join(";", byts));
sb.AppendLine("<br/<br/>");
byts = null;
}
LitResponse.Text = sb.ToString;
}

I think the issue is that in your for each loop, you're stepping through the posted files, but you're still just using ImageUpload.FileBytes each time, which I expect would be returning the same thing each time.
I'm not super familiar with the file upload control, but maybe you can use the ContentLength property of your uploaded file object to index into the byte array returned by ImageUpload.FileBytes (assuming that array contains each of the multiple files).

protected void btnSubmit_Click(object sender, EventArgs e)
{
string strImageName = txtImage.Text.ToString(); //to store image into sql database.
if (FileUpload1.PostedFile != null &&
FileUpload1.PostedFile.FileName != "")
{
byte[] imageSize = new byte[FileUpload1.PostedFile.ContentLength];
HttpPostedFile uploadedImage = FileUpload1.PostedFile;
uploadedImage.InputStream.Read(imageSize, 0, (int)FileUpload1.PostedFile.ContentLength);
// Create SQL Command
SqlCommand cmd = new SqlCommand();
cmd.CommandText = "INSERT INTO Pictures(ID,ImageName,Image)" +
" VALUES (#ID,#ImageName,#Image)";
cmd.CommandType = CommandType.Text;
cmd.Connection = conn;
//retrieve latest ID from tables which was stored in session.
int ID = Convert.ToInt32(System.Web.HttpContext.Current.Session["ID"].ToString());
SqlParameter ID = new SqlParameter
("#ID", SqlDbType.Int, 5);
ID.Value = (Int32)ID;
cmd.Parameters.Add(ID);
SqlParameter ImageName = new SqlParameter
("#ImageName", SqlDbType.VarChar, 50);
ImageName.Value = strImageName.ToString();
cmd.Parameters.Add(ImageName);
SqlParameter UploadedImage = new SqlParameter("#Image", SqlDbType.Image, imageSize.Length);
UploadedImage.Value = imageSize;
cmd.Parameters.Add(UploadedImage);
conn.Open();
int result = cmd.ExecuteNonQuery();
conn.Close();
if (result > 0)
lblMessage.Text = "File Uploaded";
lblSuccess.Text = "Successful !";
}}

Saving and retrving image from mysql

In C#, I am trying to save and load an image. I am saving it into a mysql database (type longblob) and trying to load it back into an picture box. The problem i keep getting is the error "Parameter is not valid", see code below
ConnectionClass Sqlconnection = new ConnectionClass();
Sqlconnection.ConnectionOpen();
OdbcCommand cmd = new OdbcCommand("Insert into pictest(pic) values('"+ Encoding.Unicode.GetBytes(richTextBox1.Rtf) + "')", Sqlconnection.connection);
int num = cmd.ExecuteNonQuery();
MessageBox.Show(num + " Rows inserted ");
Sqlconnection.ConnectionClose();
OdbcDataReader rd = null;
try
{
Sqlconnection.ConnectionOpen();
string query = "select * from pictest where id = 1";
cmd = new OdbcCommand(query, Sqlconnection.connection);
rd = cmd.ExecuteReader();
if (rd.Read())
{
byte[] bytes = (byte[])rd[1];
ImageConverter converter = new ImageConverter();
pictureBox1.Image = Image.FromStream(new MemoryStream(bytes)); <--Parameter is not valid
pictureBox1.Refresh();
pictureBox1.Image = Encoding.Unicode.GetString(bytes);
}
Sqlconnection.ConnectionClose();
rd.Close();
}
catch (Exception asd)
{
MessageBox.Show("Problem " + asd.Message);
Sqlconnection.ConnectionClose();
if (rd != null)
{
rd.Close();
}
}
what exact is the problem? Is the image not saving correctly? it should be as it is saving to a longblob. The record for the image says System.Byte[]

you should be able to inspect (via the debugger) the values inside OdbcDataReader before trying to cast the first field to byte[]. Take a look at what type is actually stored in the OdbcDataReader
Using SELECT * is problematic performance wise. It also leaves your rd[1] up for interpretation. If the order of columns ever changes, your code could break. Use rd["your_column_name"] to access the values. As of right now I can't tell if index 1 is correct due to the SELECT * and non-named indexing into the Items array.

First of all why you need to store image in MySql?
Why not in physical drive? If its not a crucial data go for saving it in physical drive.
However, here is code to retrieve:
public byte [] getImage(int imageNumber)
{
string strSql = "SELECT * FROM File";
DataSet ds = new DataSet("Image");
OdbcDataAdapter tempAP = new OdbcDataAdapter(strSql,this._objConn);
OdbcCommandBuilder objCommand = new OdbcCommandBuilder(tempAP);
tempAP.Fill(ds,"Table");
try
{
this._objConn.Open();
byte [] buffer = (byte [])ds.Tables["Table"].Rows[imageNumber]["Data"];
return buffer;
}
catch{this._objConn.Close();return null;}
finally{this._objConn.Close();}
}
Courtesy:
http://www.codeproject.com/Articles/6750/Storing-Images-in-MySQL-using-ASP-NET
For physical drive
http://www.codeproject.com/Articles/2113/C-Photo-Album-Viewer

Issue while inserting images to the mysql database

I am trying to insert an image from windows application to mysql database , it has been executed succesfully but there exists no data in my table.
Here I have used the following code. The execution is successful, according to my table email id and image must must be stored in table , but both the fields are saved as empty.
public void LoadImages()
{
MySqlConnection cn = new MySqlConnection(connstring);
cn.Open();
string image = txtLogo.Text;
byte[] ImageData;
FileStream fs = new FileStream(image, FileMode.Open, FileAccess.Read);
BinaryReader br = new BinaryReader(fs);
ImageData = BitConverter.GetBytes(fs.Length);
br.Close();
fs.Close();
MySqlParameter parImage = new MySqlParameter();
parImage.ParameterName = "?Images";
MySqlCommand cmd = new MySqlCommand("insert into Fn_Pictures(Images,Email)values(?Images,'" + txtEmailIdText + "')", cn);
parImage.MySqlDbType = MySqlDbType.MediumBlob;
parImage.Size = 3000000;
parImage.Value = ImageData;//here you should put your byte []
cmd.Parameters.Add(parImage);
cmd.ExecuteNonQuery();
cn.Close();
}

BitConverter.GetBytes(fs.Length);
This returns the length as a byte[4], not reads the image data.
Take a look here for reading the file:
http://msdn.microsoft.com/en-us/library/system.io.file.readallbytes(v=vs.110).aspx
You probably also want to set parImage.Size to ImageData.length, not 3000000.

upload new file first check if this file exist already in database or not then if not exist save that in database

I'm trying to create sql database that contains
Image Id (int)
Imagename (varchar(50))
Image (image)
and in aspx write in upload button this code:
protected void btnUpload_Click(object sender, EventArgs e)
{
//Condition to check if the file uploaded or not
if (fileuploadImage.HasFile)
{
//getting length of uploaded file
int length = fileuploadImage.PostedFile.ContentLength;
//create a byte array to store the binary image data
byte[] imgbyte = new byte[length];
//store the currently selected file in memeory
HttpPostedFile img = fileuploadImage.PostedFile;
//set the binary data
img.InputStream.Read(imgbyte, 0, length);
string imagename = txtImageName.Text;
//use the web.config to store the connection string
SqlConnection connection = new SqlConnection(strcon);
connection.Open();
SqlCommand cmd = new SqlCommand("INSERT INTO Image (ImageName,Image) VALUES (#imagename,#imagedata)", connection);
cmd.Parameters.Add("#imagename", SqlDbType.VarChar, 50).Value = imagename;
cmd.Parameters.Add("#imagedata", SqlDbType.Image).Value = imgbyte;
int count = cmd.ExecuteNonQuery();
connection.Close();
if (count == 1)
{
BindGridData();
txtImageName.Text = string.Empty;
ScriptManager.RegisterStartupScript(this, this.GetType(), "alertmessage", "javascript:alert('" + imagename + " image inserted successfully')", true);
}
}
}
When I'm uploading a new image I need to first check if this image already exists in database and if it doesn't exist save that in database.
Please how I can do that?

Add a method that is responsible for checking if the filename already exists in the table.
private bool FileExists(string imageName)
{
using (SqlConnection conn = new SqlConnection()) // establish connection
{
using (SqlCommand cmd =
new SqlCommand("select 1 where exists(select Id from Image where ImageName = #)", conn))
{
cmd.Parameters.Add("#imagename", SqlDbType.VarChar, 50).Value = imageName;
return cmd.ExecuteNonQuery() > 0;
}
}
}
Then I would call this like so
if (fileuploadImage.HasFile && !FileExists(txtImageName.Text))
{
...

string cmd ="if not exists (select * from Image where ImageName= #imagename); ";
\\if you want to check image data
\\ (select * from Image where SUBSTRING(ImageName, 1, 8000)= SUBSTRING(#imagename, 1, 8000) );
string cmd += "INSERT INTO Image (ImageName,Image) VALUES (#imagename,#imagedata)";
SqlCommand cmd = new SqlCommand(cmd, connection);
If you want to verify imagedata, You can try to use DATALENGTH as first line of check for the two images.
If the DATALENGTH is different, then you suppose to have a "different" picture".
You can also use SUBSTRING(Image, 1, 8000) to check first 8000 bytes.
And also SUBSTRING(Image, DATALENGTH(Image) - 7999, 8000) to check last 8000 bytes.

One of the fastest ways is to do an UPDATE and then INSERT if update returns no updates.
string cmd = #"UPDATE Image SET Image = #imagedata WHERE ImageName = #ImageName
IF ##ROWCOUNT=0
INSERT INTO Image (ImageName,Image) VALUES (#imagename,#imagedata)";
Or if query on Image itself:
string cmd = #"UPDATE Image SET ImageName = #ImageName WHERE Image = #imagedata
IF ##ROWCOUNT=0
INSERT INTO Image (ImageName,Image) VALUES (#imagename,#imagedata)";