I'm developing an app in C# with .NET and MySQL database. I need to be able to insert and retrieve images in and out of the database and I have a column named 'Image' of type LONGBLOB for that purpose. The insertion goes well but when I try to retrieve the blob the following error pops up:
GetBytes() can only be called on binary or GUID columns
I'm using the following code to select from the database:
Conn.Open();
string sql = #"SELECT `ID`, `Image`, `Note`"
+ " FROM `Item`"
+ " WHERE `ID` = ?ID";
MySqlCommand cmd = new MySqlCommand(sql, Conn);
cmd.Parameters.Add(new MySqlParameter("?ID", iD));
cmd.Prepare();
rdr = cmd.ExecuteReader(CommandBehavior.SequentialAccess);
while (rdr.Read())
{
this.ID= rdr.GetString("ID");
if (!rdr.IsDBNull(1))
{
long len = rdr.GetBytes(1, 0, null, 0, 0);
byte[] ImageBytes = new byte[len];
rdr.GetBytes(1, 0, ImageBytes, 0, (int)len);
MemoryStream ms = new MemoryStream(ImageBytes);
this.Image = Image.FromStream(ms);
}
this.Note = rdr.GetString("Note");
Despite changing the column type into binary and varbinary, I still got the same error.
Does anyone know what I'm doing wrong here?
TIA
Can't you just cast rdr["Image"] as byte[]?
Related
I am inserting docx file into an SQL table like ,
DECLARE #file AS VARBINARY(MAX)
SELECT #file = CAST(bulkcolumn AS VARBINARY(MAX))
FROM OPENROWSET(
BULK
'D:\abc.docx',
SINGLE_BLOB ) AS x
INSERT INTO ItemData(Id,fileData)
SELECT NEWID(),#file
Now file inserted into table properly.
Read File
For reading file, I am using bellow code :
"ItemNumber" is used for identity.
Everything is working fine.
But I have to show that file to the Document Viewer in WPF.
string cmdString = "Select fileData.PathName() As Path from ItemData where ItemNumber = '" + itemNumber + "' ";
SqlCommand cmd = new SqlCommand(cmdString, conn);
Object pathObj = cmd.ExecuteScalar();
if (DBNull.Value != pathObj)
filePath = (string)pathObj;
else
{
throw new System.Exception("fileData.PathName() failed to read the path name for the Chart column.");
}
this.wbControl.Navigate(filePath);
SqlTransaction transaction = conn.BeginTransaction("mainTranaction");
cmd.Transaction = transaction;
cmd.CommandText = "SELECT GET_FILESTREAM_TRANSACTION_CONTEXT()";
Object obj = cmd.ExecuteScalar();
byte[] txContext = (byte[])obj;
SqlFileStream sqlFileStream = new SqlFileStream(filePath, txContext, FileAccess.ReadWrite);
//byte[] buffer2 = new byte[(int)sqlFileStream.Length];
byte[] buffer = new byte[512];
int numBytes = 0;
string someData = "EKG data.";
Encoding unicode = Encoding.GetEncoding(0);
sqlFileStream.Write(unicode.GetBytes(someData.ToCharArray()), 0, someData.Length);
sqlFileStream.Seek(0L, SeekOrigin.Begin);
numBytes = sqlFileStream.Read(buffer, 0, buffer.Length);
string readData = unicode.GetString(buffer);
if (numBytes != 0)
Console.WriteLine(readData);
//Because reading and writing are finished, FILESTREAM
//must be closed. This closes the c# FileStream class,
//but does not necessarily close the the underlying
//FILESTREAM handle.
sqlFileStream.Close();
//The final step is to commit or roll back the read and write
//operations that were performed on the FILESTREAM BLOB.
cmd.Transaction.Commit();
How to I display SqlFileStream to Document Viewer in WPF?
I am storing docx file in database.
I don't know what's wrong with my code in retrieving image in db. I insert image without using image path file cause the image provide by the cam.
Here's my code in inserting image in db
Image img = pictureBox1.Image;
MemoryStream memStream = new MemoryStream();
img.Save(memStream, ImageFormat.Bmp);
byte[] imageBt = memStream.ToArray();
query = "";
query += "INSERT INTO table(picture) VALUES ('" + imageBt + "')";
cmd = new MySqlCommand(query, con);
cmd.ExecuteNonQuery();
con.close();
Here's my code in retrieving image in db
query = "";
query += "SELECT picture FROM table WHERE id = '1'";
cmd = new MySqlCommand(query, con);
con.Open();
MemoryStream ms = new MemoryStream();
byte[] image = (byte[])cmd.ExecuteScalar();
ms.Write(image, 0, image.Length);
con.Close();
Bitmap bmp = new Bitmap(ms)
pictureBox1.Image = bmp; //Still get the Error here parameter is not valid
Is there anywrong process in saving image in database. Btw my image type in db is Blob. I don't know why it doesn't work in retrieving image it always thrown error. Thanks
When reading, you haven't rewound the stream. If you Write, you must set ms.Position = 0; afterwards. Or simpler: create the stream from the data, then you don't need to:
byte[] image = ...
var ms = new MemoryStream(image);
When writing, you seem to have injected the data directly. That... almost certainly won't work - in fact, you're probably writing System.Byte[] to the command. Ideally, use a parameter:
query = "INSERT INTO table(picture) VALUES (#blob)";
cmd = new MySqlCommand(query, con);
cmd.Parameters.AddWithValue("blob", imageBt);
cmd.ExecuteNonQuery();
(the exact syntax may change between RDBMS implementations)
I have a table with varbinary column:
My table {
Id int primary key,
FileBody varbinary(max)
}
Now I want to read it. It's simple I can use code like in this answer but it converts varbinary to byte[] and I want to avoid it.
Is it possible to put varbinary in MemoryStream without converting to a byte[]?
You can user a SqlDataReader.GetBytes to read data from the column or use SqlDataReader.GetSqlBytes or SqlDataReader.GetStream
Example :
Using getBytes
SqlCommand command = new SqlCommand( .... );
...
SqlDataReader sqlReader = command.ExecuteReader(CommandBehavior.SequentialAccess);
byte[] outbyte = new byte[bufferSize];
sqlReader.GetBytes(1, startIndex, outbyte, 0, bufferSize);
Using GetSqlBytes
SqlCommand command = new SqlCommand( .... );
...
SqlDataReader sqlReader = command.ExecuteReader(CommandBehavior.SequentialAccess);
byte[] outbyte = sqlReader.GetSqlBytes(1).Buffer;
I believe You are searching for this:
SqlCommand command = new SqlCommand();
SqlDataReader reader = command.ExecuteReader();
System.IO.Stream stream = reader.GetStream(1); // 1 is the index of the column
GetStream method:
Retrieves binary, image, varbinary, UDT, and variant data types as a Stream.
I'm using the following code to insert into a blob field:
MySql.Data.MySqlClient.MySqlConnection conn;
MySql.Data.MySqlClient.MySqlCommand cmd;
conn = new MySql.Data.MySqlClient.MySqlConnection();
cmd = new MySql.Data.MySqlClient.MySqlCommand();
string SQL;
int FileSize;
byte[] rawData;
FileStream fs;
conn.ConnectionString = "server=192.168.1.104;uid=root;" +
"pwd=root;database=cady234;";
fs = new FileStream(#"d:\Untitled.gif", FileMode.Open, FileAccess.Read);
FileSize = (int)fs.Length;
rawData = new byte[FileSize];
fs.Read(rawData, 0, FileSize);
fs.Close();
conn.Open();
string strFileName = "test name";
SQL = "INSERT INTO file (file_name, file_size, file) VALUES ('" + strFileName + "', "+FileSize+", '"+rawData+"')";
cmd.Connection = conn;
cmd.CommandText = SQL;
cmd.ExecuteNonQuery();
conn.Close();
The insertion is ok but the image is not getting displayed while using "Open value in viewer":
The binary data isn't being properly passed to your insert as you are using string concatenation - you'll get rawData.ToString() which probably just prints out the TypeName (hence your binary data being 13 bytes in length compared to the filesize of > 3000 bytes); try this instead:
byte[] rawData = File.ReadAllBytes(#"d:\Untitled.gif");
FileInfo info = new FileInfo(#"d:\Untitled.gif");
int fileSize = Convert.ToInt32(info.Length);
using(MySqlConnection connection = new MySqlConnection("server=192.168.1.104;uid=root;pwd=root;database=cady234;"))
{
using(MySqlCommand command = new MySqlCommand())
{
command.Connection = connection;
command.CommandText = "INSERT INTO file (file_name, file_size, file) VALUES (?fileName, ?fileSize, ?rawData);";
MySqlParameter fileNameParameter = new MySqlParameter("?fileName", MySqlDbType.VarChar, 256);
MySqlParameter fileSizeParameter = new MySqlParameter("?fileSize", MySqlDbType.Int32, 11);
MySqlParameter fileContentParameter = new MySqlParameter("?rawData", MySqlDbType.Blob, rawData.Length);
fileNameParameter.Value = "test name";
fileSizeParameter.Value = fileSize;
fileContentParameter.Value = rawData;
command.Parameters.Add(fileNameParameter);
command.Parameters.Add(fileSizeParameter);
command.Parameters.Add(fileContentParameter);
connection.Open();
command.ExecuteNonQuery();
}
}
I've introduced several concepts for you here; firstly, if you are going to load all of the binary data at once, simply use the static method File.ReadAllBytes - it's a lot less code.
Secondly, there is no need to use the fully qualified namespace each time - use the using directive
Thirdly, (slightly confusingly) there is a also a using statement in C#. This ensures that any object that implements IDisposable is properly cleaned up after itself. In the case of the connection, it will explicitly call Close and Dispose if you command succeeds or fails.
Finally, I've parameterized your query. Parameters are useful for many reasons; they help protect against SQL Injection, and, in this instance, they should also ensure that your data types are handled correctly. You can read more about SqlParameter (which, like, MySqlParameter is a database specific implementation but uses the same principles).
Tested as working with MySQL 5.5.15, MySQL Connector 5.2.7 running under .Net 4
How about this:
It works fine for me.
Exepte I found out that it is the wrong one for me.
<?php
// csv invoeren naar pos.
$CSV = "uitvoer.csv";
// The CSV file has only 2 colums; The "Reference" and the image name (in my case the barcode with "thumb_" in front of it.
$username = "Username";
$password = "Passwwoorrdd";
$database = "POS";
$counter = 0;
// Create connection
$conn = new mysqli("localhost", $username, $password, $database);
// Check connection
if ($conn->connect_error) {
die("Connection failed: " . $conn->connect_error);
}
echo "Connected successfully <br>";
//$mysqli->select_db();
ini_set('max_execution_time', 1000); //300 seconds = 5 minutes
if (($handle = fopen($CSV, "r")) !== FALSE) {
while (($data = fgetcsv($handle, 1050, ",")) !== FALSE) {
// this loops through each line of your csv, putting the values into array elements
$counter++;
$IDEE = $data[0];
// It seems that after opening the image the $data is mixed up.
$imag = "photos/".$data[1]; // where "photos/' the folder is where this php file gets executed (mostly in /var/www/ of /var/www/html/)
$fh = fopen($imag, "r");
$data = addslashes(fread($fh, filesize($imag)));
fclose($fh);
echo " Ref: ".$IDEE." ----".$counter."----<br>";
// If there will be a time-out. You could erase the part what is already done minus 1.
$sql = "UPDATE PRODUCTS SET IMAGE='".$data."' WHERE CODE=$IDEE";
// The table PRODUCTS with IMAGE. There are more data in that table. But i need only to update the IMAGE. The rest is already inserted.
if ($conn->query($sql) === TRUE) {
echo "Tabel <b>products</b> updated successfully<br>";
} else {
echo "<br>Error updating tabel <b>Products</b>: " . $conn->error;
Exit();
}
}
fclose($handle);
}
?>
I have to persist a .csv in my database, but for a more testable application I prefer don't use procedures.
Basically I just generate a file and the next instruction is put this in database.
Someone have some clue about best way to do this in code?
Here is an example to insert blob data in oracle using c# and procedures (you said prefer that means you may).
using System;
using System.Data;
using Oracle.DataAccess.Client;
using Oracle.DataAccess.Types;
using System.IO;
using System.Text;
//Step 1
// Connect to database
// Note: Modify User Id, Password, Data Source as per your database setup
string constr = "User Id=Scott;Password=tiger;Data Source=orcl9i";
OracleConnection con = new OracleConnection(constr);
con.Open();
Console.WriteLine("Connected to database!");
// Step 2
// Note: Modify the Source and Destination location
// of the image as per your machine settings
String SourceLoc = "D:/Images/photo.jpg";
String DestinationLoc = "D:/Images/TestImage.jpg";
// provide read access to the file
FileStream fs = new FileStream(SourceLoc, FileMode.Open,FileAccess.Read);
// Create a byte array of file stream length
byte[] ImageData = new byte[fs.Length];
//Read block of bytes from stream into the byte array
fs.Read(ImageData,0,System.Convert.ToInt32(fs.Length));
//Close the File Stream
fs.Close();
// Step 3
// Create Anonymous PL/SQL block string
String block = " BEGIN " +
" INSERT INTO testblob (id, photo) VALUES (100, :1); " +
" SELECT photo into :2 from testblob WHERE id = 100; " +
" END; ";
// Set command to create Anonymous PL/SQL Block
OracleCommand cmd = new OracleCommand();
cmd.CommandText = block;
cmd.Connection = con;
// Since executing an anonymous PL/SQL block, setting the command type
// as Text instead of StoredProcedure
cmd.CommandType = CommandType.Text;
// Step 4
// Setting Oracle parameters
// Bind the parameter as OracleDbType.Blob to command for inserting image
OracleParameter param = cmd.Parameters.Add("blobtodb", OracleDbType.Blob);
param.Direction = ParameterDirection.Input;
// Assign Byte Array to Oracle Parameter
param.Value = ImageData;
// Bind the parameter as OracleDbType.Blob to command for retrieving the image
OracleParameter param2 = cmd.Parameters.Add("blobfromdb", OracleDbType.Blob);
param2.Direction = ParameterDirection.Output;
// Step 5
// Execute the Anonymous PL/SQL Block
// The anonymous PL/SQL block inserts the image to the
// database and then retrieves the images as an output parameter
cmd.ExecuteNonQuery();
Console.WriteLine("Image file inserted to database from " + SourceLoc);
// Step 6
// Save the retrieved image to the DestinationLoc in the file system
// Create a byte array
byte[] byteData = new byte[0];
// fetch the value of Oracle parameter into the byte array
byteData = (byte[])((OracleBlob)(cmd.Parameters[1].Value)).Value;
// get the length of the byte array
int ArraySize = new int();
ArraySize = byteData.GetUpperBound(0);
// Write the Blob data fetched from database to the filesystem at the
// destination location
FileStream fs1 = new FileStream(#DestinationLoc,
FileMode.OpenOrCreate, FileAccess.Write);
fs1.Write(byteData, 0,ArraySize);
fs1.Close();
Console.WriteLine("Image saved to " + DestinationLoc + " successfully !");
Console.WriteLine("");
Console.WriteLine("***********************************************************");
Console.WriteLine("Before running this application again, execute 'Listing 1' ");
private void btnSave_Click(object sender, EventArgs e)
{
try
{
//Read Image Bytes into a byte array
byte[] blob = ReadFile(txtPath.Text);
//Initialize Oracle Server Connection
con = new OracleConnection(conString);
//Set insert query
string qry = "insert into Imgpn (imgpath,photo) values('" + txtPath.Text + "'," + " :BlobParameter )";
OracleParameter blobParameter = new OracleParameter();
blobParameter.OracleType = OracleType.Blob;
blobParameter.ParameterName = "BlobParameter";
blobParameter.Value = blob;
//Initialize OracleCommand object for insert.
cmd = new OracleCommand(qry, con);
//We are passing Name and Blob byte data as Oracle parameters.
cmd.Parameters.Add(blobParameter);
//Open connection and execute insert query.
con.Open();
cmd.ExecuteNonQuery();
MessageBox.Show("Image added to blob field");
GetImagesFromDatabase();
cmd.Dispose();
con.Close();
//this.Close();
}
catch (Exception ex)
{
MessageBox.Show(ex.ToString());
}
}
byte[] ReadFile(string sPath)
{
//Initialize byte array with a null value initially.
byte[] data = null;
//Use FileInfo object to get file size.
FileInfo fInfo = new FileInfo(sPath);
long numBytes = fInfo.Length;
//Open FileStream to read file
FileStream fStream = new FileStream(sPath, FileMode.Open, FileAccess.Read);
//Use BinaryReader to read file stream into byte array.
BinaryReader br = new BinaryReader(fStream);
//When you use BinaryReader, you need to supply number of bytes to read from file.
//In this case we want to read entire file. So supplying total number of bytes.
data = br.ReadBytes((int)numBytes);
return data;
}
void GetImagesFromDatabase()
{
try
{
//Initialize Oracle connection.
con = new OracleConnection(conString);
//MessageBox.Show("Connection Successfull");
//Initialize Oracle adapter.
OracleDataAdapter oda = new OracleDataAdapter("Select * from Imgpn", con);
//Initialize Dataset.
DataSet DS = new DataSet();
//Fill dataset with ImagesStore table.
oda.Fill(DS, "Imgpn");
//Fill Grid with dataset.
dataGridView1.DataSource = DS.Tables["Imgpn"];
//
}
catch (Exception ex)
{
MessageBox.Show(ex.ToString());
}
}
here is the simple way to insert image into oracle database ane retrieve ane show in datagridview