Camilo Lozano III

I’ve been searching an article about storing and retrieving an image (BLOB data type) from MySQL database. Somehow, I only found the retrieving process but I created the storing process using PHP…

You may download my works, link provided below…

• idsystem_database.sql.zip – the dump file of MySQL database; import this SQL file before running the project
• the rest of the files are the project sample files

-> retrieveImg_public.zip (12) or http://camilord.kagayan.com/my.files/retrieveImg_public.zip

For the credits, Thanks to Markusek Peter…

MySqlConnection myConnection = new MySqlConnection(myConnString);

string testQuery = “SELECT sp.studePhoto, s.firstName, s.lastName

FROM students AS s, student_photos AS sp WHERE s.id = sp.studentID”;
MySqlCommand myCommand = new MySqlCommand(testQuery, myConnection);

myConnection.Open();
MySqlDataReader myReader = myCommand.ExecuteReader();

FileStream fs; // Writes the BLOB to a file (*.jpg).

BinaryWriter bw; // Streams the BLOB to the FileStream object.

int bufferSize = 100; // Size of the BLOB buffer.

// The BLOB byte[] buffer to be filled by GetBytes.

byte[] outbyte = new byte[bufferSize];
long retval; // The bytes returned from GetBytes.
long startIndex = 0; // The starting position in the BLOB output.

while (myReader.Read())
{
DateTime tmp = new DateTime();
tmp = DateTime.Now;
// Create a file to hold the output.
string filename = camilordMD5(tmp.ToLongDateString().ToString() + tmp.ToLongTimeString().ToString()) + “.jpg”;

string dest = Directory.GetCurrentDirectory() + “/” + filename;
fs = new FileStream(dest, FileMode.OpenOrCreate, FileAccess.Write);
bw = new BinaryWriter(fs);

// Reset the starting byte for the new BLOB.
startIndex = 0;
// Read the bytes into outbyte[] and retain the number of bytes returned.

//myReader.GetBytes(0, startIndex, outbyte, 0, bufferSize);
retval =(long) myReader.GetBytes(0, startIndex, outbyte, 0, bufferSize);
lblName.Text = myReader.GetString(1) + ” ” + myReader.GetString(2);

// Continue reading and writing while there are bytes beyond the size of the buffer.
while (retval == bufferSize)
{
bw.Write(outbyte);
bw.Flush();

// Reposition the start index to the end of the last buffer and fill thebuffer.
startIndex += bufferSize;
retval = myReader.GetBytes(0, startIndex, outbyte, 0, bufferSize);

}

pictureBox1.ImageLocation = Directory.GetCurrentDirectory() + “/test.jpg”;
//pictureBox1.Image = retval;

// Write the remaining buffer.

bw.Write(outbyte, 0, (int)retval – 1);
bw.Flush();

// Close the output file.
bw.Close();
fs.Close();
}

Camilo III Info.Tech, Software Development, Visual C#