MySQL Connector/NET Release Notes
To write a file to a database, we need to convert the file to a
byte array, then use the byte array as a parameter to an
INSERT
query.
The following code opens a file using a FileStream object, reads
it into a byte array, and inserts it into the
file
table:
C# Code Example
Press CTRL+C to copyMySql.Data.MySqlClient.MySqlConnection conn; MySql.Data.MySqlClient.MySqlCommand cmd; conn = new MySql.Data.MySqlClient.MySqlConnection(); cmd = new MySql.Data.MySqlClient.MySqlCommand(); string SQL; UInt32 FileSize; byte[] rawData; FileStream fs; conn.ConnectionString = "server=127.0.0.1;uid=root;" + "pwd=12345;database=test"; try { fs = new FileStream(@"c:\image.png", FileMode.Open, FileAccess.Read); FileSize = fs.Length; rawData = new byte[FileSize]; fs.Read(rawData, 0, FileSize); fs.Close(); conn.Open(); SQL = "INSERT INTO file VALUES(NULL, @FileName, @FileSize, @File)"; cmd.Connection = conn; cmd.CommandText = SQL; cmd.Parameters.AddWithValue("@FileName", strFileName); cmd.Parameters.AddWithValue("@FileSize", FileSize); cmd.Parameters.AddWithValue("@File", rawData); cmd.ExecuteNonQuery(); MessageBox.Show("File Inserted into database successfully!", "Success!", MessageBoxButtons.OK, MessageBoxIcon.Asterisk); conn.Close(); } catch (MySql.Data.MySqlClient.MySqlException ex) { MessageBox.Show("Error " + ex.Number + " has occurred: " + ex.Message, "Error", MessageBoxButtons.OK, MessageBoxIcon.Error); }
Visual Basic Code Example
Press CTRL+C to copyDim conn As New MySqlConnection Dim cmd As New MySqlCommand Dim SQL As String Dim FileSize As UInt32 Dim rawData() As Byte Dim fs As FileStream conn.ConnectionString = "server=127.0.0.1;" _ & "uid=root;" _ & "pwd=12345;" _ & "database=test" Try fs = New FileStream("c:\image.png", FileMode.Open, FileAccess.Read) FileSize = fs.Length rawData = New Byte(FileSize) {} fs.Read(rawData, 0, FileSize) fs.Close() conn.Open() SQL = "INSERT INTO file VALUES(NULL, @FileName, @FileSize, @File)" cmd.Connection = conn cmd.CommandText = SQL cmd.Parameters.AddWithValue("@FileName", strFileName) cmd.Parameters.AddWithValue("@FileSize", FileSize) cmd.Parameters.AddWithValue("@File", rawData) cmd.ExecuteNonQuery() MessageBox.Show("File Inserted into database successfully!", _ "Success!", MessageBoxButtons.OK, MessageBoxIcon.Asterisk) conn.Close() Catch ex As Exception MessageBox.Show("There was an error: " & ex.Message, "Error", _ MessageBoxButtons.OK, MessageBoxIcon.Error) End Try
The Read
method of the
FileStream
object is used to load the file
into a byte array which is sized according to the
Length
property of the
FileStream
object.
After assigning the byte array as a parameter of the
MySqlCommand
object, the
ExecuteNonQuery
method is called and the
BLOB
is inserted into the
file
table.