使用mysqldump的Mysql备份输出空文件

Question

I want to make a backup of MySQL Database in Vb.net. I'm using this code :

Dim myProcess As New Process()
myProcess.StartInfo.FileName = "cmd.exe"
myProcess.StartInfo.UseShellExecute = False
myProcess.StartInfo.WorkingDirectory = "c:\bu\"
myProcess.StartInfo.RedirectStandardInput = True
myProcess.StartInfo.RedirectStandardOutput = True

myProcess.Start()
Dim myStreamWriter As StreamWriter = myProcess.StandardInput
Dim mystreamreader As StreamReader = myProcess.StandardOutput
myStreamWriter.WriteLine("mysqldump --user=root --password=MYPASSWORD --host=localhost MYDATABASE > ""C:\bu\1.sql""")
myStreamWriter.Close()
myProcess.WaitForExit()
myProcess.Close()

Thats create a file but the file is always empty...

Answer 1

In my experience as I remember passwords are not allowed to entered by cmd commands. Try this code to get error message on output:

    Dim myProcess As New Process()
    myProcess.StartInfo.FileName = "cmd.exe"
    myProcess.StartInfo.WorkingDirectory = mysql_path + "\bin"
    myProcess.StartInfo.UseShellExecute = False
    myProcess.StartInfo.RedirectStandardInput = True
    myProcess.StartInfo.RedirectStandardOutput = True
    myProcess.StartInfo.RedirectStandardError = True

    myProcess.Start()
    Dim myStreamWriter As StreamWriter = myProcess.StandardInput
    Dim mystreamreader As StreamReader = myProcess.StandardOutput
    Dim mystreamerror As StreamReader = myProcess.StandardError
    myStreamWriter.WriteLine(String.Format("mysqldump --user=root --password=MYPASSWORD --host=localhost MYDATABASE > ""C:\bu\1.sql""")
    myStreamWriter.WriteLine(String.Format("exit"))
    myStreamWriter.Close()
    Dim msg As String = mystreamerror.ReadToEnd()
    mystreamerror.Close()
    If msg.Length > 0 Then
        MsgBox(msg)
    End If
    myProcess.WaitForExit()
    myProcess.Close()

If the problem is from setting password you can check this article for setting a password in options file.