VB.NET MySQL: How to Create, Read, Update, Delete (CRUD)

On previous articles we discussed:

Next, I'm going to give you a Step by Step Tutorial on how to Create (add new data), Read, Update, Delete.

I use table named "class" which has structure and values as below:

First, we need to prepare buttons that used to Save, Edit, Delete, Cancel, and Exit.
I'm going to create the buttons using ToolStrip Control.

Further about create and work with ToolStrip Control, read also this article:

Working with ToolStrip Control

For inputting data, add labels and textboxes as below.

Add a panel as container of those labels and textboxes for inputting data, then set property Dock = Top. Finally, add datagridview and set the property of datagridview Dock = Fill. Name control as above image.

Done with UI, let's start with code behind. Import MySqlClient and System.Data:
Imports MySql.Data.MySqlClient
Imports System.Data

Declare an object connection and a string variable for query. I name the form with frmClass.
Public Class frmClass
    Dim conn As MySqlConnection
    Dim SQL As String

End Class

Create a sub procedure named Data_Load to display data into datagridview. Make sure to place this procedure under frmClass class. I add syntax of Try Catch as error handling.
Sub Data_Load()
    Dim myCommand As New MySqlCommand
    Dim myAdapter As New MySqlDataAdapter
    Dim myData As New DataTable

    conn = New MySqlConnection()
    conn.ConnectionString = "server=localhost;user id=root;" & _
                            "password=;database=datapos"
    Try
        If conn.State = ConnectionState.Closed Then conn.Open()
        SQL = "Select classcode, classname From class"

        myCommand.Connection = conn
        myCommand.CommandText = SQL

        myAdapter.SelectCommand = myCommand
        myAdapter.Fill(myData)
        With grdData
            .DataSource = myData
            .AllowUserToAddRows = False
            .AllowUserToDeleteRows = False
            .ReadOnly = True

            .Columns(0).HeaderText = "Kode Kelas"
            .Columns(1).HeaderText = "Nama Kelas"
            .Columns(0).Width = 100
            .Columns(1).Width = 250
        End With

        conn.Close()
    Catch myerror As MySqlException
        MessageBox.Show("Error: " & myerror.Message)
    Finally
        conn.Dispose()
    End Try
End Sub

Execute the procedure under Form_Load event .
Private Sub frmClass_Load(ByVal sender As Object, _
    ByVal e As System.EventArgs) Handles Me.Load
    Data_Load()
End Sub

Keep going...., we'll create a procedure to add new data. Users will input code and name into textboxes, then click Save button for saving new data into the database. Codes that need to be added under tbrSave_Click event are as following:
Private Sub tbrSave_Click(ByVal sender As System.Object, _
    ByVal e As System.EventArgs) Handles tbrSave.Click

    Dim myCommand As New MySqlCommand

    conn = New MySqlConnection()
    conn.ConnectionString = "server=localhost;user id=root;" & _
                            "password=;database=datapos"
    Try
        conn.Open()
        SQL = "INSERT INTO class (classcode, classname) VALUES " & _
              "('" & txtCode.Text & "', '" & txtName.Text & "')"

        myCommand.Connection = conn
        myCommand.CommandText = SQL
        myCommand.ExecuteNonQuery()

        MsgBox("Data baru tersimpan")

        txtCode.Text = String.Empty
        txtName.Text = String.Empty
        Data_Load()

        conn.Close()
    Catch myerror As MySqlException
        MessageBox.Show("Error: " & myerror.Message)
    Finally
        conn.Dispose()
    End Try
End Sub

A message box is added after inserting data as an alert that data adding has already been succeeded. Data_Load procedure is called again after, for displaying the newest update.
Let run the app then try to add a new data.