Inserting data into a MySQL table using VB.NET

Question

I have a problem inserting data into a table on a MySQL database using a VB.NET application. I have a simple form where when I set some data to the textboxes and I press a

Answer 1

Dim connString as String ="server=localhost;userid=root;password=123456;database=uni_park_db"
Dim conn as MySqlConnection(connString)
Dim cmd as MysqlCommand
Dim dt as New DataTable
Dim ireturn as Boolean

Private Sub Insert_Car()

Dim sql as String = "insert into members_car (car_id, member_id, model, color, chassis_id, plate_number, code) values (@car_id,@member_id,@model,@color,@chassis_id,@plate_number,@code)"

Dim cmd = new MySqlCommand(sql, conn)

    cmd.Paramaters.AddwithValue("@car_id", txtCar.Text)
    cmd.Paramaters.AddwithValue("@member_id", txtMember.Text)
    cmd.Paramaters.AddwithValue("@model", txtModel.Text)
    cmd.Paramaters.AddwithValue("@color", txtColor.Text)
    cmd.Paramaters.AddwithValue("@chassis_id", txtChassis.Text)
    cmd.Paramaters.AddwithValue("@plate_number", txtPlateNo.Text)
    cmd.Paramaters.AddwithValue("@code", txtCode.Text)

    Try
        conn.Open()
        If cmd.ExecuteNonQuery() > 0 Then
            ireturn = True
        End If  
        conn.Close()


    Catch ex as Exception
        ireturn = False
        conn.Close()
    End Try

Return ireturn

End Sub

Answer 2

You need to use ?param instead of @param when performing queries to MySQL

 str_carSql = "insert into members_car (car_id, member_id, model, color, chassis_id, plate_number, code) values (?id,?m_id,?model,?color,?ch_id,?pt_num,?code)"
        sqlCommand.Connection = SQLConnection
        sqlCommand.CommandText = str_carSql
        sqlCommand.Parameters.AddWithValue("?id", TextBox20.Text)
        sqlCommand.Parameters.AddWithValue("?m_id", TextBox20.Text)
        sqlCommand.Parameters.AddWithValue("?model", TextBox23.Text)
        sqlCommand.Parameters.AddWithValue("?color", TextBox24.Text)
        sqlCommand.Parameters.AddWithValue("?ch_id", TextBox22.Text)
        sqlCommand.Parameters.AddWithValue("?pt_num", TextBox21.Text)
        sqlCommand.Parameters.AddWithValue("?code", ComboBox1.SelectedItem)
        sqlCommand.ExecuteNonQuery()

Change the catch block to see the actual exception:

  Catch ex As Exception
         MsgBox(ex.Message)   
          Return False

    End Try

Answer 3

After instantiating the connection, open it.

  SQLConnection = New MySqlConnection()
  SQLConnection.ConnectionString = connectionString
  SQLConnection.Open()

Also, avoid building SQL statements by just appending strings. It's better if you use parameters, that way you win on performance, your program is not prone to SQL injection attacks and your program is more stable. For example:

 str_carSql = "insert into members_car 
               (car_id, member_id, model, color, chassis_id, plate_number, code) 
               values 
               (@id,@m_id,@model,@color,@ch_id,@pt_num,@code)"

And then you do this:

sqlCommand.Parameters.AddWithValue("@id",TextBox20.Text)
sqlCommand.Parameters.AddWithValue("@m_id",TextBox23.Text)
' And so on... 

Then you call:

sqlCommand.ExecuteNonQuery()

Answer 4

You need to open the connection first:

 SQLConnection.Open();

Answer 5

• First, You missed this one: sqlCommand.CommandType = CommandType.Text
• Second, Your MySQL Parameter Declaration is wrong. It should be @ and not ?

try this:

Public Function InsertCar() As Boolean

    Dim iReturn as boolean
    Using SQLConnection As New MySqlConnection(connectionString)
        Using sqlCommand As New MySqlCommand()
            With sqlCommand
                .CommandText = "INSERT INTO members_car (`car_id`, `member_id`, `model`, `color`, `chassis_id`, `plate_number`, `code`) values (@xid,@m_id,@imodel,@icolor,@ch_id,@pt_num,@icode)"
                .Connection = SQLConnection
                .CommandType = CommandType.Text // You missed this line
                .Parameters.AddWithValue("@xid", TextBox20.Text)
                .Parameters.AddWithValue("@m_id", TextBox20.Text)
                .Parameters.AddWithValue("@imodel", TextBox23.Text)
                .Parameters.AddWithValue("@icolor", TextBox24.Text)
                .Parameters.AddWithValue("@ch_id", TextBox22.Text)
                .Parameters.AddWithValue("@pt_num", TextBox21.Text)
                .Parameters.AddWithValue("@icode", ComboBox1.SelectedItem)
            End With
            Try
                SQLConnection.Open()
                sqlCommand.ExecuteNonQuery()
                iReturn = TRUE
            Catch ex As MySqlException
                MsgBox ex.Message.ToString
                iReturn = False
            Finally
                SQLConnection.Close()
            End Try
        End Using
    End Using

   Return iReturn

End Function

Answer 6

your str_carSql should be exactly like this:

str_carSql = "insert into members_car (car_id, member_id, model, color, chassis_id, plate_number, code) values (@id,@m_id,@model,@color,@ch_id,@pt_num,@code)"

Good Luck