SQL and VISUAL BASIC 2008 Queries

How can I write a sql query that takes information f开发者_JAVA技巧rom a database, and then put in the text in a label? I'm not really sure how to do this.

MSDN has lots of examples of getting data via ADO.NET. E.g. http://msdn.microsoft.com/library/dw70f090.

You will need to adjust the connection and command types (and the connection string) to be correct for My SQL. If you have ODBC drivers for My SQL then you can follow the ODBC example with just a change of connection string.

For using MySQL with .NET I'd recommend you this tutorial, and for your problem specially part 6, about reading the data with a MySQLDataReader.

An (almost working) sample by copy&paste from there with some changes:

Private Sub getData()
      Dim conn As New MySqlConnection
      Dim myCommand As New MySqlCommand
      Dim myReader As MySqlDataReader
      Dim SQL As String

      SQL = "SELECT LabelContent FROM myTable"

      conn.ConnectionString = myConnString ' your connection string here'

      Try
           conn.Open()

           Try
                myCommand.Connection = conn
                myCommand.CommandText = SQL

                myReader = myCommand.ExecuteReader

                                        ' loop through all records'
                While myReader.Read
                 Dim myLabelValue as String
                 myLabelValue = myReader.GetString(myReader.GetOrdinal("LabelContent"))

                 ' ... do something with the value, e.g. assign to label '
                End While
           Catch myerror As MySqlException
                MsgBox("There was an error reading from the database: " & myerror.Message)
           End Try
      Catch myerror As MySqlException
            MessageBox.Show("Error connecting to the database: " & myerror.Message)
      Finally
            If conn.State <> ConnectionState.Closed Then conn.Close()
      End Try
End Sub

For selecting one column to label from ms access 2007 database just follow this step

1. Create ms access database for example i make name "test.accdb" and make 1 column for example column name is "ColumnName" and one table with name "Table1"
2. save it on whatever folder
3. open vb 2008 and make one form
4. import adodb on first writing
5. write this code inside class

Sub lihat()
    Dim str As String = "select * from Table1"
    Dim cn As New OleDb.OleDbConnection
    Dim com As New OleDb.OleDbCommand
    Dim adp As OleDb.OleDbDataReader
    With cn
        .ConnectionString = "Provider=Microsoft.ace.oledb.12.0;data source=test.accdb;persist security info=false"
        .Open()
    End With

    With com
        .Connection = cn
        .CommandText = str
    End With

    adp = com.ExecuteReader
    adp.Read()


    Label1.Text = adp(1)
    cn.Close()
End Sub

Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
    lihat()
End Sub

number 1 on adp(1) is number of column on Table1.