根据会员名称通过vb.net从数据库中获取值？

Question

I have a SQL table which looks like:

+-------------------+
| id   member   req |
+-------------------+
| 1    Jim      0   |
| 2    Mary     0   |
| 3    Hunter   0   |
+-------------------+

I need to get the id of a certain member through my vb.net application (WinForms) in Visual Basic 2010.

Lets say I wanted to get Mary 's id . What is the SQL query to return the id for Mary ?

Whats the Query for that?

--------------------------------------------------------------------------------

Possible Query Code:

'My.Settings.username is the name I'm looking up in the database to get the member id .

Dim SQLID As String = "SELECT id FROM members WHERE member= '" & My.Settings.username & "'" submitRequest(SQLID) vagueID.Text = 'ID Here'

Answer 1

First, download the MySQL connector .

Second, add a reference to the MySQL connection to your project.

Third, import the Namespace of which you'll be using many of the classes from to reduce typing (at top of .vb file):

Imports MySql.Data.MySqlClient

Finally in your Form's Load event handler (or other event handler where you wish to display the ID in the label):

'Change to your specific connection string.
Dim strConnectionString As String = "Database=YourDatabaseName;Data Source=localhost;User Id=YourUser;Password=YourPassword"

Dim sqlConnection As New MySqlConnection(strConnectionString)

Dim strCommandText = "SELECT id FROM members WHERE member = @Member"

'Assumes that the ID field is an INT type.  Use a Long type if the type is a BIGINT.
Dim intID as Integer

Try

    'Open the connection.
    sqlConnection.Open()

    'Create a command to get the ID.
    Dim sqlCommand As MySqlCommand = New MySqlCommand(strCommandText, sqlConnection)

    'It is always a good idea to use parameters.
    sqlCommand.Parameters.AddWithValue("@Member", My.Settings.username)

    vagueID.Text = Convert.ToString(sqlCommand.ExecuteScalar())

Catch ex As Exception
    'Error handling goes here.
    MsgBox(ex.Message)
Finally
    'Always close the connection!
    sqlConnection.Close()
End Try

Answer 2

MySQLCon = New MySqlConnection MySQLCon.ConnectionString = "Database=localhost;Data Source=host;User Id=root;Password=root" Dim READER As MySqlDataReader Dim COMMAND As MySqlCommand Try MySQLCon.Open() Dim SQLID As String = "SELECT id FROM members WHERE member='" & My.Settings.username & "'" COMMAND = New MySqlCommand(SQLID, MySQLCon) READER = COMMAND.ExecuteReader() While READER.Read vagueID.Value2 = READER.GetInt32("id") End While MySQLCon.Close() MySQLCon.Dispose() Catch ex As Exception 'Do Something End Try