How can I get the usernames in the account? - mysql

Question

I'm making a VB.Net application which connects to a MySql database.
My application has many Accounts, and each account has several Users. I want to show this information, but the application just shows the first user of each account.
This is the code:
Public Function id(Label2 As String) As Double
Using connection = Getconnection()
connection.Open()
Using commandid = New MySqlCommand
commandid.Connection = connection
commandid.CommandText = "SELECT *FROM player.player
Where player.account_id=" & testString & V
Dim read = commandid.ExecuteReader
If read.HasRows Then
While read.Read
ActivateUser.namecharacter = read.GetString(2)
ActivateUser.job = read.GetString(3)
End While
read.Dispose()
Return True
Else
MessageBox.Show(" no ")
Return False
End If
connection.Close()
connection.Dispose()
End Using
End Using
End Function
How can I fix this to show all the users in the account?

Answer 1

Just create you connection in the method where you use it. Get rid of GetConnection just use a class level variable for the connection string.
Don't open a connection until directly before you use it.
You can include the command in the same using block by adding a comma at the end of the first line. Commands also need to be disposed. The command constructor can take the CommandText and the Connection as parameters.
What datatype is account_id in the database? I am going to guess it is a string type. Is V a variable or is it meant to be the string "V"? I am going to guess a hardcoded string. Where does testString come from? I am going to guess Label2 (terrible non-descriptive name) is teststring.
Never concatenate strings for you sql. Always use parameters.
A reader also needs to be closed and disposed so use Using blocks. The whole idea of accessing the database is to get in and out as quickly as possible. Don't set properties of ActivateUser and never show a message box. The user could have gone to lunch and your connection is left flapping in the breeze.
You have the datatype of your function as Double but your return statements have Booleans. Won't work.
It is not necessary to close and dispose the connection. The End Using does that.
Private ConStr As String = "Your connection string"
Public Function id(Label2 As String) As DataTable
Dim dt As New DataTable
Using connection As New MySqlConnection(ConStr),
commandid As New MySqlCommand("SELECT *FROM player Where account_id= #TestString;", connection)
commandid.Parameters.Add("#TestString", MySqlDbType.VarChar).Value = Label2 & "V"
connection.Open()
Using reader = commandid.ExecuteReader
dt.Load(reader)
End Using
End Using
Return dt
End Function
Then back in the User Interface code:
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Dim dt = id(Label2.Text)
If dt.Rows.Count > 0 Then
ActivateUser.namecharacter = dt(0)(2).ToString
ActivateUser.job = dt(0)(3).ToString
Else
MessageBox.Show(" no ")
End If
End Sub
This makes a good separation of from your database code.