VB.net and SQL .... For multiple read of database table - vb.net

Question

Im am currently coding an handsfree RFID attendance monitoring system where i could just swipe and record details automatically...
I've been in trouble about this piece of code where i need to fetch a table and another table inorder to check if there is an existing record in table1 as the details and table2 as a record in in/out. I wanted it as much as possible to be able to be in a 1 while loop
**
I kept getting this error **
Invalid attempt to access a field before calling Read()
`
Private Sub TextBox7_KeyDown(sender As Object, e As KeyEventArgs) Handles TextBox7.KeyDown
If e.KeyCode = Keys.Enter Then
'Dim idnum = Val(TextBox7.Text
Dim statu As String = ""
Dim idnum = (TextBox7.Text)
Dim record As String = ""
TextBox2.Text = ""
TextBox3.Text = ""
TextBox4.Text = ""
ConnectToDB()
sql = "select * from rfidmaintest.student_details_dub where f9 = '" & idnum & "'"
cmd = New MySqlCommand(sql, cn)
dr = cmd.ExecuteReader
While dr.Read
TextBox2.Text = (dr("f2"))
TextBox3.Text = (dr("f9"))
TextBox4.Text = (dr("f4"))
TextBox5.Text = (dr("f14"))
TextBox6.Text = (dr("f3"))
TextBox7.Clear()
dr.Close()
cn.Close()
'ANOTHER FETCH
ConnectToDB()
sql = "select * from rfidmaintest.monitoring where id_num = '" & idnum & "'"
cmd = New MySqlCommand(sql, cn)
dr = cmd.ExecuteReader
**Invalid attempt to access a field before calling Read()**
If (dr("entry_record")) = String.Empty Then
status.Text = "IN"
End If
If status.Text = "IN" Then
status.Text = (dr("entry_record"))
record = "OUT"
ElseIf status.Text = "OUT" Then
record = "IN"
ElseIf status.Text = String.Empty Then
record = "IN"
End If
End While
dr.Close()
cn.Close()
`
I tried to call the table

Answer 1

You need another dr.read for the second query or you can use another reader, for example like dr2.read.
Your first While dr.read already closed with dr.close, you need to reopen the reader to continue to read the second query