Reading multiple data from multiple databases in vb.Net - vb.net

Question

I have 11 Access database files each having 20 items which needs to be stored in local variables as
RejRsnStn(i)(Reason) where i stands for station number 1 to 11 & Reason stands for Reason 1 to 20.
I am reading this data in following way:
Public Sub ReadReasonCodes()
'Station 1
For Reason = 1 To 20
DatafileStn = "E:\DATANetwork\DATAStation_1.accdb;Jet OLEDB:Database Password=xxxxxxxx"
Dim ConnstringStn As String = provider & DatafileStn
connstringwrkstn = ConnstringStn
myConnection.ConnectionString = ConnstringStn
myConnection.Open()
str = "SELECT * FROM Table_Config WHERE StationNo = 1"
cmd = New OleDbCommand(str, myConnection)
dr = cmd.ExecuteReader
While dr.Read()
RejRsnStn1(Reason) = If(IsDBNull(dr("RejectionReason" & Reason)), "NA", dr("RejectionReason" & Reason))
End While
myConnection.Close()
Next
'Station 2
For Reason = 1 To 20
DatafileStn = "E:\DATANetwork\DATAStation_2.accdb;Jet OLEDB:Database Password=xxxxxxxx"
Dim ConnstringStn As String = provider & DatafileStn
connstringwrkstn = ConnstringStn
myConnection.ConnectionString = ConnstringStn
myConnection.Open()
str = "SELECT * FROM Table_Config WHERE StationNo = 2"
cmd = New OleDbCommand(str, myConnection)
dr = cmd.ExecuteReader
While dr.Read()
RejRsnStn2(Reason) = If(IsDBNull(dr("RejectionReason" & Reason)), "NA", dr("RejectionReason" & Reason))
End While
myConnection.Close()
Next
End Sub
Can you please guide me with a concise method.
Thanks in advance.
Prashant.

Answer 1

I would do something like this:
First I would import System.Data.OleDb and then construct a class to contain all the codes:
Imports System.Data.OleDb
Public Class rCode
Dim _ReasonCode As String = ""
Public Property ReasonCode() As String
Get
Return _ReasonCode
End Get
Set(value As String)
_ReasonCode = value
End Set
End Property
End Class
Public Class RCodes
Public Property Station_1_Reasoncodes As New List(Of rCode)
Public Property Station_2_Reasoncodes As New List(Of rCode)
Public Property Station_3_Reasoncodes As New List(Of rCode)
Public Property Station_4_Reasoncodes As New List(Of rCode)
Public Property Station_5_Reasoncodes As New List(Of rCode)
Public Property Station_6_Reasoncodes As New List(Of rCode)
Public Property Station_7_Reasoncodes As New List(Of rCode)
Public Property Station_8_Reasoncodes As New List(Of rCode)
Public Property Station_9_Reasoncodes As New List(Of rCode)
Public Property Station_10_Reasoncodes As New List(Of rCode)
Public Property Station_11_Reasoncodes As New List(Of rCode)
End Class
Then I would initiate the class I just created:
public class form1
Public ReasonCodes As RCodes = New RCodes
Then I would make a subroutine to get the twenty codes from a database:
public class form1
Public ReasonCodes As RCodes = New RCodes
Public Sub GetReasonCodes(station As String)
Dim Provider As String = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source ="
Dim myConnection As New OleDbConnection
Dim DatafileStn As String = "E:\DATANetwork\DATAStation_" & station & ".accdb;Jet OLEDB:Database Password=xxxxxxxx"
Dim ConnstringStn As String = Provider & DatafileStn
myConnection.ConnectionString = ConnstringStn
myConnection.Open()
Dim cmd As New OleDbCommand("SELECT * FROM Table_Config WHERE StationNo = " & station, myConnection)
Dim dr As OleDbDataReader = cmd.ExecuteReader
Dim s As rCode = New rCode
Dim s2 As New List(Of rCode)
While dr.Read()
For Reason = 1 To 20
If IsDBNull(dr("RejectionReason" & CStr(Reason))) Then s.ReasonCode = "NA" Else s.ReasonCode = CStr(dr("RejectionReason" & CStr(Reason)))
s2.Add(s)
Next
End While
If Not dr.IsClosed Then dr.Close()
myConnection.Close()
dr = Nothing
myConnection = Nothing
Select Case station
Case "1"
ReasonCodes.Station_1_Reasoncodes = s2
Case "2"
ReasonCodes.Station_2_Reasoncodes = s2
Case "3"
ReasonCodes.Station_3_Reasoncodes = s2
Case "4"
ReasonCodes.Station_4_Reasoncodes = s2
Case "5"
ReasonCodes.Station_5_Reasoncodes = s2
Case "6"
ReasonCodes.Station_6_Reasoncodes = s2
Case "7"
ReasonCodes.Station_7_Reasoncodes = s2
Case "8"
ReasonCodes.Station_8_Reasoncodes = s2
Case "9"
ReasonCodes.Station_9_Reasoncodes = s2
Case "10"
ReasonCodes.Station_10_Reasoncodes = s2
Case "11"
ReasonCodes.Station_11_Reasoncodes = s2
End Select
End Sub
Then, I would make the initiator:
Public Sub ReadReasonCodes()
For i As Integer = 1 To 11
GetReasonCodes(CStr(i))
Next
End Sub
End Class
you can access your data from the class "ReasonCodes"
EXA:
Dim Stn6_code15 = ReasonCodes.Station_6_Reasoncodes(14).ReasonCode
'Note: since reasoncodes are stored in an Array, they are 0 based.
'So ReasonCodes.Station_6_Reasoncodes(14).ReasonCode =
'station 6, reason code 15.
Of course, I cannot test this, as I have no access DB files, but it should work, and if not it may require minor tweaks to obtain your goal.
Hope this helps you.