I'm a beginner developer and I'm currently learning Visual Basic 2008 Express Edition. I'd like create the following program:

  • search custom selected database
  • if selected database contains TABLEX and if TABLEX has data in ColumnY and it equals 0 then make some sort of signal/error/report where it's wrong and what should be changed

The code so far:

Public Class Form1

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click

        Dim sql As String ' SQL Command String
        Dim cmd As OleDb.OleDbCommand  ' New DB Command   

        Dim dbPath As String = OpenFileDialog1.FileName
        Dim connStr As String = "Provider=Microsoft.Jet.OLEDB.4.0;" _
        & "Data Source=" & dbPath & "; Persist Security Info = False;"

        Dim dBaseConnection As New System.Data.OleDb.OleDbConnection(connStr)

        If dBaseConnection.State = 1 Then
            Label1.Text = "Database loaded!"
            Label1.Text = "Database not loaded!"
        End If

        sql = "SELECT ColumnY FROM TABLEX"

        cmd = New OleDb.OleDbCommand(sql, dBaseConnection)


    End Sub

How I can make the selected data equal a variable/string or anything like that? I just coudn't find any solution regarding this. And what if it has more similar data and I want to check each of them if it's 0?

Thanks for all the help and answers in advance!

Which database are you using?

MS Access 2000.

I'm basicly interested in the method of the whole thing.

  1. I select the table, column and row
  2. I make a check on the data
  3. Making decision based on result (read number, column for example: If table with two columns: Name, Apple. If John has zero apple the program will report that "database number 1, name: John has Zero apples)

That's what I'd like to do.

Do you have two database?

Pgamer: Er... No? I have only one database as "source", but it can be changed if I set a new. It's a simple "open new database button" and it sets as the new dbPath for the system and reopens it.

So basicly I have many DB and each of them has a "TABLEX".

My two cents - you try to open the database (lines 14-22) but you continue on and try the query even if the database doesn't open. If the open fails then you should not try the query.

commented: Yeah, but what does a yellow light mean? +0