Get specific value from database to validate data - sql

Question

I want to take a value entered by the user and validate it against known values in a database.
I'm using VB.net (VS 2010) as a front end winform and dumping data into MSAccess. I have a table with values such as min weight and max weight, the user will enter a weight, and it needs to fall between the min weight and max weight values in the table.
I'm already created an open connection with the database I need, I guess I just don't know enogh VB.net and SQL to make it do what I want.
I want to have the user enter the Primary key of the table with the min weight and max weights and then use that to bring in the min max weights, then check the weight the user entered against the min max weights.
Here is all the code; the only really relevant code is the validate button click at the bottom. I just thought possibly this would give more context. Any point in the right direction will help, even if it gives me better keywords to google. Thanks!
Imports System.Data.OleDb
Public Class Form1
Dim dbInsert As New OleDb.OleDbCommand
Dim dbConnect As New OleDb.OleDbConnection
Dim Line As String = Environment.NewLine
Dim Job As VariantType
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs)
Try
dbConnect.ConnectionString = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=C:\Users\crabara\Desktop\Project Alpha 3\MDB.accdb;Persist Security Info=False;"
dbConnect.Open()
Catch ex As Exception
MessageBox.Show(ex.Message + Line + "Main Database Not Found" + Line + "Check form_AccessMaintenance source code" + Line + "Database Path", "Critical Error", MessageBoxButtons.OK, MessageBoxIcon.Error)
Me.Close()
End Try
End Sub
Private Sub btnSubmit_Click(ByVal sender As System.Object, ByVal e As System.EventArgs)
Dim Part As String, Job As String, Emp As String, Weight As String, Oven As String
Part = txtPart.Text
Job = txtJob.Text
Emp = txtEmp.Text
Weight = txtWeight.Text
Oven = txtOven.Text
If ((Job.StartsWith("JH") And Job.Length = 10) Or Job.Equals("MT")) = False Then
MsgBox("Please input the correct Job Number.")
txtJob.Clear()
txtJob.Focus()
Exit Sub
ElseIf Part.Length = 0 Then
MsgBox("Please input the correct Part Number.")
txtPart.Clear()
txtPart.Focus()
Exit Sub
ElseIf Emp.Length = 0 Then
MsgBox("Please input the correct Employee Number.")
txtEmp.Clear()
txtEmp.Focus()
Exit Sub
ElseIf Weight.Length = 0 Then
MsgBox("Please input the correct Weight.")
txtWeight.Clear()
txtWeight.Focus()
Exit Sub
ElseIf Oven.Length = 0 Then
MsgBox("Please input the correct Oven Number.")
txtOven.Clear()
txtOven.Focus()
Exit Sub
End If
dbInsert.Parameters.Add(dbInsert.CreateParameter).ParameterName = "Part"
dbInsert.Parameters.Item("Part").Value = txtPart.Text
dbInsert.Parameters.Add(dbInsert.CreateParameter).ParameterName = "Job"
dbInsert.Parameters.Item("Job").Value = txtJob.Text
dbInsert.Parameters.Add(dbInsert.CreateParameter).ParameterName = "Emp"
dbInsert.Parameters.Item("Emp").Value = txtEmp.Text
dbInsert.Parameters.Add(dbInsert.CreateParameter).ParameterName = "Weight"
dbInsert.Parameters.Item("Weight").Value = txtWeight.Text
dbInsert.Parameters.Add(dbInsert.CreateParameter).ParameterName = "Oven"
dbInsert.Parameters.Item("Oven").Value = txtOven.Text
Try
dbInsert.CommandText = "INSERT INTO Foam(Part,Job,Emp,Weight,Oven) VALUES(txtPart.Text, txtJob.Text, txtEmp.Text, txtWeight.Text, txtOven.Text);"
dbInsert.CommandType = CommandType.Text
dbInsert.Connection = dbConnect
dbInsert.ExecuteNonQuery()
MessageBox.Show("Data has been successfully submitted" + Line + txtPart.Text)
txtPart.Clear()
txtJob.Clear()
txtEmp.Clear()
txtWeight.Clear()
txtOven.Clear()
Control.MousePosition.Equals(txtPart)
Catch ex As Exception
MessageBox.Show(ex.Message)
End Try
End Sub
Private Sub txtJob_GotFocus(sender As Object, e As System.EventArgs)
txtJob.Clear()
End Sub
Private Sub txtJob_LostFocus(sender As Object, e As System.EventArgs)
Dim Job2 As String
Job2 = txtJob.Text
If txtJob.Text.Length = 8 Then
txtJob.Text = "JH" + Job2
End If
End Sub
Private Sub btnValidate_Click_1(sender As System.Object, e As System.EventArgs) Handles btnValidate.Click
Dim Pcr As Integer
Pcr = txtPcr.Text
Try
dbInsert.CommandText = "SELECT MoldVinylWeightMin FROM PROCESS_INFO where PCRNumber= '" & txtPcr.Text & "'"""
'How can I get this data I've selected into a variable I can work with, also not sure if the above command actually works also this only gives me the min I need the max too
dbInsert.CommandType = CommandType.Text
dbInsert.Connection = dbConnect
dbInsert.ExecuteNonQuery()
MessageBox.Show("Data has been successfully submitted" + Line + txtPart.Text)
Catch ex As Exception
End Try
End Sub
End Class

Answer 1

I think below code will help you
Dim table = New DataTable()
Dim adp As New System.Data.OleDb.OleDbDataAdapter("SELECT MoldVinylWeightMin FROM PROCESS_INFO where PCRNumber= '" & txtPcr.Text & "'", dbConnect)
adp.Fill(table)
If table.Rows.Count <> 0 Then
If table.Rows(0).Item("MoldVinylWeightMin") <> YourField Then
Display the message
End If
Else
No record found
End If
using this block you can get the record from the database and apply you validation.