asp.net vb website loop through database rows - vb.net

Question

I am working on my first website and need help with a loop. I have a database table containing food items named Menu with 8 categories (such as Burgers, Appetizers). I also have a menu page on website with 8 different pics to display items from each category. I need to loop through rows of database. What is happening is it's only looping through columns and repeating first line over and over. I'm aware I need a loop but for some reason cannot get that right.
This is code behind:
Partial Class Burger
Inherits System.Web.UI.Page
'String Used to build the necessary markup and product information
Dim str As String = ""
'Var used to interact with SQL database
Dim db As New Interaction
'Adds the necessary markup for each menu item, using its productName
Protected Sub printMenuBlock(ByVal productName As String)
'Set up variable storing the product
Dim product As Product
'Pull the product in from our database using the productName
product = db.ReadProduct(productName)
'Add necessary markup to str variable, with products information within
str += "<div class='storeItem'>"
' str += " <img alt='Item Picture' class='itemPicture' src='" + product.ImagePath.Substring(3).Replace("\", "/") + "' />"
' str += " <div class='itemInfo'>"
str += " <h1 class='itemName'>"
str += " " + product.Name + "</h1>"
str += " <h3 class='itemDescription'>"
str += " " + product.Description + "</h3>"
str += " <p class='itemPrice'>"
str += " " + product.Price.ToString("c") + "</p>"
str += " "
str += " </div>"
str += " </div>"
End Sub
'Uses
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
Dim productNames As New List(Of String)
'Pull the product names using the database
productNames = db.getProductNames
'Loop through all product names
For Each name As String In productNames
'Add necessary markup and product info to str variable
printMenuBlock(name)
Next
'Print the str variable in our menuPlace div
menuPlace.InnerHtml = str
End Sub
End Class
This is functions from interaction class:
Private Sub GetProduct(ByVal CatIn As String)
' SQL String
Dim strSelect As String
strSelect = "SELECT * "
strSelect &= " FROM Menu "
' strSelect &= " WHERE (ProductCat = 'Burgers')"
' Set up the connection to the datebase
cmdSelect.Connection = conIn.Connect
' Add the SQL string to the connection
cmdSelect.CommandText = strSelect
' Add the parameters to the connection
cmdSelect.Parameters.Add("#CatIn", SqlDbType.NVarChar).Value = CatIn
End Sub
'Executes the SQL statement to find a Product by ProductId
Public Function ReadProduct(ByVal CatIn As String) As Product
' Product object initalized to nothing
Dim prod As Product = Nothing
Try
Call GetProduct(CatIn)
Dim dbr As SqlDataReader
Dim strCat As String
Dim strName As String
Dim strDesc As String
Dim decPrice As Decimal
Dim strPath As String
' Execute the created SQL command from GetProduct and set to the SqlDataReader object
dbr = cmdSelect.ExecuteReader
dbr.Read()
' Check if there are any returned values
If dbr.HasRows Then
' Assign the value in column two to strName
strCat = dbr.GetString(1)
' Assign the value in column two to strName
strName = dbr.GetString(2)
' Assign the value in column three to strDesc
strDesc = dbr.GetString(3)
' Assing the value in column four to intPrice
decPrice = ToDecimal(dbr.GetValue(4))
'Assign the value in column five to strPath
'strPath = dbr.GetString(3)
' Create the new Product object from the returned values
prod = New Product(strName, strDesc, decPrice, strCat, strPath)
End If
' Clear the SQL parameters and close the connection
cmdSelect.Parameters.Clear()
dbr.Close()
Catch ex As SqlException
Dim strOut As String
strOut = ex.Message
Console.WriteLine(strOut)
End Try
' Return the Product object
Return prod
End Function
'Returns a list of Product Names
Public Function getProductNames() As List(Of String)
Dim list As New List(Of String)
Dim sql As String = "SELECT ProductName FROM Menu " +
"WHERE (ProductCat) = 'Burgers'"
'"DISTINCT 'ProductName'"
cmdSelect.CommandText = sql
cmdSelect.Connection = conIn.Connect
Dim dbr As SqlDataReader
dbr = cmdSelect.ExecuteReader
If dbr.HasRows Then
Do While dbr.Read()
list.Add(dbr.GetString(0))
Loop
End If
dbr.Close()
Return list
End Function
There is obviously a Product Class but don't think that is necessary to show on here.
Also, ignore the string path, that will be for images later. Thanks for any help. I'm pretty sure instead of do while I need a for each somewhere but just can't get her done. Thanks in advance.
Products Class:
Public Class Product
Private pName As String
Private pDescription As String
Private pPrice As Integer
Private pPath As String
Private pCat As String
'Constructor, uses database to populate properties based on productName
Public Sub New(ByVal productName As String)
Dim data As New Interaction
Dim work As Product
work = data.ReadProduct(productName)
pCat = work.Cat
pName = work.Name
pDescription = work.Description
pPrice = work.Price
End Sub
'Constructor, populates properties from passed in values
Public Sub New(ByVal NameIn As String,
ByVal DescriptionIn As String, ByVal PriceIn As Integer, ByVal CatIn As String, ByVal ImagePathIn As String)
pName = NameIn
pDescription = DescriptionIn
pPrice = PriceIn
pPath = ImagePathIn
pCat = CatIn
End Sub
'Stores name of product
Public ReadOnly Property Name() As String
Get
Return pName
End Get
End Property
'Stores a description of the product
Public ReadOnly Property Description() As String
Get
Return pDescription
End Get
End Property
'Stores the price of the product
Public ReadOnly Property Price() As Integer
Get
Return pPrice
End Get
End Property
'Stores the path to the image associated with this product
Public ReadOnly Property ImagePath() As String
Get
Return pPath
End Get
End Property
'Stores name of product
Public ReadOnly Property Cat() As String
Get
Return pCat
End Get
End Property
End Class

Answer 1

Use this instead
Public Function ReadProduct(ByVal CatIn As String) As List(Of Dictionary(String, Of String))
Dim ReturnProducts As New List(Of Dictionary(String, Of String))
Try
Call GetProduct(CatIn)
Dim dbr As SqlDataReader
' Execute the created SQL command from GetProduct and set to the SqlDataReader object
dbr = cmdSelect.ExecuteReader
Dim FieldCount = dbr.FieldCount()
Dim ColumnList as New List(Of String)
For i as Integer = 0 to FieldCount - 1
ColumnList.Add(dbr.GetName(i))
Next
While dbr.Read()
Dim ReturnProduct As New Dictionary(String, Of String)
For i as Integer = 0 to FieldCount - 1
ReturnProduct.Add(ColumnList(i), dbr.GetValue(i).toString())
Next
ReturnProducts.Add(ReturnProduct)
End While
cmdSelect.Parameters.Clear()
dbr.Close()
Catch ex As SqlException
Dim strOut As String
strOut = ex.Message
Console.WriteLine(strOut)
End Try
' Return the Product object
Return ReturnProducts
End Function
then, inside printMenuBlock, you declare product with
Dim product = db.ReadProduct(productName)
and later, you access it like so
For i as Integer = 0 to product.Count - 1
'do everything normally for building str except, for example, if you want
'to acccess product.Name as before, access it with product(i).Item("Name"),
'assuming that your column name/alias for "Name" is in fact "Name"
'i personally like to align column names to variable names for laziness's sake
'bad obfuscation practice tho if you don't use aliases
Next