[英]Apply filters from multiple checkboxList to filter ListView in VB.net
我的Web應用程序中有1000種產品,因此需要多個過濾器。 我總共有4個checkboxList。 現在我的問題是,如果我從checkboxList中的任何一個應用過濾器,那么它將檢查查詢中指定的所有列的選定值。 我想要的是下面的樣子
SELECT * FROM products WHERE price_rang IN ('selectedValueFromCheckBoxList1') And category IN ('selectedValueFromCheckBoxList2')
現在發生了什么
SELECT * FROM `products` WHERE price_range IN ('selectedValueFromCheckBoxList2') AND category IN ('selectedValueFromCheckBoxList2')
因此,在此查詢中,假設如果我從checkboxList2中選擇值First,那么對於這兩個列,它都將采用該值並不會顯示結果。
下面是我的過濾過程代碼
Private Sub getResult()
Dim constr As String = ConfigurationManager.ConnectionStrings("conio").ConnectionString
Dim query As String = "select * from products"
Dim condition As String = String.Empty
For Each price As ListItem In priceFilter.Items
condition += If(price.Selected, String.Format("'{0}',", price.Value), String.Empty)
Next
For Each sub_category As ListItem In category.Items
condition += If(sub_category.Selected, String.Format("'{0}',", sub_category.Value), String.Empty)
Next
If Not String.IsNullOrEmpty(condition) Then
condition = String.Format(" WHERE price_range IN ({0}) and sub_category IN ({0})", condition.Substring(0, condition.Length - 1))
End If
Using con As New MySqlConnection(constr)
Using cmd As New MySqlCommand(query & condition)
Using sda As New MySqlDataAdapter(cmd)
cmd.Connection = con
Using dt As New DataTable()
sda.Fill(dt)
products.DataSource = dt
products.DataBind()
End Using
End Using
End Using
End Using
End Sub
這是一個選項,因為您只對選中的項目感興趣。
Public Function buildWhereClause() As String
Dim query As String = "select * from products"
Dim joiner As String = " "
Dim condition As String = String.Empty
Dim priceCondition As String = String.Empty
For i = 0 To priceFilter.Items.Count - 1
If priceFilter.Items(i).Selected Then
Dim price As String = priceFilter.Items(i).ToString
priceCondition = String.Concat(priceCondition, joiner, String.Format("'{0}'", price))
If joiner = " " Then joiner = ", "
End If
Next
Dim categoryCondition As String = String.Empty
joiner = " "
For i = 0 To categoryFilter.Items.Count - 1
If categoryFilter.Items(i).Selected Then
Dim category As String = categoryFilter.Items(i).ToString
categoryCondition = String.Concat(categoryCondition, joiner, String.Format("'{0}'", category))
If joiner = " " Then joiner = ", "
End If
Next
Dim whereClause As String = String.Empty
joiner = " where "
If Not String.IsNullOrEmpty(priceCondition) Then
whereClause = String.Concat(whereClause, joiner, String.Format(" price_range IN ({0})", priceCondition)) ' and sub_category IN ({0})", condition.Substring(0, condition.Length - 1))
joiner = " and "
End If
If Not String.IsNullOrEmpty(categoryCondition) Then
whereClause = String.Concat(whereClause, joiner, String.Format(" sub_category in ({0})", categoryCondition))
joiner = " and "
End If
Return String.Concat(query, whereClause)
End Function
聲明:本站的技術帖子網頁,遵循CC BY-SA 4.0協議,如果您需要轉載,請注明本站網址或者原文地址。任何問題請咨詢:yoyou2525@163.com.