[英]vb.net Listboxes and sql
我有4個列表框,我檢查,其中的內容去彌補放入sql語句的變量。這很好。問題是我必須檢查所有的框。如果我留下任何框out sql語句不起作用。 我嘗試添加“”到列表框但這不起作用,它看起來很亂。有一種解決方法。很多感謝吉姆這里是我的代碼:
Imports System.Data
Imports System.Data.OleDb
Imports System.Data.Odbc
Imports System.Data.DataTable
Public Class Form1
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
End Sub
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim con As New OleDb.OleDbConnection
Dim dbProvider As String
Dim dbSource As String
Dim ds As New DataSet
Dim tables As DataTableCollection = ds.Tables
Dim source1 As New BindingSource()
Dim da As New OleDb.OleDbDataAdapter
Dim sql As String
Dim aa As String = authorList.Text
Dim bb As String = publisherList.Text
Dim cc As String = yearpublishedList.Text
Dim dd As String = genreList.Text
dbProvider = "PROVIDER=Microsoft.ACE.OLEDB.12.0;"
dbSource = "Data Source =C:\Documents and Settings\james\Desktop\Authors.accdb"
con.ConnectionString = dbProvider & dbSource
con.Open()
sql = "SELECT * FROM books WHERE author = '" & aa & "' AND publisher = '" & bb & "' AND yearpublished = '" & cc & "' AND genre = '" & dd & "' "
da = New OleDb.OleDbDataAdapter(sql, con)
da.Fill(ds, "Authors")
Dim view1 As New DataView(tables(0))
source1.DataSource = view1
DataGridView1.DataSource = view1
DataGridView1.Refresh()
'MsgBox("OPEN FOR LUNCH")
'MsgBox("CLOSED FOR THE DAY")
con.Close()
End Sub
End Class
您正在將復選框解析為字符串,因此當您這樣做時,您會得到:
1,2,3,4,5,6,7
如果您沒有選中一個復選框,它將如下所示:
1,2,3,,5,6,7
所以SQL會破解
有幾種方法可以解決這個問題,所以我不打算嘗試一下。 但是,這應該有希望向你解釋發生了什么以及它為什么會發生,所以你可以繼續修復
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