Question

asp.net 用户代码未处理OleDbException。如何处理？

Imports System.Data.OleDb
Partial Class Default2
Inherits System.Web.UI.Page

Public Sub check_log1()
Dim myconnection As Data.OleDb.OleDbConnection
myconnection = New Data.OleDb.OleDbConnection("provider=microsoft.jet.oledb.4.0;data source=" & Server.MapPath("db1.mdb"))
Dim searchcmd As String
searchcmd = "select * from student where 姓名='" & user_id.Text & "' and 学号='" & password.Text & "'"
Dim mycommand As Data.OleDb.OleDbCommand = New Data.OleDb.OleDbCommand(searchcmd, myconnection)
mycommand.connection.open()
Dim myreader As Data.OleDb.OleDbDataReader = mycommand.ExecuteReader()
If myreader.Read() Then
Session("userid") = user_id.Text
Response.Redirect("comm_user.aspx")
ElseIf Not myreader.Read() Then
message.text = "你的输入有误"
message.style("color") = "red"

End If
mycommand.connection.close()
End Sub
Public Sub check_log2()
Dim myconnection As Data.OleDb.OleDbConnection
myconnection = New Data.OleDb.OleDbConnection("provider=microsoft.jet.oledb.4.0;data source=" & Server.MapPath("library.mdb"))
Dim searchcmd As String
searchcmd = "select * from manage where 姓名='" & user_id.Text & "' and 学号='" & password.Text & "'"
Dim mycommand As Data.OleDb.OleDbCommand = New Data.OleDb.OleDbCommand(searchcmd, myconnection)
mycommand.connection.open()
Dim myreader As Data.OleDb.OleDbDataReader = mycommand.ExecuteReader()
If myreader.Read() Then
Session("userid") = user_id.Text
Response.Redirect("admin.aspx")
ElseIf Not myreader.Read() Then
message.text = "你的输入有误"
message.style("color") = "red"

End If
mycommand.connection.close()
End Sub
Protected Sub Button1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button1.Click
If RadioButton1.Checked Then
check_log1()
ElseIf RadioButton2.Checked Then
check_log2()
End If
End Sub
End Class

Answer 1

在使用OleDbConnection的地方用下面代码括起来：

try
'...省略数据库操作
catch oledbex as OleDbException
'..
catch ex as Exception
'..
end try

追问

运行过了么？意思不太明白，代码加在哪里？

追答

楼主需要学习一下VB.Net 的异常捕获。
代码太长了，只写了check_log1()。

Public Sub check_log1()
try
Dim myconnection As Data.OleDb.OleDbConnection
myconnection = New Data.OleDb.OleDbConnection("provider=microsoft.jet.oledb.4.0;data source=" & Server.MapPath("db1.mdb"))
Dim searchcmd As String
searchcmd = "select * from student where 姓名='" & user_id.Text & "' and 学号='" & password.Text & "'"
Dim mycommand As Data.OleDb.OleDbCommand = New Data.OleDb.OleDbCommand(searchcmd, myconnection)
mycommand.connection.open()
Dim myreader As Data.OleDb.OleDbDataReader = mycommand.ExecuteReader()
If myreader.Read() Then
Session("userid") = user_id.Text
Response.Redirect("comm_user.aspx")
ElseIf Not myreader.Read() Then
message.text = "你的输入有误"
message.style("color") = "red"

End If
mycommand.connection.close()
catch oledbex as OleDbException
'..
catch ex as Exception
'..
endtry
End Sub

Answer 2

Imports System.Data.OleDb
Partial Class Default2
Inherits System.Web.UI.Page

Public Sub check_log1()
Dim myconnection As Data.OleDb.OleDbConnection
myconnection = New Data.OleDb.OleDbConnection("provider=microsoft.jet.oledb.4.0;data source=" & Server.MapPath("db1.mdb"))
Dim searchcmd As String
searchcmd = "select * from studen