Modify code so the datbase server will not crash

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How do you modify code so that it will not crash if the database server is unavailable when you attempt to access it? If this happens then there must be an appropriate way to handle the error. I do not know where to put the Try..Catch procedure.

VB

Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
        Dim db As New DBWrapper
        Dim l As ArrayList



        If Not IsPostBack Then
            Dim o As New Order
            o = Session("CurrentOrder")
            'Code so the program will not crash if the database server is unavailable when trying to access it.
            ' Try
            'Do something
            'Catch ex As Exception
            'Handle exception by displaying a message box
            'msgbox("Error happened because the database is not available" & ex.tostring())
            'Finally
            'dbwrapper.End
            ' End Try
            l = db.GetCustomersForLookup
            lstCustomer.DataSource = l

            lstCustomer.DataValueField = "Value"
            lstCustomer.DataTextField = "Description"
            lstCustomer.DataBind()


            If o Is Nothing Then

                calOrderDate.SelectedDate = Date.Today

            Else
                calOrderDate.SelectedDate = o.OrderDate


            End If

            SetFormToInitialState()
        End If


    End Sub

Posted 29-Apr-12 16:16pm

Member 8885701

Updated 29-Apr-12 16:54pm

v2

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satrio_budidharmawan · Answer 1 · 2012-04-29T16:40:00

Solution 1

Use error handling such as try...catch

Simply just do this

VB

try
 <some code="" to="" use="" with="" database="">
catch (e as exception)
 <some code="" to="" do="" if="" above="" for="" example="">
 msgbox("Error happened at "+e.toString())
end try</some></some>

Posted 29-Apr-12 16:40pm

satrio_budidharmawan

Sandeep Mewara · Answer 2 · 2012-04-29T19:13:00

You wrap try-catch around the code that has potential of getting an error.

Here, in your code the line that tries to connect to DB and get back data is one of those places where probability of having an error is high.
Wrap your try-catch around the following line:

C#

l = db.GetCustomersForLookup