Handling NULL in ASP.NET

HI

I am using PgSQL as Database. Front End is asp.net.

I am reading values from database using Reader classes. For example

Dim x as string
x= memberReader.getString(0)

Now if the value of memberReader.getString(0) is null then its throwing an error.

Error is like "Object cannot be cast from DBNull to other types". Obviously it will give an error.

So how do I check whether the incoming value is null or not.

Not getting much help from Gooooogle.

Help me as soon as possible

thnx in advance

Handling null values returned from database resultsets is different in .NET from VB6.

this function returns that the value os null

Code:

---

Public Function IsDBNull(ByVal dbvalue) As Boolean
    Return dbvalue Is DBNull.Value
End Function

---

this function changes thevalue from null to ""

Code:

---

Public Function FixNull(ByVal dbvalue) As String
        If dbvalue Is DBNull.Value Then
            Return ""
        Else
            'NOTE: This will cast value to string if
            'it isn't a string.

            Return dbvalue.ToString
        End If
End Function

---

Hi

Still I have not got the solution.

I created the function as you suggested

Code:

---

Public Function IsDBNull(ByVal dbvalue) As Boolean
  Return dbvalue Is DBNull.Value
End Function

---

And I am using that function to check whether the data that I have read is NULL or not

Code:

---

        Dim BirthDate as new Date
        Dim memberConnection As New NpgsqlConnection(StudentSpace.Global.ConString)
        Dim memberCommand As NpgsqlCommand
        Dim memberReader As NpgsqlDataReader

        id = uId

        memberCommand = New NpgsqlCommand("select BirthDate from Student where UserID=:ID", memberConnection)
        memberCommand.Parameters.Add(":ID", NpgsqlTypes.NpgsqlDbType.Integer).Value = id
        memberConnection.Open()
        memberReader = memberCommand.ExecuteReader()
        memberReader.Read()

        If Not IsDBNull(memberReader.GetDateTime(0)) Then ' Ur Function Call
            BirthDate = memberReader.GetDateTime(0)
        End If

---

Then also I am getting the error

Error is Object cannot be cast from DBNull to other types.

What should I do :dumbo: :dumbo: :dumbo:

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dotnetguy