Best way to substitute empty string for DBNull?

Question

If a column in a DataRow might be DBNull, is the following the shortest way to substitute an empty string for DBNull?

Dim result As String = if(isDBNull(dataRow1("column1")), "", dataRow1("column1"))

possible duplicate of [Change a datarow item from DBNull to a string value](http://stackoverflow.com/questions/15507675/change-a-datarow-item-from-dbnull-to-a-string-value) — Ken White, Jul 25 '13 at 01:07
That does not look like valid C#. I think you want to use the ternary operator "? :" for that. — fcuesta, Jul 25 '13 at 03:08

score 2 · Answer 1 · answered Jul 25 '13 at 03:09

2

dataRow1("column1") & "" will produce the desired result in VB.

answered Jul 25 '13 at 03:09

CJ7

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This will not work in typesafe code (with `OPTION STRICT ON`) – sloth Jul 25 '13 at 10:31

score 1 · Answer 2 · answered Jul 25 '13 at 10:25

1

Just use the Field(Of T) methods, which will convert DBNull values to Nothing for you. Also, they are typesafe.

Dim result = If(dataRow1.Field(Of String)("column1"), String.Empty)

answered Jul 25 '13 at 10:25

sloth

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score 0 · Answer 3 · answered Jul 25 '13 at 10:09

you might want to create an extension method for ease of use (not tested):

Imports System.Data
Imports System.Runtime.CompilerServices

Module Extensions
    <Extension()>
    Public Function GetStringValue(dataRow As DataRow, columnName As String, Optional substituesForDBNull As String = Nothing) As String
        If IsDBNull(dataRow(columnName)) Then
            Return substituesForDBNull
        End If
        Return CStr(dataRow(columnName))
    End Function
End Module

Best way to substitute empty string for DBNull?

3 Answers3