• RegEx_HasMatches soll uns sagen ob überhaupt Matches auftreten
• RegEx_MatchCount soll uns sagen wie viele Matches auftreten
• RegEx_GetMatches soll uns die Matches aufsgeben

Für die Copy+Paster unter euch ;) :

    <SqlFunction()> _
    Public Shared Function RegEx_HasMatches(ByVal inputstring As SqlString, ByVal regexstring As SqlString) As SqlBoolean
        If Regex.Matches(inputstring.Value, regexstring.Value, RegexOptions.IgnoreCase).Count > 0 Then
            Return True
        Else
            Return False
        End If
    End Function

    <SqlFunction()> _
    Public Shared Function RegEx_MatchCount(ByVal inputstring As SqlString, ByVal regexstring As SqlString) As SqlInt64
        Return Regex.Matches(inputstring.Value, regexstring.Value, RegexOptions.IgnoreCase).Count
    End Function

    <SqlFunction()> _
    Public Shared Sub RegEx_GetMatches(ByVal inputstring As SqlString, ByVal regexstring As SqlString)
        Dim mc As MatchCollection = Regex.Matches(inputstring.Value, regexstring.Value, RegexOptions.IgnoreCase)
        Dim result As New SqlDataRecord(New SqlMetaData("Match", SqlDbType.NVarChar, 4000))
        Dim pipe As SqlPipe = SqlContext.Pipe
        pipe.SendResultsStart(result)
        For Each item As Match In mc
            result.SetString(0, item.Value)
            pipe.SendResultsRow(result)
        Next
        pipe.SendResultsEnd()
    End Sub

Nach dem Bereitstellen können wir das ganze auch schon testen:

declare @inputstring nvarchar(4000)
set @inputstring= 'My favorite web sites include:
	</P><A HREF="http://www.xentrope.de">Xylon''s Blog</A></P>
	<A HREF="http://dotnet-forum.de">.NET Forum</A></P>
	<A HREF="http://blogs.msdn.com/bclteam">.NET Base Class Library blog</A></P>'

declare @regexstring nvarchar(4000)
set @regexstring = 'href\s*=\s*(?:"(?<1>[^"]*)"|(?<1>\S+))'

select dbo.RegEx_HasMatches(@inputstring,@regexstring) 'HasMatches'
	,dbo.RegEx_MatchCount(@inputstring,@regexstring) 'Nr of Matches'
exec dbo.RegEx_GetMatches @inputstring,@regexstring

Und als Ergebnisse bekommen wir:

HasMatches	Nr of Matches
1			3

Match
HREF="http://www.xentrope.de"
HREF="http://dotnet-forum.de"
HREF="http://blogs.msdn.com/bclteam"

Coole Sache! :)