// original, brain-dead retarded
public static string CommaListToSingleQuotedCommaList( string commaList ) {
	string result = "";
	try {
		do {
			if ( string.IsNullOrEmpty( commaList ) )
				break;
			string[] commaListItems = commaList.Split( "," );
			if ( ( commaListItems == null ) || ( commaListItems.Count() <= 0 ) )
				break;
			string quotedList = "";
			foreach ( string commaListItem in commaListItems ) {
				quotedList = quotedList + ( !string.IsNullOrEmpty( quotedList ) ? "," : "" ) + "'" + commaListItem.Trim() + "'";
			}
			result = quotedList;
		} while ( false );
	} catch {
		result = "";
	}
	return result;
}


// fixed
public static System.String TrimToNull( this System.String @string ) {
	if ( System.String.IsNullOrEmpty( @string ) ) {
		return null;
	}
	@string = @string.Trim();
	if ( System.String.IsNullOrEmpty( @string ) ) {
		return null;
	}
	return @string;
}
public static System.String CommaListToSingleQuotedCommaList( System.String commaList ) {
	commaList = commaList.TrimToNull();
	if ( System.String.IsNullOrEmpty( commaList ) ) {
		return null;
	}
	return System.String.Join(
		",",
		commaList.Split( new System.Char[ 1 ] { ',' },
		System.StringSplitOptions.RemoveEmptyEntries
	).Select(
		x => "'" + x.TrimToNull() + "'"
	) );
}