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