SQL Server添加值

Question

SELECT @s = ISNULL(@s +'.','')+ [评论]来自[客户]

RETURN @s   

我怎样才能捕获Null或'',这样如果它不会附加到字符串而不添加'.'

谢谢

雅各

Answer 1

SELECT
    @s = ISNULL(NULLIF(@s, '') + '.', '') + comments
FROM
    [Customers]

RETURN @s