Question

基本上我有三个字段，我正在创建一个新的字段，这三个字段组合成一个可邮寄的地址;问题是某些字段包含空值并将myString添加到null只会在sql中生成null。

所以这是我的代码，任何人都可以使它更干净吗？它仍然看起来很漂亮！

  UPDATE [mydb].[dbo].[Account]
  SET [Billing Street] = CASE
  WHEN [(Billing Address 1)] is null and [(Billing Address 2)] is null THEN [(Billing Address 3)]
  WHEN [(Billing Address 1)] is null and [(Billing Address 3)] is null THEN [(Billing Address 2)]
  WHEN [(Billing Address 2)] is null and [(Billing Address 3)] is null THEN [(Billing Address 1)]
  WHEN [(Billing Address 1)] is null THEN [(Billing Address 2)] + ' ' + [(Billing Address 3)]
  WHEN [(Billing Address 2)] is null THEN [(Billing Address 1)] + ' ' + [(Billing Address 3)]
  WHEN [(Billing Address 3)] is null THEN [(Billing Address 1)] + ' ' + [(Billing Address 2)]
  ELSE [(Billing Address 1)] + ' ' + [(Billing Address 2)] + ' ' + [(Billing Address 3)]
  END

Answer 1

您可以使用isnull和ltrim删除任何前导空格：

update [mydb].[dbo].[Account]
set [Billing Street] = ltrim(isnull([(Billing Address 1)], '') +
                       isnull(' ' + [(Billing Address 2)], '') +
                       isnull(' ' + [(Billing Address 3)], ''))

Answer 2

如果旧列和新列共存，您最好创建一个计算列 - 这样，它们就不会彼此“不同步”。

接受Andomars声明，并将其更改为：

ALTER TABLE Account ADD
  [Billing Street] AS LTRIM...

LTRIM ......在Andomar的回答中继续......

你能优化这段代码吗？ T-SQL

2 个答案: