Question

我有3次更新

UPDATE [Person]
SET [Email] = @Prefix
WHERE [Id] = @PersonId AND ISNULL([Email], '') <> ''

UPDATE [Person]
SET [Phone] = @Phone
WHERE [Id] = @PersonId AND ISNULL([Phone], '') <> ''

UPDATE [Person]
SET [Skype] = @Skype
WHERE [Id] = @PersonId AND ISNULL([Skype], '') <> ''

我可以将它组合成一个或如何编写更多性能操作？感谢

Answer 1

我的意思是，你可以将它们结合起来：

UPDATE [Person]
SET [Email] = CASE WHEN ISNULL([Email], '') <> '' THEN @Prefix ELSE [Email] END,
    [Phone] = CASE WHEN ISNULL([Phone], '') <> '' THEN @Phone ELSE [Phone] END,
    [Skype] = CASE WHEN ISNULL([Skype], '') <> '' THEN @Skype ELSE [Skype] END
WHERE [Id] = @PersonId 
AND (ISNULL([Email], '') <> '' OR ISNULL([Phone], '') <> '' OR ISNULL([Skype], '') <> '');

不确定这是否会实际改善性能

Answer 2

试一试。但是，如果只有一个新值，它将覆盖其他两个值。

UPDATE [Person]
SET [Email] = CASE WHEN ISNULL([Email], '') <> '' THEN @Prefix ELSE [Email] END,
SET [Phone] = CASE WHEN ISNULL([Phone], '') <> '' THEN @Phone ELSE [Phone] END,
SET [Skype] = CASE WHEN ISNULL([Skype], '') <> '' THEN @Skype ELSE [Skype] END
WHERE [Id] = @PersonId 
AND (ISNULL([Email], '') <> ''
OR ISNULL([Phone], '') <> ''
OR ISNULL([Skype], '') <> '')

如何将3个更新合并为一个

2 个答案: