45、SQL Server编程：从T-SQL到CLR的选择与实践

wind

于 2025-07-12 10:02:44 发布

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分类专栏： SQL Server数据库设计与优化精华文章标签： SQL Server T-SQL CLR

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SQL Server编程：从T-SQL到CLR的选择与实践

1. SQL操作代码示例与分析

首先来看一段SQL代码：

UPDATE contact
SET    contactNotes = inserted.contactNotes
FROM   sales.contact as contact
JOIN inserted
ON inserted.contactId = contact.contactId
--this correlated subquery checks for rows that have changed
WHERE  EXISTS (SELECT *
FROM   deleted
WHERE  deleted.contactId = inserted.contactId
AND  deleted.contactNotes <> inserted.contactNotes
or (deleted.contactNotes is null and
inserted.contactNotes is not null)
or (deleted.contactNotes is not null and
inserted.contactNotes is null))
END TRY
BEGIN CATCH
IF @@trancount > 0
ROLLBACK TRANSACTION
EXECUTE dbo.errorLog$insert
DECLARE @ERROR_MESSAGE varchar(8000)
SET @ERROR_MESSAGE = ERROR_MESSAGE()
RAISERROR (@ERR