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ACID
概念AtomicityMain article: Atomicity (database systems)Atomicity requires that database modifications must follow an "all or nothing" rule. Each transaction is said to be atomic. If one part...原创 2012-02-01 15:27:30 · 134 阅读 · 0 评论 -
【SQL】SQL知识点概要
IN/NOT IN/EXISTS/NOT EXISTS简单用法 见http://space.itpub.net/12928228/viewspace-439094,其中EXISTS/NOT EXISTS用于取交集和差集。 SELECT DISTINCT pub_name FROM publishers WHERE EXISTS (SELECT * FROM titles WHE...原创 2012-06-19 09:01:26 · 258 阅读 · 0 评论