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Oracle merge从9i到10g的增强

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Release: 2016-06-07 17:18:04
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MERGE语句是Oracle9i新增的语法,用来合并UPDATE和INSERT语句。连接条件匹配上的进行UPDATE,无法匹配的执行INSERT。这个语法仅需

MERGE语句是Oracle9i新增的语法,用来合并UPDATE和INSERT语句。连接条件匹配上的进行UPDATE,无法匹配的执行INSERT。这个语法仅需要一次全表扫描就完成了全部工作,执行效率要高于INSERT+UPDATE。

Oracle merge从9i到10g的增强

下面看个具体例子:

下面稍微修改一下例子:

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