{"id":15661,"date":"2023-12-04T21:35:41","date_gmt":"2023-12-04T13:35:41","guid":{"rendered":"https:\/\/wx.kaifamiao.info\/?p=15661"},"modified":"2023-12-04T21:36:06","modified_gmt":"2023-12-04T13:36:06","slug":"oracle-zhong-exits-he-in-zai-oracle-shu-ju-ku-zhon","status":"publish","type":"post","link":"http:\/\/wx.kaifamiao.info\/index.php\/2023\/12\/04\/oracle-zhong-exits-he-in-zai-oracle-shu-ju-ku-zhon\/","title":{"rendered":"Oracle \u4e2d exits \u548c in \u5728 ORACLE \u6570\u636e\u5e93\u4e2d\u90a3\u4e2a\u6267\u884c\u6548\u7387\u66f4\u9ad8\uff1f"},"content":{"rendered":"<p>\u5728 Oracle \u6570\u636e\u5e93\u4e2d\uff0c\u9488\u5bf9 <code>EXISTS<\/code> \u548c <code>IN<\/code> \u8fd9\u4e24\u4e2a\u64cd\u4f5c\u7b26\u7684\u6267\u884c\u6548\u7387\uff0c\u901a\u5e38\u6765\u8bf4\uff0c<code>EXISTS<\/code> \u66f4\u503e\u5411\u4e8e\u66f4\u9ad8\u7684\u6267\u884c\u6548\u7387\u3002<\/p>\n<p>\u8fd9\u91cc\u662f\u4e00\u4e9b\u539f\u56e0\uff1a<\/p>\n<ol>\n<li>\n<strong>\u8bed\u4e49\u5dee\u5f02\uff1a<\/strong><\/p>\n<ul>\n<li><code>EXISTS<\/code> \u7528\u4e8e\u68c0\u67e5\u5b50\u67e5\u8be2\u662f\u5426\u8fd4\u56de\u7ed3\u679c\uff0c\u5f53\u5b50\u67e5\u8be2\u8fd4\u56de\u81f3\u5c11\u4e00\u884c\u65f6\uff0c<code>EXISTS<\/code> \u8fd4\u56de <code>TRUE<\/code>\uff0c\u5426\u5219\u8fd4\u56de <code>FALSE<\/code>\u3002<\/li>\n<li><code>IN<\/code> \u7528\u4e8e\u6bd4\u8f83\u4e00\u4e2a\u503c\u662f\u5426\u5728\u5b50\u67e5\u8be2\u8fd4\u56de\u7684\u7ed3\u679c\u96c6\u4e2d\uff0c\u5b83\u4f1a\u9010\u4e2a\u6bd4\u8f83\u503c\u662f\u5426\u5728\u96c6\u5408\u4e2d\u3002<\/li>\n<\/ul>\n<\/li>\n<li>\n<strong>\u4f18\u5316\u5668\u5904\u7406\uff1a<\/strong><\/p>\n<ul>\n<li>Oracle \u4f18\u5316\u5668\u5728\u5904\u7406 <code>EXISTS<\/code> \u65f6\u66f4\u6709\u53ef\u80fd\u6267\u884c\u201c\u534a\u8fde\u63a5\u201d\uff08Semi Join\uff09\u4f18\u5316\uff0c\u5b83\u4f1a\u5728\u5b50\u67e5\u8be2\u8fd4\u56de\u7ed3\u679c\u540e\u7acb\u5373\u505c\u6b62\u6267\u884c\uff0c\u4e0d\u4f1a\u53d6\u56de\u6574\u4e2a\u7ed3\u679c\u96c6\u3002\u8fd9\u79cd\u65b9\u5f0f\u53ef\u80fd\u4f1a\u66f4\u9ad8\u6548\uff0c\u7279\u522b\u662f\u5f53\u5b50\u67e5\u8be2\u8fd4\u56de\u5927\u91cf\u884c\u65f6\u3002<\/li>\n<li><code>IN<\/code> \u64cd\u4f5c\u7b26\u901a\u5e38\u9700\u8981\u53d6\u56de\u6574\u4e2a\u5b50\u67e5\u8be2\u7684\u7ed3\u679c\u96c6\uff0c\u7136\u540e\u518d\u5bf9\u7ed3\u679c\u8fdb\u884c\u5339\u914d\uff0c\u8fd9\u53ef\u80fd\u4f1a\u5bfc\u81f4\u66f4\u591a\u7684 I\/O \u64cd\u4f5c\u548c\u5185\u5b58\u5360\u7528\u3002<\/li>\n<\/ul>\n<\/li>\n<\/ol>\n<p>\u867d\u7136 <code>EXISTS<\/code> \u5728\u5927\u591a\u6570\u60c5\u51b5\u4e0b\u53ef\u80fd\u66f4\u9ad8\u6548\uff0c\u4f46\u6548\u7387\u95ee\u9898\u4e5f\u4e0e\u5177\u4f53\u7684\u67e5\u8be2\u548c\u7d22\u5f15\u4f7f\u7528\u60c5\u51b5\u76f8\u5173\u3002\u6700\u4f73\u5b9e\u8df5\u662f\u6839\u636e\u7279\u5b9a\u573a\u666f\u4e0b\u7684\u9700\u6c42\u548c\u6570\u636e\u7ed3\u6784\u9009\u62e9\u5408\u9002\u7684\u64cd\u4f5c\u7b26\uff0c\u5e76\u901a\u8fc7\u6d4b\u8bd5\u6765\u8bc4\u4f30\u5176\u6027\u80fd\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u5728 Oracle \u6570\u636e\u5e93\u4e2d\uff0c\u9488\u5bf9 EXISTS \u548c IN \u8fd9\u4e24\u4e2a\u64cd\u4f5c\u7b26\u7684\u6267\u884c\u6548\u7387\uff0c\u901a\u5e38\u6765\u8bf4\uff0cEXISTS \u66f4\u503e [&hellip;]<\/p>\n","protected":false},"author":11,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[120],"tags":[],"class_list":["post-15661","post","type-post","status-publish","format-standard","hentry","category-oracel"],"_links":{"self":[{"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/posts\/15661","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/users\/11"}],"replies":[{"embeddable":true,"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/comments?post=15661"}],"version-history":[{"count":1,"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/posts\/15661\/revisions"}],"predecessor-version":[{"id":15662,"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/posts\/15661\/revisions\/15662"}],"wp:attachment":[{"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/media?parent=15661"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/categories?post=15661"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/tags?post=15661"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}