{"id":200150,"date":"2025-05-06T10:13:38","date_gmt":"2025-05-06T02:13:38","guid":{"rendered":"https:\/\/server.hk\/cnblog\/200150\/"},"modified":"2025-05-06T10:13:38","modified_gmt":"2025-05-06T02:13:38","slug":"mysql%e4%bc%aa%e8%a1%a8dual%e6%9c%89%e4%bb%80%e4%b9%88%e4%bd%9c%e7%94%a8%ef%bc%9f","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/200150\/","title":{"rendered":"MySQL\u4f2a\u8868dual\u6709\u4ec0\u4e48\u4f5c\u7528\uff1f"},"content":{"rendered":"<p><b><\/b> <\/p>\n<h1>MySQL\u4f2a\u8868dual\u6709\u4ec0\u4e48\u4f5c\u7528\uff1f<\/h1>\n<p>\u54c8\u55bd\uff01\u5927\u5bb6\u597d\uff0c\u5f88\u9ad8\u5174\u53c8\u89c1\u9762\u4e86\uff0c\u6211\u662f\u4e3b\u673a\u5b9d\u8d1d\u7684\u4e00\u540d\u4f5c\u8005\uff0c\u4eca\u5929\u7531\u6211\u7ed9\u5927\u5bb6\u5e26\u6765\u4e00\u7bc7\uff0c\u672c\u6587\u4e3b\u8981\u4f1a\u8bb2\u5230\u7b49\u7b49\u77e5\u8bc6\u70b9\uff0c\u5e0c\u671b\u5927\u5bb6\u4e00\u8d77\u5b66\u4e60\u8fdb\u6b65\uff0c\u4e5f\u6b22\u8fce\u5927\u5bb6\u5173\u6ce8\u3001\u70b9\u8d5e\u3001\u6536\u85cf\u3001\u8f6c\u53d1! \u4e0b\u9762\u5c31\u4e00\u8d77\u6765\u770b\u770b\u5427\uff01<\/p>\n<p><img decoding=\"async\" src=\"https:\/\/www.17golang.com\/uploads\/20241025\/1729836784671b36f08dcc0.jpg\" class=\"aligncenter\"><\/p>\n<p><strong>mysql \u4e2d\u7684\u4f2a\u8868 dual<\/strong><\/p>\n<p>\u4f7f\u7528\u4f2a\u8868 dual \u53ef\u4ee5\u4ece\u4e00\u4e2a\u4e0d\u5305\u542b\u4efb\u4f55\u771f\u5b9e\u6570\u636e\u7684\u865a\u62df\u8868\u4e2d\u68c0\u7d22\u6570\u636e\u3002\u5728 mysql \u4e2d\uff0cdual \u4f2a\u8868\u4e0e from \u5b50\u53e5\u4e2d\u4e0d\u5305\u542b\u4efb\u4f55\u8868\u7684\u67e5\u8be2\u5177\u6709\u76f8\u540c\u7684\u6548\u679c\u3002<\/p>\n<p><strong>\u67e5\u8be2\u533a\u522b<\/strong><\/p>\n<p>\u63d0\u4f9b\u7684\u4e24\u4e2a\u67e5\u8be2\uff1a<\/p>\n<pre>select 6+6 from dual;\nselect 6+6;<\/pre>\n<p>\u4ea7\u751f\u76f8\u540c\u7684\u7ed3\u679c\uff0812\uff09\uff0c\u56e0\u4e3a mysql \u5728\u4e0d\u4f7f\u7528 from \u5b50\u53e5\u7684\u60c5\u51b5\u4e0b\u76f4\u63a5\u4ece\u4f2a\u8868 dual \u4e2d\u68c0\u7d22\u6570\u636e\u3002<\/p>\n<p><strong>\u4f2a\u8868\u7684\u7528\u6cd5<\/strong><\/p>\n<p>\u4f2a\u8868 dual \u5e38\u7528\u4e8e\u4ee5\u4e0b\u573a\u666f\uff1a<\/p>\n<ul>\n<li><strong>\u521d\u59cb\u5316\u5e8f\u5217\u548c\u6807\u8bc6\u5217\uff1a<\/strong>\u53ef\u4ee5\u4f7f\u7528 dual \u8868\u6765\u83b7\u53d6\u5e8f\u5217\u503c\u7684\u4e0b\u4e00\u4e2a\u503c\uff0c\u6216\u521d\u59cb\u5316\u6807\u8bc6\u5217\u7684\u503c\u3002<\/li>\n<li><strong>\u9a8c\u8bc1\u67e5\u8be2\u8bed\u6cd5\uff1a<\/strong>\u4ece dual \u8868\u4e2d\u68c0\u7d22\u6570\u636e\u53ef\u4ee5\u6d4b\u8bd5\u67e5\u8be2\u7684\u8bed\u6cd5\u662f\u5426\u6b63\u786e\uff0c\u800c\u65e0\u9700\u4f7f\u7528\u5b9e\u9645\u7684\u8868\u6570\u636e\u3002<\/li>\n<li><strong>\u63d0\u4f9b\u9ed8\u8ba4\u503c\uff1a<\/strong>\u5982\u679c\u5728\u67d0\u4e2a\u67e5\u8be2\u4e2d\u9700\u8981\u4e00\u4e2a\u9ed8\u8ba4\u503c\uff0c\u53ef\u4ee5\u4f7f\u7528 dual \u8868\u6765\u63d0\u4f9b\u8fd9\u4e2a\u503c\u3002<\/li>\n<li><strong>\u751f\u6210\u6d4b\u8bd5\u6570\u636e\uff1a<\/strong>\u53ef\u4ee5\u4f7f\u7528 dual \u8868\u6765\u751f\u6210\u4e00\u7ec4\u6d4b\u8bd5\u6570\u636e\uff0c\u4f8b\u5982\u7528\u4e8e\u6d4b\u8bd5\u51fd\u6570\u6216\u5b58\u50a8\u8fc7\u7a0b\u3002<\/li>\n<\/ul>\n<p>\u7ec8\u4e8e\u4ecb\u7ecd\u5b8c\u5566\uff01\u5c0f\u4f19\u4f34\u4eec\uff0c\u8fd9\u7bc7\u5173\u4e8e\u300aMySQL\u4f2a\u8868dual\u6709\u4ec0\u4e48\u4f5c\u7528\uff1f\u300b\u7684\u4ecb\u7ecd\u5e94\u8be5\u8ba9\u4f60\u6536\u83b7\u591a\u591a\u4e86\u5427\uff01\u6b22\u8fce\u5927\u5bb6\u6536\u85cf\u6216\u5206\u4eab\u7ed9\u66f4\u591a\u9700\u8981\u5b66\u4e60\u7684\u670b\u53cb\u5427~\u4e3b\u673a\u5b9d\u8d1d\u516c\u4f17\u53f7\u4e5f\u4f1a\u53d1\u5e03\u6570\u636e\u5e93\u76f8\u5173\u77e5\u8bc6\uff0c\u5feb\u6765\u5173\u6ce8\u5427\uff01<\/p>\n<p> \u7248\u672c\u58f0\u660e \u672c\u6587\u8f6c\u8f7d\u4e8e\uff1aphp \u5982\u6709\u4fb5\u72af\uff0c\u8bf7\u8054\u7cfb \u5220\u9664 <\/p>\n<dl>\n<dt>\n <\/dt>\n<\/dl>\n","protected":false},"excerpt":{"rendered":"<p>MySQL\u4f2a\u8868dual\u6709\u4ec0\u4e48\u4f5c\u7528&#46;&#46;&#46;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[101],"tags":[],"class_list":["post-200150","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/200150","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/comments?post=200150"}],"version-history":[{"count":0,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/200150\/revisions"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=200150"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=200150"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=200150"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}