{"id":199834,"date":"2025-05-06T09:55:03","date_gmt":"2025-05-06T01:55:03","guid":{"rendered":"https:\/\/server.hk\/cnblog\/199834\/"},"modified":"2025-05-06T09:55:03","modified_gmt":"2025-05-06T01:55:03","slug":"%e6%8c%87%e5%af%bc%e6%82%a8%e5%a6%82%e4%bd%95%e5%ae%9e%e9%99%85%e5%ba%94%e7%94%a8%e5%92%8c%e5%ae%9e%e8%b7%b5oracle-decode%e5%87%bd%e6%95%b0","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/199834\/","title":{"rendered":"\u6307\u5bfc\u60a8\u5982\u4f55\u5b9e\u9645\u5e94\u7528\u548c\u5b9e\u8df5Oracle DECODE\u51fd\u6570"},"content":{"rendered":"<p><b><\/b> <\/p>\n<h1>\u6307\u5bfc\u60a8\u5982\u4f55\u5b9e\u9645\u5e94\u7528\u548c\u5b9e\u8df5Oracle DECODE\u51fd\u6570<\/h1>\n<p>\u4e3b\u673a\u5b9d\u8d1d\u4eca\u5929\u5c06\u7ed9\u5927\u5bb6\u5e26\u6765\uff0c\u611f\u5174\u8da3\u7684\u670b\u53cb\u8bf7\u7ee7\u7eed\u770b\u4e0b\u53bb\u5427\uff01\u4ee5\u4e0b\u5185\u5bb9\u5c06\u4f1a\u6d89\u53ca\u5230\u7b49\u7b49\u77e5\u8bc6\u70b9\uff0c\u5982\u679c\u4f60\u662f\u6b63\u5728\u5b66\u4e60\u6216\u8005\u5df2\u7ecf\u662f\u5927\u4f6c\u7ea7\u522b\u4e86\uff0c\u90fd\u975e\u5e38\u6b22\u8fce\u4e5f\u5e0c\u671b\u5927\u5bb6\u90fd\u80fd\u7ed9\u6211\u5efa\u8bae\u8bc4\u8bba\u54c8~\u5e0c\u671b\u80fd\u5e2e\u52a9\u5230\u5927\u5bb6\uff01<\/p>\n<p>Oracle\u6570\u636e\u5e93\u4e2d\u7684DECODE\u51fd\u6570\u662f\u4e00\u79cd\u975e\u5e38\u5e38\u7528\u7684\u51fd\u6570\uff0c\u5b83\u53ef\u4ee5\u6839\u636e\u6761\u4ef6\u503c\u6765\u8fd4\u56de\u4e0d\u540c\u7684\u7ed3\u679c\u3002\u5728\u5b9e\u9645\u7684\u6570\u636e\u5904\u7406\u4e2d\uff0cDECODE\u51fd\u6570\u80fd\u591f\u5e2e\u52a9\u6211\u4eec\u8fdb\u884c\u6570\u636e\u8f6c\u6362\u3001\u6761\u4ef6\u5224\u65ad\u548c\u7ed3\u679c\u8fd4\u56de\u7b49\u64cd\u4f5c\u3002\u672c\u6587\u5c06\u4ecb\u7ecdDECODE\u51fd\u6570\u7684\u7528\u6cd5\uff0c\u63d0\u4f9b\u5b9e\u9645\u5e94\u7528\u6307\u5357\u548c\u6700\u4f73\u5b9e\u8df5\uff0c\u540c\u65f6\u914d\u4ee5\u5177\u4f53\u7684\u4ee3\u7801\u793a\u4f8b\u3002<\/p>\n<h2>1. DECODE\u51fd\u6570\u4ecb\u7ecd<\/h2>\n<p>DECODE\u51fd\u6570\u7684\u57fa\u672c\u8bed\u6cd5\u4e3a\uff1a<\/p>\n<pre>DECODE(expression, search1, result1, search2, result2, ..., default_result)<\/pre>\n<p>DECODE\u51fd\u6570\u4f1a\u4f9d\u6b21\u6bd4\u8f83expression\u4e0esearch1\u3001search2\u7b49\u7684\u503c\uff0c\u5982\u679c\u627e\u5230\u5339\u914d\u7684\u503c\uff0c\u5219\u8fd4\u56de\u76f8\u5e94\u7684result\u503c\uff1b\u5982\u679c\u6ca1\u6709\u627e\u5230\u5339\u914d\u7684\u503c\uff0c\u5219\u8fd4\u56dedefault_result\u3002<\/p>\n<h2>2. DECODE\u51fd\u6570\u5b9e\u9645\u5e94\u7528\u6307\u5357<\/h2>\n<h3>2.1 \u6570\u636e\u8f6c\u6362<\/h3>\n<p>DECODE\u51fd\u6570\u53ef\u4ee5\u7528\u6765\u8fdb\u884c\u6570\u636e\u8f6c\u6362\uff0c\u4f8b\u5982\u5c061\u548c0\u5206\u522b\u8f6c\u6362\u6210&#8221;\u662f&#8221;\u548c&#8221;\u5426&#8221;\uff1a<\/p>\n<pre>SELECT DECODE(status, 1, '\u662f', 0, '\u5426') AS status_text\nFROM employees;<\/pre>\n<h3>2.2 \u6761\u4ef6\u5224\u65ad<\/h3>\n<p>DECODE\u51fd\u6570\u4e5f\u53ef\u4ee5\u7528\u6765\u8fdb\u884c\u6761\u4ef6\u5224\u65ad\uff0c\u4f8b\u5982\u6839\u636e\u4e0d\u540c\u7684\u6761\u4ef6\u8fd4\u56de\u4e0d\u540c\u7684\u7ed3\u679c\uff1a<\/p>\n<pre>SELECT employee_name, DECODE(job, 'Manager', '\u9ad8\u7ea7\u7ba1\u7406\u4eba\u5458', '\u666e\u901a\u5458\u5de5') AS job_title\nFROM employees;<\/pre>\n<h3>2.3 \u7ed3\u679c\u8fd4\u56de<\/h3>\n<p>DECODE\u51fd\u6570\u8fd8\u53ef\u4ee5\u7528\u6765\u8fd4\u56de\u591a\u4e2a\u6761\u4ef6\u503c\u4e2d\u7684\u7b2c\u4e00\u4e2a\u5339\u914d\u503c\uff1a<\/p>\n<pre>SELECT student_name, DECODE(score, 90, '\u4f18\u79c0', 80, '\u826f\u597d', 60, '\u53ca\u683c', '\u4e0d\u53ca\u683c') AS grade\nFROM students;<\/pre>\n<h2>3. DECODE\u51fd\u6570\u6700\u4f73\u5b9e\u8df5<\/h2>\n<ul>\n<li><strong>\u907f\u514d\u8fc7\u5ea6\u590d\u6742\u7684\u903b\u8f91<\/strong> <br \/>\u5728\u4f7f\u7528DECODE\u51fd\u6570\u65f6\uff0c\u5e94\u5c3d\u91cf\u907f\u514d\u8fc7\u5ea6\u590d\u6742\u7684\u903b\u8f91\uff0c\u4ee5\u514d\u9020\u6210\u4ee3\u7801\u96be\u4ee5\u7ef4\u62a4\u548c\u7406\u89e3\u3002<\/li>\n<li><strong>\u4f7f\u7528\u522b\u540d<\/strong> <br \/>\u4e3aDECODE\u51fd\u6570\u7684\u8fd4\u56de\u7ed3\u679c\u6dfb\u52a0\u522b\u540d\uff0c\u53ef\u4ee5\u63d0\u9ad8\u4ee3\u7801\u7684\u53ef\u8bfb\u6027\uff0c\u65b9\u4fbf\u540e\u7eed\u7ef4\u62a4\u548c\u8c03\u8bd5\u3002<\/li>\n<li><strong>\u907f\u514d\u6df7\u6dc6<\/strong> <br \/>\u5728\u4f7f\u7528DECODE\u51fd\u6570\u65f6\uff0c\u9700\u8981\u786e\u4fdd\u53c2\u6570\u7684\u987a\u5e8f\u548c\u903b\u8f91\u6e05\u6670\u660e\u4e86\uff0c\u907f\u514d\u51fa\u73b0\u6df7\u6dc6\u548c\u9519\u8bef\u7684\u60c5\u51b5\u3002<\/li>\n<\/ul>\n<h2>4. \u5177\u4f53\u4ee3\u7801\u793a\u4f8b<\/h2>\n<p>\u4ee5\u4e0b\u662f\u4e00\u4e2aDECODE\u51fd\u6570\u7684\u5177\u4f53\u4ee3\u7801\u793a\u4f8b\uff0c\u7528\u4e8e\u5c06\u90e8\u95e8\u7f16\u53f7\u8f6c\u6362\u6210\u90e8\u95e8\u540d\u79f0\uff1a<\/p>\n<pre>SELECT employee_name, \n       DECODE(department_id,\n              10, '\u6280\u672f\u90e8',\n              20, '\u9500\u552e\u90e8',\n              30, '\u8d22\u52a1\u90e8',\n              '\u5176\u4ed6\u90e8\u95e8') AS department_name\nFROM employees;<\/pre>\n<p>\u901a\u8fc7\u4ee5\u4e0a\u4ecb\u7ecd\uff0c\u76f8\u4fe1\u8bfb\u8005\u5bf9\u4e8eOracle\u6570\u636e\u5e93\u4e2dDECODE\u51fd\u6570\u7684\u5b9e\u9645\u5e94\u7528\u548c\u6700\u4f73\u5b9e\u8df5\u6709\u4e86\u66f4\u52a0\u6e05\u6670\u7684\u4e86\u89e3\u3002\u5728\u5b9e\u9643\u7684\u6570\u636e\u5904\u7406\u8fc7\u7a0b\u4e2d\uff0c\u5408\u7406\u5730\u8fd0\u7528DECODE\u51fd\u6570\u80fd\u591f\u63d0\u9ad8\u6570\u636e\u5904\u7406\u6548\u7387\uff0c\u7b80\u5316\u4ee3\u7801\u903b\u8f91\uff0c\u4ece\u800c\u63d0\u5347\u6570\u636e\u5e93\u64cd\u4f5c\u7684\u6548\u7387\u548c\u53ef\u9760\u6027\u3002\u5e0c\u671b\u672c\u6587\u7684\u5185\u5bb9\u5bf9\u8bfb\u8005\u6709\u6240\u5e2e\u52a9\uff0c\u8c22\u8c22\u9605\u8bfb\uff01<\/p>\n<p>\u597d\u4e86\uff0c\u672c\u6587\u5230\u6b64\u7ed3\u675f\uff0c\u5e26\u5927\u5bb6\u4e86\u89e3\u4e86\u300a\u6307\u5bfc\u60a8\u5982\u4f55\u5b9e\u9645\u5e94\u7528\u548c\u5b9e\u8df5Oracle DECODE\u51fd\u6570\u300b\uff0c\u5e0c\u671b\u672c\u6587\u5bf9\u4f60\u6709\u6240\u5e2e\u52a9\uff01\u5173\u6ce8\u4e3b\u673a\u5b9d\u8d1d\u516c\u4f17\u53f7\uff0c\u7ed9\u5927\u5bb6\u5206\u4eab\u66f4\u591a\u6570\u636e\u5e93\u77e5\u8bc6\uff01<\/p>\n<dl>\n<dt>\n <\/dt>\n<\/dl>\n","protected":false},"excerpt":{"rendered":"<p>\u6307\u5bfc\u60a8\u5982\u4f55\u5b9e\u9645\u5e94\u7528\u548c\u5b9e\u8df5Orac&#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-199834","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/199834","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=199834"}],"version-history":[{"count":0,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/199834\/revisions"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=199834"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=199834"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=199834"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}