{"id":5302,"date":"2024-11-14T09:29:08","date_gmt":"2024-11-14T01:29:08","guid":{"rendered":"https:\/\/fwq.ai\/blog\/5302\/"},"modified":"2024-11-14T09:29:08","modified_gmt":"2024-11-14T01:29:08","slug":"oracle-decode%e6%80%8e%e4%b9%88%e6%8e%92%e5%ba%8f%e7%9a%84","status":"publish","type":"post","link":"https:\/\/fwq.ai\/blog\/5302\/","title":{"rendered":"oracle\u00a0decode\u600e\u4e48\u6392\u5e8f\u7684"},"content":{"rendered":"<p><strong>decode \u51fd\u6570\u4e2d\u7684\u6392\u5e8f<\/strong><\/p>\n<p>Oracle DECODE \u51fd\u6570\u5141\u8bb8\u7528\u6237\u6839\u636e\u4e00\u4e2a\u6216\u591a\u4e2a\u6761\u4ef6\u8fd4\u56de\u4e0d\u540c\u7684\u503c\u3002\u6392\u5e8f\u662f\u5982\u4f55\u5728 DECODE \u51fd\u6570\u4e2d\u5de5\u4f5c\u7684\uff0c\u8fd9\u662f\u4e00\u4e2a\u5e38\u89c1\u7684\u95ee\u9898\u3002<\/p>\n<p><strong>\u6392\u5e8f\u673a\u5236<\/strong><\/p>\n<p>DECODE \u51fd\u6570\u4e2d\u7684\u6392\u5e8f\u662f<strong>\u4f18\u5148\u7ea7<\/strong>\u6392\u5e8f\u3002<\/p>\n<ul>\n<li>\u6761\u4ef6\u6309\u5176\u51fa\u73b0\u7684\u987a\u5e8f\u8fdb\u884c\u8bc4\u4f30\u3002<\/li>\n<li>\u4e00\u65e6\u627e\u5230\u6ee1\u8db3\u6761\u4ef6\u7684\u884c\uff0c\u5219\u8fd4\u56de\u76f8\u5e94\u7684\u8fd4\u56de\u503c\u3002<\/li>\n<li>\u8bc4\u4f30\u505c\u6b62\uff0c\u51fd\u6570\u4e0d\u4f1a\u7ee7\u7eed\u8bc4\u4f30\u5176\u4ed6\u6761\u4ef6\u3002<\/li>\n<\/ul>\n<p><strong>\u793a\u4f8b<\/strong><\/p>\n<p>\u4ee5\u4e0b DECODE \u51fd\u6570\u793a\u4f8b\u8bf4\u660e\u4e86\u6392\u5e8f\u673a\u5236\uff1a<\/p>\n<pre>DECODE(deptno, 10, 'Sales', 20, 'Marketing', 30, 'Finance', 'Other')<\/pre>\n<p> \u767b\u5f55\u540e\u590d\u5236 <\/p>\n<ul>\n<li>\u5982\u679c deptno \u7b49\u4e8e 10\uff0c\u5219\u51fd\u6570\u8fd4\u56de &#8216;Sales&#8217;\u3002<\/li>\n<li>\u5373\u4f7f\u6ee1\u8db3\u540e\u7eed\u6761\u4ef6\uff08\u4f8b\u5982 deptno \u7b49\u4e8e 20 \u6216 30\uff09\uff0c\u51fd\u6570\u4e5f\u4e0d\u4f1a\u6267\u884c\u8fd9\u4e9b\u6761\u4ef6\u3002<\/li>\n<\/ul>\n<p><strong>\u6392\u5e8f\u4f18\u5148\u7ea7<\/strong><\/p>\n<p>\u6761\u4ef6\u5728 DECODE \u51fd\u6570\u4e2d\u6309 <strong>\u5148\u540e\u987a\u5e8f<\/strong> \u8bc4\u4f30\u3002\u8fd9\u610f\u5473\u7740<strong>\u7b2c\u4e00\u4e2a\u6ee1\u8db3\u7684\u6761\u4ef6<\/strong>\u5177\u6709\u6700\u9ad8\u7684\u4f18\u5148\u7ea7\u3002<\/p>\n<p><strong>\u907f\u514d\u6b67\u4e49<\/strong><\/p>\n<p>\u4e3a\u4e86\u907f\u514d\u6b67\u4e49\uff0c\u786e\u4fdd\u6761\u4ef6\u4e0d\u91cd\u53e0\u3002\u5982\u679c\u4e24\u4e2a\u6761\u4ef6\u8fd4\u56de\u76f8\u540c\u7684\u503c\uff0c\u5219\u7b2c\u4e00\u4e2a\u6761\u4ef6\u5177\u6709\u66f4\u9ad8\u7684\u4f18\u5148\u7ea7\u3002<\/p>\n<p><strong>\u6392\u5e8f\u793a\u4f8b<\/strong><\/p>\n<p>\u4ee5\u4e0b\u793a\u4f8b\u6f14\u793a\u4e86\u6392\u5e8f\u4f18\u5148\u7ea7\uff1a<\/p>\n<pre>DECODE(salary, 10000, 'Low', 20000, 'Medium', 20000, 'High')<\/pre>\n<p> \u767b\u5f55\u540e\u590d\u5236 <\/p>\n<ul>\n<li>\u5982\u679c salary \u7b49\u4e8e 20000\uff0c\u5219\u51fd\u6570\u8fd4\u56de &#8216;Medium&#8217;\u3002<\/li>\n<li>\u8fd9\u662f\u56e0\u4e3a\u7b2c\u4e8c\u4e2a\u6761\u4ef6 salary \u7b49\u4e8e 20000 \u5177\u6709\u66f4\u9ad8\u7684\u4f18\u5148\u7ea7\uff0c\u5373\u4f7f\u8fd9\u4e24\u4e2a\u6761\u4ef6\u8fd4\u56de\u76f8\u540c\u7684\u503c\u3002<\/li>\n<\/ul>\n<p>\u4ee5\u4e0a\u5c31\u662f&nbsp;decode\u600e\u4e48\u6392\u5e8f\u7684\u7684\u8be6\u7ec6\u5185\u5bb9\uff0c\u66f4\u591a\u8bf7\u5173\u6ce8\u7c73\u4e91\u7f51\u5176\u5b83\u76f8\u5173\u6587\u7ae0\uff01<\/p>\n","protected":false},"excerpt":{"rendered":"<p>decode \u51fd\u6570\u4e2d\u7684\u6392\u5e8f Oracle DECODE \u51fd\u6570\u5141\u8bb8\u7528\u6237\u6839\u636e\u4e00\u4e2a\u6216\u591a\u4e2a\u6761\u4ef6\u8fd4\u56de\u4e0d\u540c\u7684\u503c\u3002\u6392\u5e8f\u662f\u5982\u4f55\u5728 DECODE \u51fd\u6570\u4e2d\u5de5\u4f5c\u7684\uff0c\u8fd9\u662f\u4e00\u4e2a\u5e38\u89c1\u7684\u95ee\u9898\u3002 \u6392\u5e8f\u673a\u5236 DECODE \u51fd\u6570\u4e2d\u7684\u6392\u5e8f\u662f\u4f18\u5148\u7ea7\u6392\u5e8f\u3002 \u6761\u4ef6\u6309\u5176\u51fa\u73b0\u7684\u987a\u5e8f\u8fdb\u884c\u8bc4\u4f30\u3002 \u4e00\u65e6\u627e\u5230\u6ee1\u8db3\u6761\u4ef6\u7684\u884c\uff0c\u5219\u8fd4\u56de\u76f8\u5e94\u7684\u8fd4\u56de\u503c\u3002 \u8bc4\u4f30\u505c\u6b62\uff0c\u51fd\u6570\u4e0d\u4f1a\u7ee7\u7eed\u8bc4\u4f30\u5176\u4ed6\u6761\u4ef6\u3002 \u793a\u4f8b \u4ee5\u4e0b DECODE \u51fd\u6570\u793a\u4f8b\u8bf4\u660e\u4e86\u6392\u5e8f\u673a\u5236\uff1a DECODE(deptno, 10, &#8216;Sales&#8217;, 20, &#8216;Marketing&#8217;, 30, &#8216;Finance&#8217;, &#8216;Other&#8217;) \u767b\u5f55\u540e\u590d\u5236 \u5982\u679c deptno \u7b49\u4e8e 10\uff0c\u5219\u51fd\u6570\u8fd4\u56de &#8216;Sales&#8217;\u3002 \u5373\u4f7f\u6ee1\u8db3\u540e\u7eed\u6761\u4ef6\uff08\u4f8b\u5982 deptno \u7b49\u4e8e 20 \u6216 30\uff09\uff0c\u51fd\u6570\u4e5f\u4e0d\u4f1a\u6267\u884c\u8fd9\u4e9b\u6761\u4ef6\u3002 \u6392\u5e8f\u4f18\u5148\u7ea7 \u6761\u4ef6\u5728 DECODE \u51fd\u6570\u4e2d\u6309 \u5148\u540e\u987a\u5e8f \u8bc4\u4f30\u3002\u8fd9\u610f\u5473\u7740\u7b2c\u4e00\u4e2a\u6ee1\u8db3\u7684\u6761\u4ef6\u5177\u6709\u6700\u9ad8\u7684\u4f18\u5148\u7ea7\u3002 \u907f\u514d\u6b67\u4e49 \u4e3a\u4e86\u907f\u514d\u6b67\u4e49\uff0c\u786e\u4fdd\u6761\u4ef6\u4e0d\u91cd\u53e0\u3002\u5982\u679c\u4e24\u4e2a\u6761\u4ef6\u8fd4\u56de\u76f8\u540c\u7684\u503c\uff0c\u5219\u7b2c\u4e00\u4e2a\u6761\u4ef6\u5177\u6709\u66f4\u9ad8\u7684\u4f18\u5148\u7ea7\u3002 \u6392\u5e8f\u793a\u4f8b \u4ee5\u4e0b\u793a\u4f8b\u6f14\u793a\u4e86\u6392\u5e8f\u4f18\u5148\u7ea7\uff1a DECODE(salary, 10000, &#8216;Low&#8217;, 20000, &#8216;Medium&#8217;, 20000, &#8216;High&#8217;) \u767b\u5f55\u540e\u590d\u5236 [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[16],"tags":[],"class_list":["post-5302","post","type-post","status-publish","format-standard","hentry","category-16"],"_links":{"self":[{"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/posts\/5302","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/comments?post=5302"}],"version-history":[{"count":0,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/posts\/5302\/revisions"}],"wp:attachment":[{"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/media?parent=5302"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/categories?post=5302"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/tags?post=5302"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}