{"id":160633,"date":"2024-11-03T23:43:21","date_gmt":"2024-11-03T15:43:21","guid":{"rendered":"https:\/\/server.hk\/cnblog\/160633\/"},"modified":"2024-11-03T23:43:22","modified_gmt":"2024-11-03T15:43:22","slug":"oceanbase%e6%95%99%e7%a8%8b%ef%bc%9aoceanbase-%e5%ad%97%e5%85%83%e9%80%a3%e6%8e%a5%e9%81%8b%e7%ae%97%e7%ac%a6","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/160633\/","title":{"rendered":"OCEANBASE\u6559\u7a0b\uff1aOceanBase \u5b57\u5143\u9023\u63a5\u904b\u7b97\u7b26"},"content":{"rendered":"<h1 id=\"oceanbase%e6%95%99%e7%a8%8b%ef%bc%9aoceanbase-%e5%ad%97%e5%85%83%e9%80%a3%e6%8e%a5%e9%81%8b%e7%ae%97%e7%ac%a6-UFDLoXsPHU\">OCEANBASE\u6559\u7a0b\uff1aOceanBase \u5b57\u5143\u9023\u63a5\u904b\u7b97\u7b26<\/h1>\n<p>\u5728\u7576\u4eca\u7684\u6578\u64da\u5eab\u7ba1\u7406\u7cfb\u7d71\u4e2d\uff0cOceanBase \u4f5c\u70ba\u4e00\u500b\u9ad8\u6548\u80fd\u7684\u5206\u4f48\u5f0f\u6578\u64da\u5eab\uff0c\u8d8a\u4f86\u8d8a\u53d7\u5230\u958b\u767c\u8005\u7684\u9752\u775e\u3002\u5b83\u4e0d\u50c5\u652f\u6301\u9ad8\u4f75\u767c\u7684\u8b80\u5beb\u64cd\u4f5c\uff0c\u9084\u5177\u5099\u826f\u597d\u7684\u64f4\u5c55\u6027\u548c\u5bb9\u932f\u80fd\u529b\u3002\u5728\u9019\u7bc7\u6587\u7ae0\u4e2d\uff0c\u6211\u5011\u5c07\u6df1\u5165\u63a2\u8a0e OceanBase \u4e2d\u7684\u5b57\u5143\u9023\u63a5\u904b\u7b97\u7b26\uff0c\u5e6b\u52a9\u958b\u767c\u8005\u66f4\u597d\u5730\u7406\u89e3\u548c\u4f7f\u7528\u9019\u4e00\u529f\u80fd\u3002<\/p>\n<h2 id=\"%e4%bb%80%e9%ba%bc%e6%98%af%e5%ad%97%e5%85%83%e9%80%a3%e6%8e%a5%e9%81%8b%e7%ae%97%e7%ac%a6%ef%bc%9f-UFDLoXsPHU\">\u4ec0\u9ebc\u662f\u5b57\u5143\u9023\u63a5\u904b\u7b97\u7b26\uff1f<\/h2>\n<p>\u5b57\u5143\u9023\u63a5\u904b\u7b97\u7b26\uff08Concatenation Operator\uff09\u662f\u4e00\u7a2e\u7528\u65bc\u5c07\u591a\u500b\u5b57\u4e32\u9023\u63a5\u6210\u4e00\u500b\u5b57\u4e32\u7684\u904b\u7b97\u7b26\u3002\u5728 OceanBase \u4e2d\uff0c\u5b57\u5143\u9023\u63a5\u904b\u7b97\u7b26\u662f\u300c||\u300d\u3002\u9019\u500b\u904b\u7b97\u7b26\u53ef\u4ee5\u7528\u4f86\u5408\u4f75\u5169\u500b\u6216\u591a\u500b\u5b57\u4e32\uff0c\u5f9e\u800c\u751f\u6210\u4e00\u500b\u65b0\u7684\u5b57\u4e32\u3002<\/p>\n<h2 id=\"%e5%9f%ba%e6%9c%ac%e7%94%a8%e6%b3%95-UFDLoXsPHU\">\u57fa\u672c\u7528\u6cd5<\/h2>\n<p>\u5728 OceanBase \u4e2d\uff0c\u4f7f\u7528\u5b57\u5143\u9023\u63a5\u904b\u7b97\u7b26\u975e\u5e38\u7c21\u55ae\u3002\u4ee5\u4e0b\u662f\u4e00\u4e9b\u57fa\u672c\u7684\u7528\u6cd5\u793a\u4f8b\uff1a<\/p>\n<pre><code>SELECT 'Hello' || ' ' || 'World' AS greeting;\n<\/code><\/pre>\n<p>\u4e0a\u8ff0\u67e5\u8a62\u5c07\u8fd4\u56de\u4e00\u500b\u540d\u70ba <code>greeting<\/code> \u7684\u6b04\u4f4d\uff0c\u5176\u503c\u70ba <code>Hello World<\/code>\u3002<\/p>\n<h2 id=\"%e4%bd%bf%e7%94%a8%e5%ad%97%e5%85%83%e9%80%a3%e6%8e%a5%e9%81%8b%e7%ae%97%e7%ac%a6%e7%9a%84%e5%af%a6%e9%9a%9b%e6%a1%88%e4%be%8b-UFDLoXsPHU\">\u4f7f\u7528\u5b57\u5143\u9023\u63a5\u904b\u7b97\u7b26\u7684\u5be6\u969b\u6848\u4f8b<\/h2>\n<p>\u5728\u5be6\u969b\u958b\u767c\u4e2d\uff0c\u5b57\u5143\u9023\u63a5\u904b\u7b97\u7b26\u53ef\u4ee5\u7528\u65bc\u591a\u7a2e\u5834\u666f\uff0c\u4f8b\u5982\u751f\u6210\u5b8c\u6574\u7684\u5730\u5740\u3001\u7d44\u5408\u7528\u6236\u540d\u548c\u96fb\u5b50\u90f5\u4ef6\u7b49\u3002\u4ee5\u4e0b\u662f\u4e00\u500b\u66f4\u5177\u9ad4\u7684\u4f8b\u5b50\uff1a<\/p>\n<pre><code>SELECT first_name || ' ' || last_name AS full_name\nFROM users;\n<\/code><\/pre>\n<p>\u5728\u9019\u500b\u67e5\u8a62\u4e2d\uff0c\u6211\u5011\u5f9e <code>users<\/code> \u8868\u4e2d\u9078\u53d6 <code>first_name<\/code> \u548c <code>last_name<\/code> \u6b04\u4f4d\uff0c\u4e26\u5c07\u5b83\u5011\u9023\u63a5\u6210\u4e00\u500b\u5b8c\u6574\u7684\u59d3\u540d <code>full_name<\/code>\u3002<\/p>\n<h2 id=\"%e8%99%95%e7%90%86-null-%e5%80%bc-UFDLoXsPHU\">\u8655\u7406 NULL \u503c<\/h2>\n<p>\u5728\u4f7f\u7528\u5b57\u5143\u9023\u63a5\u904b\u7b97\u7b26\u6642\uff0c\u958b\u767c\u8005\u9700\u8981\u6ce8\u610f NULL \u503c\u7684\u8655\u7406\u3002\u5982\u679c\u5176\u4e2d\u4e00\u500b\u5b57\u4e32\u70ba NULL\uff0c\u5247\u6574\u500b\u9023\u63a5\u7684\u7d50\u679c\u4e5f\u5c07\u662f NULL\u3002\u70ba\u4e86\u89e3\u6c7a\u9019\u500b\u554f\u984c\uff0c\u53ef\u4ee5\u4f7f\u7528 <code>COALESCE<\/code> \u51fd\u6578\u4f86\u66ff\u4ee3 NULL \u503c\u3002\u4ee5\u4e0b\u662f\u793a\u4f8b\uff1a<\/p>\n<pre><code>SELECT COALESCE(first_name, 'N\/A') || ' ' || COALESCE(last_name, 'N\/A') AS full_name\nFROM users;\n<\/code><\/pre>\n<p>\u9019\u6a23\uff0c\u5373\u4f7f <code>first_name<\/code> \u6216 <code>last_name<\/code> \u70ba NULL\uff0c\u67e5\u8a62\u7d50\u679c\u4e5f\u6703\u8fd4\u56de <code>N\/A<\/code> \u4f5c\u70ba\u66ff\u4ee3\u503c\u3002<\/p>\n<h2 id=\"%e5%ad%97%e5%85%83%e9%80%a3%e6%8e%a5%e9%81%8b%e7%ae%97%e7%ac%a6%e7%9a%84%e6%80%a7%e8%83%bd%e8%80%83%e9%87%8f-UFDLoXsPHU\">\u5b57\u5143\u9023\u63a5\u904b\u7b97\u7b26\u7684\u6027\u80fd\u8003\u91cf<\/h2>\n<p>\u5728\u4f7f\u7528\u5b57\u5143\u9023\u63a5\u904b\u7b97\u7b26\u6642\uff0c\u6027\u80fd\u662f\u53e6\u4e00\u500b\u9700\u8981\u8003\u616e\u7684\u56e0\u7d20\u3002\u7576\u9023\u63a5\u5927\u91cf\u5b57\u4e32\u6642\uff0c\u53ef\u80fd\u6703\u5f71\u97ff\u67e5\u8a62\u7684\u57f7\u884c\u6548\u7387\u3002\u56e0\u6b64\uff0c\u5efa\u8b70\u958b\u767c\u8005\u5728\u8a2d\u8a08\u6578\u64da\u5eab\u67e5\u8a62\u6642\uff0c\u76e1\u91cf\u6e1b\u5c11\u4e0d\u5fc5\u8981\u7684\u5b57\u4e32\u9023\u63a5\u64cd\u4f5c\uff0c\u7279\u5225\u662f\u5728\u8655\u7406\u5927\u6578\u64da\u91cf\u6642\u3002<\/p>\n<h2 id=\"%e7%b8%bd%e7%b5%90-UFDLoXsPHU\">\u7e3d\u7d50<\/h2>\n<p>OceanBase \u7684\u5b57\u5143\u9023\u63a5\u904b\u7b97\u7b26\u63d0\u4f9b\u4e86\u4e00\u7a2e\u7c21\u55ae\u800c\u6709\u6548\u7684\u65b9\u5f0f\u4f86\u5408\u4f75\u5b57\u4e32\uff0c\u5c0d\u65bc\u958b\u767c\u8005\u4f86\u8aaa\uff0c\u638c\u63e1\u9019\u4e00\u904b\u7b97\u7b26\u7684\u4f7f\u7528\u65b9\u6cd5\u5c07\u6709\u52a9\u65bc\u63d0\u9ad8\u6578\u64da\u8655\u7406\u7684\u9748\u6d3b\u6027\u548c\u6548\u7387\u3002\u5728\u5be6\u969b\u61c9\u7528\u4e2d\uff0c\u5408\u7406\u8655\u7406 NULL \u503c\u548c\u8003\u616e\u6027\u80fd\u554f\u984c\u4e5f\u662f\u81f3\u95dc\u91cd\u8981\u7684\u3002<\/p>\n<p>\u5982\u679c\u60a8\u5c0d\u65bc <a href=\"https:\/\/server.hk\">\u9999\u6e2fVPS<\/a> \u670d\u52d9\u6709\u8208\u8da3\uff0c\u6216\u60f3\u4e86\u89e3\u66f4\u591a\u95dc\u65bc <a href=\"https:\/\/server.hk\">\u96f2\u4f3a\u670d\u5668<\/a> \u7684\u8cc7\u8a0a\uff0c\u6b61\u8fce\u8a2a\u554f\u6211\u5011\u7684\u7db2\u7ad9\u4ee5\u7372\u53d6\u66f4\u591a\u8a73\u7d30\u8cc7\u6599\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u5b78\u7fd2 OceanBase \u5b57\u5143\u9023\u63a5\u904b\u7b97\u7b26\u7684\u4f7f\u7528\u65b9\u6cd5\uff0c\u63d0\u5347\u6578\u64da\u8655\u7406\u6548\u7387\uff0c\u638c\u63e1\u95dc\u9375\u6280\u5de7\uff0c\u8f15\u9b06\u61c9\u5c0d\u5be6\u969b\u61c9\u7528\u3002<\/p>\n","protected":false},"author":0,"featured_media":0,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[101],"tags":[],"class_list":["post-160633","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/160633","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"}],"replies":[{"embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/comments?post=160633"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/160633\/revisions"}],"predecessor-version":[{"id":160634,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/160633\/revisions\/160634"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=160633"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=160633"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=160633"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}