{"id":160191,"date":"2024-11-03T21:02:22","date_gmt":"2024-11-03T13:02:22","guid":{"rendered":"https:\/\/server.hk\/cnblog\/160191\/"},"modified":"2024-11-03T21:02:23","modified_gmt":"2024-11-03T13:02:23","slug":"oceanbase-%e6%95%99%e7%a8%8b%ef%bc%9aoceanbase-nvl2","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/160191\/","title":{"rendered":"OceanBase \u6559\u7a0b\uff1aOceanBase NVL2"},"content":{"rendered":"<h1 id=\"oceanbase-%e6%95%99%e7%a8%8b%ef%bc%9aoceanbase-nvl2-FcijElFyOC\">OceanBase \u6559\u7a0b\uff1aOceanBase NVL2<\/h1>\n<p>\u5728\u7576\u4eca\u7684\u6578\u64da\u5eab\u7ba1\u7406\u7cfb\u7d71\u4e2d\uff0cOceanBase \u4f5c\u70ba\u4e00\u500b\u9ad8\u6027\u80fd\u7684\u5206\u4f48\u5f0f\u6578\u64da\u5eab\uff0c\u8d8a\u4f86\u8d8a\u53d7\u5230\u958b\u767c\u8005\u548c\u4f01\u696d\u7684\u9752\u775e\u3002\u5b83\u4e0d\u50c5\u652f\u6301\u9ad8\u4e26\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 NVL2 \u51fd\u6578\uff0c\u4e26\u63d0\u4f9b\u4e00\u4e9b\u5be6\u7528\u7684\u793a\u4f8b\u4f86\u5e6b\u52a9\u8b80\u8005\u66f4\u597d\u5730\u7406\u89e3\u5176\u7528\u6cd5\u3002<\/p>\n<h2 id=\"%e4%bb%80%e9%ba%bc%e6%98%af-nvl2-%e5%87%bd%e6%95%b8%ef%bc%9f-FcijElFyOC\">\u4ec0\u9ebc\u662f NVL2 \u51fd\u6578\uff1f<\/h2>\n<p>NVL2 \u51fd\u6578\u662f\u4e00\u500b\u7528\u65bc\u8655\u7406\u7a7a\u503c\u7684\u51fd\u6578\uff0c\u4e3b\u8981\u7528\u65bc\u5224\u65b7\u67d0\u500b\u8868\u9054\u5f0f\u662f\u5426\u70ba\u7a7a\u3002\u6839\u64da\u8a72\u8868\u9054\u5f0f\u7684\u503c\uff0cNVL2 \u51fd\u6578\u6703\u8fd4\u56de\u4e0d\u540c\u7684\u7d50\u679c\u3002\u5176\u57fa\u672c\u8a9e\u6cd5\u5982\u4e0b\uff1a<\/p>\n<pre><code>NVL2(expr1, expr2, expr3)<\/code><\/pre>\n<p>\u5728\u9019\u88e1\uff0c<code>expr1<\/code> \u662f\u8981\u6aa2\u67e5\u7684\u8868\u9054\u5f0f\uff1b<code>expr2<\/code> \u662f\u7576 <code>expr1<\/code> \u4e0d\u70ba\u7a7a\u6642\u8fd4\u56de\u7684\u503c\uff1b<code>expr3<\/code> \u662f\u7576 <code>expr1<\/code> \u70ba\u7a7a\u6642\u8fd4\u56de\u7684\u503c\u3002<\/p>\n<h2 id=\"nvl2-%e5%87%bd%e6%95%b8%e7%9a%84%e4%bd%bf%e7%94%a8%e5%a0%b4%e6%99%af-FcijElFyOC\">NVL2 \u51fd\u6578\u7684\u4f7f\u7528\u5834\u666f<\/h2>\n<p>NVL2 \u51fd\u6578\u901a\u5e38\u7528\u65bc\u6578\u64da\u6e05\u7406\u548c\u5831\u544a\u751f\u6210\u4e2d\uff0c\u7279\u5225\u662f\u5728\u9700\u8981\u6839\u64da\u67d0\u4e9b\u689d\u4ef6\u986f\u793a\u4e0d\u540c\u6578\u64da\u6642\u3002\u4ee5\u4e0b\u662f\u4e00\u4e9b\u5e38\u898b\u7684\u4f7f\u7528\u5834\u666f\uff1a<\/p>\n<ul>\n<li>\u5728\u67e5\u8a62\u4e2d\u66ff\u63db\u7a7a\u503c\uff1a\u7576\u67d0\u500b\u5b57\u6bb5\u7684\u503c\u70ba\u7a7a\u6642\uff0c\u53ef\u4ee5\u7528\u9810\u8a2d\u503c\u66ff\u4ee3\u3002<\/li>\n<li>\u751f\u6210\u5831\u544a\u6642\u6839\u64da\u4e0d\u540c\u689d\u4ef6\u986f\u793a\u4e0d\u540c\u7684\u6578\u64da\u3002<\/li>\n<li>\u5728\u6578\u64da\u5206\u6790\u4e2d\uff0c\u6839\u64da\u7a7a\u503c\u7684\u5b58\u5728\u8207\u5426\u9032\u884c\u4e0d\u540c\u7684\u8a08\u7b97\u3002<\/li>\n<\/ul>\n<h2 id=\"nvl2-%e5%87%bd%e6%95%b8%e7%9a%84%e7%a4%ba%e4%be%8b-FcijElFyOC\">NVL2 \u51fd\u6578\u7684\u793a\u4f8b<\/h2>\n<p>\u4ee5\u4e0b\u662f\u4e00\u500b\u4f7f\u7528 NVL2 \u51fd\u6578\u7684\u793a\u4f8b\uff0c\u5047\u8a2d\u6211\u5011\u6709\u4e00\u500b\u540d\u70ba <code>employees<\/code> \u7684\u8868\uff0c\u8a72\u8868\u5305\u542b\u54e1\u5de5\u7684\u59d3\u540d\u548c\u734e\u91d1\u4fe1\u606f\uff1a<\/p>\n<pre><code>SELECT \n    name,\n    NVL2(bonus, '\u6709\u734e\u91d1', '\u7121\u734e\u91d1') AS bonus_status\nFROM \n    employees;<\/code><\/pre>\n<p>\u5728\u9019\u500b\u67e5\u8a62\u4e2d\uff0c\u7576 <code>bonus<\/code> \u5b57\u6bb5\u4e0d\u70ba\u7a7a\u6642\uff0c\u5c07\u8fd4\u56de &#8216;\u6709\u734e\u91d1&#8217;\uff0c\u5426\u5247\u8fd4\u56de &#8216;\u7121\u734e\u91d1&#8217;\u3002\u9019\u6a23\u53ef\u4ee5\u65b9\u4fbf\u5730\u4e86\u89e3\u6bcf\u4f4d\u54e1\u5de5\u7684\u734e\u91d1\u72c0\u614b\u3002<\/p>\n<h2 id=\"%e7%b5%90%e5%90%88%e5%85%b6%e4%bb%96%e5%87%bd%e6%95%b8%e4%bd%bf%e7%94%a8-FcijElFyOC\">\u7d50\u5408\u5176\u4ed6\u51fd\u6578\u4f7f\u7528<\/h2>\n<p>NVL2 \u51fd\u6578\u4e5f\u53ef\u4ee5\u8207\u5176\u4ed6 SQL \u51fd\u6578\u7d50\u5408\u4f7f\u7528\uff0c\u4ee5\u5be6\u73fe\u66f4\u8907\u96dc\u7684\u908f\u8f2f\u3002\u4f8b\u5982\uff0c\u60a8\u53ef\u4ee5\u5c07 NVL2 \u8207 <code>SUM<\/code> \u51fd\u6578\u7d50\u5408\uff0c\u4f86\u8a08\u7b97\u734e\u91d1\u7684\u7e3d\u548c\uff1a<\/p>\n<pre><code>SELECT \n    SUM(NVL2(bonus, bonus, 0)) AS total_bonus\nFROM \n    employees;<\/code><\/pre>\n<p>\u5728\u9019\u500b\u67e5\u8a62\u4e2d\uff0c\u7576 <code>bonus<\/code> \u4e0d\u70ba\u7a7a\u6642\uff0c\u5c07\u5176\u503c\u52a0\u7e3d\uff1b\u5982\u679c\u70ba\u7a7a\uff0c\u5247\u7528 0 \u4ee3\u66ff\u3002\u9019\u6a23\u53ef\u4ee5\u78ba\u4fdd\u8a08\u7b97\u7684\u6e96\u78ba\u6027\u3002<\/p>\n<h2 id=\"%e7%b8%bd%e7%b5%90-FcijElFyOC\">\u7e3d\u7d50<\/h2>\n<p>NVL2 \u51fd\u6578\u5728 OceanBase \u4e2d\u662f\u4e00\u500b\u975e\u5e38\u5be6\u7528\u7684\u5de5\u5177\uff0c\u80fd\u5920\u5e6b\u52a9\u958b\u767c\u8005\u6709\u6548\u5730\u8655\u7406\u7a7a\u503c\u554f\u984c\u3002\u901a\u904e\u9748\u6d3b\u904b\u7528 NVL2 \u51fd\u6578\uff0c\u60a8\u53ef\u4ee5\u5728\u6578\u64da\u67e5\u8a62\u548c\u5831\u544a\u751f\u6210\u4e2d\u7372\u5f97\u66f4\u597d\u7684\u7d50\u679c\u3002\u7121\u8ad6\u662f\u5728\u6578\u64da\u6e05\u7406\u9084\u662f\u6578\u64da\u5206\u6790\u4e2d\uff0c\u638c\u63e1 NVL2 \u51fd\u6578\u7684\u4f7f\u7528\u90fd\u5c07\u5927\u5927\u63d0\u9ad8\u60a8\u7684\u5de5\u4f5c\u6548\u7387\u3002<\/p>\n<p>\u5982\u679c\u60a8\u5c0d\u65bc <a href=\"https:\/\/server.hk\">\u9999\u6e2f VPS<\/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>\u5b66\u4e60\u5982\u4f55\u4f7f\u7528 OceanBase NVL2 \u51fd\u6570\uff0c\u638c\u63e1\u6570\u636e\u5904\u7406\u6280\u5de7\uff0c\u63d0\u5347\u6570\u636e\u5e93\u64cd\u4f5c\u6548\u7387\uff0c\u8f7b\u677e\u5e94\u5bf9\u590d\u6742\u67e5\u8be2\u9700\u6c42\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-160191","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/160191","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=160191"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/160191\/revisions"}],"predecessor-version":[{"id":160192,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/160191\/revisions\/160192"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=160191"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=160191"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=160191"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}