{"id":160545,"date":"2024-11-03T22:59:20","date_gmt":"2024-11-03T14:59:20","guid":{"rendered":"https:\/\/server.hk\/cnblog\/160545\/"},"modified":"2024-11-03T22:59:20","modified_gmt":"2024-11-03T14:59:20","slug":"oceanbase-%e6%95%99%e7%a8%8b%ef%bc%9aoceanbase-%e5%85%b6%e4%bb%96%e5%87%bd%e6%95%b8","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/160545\/","title":{"rendered":"OceanBase \u6559\u7a0b\uff1aOceanBase \u5176\u4ed6\u51fd\u6578"},"content":{"rendered":"<h1 id=\"oceanbase-%e6%95%99%e7%a8%8b%ef%bc%9aoceanbase-%e5%85%b6%e4%bb%96%e5%87%bd%e6%95%b8-GwKHyXOEsD\">OceanBase \u6559\u7a0b\uff1aOceanBase \u5176\u4ed6\u51fd\u6578<\/h1>\n<p>OceanBase \u662f\u4e00\u6b3e\u9ad8\u6027\u80fd\u7684\u5206\u5e03\u5f0f\u5173\u7cfb\u6570\u636e\u5e93\uff0c\u5e7f\u6cdb\u5e94\u7528\u4e8e\u91d1\u878d\u3001\u7535\u5546\u7b49\u9886\u57df\u3002\u9664\u4e86\u57fa\u672c\u7684 SQL \u67e5\u8be2\u529f\u80fd\u5916\uff0cOceanBase \u8fd8\u63d0\u4f9b\u4e86\u591a\u79cd\u5176\u4ed6\u51fd\u6570\uff0c\u5e2e\u52a9\u5f00\u53d1\u8005\u66f4\u9ad8\u6548\u5730\u5904\u7406\u6570\u636e\u3002\u672c\u6587\u5c06\u4ecb\u7ecd\u4e00\u4e9b OceanBase \u4e2d\u5e38\u7528\u7684\u5176\u4ed6\u51fd\u6570\u53ca\u5176\u5e94\u7528\u793a\u4f8b\u3002<\/p>\n<h2 id=\"1-%e5%ad%97%e7%ac%a6%e4%b8%b2%e5%a4%84%e7%90%86%e5%87%bd%e6%95%b0-GwKHyXOEsD\">1. \u5b57\u7b26\u4e32\u5904\u7406\u51fd\u6570<\/h2>\n<p>\u5728\u6570\u636e\u5904\u7406\u4e2d\uff0c\u5b57\u7b26\u4e32\u64cd\u4f5c\u662f\u975e\u5e38\u5e38\u89c1\u7684\u9700\u6c42\u3002OceanBase \u63d0\u4f9b\u4e86\u591a\u79cd\u5b57\u7b26\u4e32\u5904\u7406\u51fd\u6570\uff0c\u4ee5\u4e0b\u662f\u4e00\u4e9b\u5e38\u7528\u7684\u51fd\u6570\uff1a<\/p>\n<ul>\n<li><code>LENGTH(str)<\/code>\uff1a\u8fd4\u56de\u5b57\u7b26\u4e32\u7684\u957f\u5ea6\u3002<\/li>\n<li><code>UPPER(str)<\/code>\uff1a\u5c06\u5b57\u7b26\u4e32\u8f6c\u6362\u4e3a\u5927\u5199\u3002<\/li>\n<li><code>LOWER(str)<\/code>\uff1a\u5c06\u5b57\u7b26\u4e32\u8f6c\u6362\u4e3a\u5c0f\u5199\u3002<\/li>\n<li><code>SUBSTRING(str, start, length)<\/code>\uff1a\u8fd4\u56de\u4ece\u6307\u5b9a\u4f4d\u7f6e\u5f00\u59cb\u7684\u5b50\u5b57\u7b26\u4e32\u3002<\/li>\n<\/ul>\n<p>\u4f8b\u5982\uff0c\u5047\u8bbe\u6211\u4eec\u6709\u4e00\u4e2a\u7528\u6237\u8868\uff0c\u5305\u542b\u7528\u6237\u7684\u59d3\u540d\u5b57\u6bb5\uff0c\u6211\u4eec\u53ef\u4ee5\u4f7f\u7528\u4ee5\u4e0b SQL \u67e5\u8be2\u6765\u83b7\u53d6\u7528\u6237\u59d3\u540d\u7684\u957f\u5ea6\uff1a<\/p>\n<pre><code>SELECT LENGTH(name) AS name_length FROM users;<\/code><\/pre>\n<h2 id=\"2-%e6%97%a5%e6%9c%9f%e5%92%8c%e6%97%b6%e9%97%b4%e5%87%bd%e6%95%b0-GwKHyXOEsD\">2. \u65e5\u671f\u548c\u65f6\u95f4\u51fd\u6570<\/h2>\n<p>\u65e5\u671f\u548c\u65f6\u95f4\u7684\u5904\u7406\u5728\u6570\u636e\u5e93\u4e2d\u540c\u6837\u91cd\u8981\u3002OceanBase \u63d0\u4f9b\u4e86\u4e00\u7cfb\u5217\u65e5\u671f\u548c\u65f6\u95f4\u51fd\u6570\uff0c\u5e2e\u52a9\u7528\u6237\u8fdb\u884c\u65f6\u95f4\u8ba1\u7b97\u548c\u683c\u5f0f\u5316\uff1a<\/p>\n<ul>\n<li><code>NOW()<\/code>\uff1a\u8fd4\u56de\u5f53\u524d\u7684\u65e5\u671f\u548c\u65f6\u95f4\u3002<\/li>\n<li><code>DATE_FORMAT(date, format)<\/code>\uff1a\u683c\u5f0f\u5316\u65e5\u671f\u3002<\/li>\n<li><code>DATEDIFF(date1, date2)<\/code>\uff1a\u8fd4\u56de\u4e24\u4e2a\u65e5\u671f\u4e4b\u95f4\u7684\u5929\u6570\u5dee\u3002<\/li>\n<li><code>DATE_ADD(date, INTERVAL expr unit)<\/code>\uff1a\u5728\u6307\u5b9a\u65e5\u671f\u4e0a\u6dfb\u52a0\u65f6\u95f4\u95f4\u9694\u3002<\/li>\n<\/ul>\n<p>\u4f8b\u5982\uff0c\u82e5\u8981\u83b7\u53d6\u5f53\u524d\u65e5\u671f\u548c\u65f6\u95f4\uff0c\u53ef\u4ee5\u4f7f\u7528\u4ee5\u4e0b\u67e5\u8be2\uff1a<\/p>\n<pre><code>SELECT NOW() AS current_time;<\/code><\/pre>\n<h2 id=\"3-%e6%95%b0%e5%ad%a6%e5%87%bd%e6%95%b0-GwKHyXOEsD\">3. \u6570\u5b66\u51fd\u6570<\/h2>\n<p>OceanBase \u8fd8\u63d0\u4f9b\u4e86\u4e00\u4e9b\u6570\u5b66\u51fd\u6570\uff0c\u65b9\u4fbf\u7528\u6237\u8fdb\u884c\u6570\u503c\u8ba1\u7b97\uff1a<\/p>\n<ul>\n<li><code>ABS(x)<\/code>\uff1a\u8fd4\u56de x \u7684\u7edd\u5bf9\u503c\u3002<\/li>\n<li><code>ROUND(x, d)<\/code>\uff1a\u5c06 x \u56db\u820d\u4e94\u5165\u5230 d \u4f4d\u5c0f\u6570\u3002<\/li>\n<li><code>FLOOR(x)<\/code>\uff1a\u8fd4\u56de\u5c0f\u4e8e\u6216\u7b49\u4e8e x \u7684\u6700\u5927\u6574\u6570\u3002<\/li>\n<li><code>CEIL(x)<\/code>\uff1a\u8fd4\u56de\u5927\u4e8e\u6216\u7b49\u4e8e x \u7684\u6700\u5c0f\u6574\u6570\u3002<\/li>\n<\/ul>\n<p>\u4f8b\u5982\uff0c\u82e5\u8981\u8ba1\u7b97\u67d0\u4e2a\u6570\u503c\u7684\u7edd\u5bf9\u503c\uff0c\u53ef\u4ee5\u4f7f\u7528\uff1a<\/p>\n<pre><code>SELECT ABS(-10) AS absolute_value;<\/code><\/pre>\n<h2 id=\"4-%e8%81%9a%e5%90%88%e5%87%bd%e6%95%b0-GwKHyXOEsD\">4. \u805a\u5408\u51fd\u6570<\/h2>\n<p>\u805a\u5408\u51fd\u6570\u7528\u4e8e\u5bf9\u4e00\u7ec4\u503c\u8fdb\u884c\u8ba1\u7b97\uff0c\u8fd4\u56de\u5355\u4e00\u503c\u3002OceanBase \u652f\u6301\u591a\u79cd\u805a\u5408\u51fd\u6570\uff1a<\/p>\n<ul>\n<li><code>COUNT(expr)<\/code>\uff1a\u8fd4\u56de\u6ee1\u8db3\u6761\u4ef6\u7684\u884c\u6570\u3002<\/li>\n<li><code>SUM(expr)<\/code>\uff1a\u8fd4\u56de\u6307\u5b9a\u5217\u7684\u603b\u548c\u3002<\/li>\n<li><code>AVG(expr)<\/code>\uff1a\u8fd4\u56de\u6307\u5b9a\u5217\u7684\u5e73\u5747\u503c\u3002<\/li>\n<li><code>MAX(expr)<\/code>\uff1a\u8fd4\u56de\u6307\u5b9a\u5217\u7684\u6700\u5927\u503c\u3002<\/li>\n<li><code>MIN(expr)<\/code>\uff1a\u8fd4\u56de\u6307\u5b9a\u5217\u7684\u6700\u5c0f\u503c\u3002<\/li>\n<\/ul>\n<p>\u4f8b\u5982\uff0c\u82e5\u8981\u8ba1\u7b97\u7528\u6237\u8868\u4e2d\u6240\u6709\u7528\u6237\u7684\u5e73\u5747\u5e74\u9f84\uff0c\u53ef\u4ee5\u4f7f\u7528\uff1a<\/p>\n<pre><code>SELECT AVG(age) AS average_age FROM users;<\/code><\/pre>\n<h2 id=\"%e6%80%bb%e7%bb%93-GwKHyXOEsD\">\u603b\u7ed3<\/h2>\n<p>OceanBase \u63d0\u4f9b\u4e86\u4e30\u5bcc\u7684\u5176\u4ed6\u51fd\u6570\uff0c\u6db5\u76d6\u5b57\u7b26\u4e32\u5904\u7406\u3001\u65e5\u671f\u65f6\u95f4\u5904\u7406\u3001\u6570\u5b66\u8ba1\u7b97\u53ca\u805a\u5408\u7b49\u591a\u79cd\u529f\u80fd\u3002\u8fd9\u4e9b\u51fd\u6570\u7684\u7075\u6d3b\u8fd0\u7528\u53ef\u4ee5\u5927\u5927\u63d0\u9ad8\u6570\u636e\u5904\u7406\u7684\u6548\u7387\u548c\u51c6\u786e\u6027\u3002\u5bf9\u4e8e\u9700\u8981\u9ad8\u6027\u80fd\u6570\u636e\u5e93\u89e3\u51b3\u65b9\u6848\u7684\u7528\u6237\uff0c\u9009\u62e9\u5408\u9002\u7684 <a href=\"https:\/\/server.hk\">VPS<\/a> \u6216 <a href=\"https:\/\/server.hk\">\u4e91\u670d\u52a1\u5668<\/a> \u662f\u81f3\u5173\u91cd\u8981\u7684\u3002\u4e86\u89e3 OceanBase \u7684\u5404\u79cd\u51fd\u6570\uff0c\u5c06\u6709\u52a9\u4e8e\u5f00\u53d1\u8005\u66f4\u597d\u5730\u5229\u7528\u8fd9\u4e00\u5f3a\u5927\u7684\u6570\u636e\u5e93\u7cfb\u7edf\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u63a2\u7d22 OceanBase \u6559\u7a0b\uff0c\u6df1\u5165\u4e86\u89e3 OceanBase \u5176\u4ed6\u51fd\u6578\u7684\u4f7f\u7528\u65b9\u6cd5\u4e0e\u6280\u5de7\uff0c\u63d0\u5347\u6570\u636e\u5e93\u64cd\u4f5c\u6548\u7387\u4e0e\u6027\u80fd\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-160545","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/160545","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=160545"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/160545\/revisions"}],"predecessor-version":[{"id":160546,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/160545\/revisions\/160546"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=160545"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=160545"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=160545"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}