{"id":160303,"date":"2024-11-03T21:58:22","date_gmt":"2024-11-03T13:58:22","guid":{"rendered":"https:\/\/server.hk\/cnblog\/160303\/"},"modified":"2024-11-03T21:58:23","modified_gmt":"2024-11-03T13:58:23","slug":"oceanbase-%e6%95%99%e7%a8%8b%ef%bc%9aoceanbase-%e6%a8%99%e9%87%8f%e5%ad%90%e6%9f%a5%e8%a9%a2%e8%a1%a8%e9%81%94%e5%bc%8f","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/160303\/","title":{"rendered":"OceanBase \u6559\u7a0b\uff1aOceanBase \u6a19\u91cf\u5b50\u67e5\u8a62\u8868\u9054\u5f0f"},"content":{"rendered":"<h1 id=\"oceanbase-%e6%95%99%e7%a8%8b%ef%bc%9aoceanbase-%e6%a8%99%e9%87%8f%e5%ad%90%e6%9f%a5%e8%a9%a2%e8%a1%a8%e9%81%94%e5%bc%8f-uRAEvdzzgE\">OceanBase \u6559\u7a0b\uff1aOceanBase \u6a19\u91cf\u5b50\u67e5\u8a62\u8868\u9054\u5f0f<\/h1>\n<p>\u5728\u7576\u4eca\u7684\u6578\u64da\u9a45\u52d5\u6642\u4ee3\uff0c\u6578\u64da\u5eab\u6280\u8853\u7684\u9078\u64c7\u5c0d\u65bc\u4f01\u696d\u7684\u904b\u71df\u81f3\u95dc\u91cd\u8981\u3002OceanBase \u4f5c\u70ba\u4e00\u6b3e\u9ad8\u6027\u80fd\u7684\u5206\u4f48\u5f0f\u6578\u64da\u5eab\uff0c\u56e0\u5176\u512a\u8d8a\u7684\u53ef\u64f4\u5c55\u6027\u548c\u9ad8\u53ef\u7528\u6027\u800c\u53d7\u5230\u5ee3\u6cdb\u95dc\u6ce8\u3002\u672c\u6587\u5c07\u6df1\u5165\u63a2\u8a0e OceanBase \u7684\u6a19\u91cf\u5b50\u67e5\u8a62\u8868\u9054\u5f0f\uff0c\u5e6b\u52a9\u8b80\u8005\u66f4\u597d\u5730\u7406\u89e3\u5176\u7528\u6cd5\u53ca\u61c9\u7528\u5834\u666f\u3002<\/p>\n<h2 id=\"%e4%bb%80%e9%ba%bc%e6%98%af%e6%a8%99%e9%87%8f%e5%ad%90%e6%9f%a5%e8%a9%a2%e8%a1%a8%e9%81%94%e5%bc%8f%ef%bc%9f-uRAEvdzzgE\">\u4ec0\u9ebc\u662f\u6a19\u91cf\u5b50\u67e5\u8a62\u8868\u9054\u5f0f\uff1f<\/h2>\n<p>\u6a19\u91cf\u5b50\u67e5\u8a62\u8868\u9054\u5f0f\uff08Scalar Subquery\uff09\u662f\u6307\u5728 SQL \u67e5\u8a62\u4e2d\u5d4c\u5957\u7684\u67e5\u8a62\uff0c\u9019\u4e9b\u67e5\u8a62\u8fd4\u56de\u55ae\u4e00\u503c\u3002\u9019\u7a2e\u67e5\u8a62\u901a\u5e38\u7528\u65bc\u9700\u8981\u5f9e\u5176\u4ed6\u8868\u4e2d\u7372\u53d6\u55ae\u4e00\u6578\u64da\u7684\u60c5\u6cc1\u3002\u6a19\u91cf\u5b50\u67e5\u8a62\u53ef\u4ee5\u7528\u65bc SELECT\u3001WHERE \u548c HAVING \u5b50\u53e5\u4e2d\uff0c\u4e26\u4e14\u5728 OceanBase \u4e2d\u7684\u4f7f\u7528\u65b9\u5f0f\u8207\u5176\u4ed6 SQL \u6578\u64da\u5eab\u76f8\u4f3c\u3002<\/p>\n<h2 id=\"oceanbase-%e4%b8%ad%e7%9a%84%e6%a8%99%e9%87%8f%e5%ad%90%e6%9f%a5%e8%a9%a2%e8%aa%9e%e6%b3%95-uRAEvdzzgE\">OceanBase \u4e2d\u7684\u6a19\u91cf\u5b50\u67e5\u8a62\u8a9e\u6cd5<\/h2>\n<p>\u5728 OceanBase \u4e2d\uff0c\u6a19\u91cf\u5b50\u67e5\u8a62\u7684\u57fa\u672c\u8a9e\u6cd5\u5982\u4e0b\uff1a<\/p>\n<pre><code>\nSELECT column1, column2, \n    (SELECT single_value FROM table_name WHERE condition) AS alias_name\nFROM main_table\nWHERE condition;\n<\/code><\/pre>\n<p>\u5728\u9019\u6bb5\u4ee3\u78bc\u4e2d\uff0c\u5167\u90e8\u7684 SELECT \u8a9e\u53e5\u662f\u6a19\u91cf\u5b50\u67e5\u8a62\uff0c\u5b83\u8fd4\u56de\u4e00\u500b\u55ae\u4e00\u503c\uff0c\u4e26\u4e14\u53ef\u4ee5\u5728\u5916\u90e8\u67e5\u8a62\u4e2d\u4f7f\u7528\u3002<\/p>\n<h2 id=\"%e6%a8%99%e9%87%8f%e5%ad%90%e6%9f%a5%e8%a9%a2%e7%9a%84%e5%af%a6%e9%9a%9b%e6%87%89%e7%94%a8-uRAEvdzzgE\">\u6a19\u91cf\u5b50\u67e5\u8a62\u7684\u5be6\u969b\u61c9\u7528<\/h2>\n<p>\u4ee5\u4e0b\u662f\u4e00\u500b\u5177\u9ad4\u7684\u4f8b\u5b50\uff0c\u5c55\u793a\u5982\u4f55\u5728 OceanBase \u4e2d\u4f7f\u7528\u6a19\u91cf\u5b50\u67e5\u8a62\uff1a<\/p>\n<pre><code>\nSELECT employee_id, employee_name, \n    (SELECT department_name FROM departments WHERE department_id = employees.department_id) AS department\nFROM employees;\n<\/code><\/pre>\n<p>\u5728\u9019\u500b\u4f8b\u5b50\u4e2d\uff0c\u6211\u5011\u5f9e\u54e1\u5de5\u8868\u4e2d\u9078\u64c7\u54e1\u5de5 ID \u548c\u59d3\u540d\uff0c\u540c\u6642\u901a\u904e\u6a19\u91cf\u5b50\u67e5\u8a62\u7372\u53d6\u6bcf\u4f4d\u54e1\u5de5\u6240\u5c6c\u7684\u90e8\u9580\u540d\u7a31\u3002\u9019\u6a23\u7684\u67e5\u8a62\u80fd\u5920\u6709\u6548\u5730\u5c07\u591a\u500b\u8868\u7684\u6578\u64da\u6574\u5408\u5728\u4e00\u8d77\uff0c\u63d0\u4f9b\u66f4\u5168\u9762\u7684\u4fe1\u606f\u3002<\/p>\n<h2 id=\"%e6%80%a7%e8%83%bd%e8%80%83%e9%87%8f-uRAEvdzzgE\">\u6027\u80fd\u8003\u91cf<\/h2>\n<p>\u96d6\u7136\u6a19\u91cf\u5b50\u67e5\u8a62\u5728\u67d0\u4e9b\u60c5\u6cc1\u4e0b\u975e\u5e38\u65b9\u4fbf\uff0c\u4f46\u5728\u6027\u80fd\u65b9\u9762\u9700\u8981\u8b39\u614e\u4f7f\u7528\u3002\u904e\u591a\u7684\u6a19\u91cf\u5b50\u67e5\u8a62\u53ef\u80fd\u6703\u5c0e\u81f4\u67e5\u8a62\u6548\u7387\u4e0b\u964d\uff0c\u7279\u5225\u662f\u5728\u8655\u7406\u5927\u91cf\u6578\u64da\u6642\u3002\u56e0\u6b64\uff0c\u5efa\u8b70\u5728\u4f7f\u7528\u6a19\u91cf\u5b50\u67e5\u8a62\u6642\uff0c\u8003\u616e\u4ee5\u4e0b\u5e7e\u9ede\uff1a<\/p>\n<ul>\n<li>\u76e1\u91cf\u6e1b\u5c11\u5d4c\u5957\u67e5\u8a62\u7684\u5c64\u6578\u3002<\/li>\n<li>\u8003\u616e\u4f7f\u7528 JOIN \u64cd\u4f5c\u4f86\u66ff\u4ee3\u6a19\u91cf\u5b50\u67e5\u8a62\uff0c\u7279\u5225\u662f\u5728\u9700\u8981\u5f9e\u591a\u500b\u8868\u4e2d\u7372\u53d6\u6578\u64da\u6642\u3002<\/li>\n<li>\u5c0d\u65bc\u983b\u7e41\u4f7f\u7528\u7684\u67e5\u8a62\uff0c\u53ef\u4ee5\u8003\u616e\u5c07\u7d50\u679c\u7de9\u5b58\uff0c\u4ee5\u63d0\u9ad8\u6027\u80fd\u3002<\/li>\n<\/ul>\n<h2 id=\"%e7%b5%90%e8%ab%96-uRAEvdzzgE\">\u7d50\u8ad6<\/h2>\n<p>\u6a19\u91cf\u5b50\u67e5\u8a62\u8868\u9054\u5f0f\u5728 OceanBase \u4e2d\u662f\u4e00\u500b\u5f37\u5927\u7684\u5de5\u5177\uff0c\u80fd\u5920\u5e6b\u52a9\u958b\u767c\u8005\u5728\u67e5\u8a62\u4e2d\u9748\u6d3b\u5730\u7372\u53d6\u6240\u9700\u7684\u6578\u64da\u3002\u96d6\u7136\u5b83\u63d0\u4f9b\u4e86\u4fbf\u5229\uff0c\u4f46\u5728\u4f7f\u7528\u6642\u4e5f\u9700\u8003\u616e\u6027\u80fd\u554f\u984c\uff0c\u9078\u64c7\u5408\u9069\u7684\u67e5\u8a62\u65b9\u5f0f\u4ee5\u9054\u5230\u6700\u4f73\u6548\u679c\u3002\u96a8\u8457\u6578\u64da\u5eab\u6280\u8853\u7684\u767c\u5c55\uff0c\u638c\u63e1\u9019\u4e9b\u67e5\u8a62\u6280\u5de7\u5c07\u5c0d\u65bc\u6578\u64da\u5206\u6790\u548c\u61c9\u7528\u958b\u767c\u81f3\u95dc\u91cd\u8981\u3002<\/p>\n<p>\u5982\u9700\u4e86\u89e3\u66f4\u591a\u95dc\u65bc <a href=\"https:\/\/server.hk\">VPS<\/a> \u53ca\u5176\u4ed6\u96f2\u670d\u52d9\u7684\u8cc7\u8a0a\uff0c\u8acb\u8a2a\u554f\u6211\u5011\u7684\u7db2\u7ad9\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u63a2\u7d22 OceanBase \u6559\u7a0b\uff0c\u6df1\u5165\u4e86\u89e3\u6a19\u91cf\u5b50\u67e5\u8a62\u8868\u9054\u5f0f\u7684\u4f7f\u7528\uff0c\u63d0\u5347\u6578\u64da\u67e5\u8a62\u6548\u7387\u8207\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-160303","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/160303","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=160303"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/160303\/revisions"}],"predecessor-version":[{"id":160304,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/160303\/revisions\/160304"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=160303"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=160303"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=160303"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}