{"id":95780,"date":"2024-10-20T03:56:18","date_gmt":"2024-10-19T19:56:18","guid":{"rendered":"https:\/\/server.hk\/cnblog\/95780\/"},"modified":"2024-10-20T03:56:18","modified_gmt":"2024-10-19T19:56:18","slug":"oracle%e6%95%b8%e6%93%9a%e5%ba%ab%e5%a6%82%e4%bd%95%e9%80%b2%e8%a1%8c%e5%85%a9%e8%a1%8c%e6%af%8f%e5%88%97%e7%9a%84%e6%af%94%e8%bc%83%e5%88%86%e6%9e%90-oracle%e5%a6%82%e4%bd%95%e5%b0%8d%e6%af%94","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/95780\/","title":{"rendered":"Oracle\u6578\u64da\u5eab\u5982\u4f55\u9032\u884c\u5169\u884c\u6bcf\u5217\u7684\u6bd4\u8f03\u5206\u6790 (oracle\u5982\u4f55\u5c0d\u6bd4\u5169\u884c\u6bcf\u5217\u6578\u64da\u5eab)"},"content":{"rendered":"

Oracle\u6578\u64da\u5eab\u5982\u4f55\u9032\u884c\u5169\u884c\u6bcf\u5217\u7684\u6bd4\u8f03\u5206\u6790<\/h1>\n

\u5728\u6578\u64da\u5eab\u7ba1\u7406\u4e2d\uff0c\u5c0d\u6bd4\u5169\u884c\u6578\u64da\u7684\u9700\u6c42\u7d93\u5e38\u51fa\u73fe\uff0c\u5c24\u5176\u662f\u5728\u6578\u64da\u6e05\u7406\u3001\u6578\u64da\u9077\u79fb\u6216\u6578\u64da\u5206\u6790\u7684\u904e\u7a0b\u4e2d\u3002Oracle\u6578\u64da\u5eab\u63d0\u4f9b\u4e86\u591a\u7a2e\u65b9\u6cd5\u4f86\u5be6\u73fe\u9019\u4e00\u529f\u80fd\uff0c\u672c\u6587\u5c07\u63a2\u8a0e\u5982\u4f55\u5728Oracle\u4e2d\u9032\u884c\u5169\u884c\u6bcf\u5217\u7684\u6bd4\u8f03\u5206\u6790\u3002<\/p>\n

\u57fa\u672c\u6982\u5ff5<\/h2>\n

\u5728Oracle\u6578\u64da\u5eab\u4e2d\uff0c\u6578\u64da\u901a\u5e38\u4ee5\u8868\u683c\u7684\u5f62\u5f0f\u5b58\u5132\uff0c\u6bcf\u4e00\u884c\u4ee3\u8868\u4e00\u500b\u8a18\u9304\uff0c\u6bcf\u4e00\u5217\u4ee3\u8868\u4e00\u500b\u5c6c\u6027\u3002\u7576\u9700\u8981\u6bd4\u8f03\u5169\u884c\u6578\u64da\u6642\uff0c\u901a\u5e38\u662f\u70ba\u4e86\u627e\u51fa\u5b83\u5011\u4e4b\u9593\u7684\u5dee\u7570\u6216\u76f8\u4f3c\u4e4b\u8655\u3002\u9019\u53ef\u4ee5\u901a\u904eSQL\u67e5\u8a62\u4f86\u5be6\u73fe\uff0c\u7279\u5225\u662f\u4f7f\u7528\u81ea\u9023\u63a5\uff08self-join\uff09\u6216\u7a97\u53e3\u51fd\u6578\uff08window functions\uff09\u3002<\/p>\n

\u4f7f\u7528\u81ea\u9023\u63a5\u9032\u884c\u6bd4\u8f03<\/h2>\n

\u81ea\u9023\u63a5\u662f\u4e00\u7a2e\u5c07\u8868\u683c\u8207\u81ea\u8eab\u9032\u884c\u9023\u63a5\u7684\u6280\u8853\uff0c\u9019\u6a23\u53ef\u4ee5\u5728\u540c\u4e00\u67e5\u8a62\u4e2d\u6bd4\u8f03\u4e0d\u540c\u7684\u884c\u3002\u4ee5\u4e0b\u662f\u4e00\u500b\u793a\u4f8b\uff0c\u5047\u8a2d\u6211\u5011\u6709\u4e00\u500b\u540d\u70ba\u201cemployees\u201d\u7684\u8868\uff0c\u8a72\u8868\u5305\u542b\u54e1\u5de5\u7684ID\u3001\u59d3\u540d\u548c\u85aa\u6c34\u3002<\/p>\n

SELECT \n    e1.id AS employee_id_1,\n    e1.name AS employee_name_1,\n    e1.salary AS employee_salary_1,\n    e2.id AS employee_id_2,\n    e2.name AS employee_name_2,\n    e2.salary AS employee_salary_2\nFROM \n    employees e1\nJOIN \n    employees e2 ON e1.id != e2.id\nWHERE \n    e1.salary != e2.salary;<\/code><\/pre>\n
\u5728\u9019\u500b\u67e5\u8a62\u4e2d\uff0c\u6211\u5011\u5c07\u201cemployees\u201d\u8868\u81ea\u9023\u63a5\uff0c\u4e26\u6bd4\u8f03\u4e0d\u540c\u54e1\u5de5\u7684\u85aa\u6c34\u3002\u9019\u6a23\u53ef\u4ee5\u627e\u51fa\u85aa\u6c34\u4e0d\u540c\u7684\u54e1\u5de5\u5c0d\u3002<\/p>\n
\u4f7f\u7528\u7a97\u53e3\u51fd\u6578\u9032\u884c\u6bd4\u8f03<\/h2>\n
\u7a97\u53e3\u51fd\u6578\u662f\u4e00\u7a2e\u5f37\u5927\u7684\u5de5\u5177\uff0c\u53ef\u4ee5\u5728\u4e0d\u9700\u8981\u81ea\u9023\u63a5\u7684\u60c5\u6cc1\u4e0b\u9032\u884c\u884c\u9593\u6bd4\u8f03\u3002\u4ee5\u4e0b\u662f\u4e00\u500b\u4f7f\u7528\u7a97\u53e3\u51fd\u6578\u7684\u793a\u4f8b\uff0c\u8a72\u793a\u4f8b\u5c07\u8a08\u7b97\u6bcf\u4f4d\u54e1\u5de5\u7684\u85aa\u6c34\u8207\u5176\u524d\u4e00\u4f4d\u54e1\u5de5\u7684\u85aa\u6c34\u4e4b\u9593\u7684\u5dee\u7570\u3002<\/p>\n
SELECT \n    id,\n    name,\n    salary,\n    LAG(salary) OVER (ORDER BY id) AS previous_salary,\n    salary - LAG(salary) OVER (ORDER BY id) AS salary_difference\nFROM \n    employees;<\/code><\/pre>\n
\u5728\u9019\u500b\u67e5\u8a62\u4e2d\uff0cLAG\u51fd\u6578\u7528\u65bc\u7372\u53d6\u524d\u4e00\u884c\u7684\u85aa\u6c34\uff0c\u7136\u5f8c\u8a08\u7b97\u7576\u524d\u884c\u8207\u524d\u4e00\u884c\u4e4b\u9593\u7684\u5dee\u7570\u3002\u9019\u7a2e\u65b9\u6cd5\u7279\u5225\u9069\u5408\u65bc\u9700\u8981\u5206\u6790\u6578\u64da\u8b8a\u5316\u8da8\u52e2\u7684\u60c5\u6cc1\u3002<\/p>\n
\u6bd4\u8f03\u591a\u5217\u6578\u64da<\/h2>\n
\u5982\u679c\u9700\u8981\u6bd4\u8f03\u591a\u5217\u6578\u64da\uff0c\u53ef\u4ee5\u64f4\u5c55\u4e0a\u8ff0\u65b9\u6cd5\u3002\u4ee5\u4e0b\u662f\u4e00\u500b\u793a\u4f8b\uff0c\u5047\u8a2d\u6211\u5011\u9700\u8981\u6bd4\u8f03\u54e1\u5de5\u7684\u59d3\u540d\u548c\u85aa\u6c34\u3002<\/p>\n
SELECT \n    e1.id AS employee_id_1,\n    e1.name AS employee_name_1,\n    e1.salary AS employee_salary_1,\n    e2.id AS employee_id_2,\n    e2.name AS employee_name_2,\n    e2.salary AS employee_salary_2\nFROM \n    employees e1\nJOIN \n    employees e2 ON e1.id != e2.id\nWHERE \n    e1.name != e2.name OR e1.salary != e2.salary;<\/code><\/pre>\n
\u9019\u6a23\u7684\u67e5\u8a62\u53ef\u4ee5\u5e6b\u52a9\u6211\u5011\u627e\u51fa\u5728\u59d3\u540d\u6216\u85aa\u6c34\u4e0a\u6709\u5dee\u7570\u7684\u54e1\u5de5\u3002<\/p>\n
\u7e3d\u7d50<\/h2>\n
\u5728Oracle\u6578\u64da\u5eab\u4e2d\uff0c\u5c0d\u6bd4\u5169\u884c\u6bcf\u5217\u7684\u6578\u64da\u53ef\u4ee5\u901a\u904e\u81ea\u9023\u63a5\u548c\u7a97\u53e3\u51fd\u6578\u7b49\u591a\u7a2e\u65b9\u6cd5\u5be6\u73fe\u3002\u9019\u4e9b\u6280\u8853\u4e0d\u50c5\u80fd\u5920\u5e6b\u52a9\u7528\u6236\u5feb\u901f\u627e\u51fa\u6578\u64da\u4e4b\u9593\u7684\u5dee\u7570\uff0c\u9084\u80fd\u5920\u652f\u6301\u66f4\u8907\u96dc\u7684\u6578\u64da\u5206\u6790\u9700\u6c42\u3002\u7121\u8ad6\u662f\u9032\u884c\u6578\u64da\u6e05\u7406\u9084\u662f\u6578\u64da\u5206\u6790\uff0c\u638c\u63e1\u9019\u4e9b\u6280\u5de7\u90fd\u662f\u975e\u5e38\u91cd\u8981\u7684\u3002<\/p>\n
\u5982\u679c\u60a8\u6b63\u5728\u5c0b\u627e\u9ad8\u6548\u7684\u6578\u64da\u5eab\u89e3\u6c7a\u65b9\u6848\uff0c\u8003\u616e\u4f7f\u7528\u9999\u6e2fVPS<\/a>\u6216\u9999\u6e2f\u4f3a\u670d\u5668<\/a>\u4f86\u652f\u6301\u60a8\u7684\u696d\u52d9\u9700\u6c42\u3002\u7121\u8ad6\u662f\u6578\u64da\u5b58\u5132\u9084\u662f\u6578\u64da\u8655\u7406\uff0c\u6211\u5011\u90fd\u80fd\u63d0\u4f9b\u7a69\u5b9a\u7684\u670d\u52d9\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"
\u5b78\u7fd2\u5982\u4f55\u5728Oracle\u6578\u64da\u5eab\u4e2d\u9032\u884c\u5169\u884c\u6bcf\u5217\u7684\u6bd4\u8f03\u5206\u6790\uff0c\u638c\u63e1\u6709\u6548\u7684\u67e5\u8a62\u6280\u5de7\u548c\u6578\u64da\u8655\u7406\u65b9\u6cd5\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-95780","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/95780","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=95780"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/95780\/revisions"}],"predecessor-version":[{"id":95781,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/95780\/revisions\/95781"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=95780"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=95780"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=95780"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}