{"id":199776,"date":"2025-05-06T09:20:51","date_gmt":"2025-05-06T01:20:51","guid":{"rendered":"https:\/\/server.hk\/cnblog\/199776\/"},"modified":"2025-05-06T09:20:51","modified_gmt":"2025-05-06T01:20:51","slug":"%e4%bb%8b%e7%bb%8doracle%e5%87%bd%e6%95%b0%e7%9a%84%e4%b8%8d%e5%90%8c%e7%b1%bb%e5%9e%8b%e5%92%8c%e5%8a%9f%e8%83%bd","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/199776\/","title":{"rendered":"\u4ecb\u7ecdOracle\u51fd\u6570\u7684\u4e0d\u540c\u7c7b\u578b\u548c\u529f\u80fd"},"content":{"rendered":"

<\/b> <\/p>\n

\u4ecb\u7ecdOracle\u51fd\u6570\u7684\u4e0d\u540c\u7c7b\u578b\u548c\u529f\u80fd<\/h1>\n

\u6765\u5230\u4e3b\u673a\u5b9d\u8d1d\u7684\u5927\u5bb6\uff0c\u76f8\u4fe1\u90fd\u662f\u7f16\u7a0b\u5b66\u4e60\u7231\u597d\u8005\uff0c\u5e0c\u671b\u5728\u8fd9\u91cc\u5b66\u4e60\u6570\u636e\u5e93\u76f8\u5173\u7f16\u7a0b\u77e5\u8bc6\u3002\u4e0b\u9762\u672c\u7bc7\u6587\u7ae0\u5c31\u6765\u5e26\u5927\u5bb6\u804a\u804a\u300a\u4ecb\u7ecdOracle\u51fd\u6570\u7684\u4e0d\u540c\u7c7b\u578b\u548c\u529f\u80fd\u300b\uff0c\u4ecb\u7ecd\u4e00\u4e0b\uff0c\u5e0c\u671b\u5bf9\u5927\u5bb6\u7684\u77e5\u8bc6\u79ef\u7d2f\u6709\u6240\u5e2e\u52a9\uff0c\u52a9\u529b\u5b9e\u6218\u5f00\u53d1\uff01<\/p>\n

Oracle SQL \u662f\u5e94\u7528\u5e7f\u6cdb\u7684\u5173\u7cfb\u578b\u6570\u636e\u5e93\u7ba1\u7406\u7cfb\u7edf\uff0c\u5728\u8fdb\u884c\u6570\u636e\u5904\u7406\u65f6\uff0c\u51fd\u6570\u662f\u4e00\u79cd\u975e\u5e38\u91cd\u8981\u7684\u529f\u80fd\u3002Oracle \u63d0\u4f9b\u4e86\u591a\u79cd\u4e0d\u540c\u7c7b\u578b\u7684\u51fd\u6570\uff0c\u53ef\u4ee5\u5728 SQL \u8bed\u53e5\u4e2d\u4f7f\u7528\uff0c\u63d0\u4f9b\u4e86\u5f3a\u5927\u7684\u6570\u636e\u5904\u7406\u80fd\u529b\u3002\u672c\u6587\u5c06\u4ecb\u7ecd\u4e00\u4e9b\u5e38\u7528\u7684 Oracle \u51fd\u6570\u79cd\u7c7b\u53ca\u5176\u529f\u80fd\uff0c\u5e76\u63d0\u4f9b\u5177\u4f53\u7684\u4ee3\u7801\u793a\u4f8b\u3002<\/p>\n

1. \u805a\u5408\u51fd\u6570<\/h3>\n

\u805a\u5408\u51fd\u6570\u7528\u4e8e\u5728\u67e5\u8be2\u7ed3\u679c\u96c6\u4e2d\u8ba1\u7b97\u603b\u548c\u3001\u5e73\u5747\u503c\u3001\u6700\u5927\u503c\u3001\u6700\u5c0f\u503c\u7b49\u7edf\u8ba1\u4fe1\u606f\u3002\u5e38\u7528\u7684\u805a\u5408\u51fd\u6570\u5305\u62ec SUM\u3001AVG\u3001MAX\u3001MIN\u3001COUNT \u7b49\u3002\u4ee5\u4e0b\u662f\u4e00\u4e9b\u5e38\u7528\u805a\u5408\u51fd\u6570\u7684\u793a\u4f8b\uff1a<\/p>\n

-- \u8ba1\u7b97\u9500\u552e\u8ba2\u5355\u603b\u91d1\u989d\nSELECT SUM(order_amount) AS total_amount\nFROM orders;\n\n-- \u8ba1\u7b97\u9500\u552e\u8ba2\u5355\u5e73\u5747\u91d1\u989d\nSELECT AVG(order_amount) AS average_amount\nFROM orders;\n\n-- \u7edf\u8ba1\u8ba2\u5355\u6570\u91cf\nSELECT COUNT(*) AS total_orders\nFROM orders;<\/pre>\n
2. \u6807\u91cf\u51fd\u6570<\/h3>\n
\u6807\u91cf\u51fd\u6570\u8fd4\u56de\u5355\u4e2a\u503c\uff0c\u5e76\u53ef\u4ee5\u5728 SQL \u67e5\u8be2\u4e2d\u4f7f\u7528\u3002\u5e38\u7528\u7684\u6807\u91cf\u51fd\u6570\u5305\u62ec UPPER\u3001LOWER\u3001SUBSTR\u3001TO_DATE \u7b49\u3002\u4ee5\u4e0b\u662f\u4e00\u4e9b\u6807\u91cf\u51fd\u6570\u7684\u793a\u4f8b\uff1a<\/p>\n
-- \u5c06\u5b57\u7b26\u4e32\u8f6c\u6362\u4e3a\u5927\u5199\nSELECT UPPER('hello') AS upper_str\nFROM dual;\n\n-- \u5c06\u5b57\u7b26\u4e32\u8f6c\u6362\u4e3a\u5c0f\u5199\nSELECT LOWER('WORLD') AS lower_str\nFROM dual;\n\n-- \u622a\u53d6\u5b57\u7b26\u4e32\u7684\u5b50\u4e32\nSELECT SUBSTR('hello world', 1, 5) AS sub_str\nFROM dual;\n\n-- \u5c06\u5b57\u7b26\u4e32\u8f6c\u6362\u4e3a\u65e5\u671f\u683c\u5f0f\nSELECT TO_DATE('2022-01-01', 'YYYY-MM-DD') AS order_date\nFROM dual;<\/pre>\n
3. \u7a97\u53e3\u51fd\u6570<\/h3>\n
\u7a97\u53e3\u51fd\u6570\u7528\u4e8e\u5728\u67e5\u8be2\u7ed3\u679c\u96c6\u7684\u7279\u5b9a\u7a97\u53e3\u5185\u6267\u884c\u805a\u5408\u64cd\u4f5c\uff0c\u5e38\u7528\u7684\u7a97\u53e3\u51fd\u6570\u5305\u62ec ROW_NUMBER\u3001RANK\u3001DENSE_RANK\u3001LEAD\u3001LAG \u7b49\u3002\u4ee5\u4e0b\u662f\u4e00\u4e9b\u7a97\u53e3\u51fd\u6570\u7684\u793a\u4f8b\uff1a<\/p>\n
-- \u5bf9\u67e5\u8be2\u7ed3\u679c\u96c6\u8fdb\u884c\u7f16\u53f7\nSELECT employee_id, salary, ROW_NUMBER() OVER (ORDER BY salary DESC) AS rank\nFROM employees;\n\n-- \u8ba1\u7b97\u5458\u5de5\u85aa\u6c34\u6392\u540d\nSELECT employee_id, salary, RANK() OVER (ORDER BY salary DESC) AS salary_rank\nFROM employees;\n\n-- \u8ba1\u7b97\u90e8\u95e8\u5185\u5458\u5de5\u85aa\u6c34\u6392\u540d\nSELECT department_id, employee_id, salary, DENSE_RANK() OVER (PARTITION BY department_id ORDER BY salary DESC) AS department_rank\nFROM employees;<\/pre>\n
4. \u8f6c\u6362\u51fd\u6570<\/h3>\n
\u8f6c\u6362\u51fd\u6570\u7528\u4e8e\u5bf9\u6570\u636e\u8fdb\u884c\u7c7b\u578b\u8f6c\u6362\u6216\u683c\u5f0f\u8f6c\u6362\uff0c\u5e38\u7528\u7684\u8f6c\u6362\u51fd\u6570\u5305\u62ec TO_CHAR\u3001TO_NUMBER\u3001TO_DATE \u7b49\u3002\u4ee5\u4e0b\u662f\u4e00\u4e9b\u8f6c\u6362\u51fd\u6570\u7684\u793a\u4f8b\uff1a<\/p>\n
-- \u5c06\u65e5\u671f\u8f6c\u6362\u4e3a\u5b57\u7b26\u4e32\nSELECT TO_CHAR(order_date, 'YYYY-MM-DD') AS formatted_date\nFROM orders;\n\n-- \u5c06\u5b57\u7b26\u4e32\u8f6c\u6362\u4e3a\u6570\u503c\nSELECT TO_NUMBER('123.45', '999.99') AS number_value\nFROM dual;\n\n-- \u5c06\u5b57\u7b26\u4e32\u8f6c\u6362\u4e3a\u65e5\u671f\nSELECT TO_DATE('2022-01-01', 'YYYY-MM-DD') AS order_date\nFROM dual;<\/pre>\n
\u5728\u5b9e\u9645\u7684\u6570\u636e\u5e93\u67e5\u8be2\u4e2d\uff0c\u4ee5\u4e0a\u4ecb\u7ecd\u7684 Oracle \u51fd\u6570\u79cd\u7c7b\u90fd\u53ef\u4ee5\u5e2e\u52a9\u6211\u4eec\u66f4\u9ad8\u6548\u5730\u5904\u7406\u6570\u636e\uff0c\u63d0\u5347\u6570\u636e\u5904\u7406\u7684\u6548\u7387\u548c\u51c6\u786e\u6027\u3002\u5e0c\u671b\u672c\u6587\u5bf9\u8bfb\u8005\u4e86\u89e3 Oracle \u51fd\u6570\u7684\u79cd\u7c7b\u53ca\u529f\u80fd\u6709\u6240\u5e2e\u52a9\u3002<\/p>\n
\u597d\u4e86\uff0c\u672c\u6587\u5230\u6b64\u7ed3\u675f\uff0c\u5e26\u5927\u5bb6\u4e86\u89e3\u4e86\u300a\u4ecb\u7ecdOracle\u51fd\u6570\u7684\u4e0d\u540c\u7c7b\u578b\u548c\u529f\u80fd\u300b\uff0c\u5e0c\u671b\u672c\u6587\u5bf9\u4f60\u6709\u6240\u5e2e\u52a9\uff01\u5173\u6ce8\u4e3b\u673a\u5b9d\u8d1d\u516c\u4f17\u53f7\uff0c\u7ed9\u5927\u5bb6\u5206\u4eab\u66f4\u591a\u6570\u636e\u5e93\u77e5\u8bc6\uff01<\/p>\n
\n
\n <\/dt>\n<\/dl>\n","protected":false},"excerpt":{"rendered":"
\u4ecb\u7ecdOracle\u51fd\u6570\u7684\u4e0d\u540c\u7c7b\u578b\u548c...<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[101],"tags":[],"class_list":["post-199776","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/199776","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"}],"author":[{"embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/comments?post=199776"}],"version-history":[{"count":0,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/199776\/revisions"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=199776"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=199776"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=199776"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}