{"id":161911,"date":"2024-11-04T10:22:47","date_gmt":"2024-11-04T02:22:47","guid":{"rendered":"https:\/\/server.hk\/cnblog\/161911\/"},"modified":"2024-11-04T10:22:48","modified_gmt":"2024-11-04T02:22:48","slug":"%e8%a8%88%e7%ae%97%e6%99%82%e9%96%93%e5%b7%ae%e7%9a%84-oracle-%e5%87%bd%e6%95%b8","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/161911\/","title":{"rendered":"\u8a08\u7b97\u6642\u9593\u5dee\u7684 Oracle \u51fd\u6578"},"content":{"rendered":"

\u8a08\u7b97\u6642\u9593\u5dee\u7684 Oracle \u51fd\u6578<\/h1>\n

\u5728\u8cc7\u6599\u5eab\u7ba1\u7406\u4e2d\uff0c\u6642\u9593\u7684\u8a08\u7b97\u662f\u4e00\u500b\u5e38\u898b\u7684\u9700\u6c42\uff0c\u5c24\u5176\u662f\u5728\u9700\u8981\u8655\u7406\u6642\u9593\u6233\u8a18\u3001\u65e5\u671f\u548c\u6642\u9593\u5dee\u7684\u60c5\u6cc1\u4e0b\u3002Oracle \u8cc7\u6599\u5eab\u63d0\u4f9b\u4e86\u591a\u7a2e\u51fd\u6578\u4f86\u5e6b\u52a9\u7528\u6236\u8a08\u7b97\u6642\u9593\u5dee\uff0c\u9019\u4e9b\u51fd\u6578\u4e0d\u50c5\u80fd\u5920\u63d0\u9ad8\u6548\u7387\uff0c\u9084\u80fd\u78ba\u4fdd\u8a08\u7b97\u7684\u6e96\u78ba\u6027\u3002\u672c\u6587\u5c07\u4ecb\u7d39\u5e7e\u500b\u5e38\u7528\u7684 Oracle \u51fd\u6578\uff0c\u4e26\u63d0\u4f9b\u76f8\u61c9\u7684\u7bc4\u4f8b\u4f86\u8aaa\u660e\u5982\u4f55\u4f7f\u7528\u9019\u4e9b\u51fd\u6578\u4f86\u8a08\u7b97\u6642\u9593\u5dee\u3002<\/p>\n

1. \u4f7f\u7528 `SYSDATE` \u548c `SYSTIMESTAMP`<\/h2>\n

\u5728 Oracle \u4e2d\uff0c`SYSDATE` \u51fd\u6578\u8fd4\u56de\u7576\u524d\u7684\u65e5\u671f\u548c\u6642\u9593\uff0c\u800c `SYSTIMESTAMP` \u5247\u8fd4\u56de\u7576\u524d\u7684\u6642\u9593\u6233\u8a18\uff0c\u5305\u62ec\u6642\u5340\u4fe1\u606f\u3002\u9019\u5169\u500b\u51fd\u6578\u662f\u8a08\u7b97\u6642\u9593\u5dee\u7684\u57fa\u790e\u3002<\/p>\n

SELECT SYSDATE AS current_date,\n       SYSTIMESTAMP AS current_timestamp\nFROM dual;<\/code><\/pre>\n
2. \u8a08\u7b97\u5169\u500b\u65e5\u671f\u4e4b\u9593\u7684\u5dee\u7570<\/h2>\n
\u8981\u8a08\u7b97\u5169\u500b\u65e5\u671f\u4e4b\u9593\u7684\u5dee\u7570\uff0c\u53ef\u4ee5\u76f4\u63a5\u7528\u6e1b\u6cd5\u904b\u7b97\u3002Oracle \u6703\u81ea\u52d5\u5c07\u65e5\u671f\u8f49\u63db\u70ba\u6578\u5b57\uff0c\u4e26\u8fd4\u56de\u76f8\u5dee\u7684\u5929\u6578\u3002<\/p>\n
SELECT (TO_DATE('2023-10-01', 'YYYY-MM-DD') - TO_DATE('2023-09-01', 'YYYY-MM-DD')) AS days_difference\nFROM dual;<\/code><\/pre>\n
\u4e0a\u8ff0\u67e5\u8a62\u5c07\u8fd4\u56de 30\uff0c\u8868\u793a\u5169\u500b\u65e5\u671f\u4e4b\u9593\u76f8\u5dee 30 \u5929\u3002<\/p>\n
3. \u4f7f\u7528 `NUMTODSINTERVAL` \u548c `NUMTOYMINTERVAL` \u51fd\u6578<\/h2>\n
\u5982\u679c\u9700\u8981\u5c07\u6578\u5b57\u8f49\u63db\u70ba\u6642\u9593\u9593\u9694\uff0c\u53ef\u4ee5\u4f7f\u7528 `NUMTODSINTERVAL` \u548c `NUMTOYMINTERVAL` \u51fd\u6578\u3002\u9019\u4e9b\u51fd\u6578\u53ef\u4ee5\u5c07\u6578\u5b57\u8f49\u63db\u70ba\u5929\u3001\u79d2\u6216\u5e74\u3001\u6708\u7684\u6642\u9593\u9593\u9694\u3002<\/p>\n
SELECT NUMTODSINTERVAL(5, 'DAY') AS interval_in_days,\n       NUMTOYMINTERVAL(2, 'YEAR') AS interval_in_years\nFROM dual;<\/code><\/pre>\n
\u9019\u5c07\u8fd4\u56de\u4e00\u500b\u8868\u793a 5 \u5929\u548c 2 \u5e74\u7684\u6642\u9593\u9593\u9694\u3002<\/p>\n
4. \u4f7f\u7528 `EXTRACT` \u51fd\u6578<\/h2>\n
`EXTRACT` \u51fd\u6578\u53ef\u4ee5\u5f9e\u65e5\u671f\u4e2d\u63d0\u53d6\u7279\u5b9a\u7684\u90e8\u5206\uff0c\u4f8b\u5982\u5e74\u3001\u6708\u3001\u65e5\u3001\u6642\u3001\u5206\u548c\u79d2\u3002\u9019\u5c0d\u65bc\u8a08\u7b97\u6642\u9593\u5dee\u6642\u975e\u5e38\u6709\u7528\u3002<\/p>\n
SELECT EXTRACT(YEAR FROM SYSTIMESTAMP) AS current_year,\n       EXTRACT(MONTH FROM SYSTIMESTAMP) AS current_month,\n       EXTRACT(DAY FROM SYSTIMESTAMP) AS current_day\nFROM dual;<\/code><\/pre>\n
5. \u5be6\u969b\u7bc4\u4f8b\uff1a\u8a08\u7b97\u5de5\u4f5c\u6642\u9577<\/h2>\n
\u5047\u8a2d\u6211\u5011\u6709\u4e00\u500b\u8868\u683c\u8a18\u9304\u4e86\u54e1\u5de5\u7684\u5de5\u4f5c\u958b\u59cb\u548c\u7d50\u675f\u6642\u9593\uff0c\u6211\u5011\u53ef\u4ee5\u4f7f\u7528\u4e0a\u8ff0\u51fd\u6578\u4f86\u8a08\u7b97\u6bcf\u4f4d\u54e1\u5de5\u7684\u5de5\u4f5c\u6642\u9577\u3002<\/p>\n
CREATE TABLE employee_work_hours (\n    employee_id NUMBER,\n    start_time TIMESTAMP,\n    end_time TIMESTAMP\n);\n\nINSERT INTO employee_work_hours (employee_id, start_time, end_time)\nVALUES (1, TO_TIMESTAMP('2023-10-01 09:00:00', 'YYYY-MM-DD HH24:MI:SS'),\n                TO_TIMESTAMP('2023-10-01 17:00:00', 'YYYY-MM-DD HH24:MI:SS'));\n\nSELECT employee_id,\n       (end_time - start_time) * 24 AS hours_worked\nFROM employee_work_hours;<\/code><\/pre>\n
\u9019\u5c07\u8fd4\u56de\u6bcf\u4f4d\u54e1\u5de5\u7684\u5de5\u4f5c\u6642\u9577\uff0c\u4ee5\u5c0f\u6642\u70ba\u55ae\u4f4d\u3002<\/p>\n
\u7e3d\u7d50<\/h2>\n
\u5728 Oracle \u8cc7\u6599\u5eab\u4e2d\uff0c\u8a08\u7b97\u6642\u9593\u5dee\u7684\u51fd\u6578\u63d0\u4f9b\u4e86\u9748\u6d3b\u4e14\u5f37\u5927\u7684\u5de5\u5177\uff0c\u5e6b\u52a9\u7528\u6236\u6709\u6548\u5730\u8655\u7406\u65e5\u671f\u548c\u6642\u9593\u7684\u8a08\u7b97\u9700\u6c42\u3002\u7121\u8ad6\u662f\u4f7f\u7528\u57fa\u672c\u7684\u65e5\u671f\u904b\u7b97\uff0c\u9084\u662f\u5229\u7528\u66f4\u8907\u96dc\u7684\u6642\u9593\u9593\u9694\u51fd\u6578\uff0c\u9019\u4e9b\u5de5\u5177\u90fd\u80fd\u5920\u6eff\u8db3\u5404\u7a2e\u696d\u52d9\u9700\u6c42\u3002\u5982\u679c\u60a8\u9700\u8981\u7a69\u5b9a\u4e14\u9ad8\u6548\u7684 VPS<\/a> \u89e3\u6c7a\u65b9\u6848\u4f86\u904b\u884c\u60a8\u7684 Oracle \u8cc7\u6599\u5eab\uff0c\u8acb\u8003\u616e\u6211\u5011\u7684\u670d\u52d9\uff0c\u8b93\u60a8\u7684\u696d\u52d9\u904b\u884c\u66f4\u52a0\u9806\u66a2\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"
\u63a2\u7d22 Oracle \u51fd\u6578\u8a08\u7b97\u6642\u9593\u5dee\u7684\u6280\u5de7\uff0c\u8f15\u9b06\u7372\u53d6\u65e5\u671f\u548c\u6642\u9593\u4e4b\u9593\u7684\u5dee\u7570\uff0c\u63d0\u5347\u6578\u64da\u8655\u7406\u6548\u7387\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-161911","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/161911","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=161911"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/161911\/revisions"}],"predecessor-version":[{"id":161912,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/161911\/revisions\/161912"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=161911"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=161911"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=161911"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}