{"id":60435,"date":"2024-10-13T02:50:18","date_gmt":"2024-10-12T18:50:18","guid":{"rendered":"https:\/\/server.hk\/cnblog\/60435\/"},"modified":"2024-10-13T02:50:19","modified_gmt":"2024-10-12T18:50:19","slug":"db2%e5%b8%b8%e7%94%a8%e5%87%bd%e6%95%b8%e8%88%87oracle%e6%9c%89%e4%bb%80%e9%ba%bc%e4%b8%8d%e5%90%8c%ef%bc%9f","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/60435\/","title":{"rendered":"DB2\u5e38\u7528\u51fd\u6578\u8207Oracle\u6709\u4ec0\u9ebc\u4e0d\u540c\uff1f"},"content":{"rendered":"

DB2\u5e38\u7528\u51fd\u6578\u8207Oracle\u6709\u4ec0\u9ebc\u4e0d\u540c\uff1f<\/h1>\n

\u5728\u6578\u64da\u5eab\u7ba1\u7406\u7cfb\u7d71\u4e2d\uff0cIBM\u7684DB2\u548cOracle\u90fd\u662f\u975e\u5e38\u6d41\u884c\u7684\u9078\u64c7\u3002\u96d6\u7136\u5b83\u5011\u90fd\u63d0\u4f9b\u4e86\u5f37\u5927\u7684\u529f\u80fd\u548c\u9748\u6d3b\u6027\uff0c\u4f46\u5728\u51fd\u6578\u7684\u4f7f\u7528\u4e0a\u537b\u5b58\u5728\u4e00\u4e9b\u986f\u8457\u7684\u5dee\u7570\u3002\u672c\u6587\u5c07\u63a2\u8a0eDB2\u548cOracle\u4e4b\u9593\u7684\u5e38\u7528\u51fd\u6578\u5dee\u7570\uff0c\u5e6b\u52a9\u958b\u767c\u8005\u66f4\u597d\u5730\u7406\u89e3\u9019\u5169\u7a2e\u6578\u64da\u5eab\u7cfb\u7d71\u3002<\/p>\n

1. \u5b57\u7b26\u4e32\u8655\u7406\u51fd\u6578<\/h2>\n

\u5728\u5b57\u7b26\u4e32\u8655\u7406\u65b9\u9762\uff0cDB2\u548cOracle\u90fd\u63d0\u4f9b\u4e86\u591a\u7a2e\u51fd\u6578\uff0c\u4f46\u5176\u8a9e\u6cd5\u548c\u529f\u80fd\u7565\u6709\u4e0d\u540c\u3002<\/p>\n

1.1 \u5b57\u7b26\u4e32\u9023\u63a5<\/h3>\n

\u5728DB2\u4e2d\uff0c\u5b57\u7b26\u4e32\u9023\u63a5\u4f7f\u7528\u300c||\u300d\u904b\u7b97\u7b26\uff0c\u800c\u5728Oracle\u4e2d\u5247\u540c\u6a23\u4f7f\u7528\u300c||\u300d\u3002\u4f8b\u5982\uff1a<\/p>\n

-- DB2 \u548c Oracle\nSELECT 'Hello' || ' World' AS Greeting FROM SYSIBM.SYSDUMMY1;\n<\/code><\/pre>\n
1.2 \u5b57\u7b26\u4e32\u9577\u5ea6<\/h3>\n
\u5728DB2\u4e2d\uff0c\u4f7f\u7528\u51fd\u6578 LENGTH()<\/code> \u4f86\u7372\u53d6\u5b57\u7b26\u4e32\u7684\u9577\u5ea6\uff0c\u800c\u5728Oracle\u4e2d\u5247\u4f7f\u7528 LEN()<\/code>\u3002\u4f8b\u5982\uff1a<\/p>\n
-- DB2\nSELECT LENGTH('Hello World') AS Length FROM SYSIBM.SYSDUMMY1;\n\n-- Oracle\nSELECT LENGTH('Hello World') AS Length FROM DUAL;\n<\/code><\/pre>\n
2. \u65e5\u671f\u548c\u6642\u9593\u51fd\u6578<\/h2>\n
\u65e5\u671f\u548c\u6642\u9593\u7684\u8655\u7406\u5728DB2\u548cOracle\u4e2d\u4e5f\u6709\u4e0d\u540c\u7684\u51fd\u6578\u3002<\/p>\n
2.1 \u7576\u524d\u65e5\u671f\u548c\u6642\u9593<\/h3>\n
\u5728DB2\u4e2d\uff0c\u4f7f\u7528 CURRENT TIMESTAMP<\/code> \u4f86\u7372\u53d6\u7576\u524d\u7684\u65e5\u671f\u548c\u6642\u9593\uff0c\u800c\u5728Oracle\u4e2d\u5247\u4f7f\u7528 SYSDATE<\/code>\u3002\u4f8b\u5982\uff1a<\/p>\n
-- DB2\nSELECT CURRENT TIMESTAMP AS CurrentTime FROM SYSIBM.SYSDUMMY1;\n\n-- Oracle\nSELECT SYSDATE AS CurrentTime FROM DUAL;\n<\/code><\/pre>\n
2.2 \u65e5\u671f\u52a0\u6e1b<\/h3>\n
\u5728DB2\u4e2d\uff0c\u53ef\u4ee5\u4f7f\u7528 ADD DAYS<\/code> \u4f86\u9032\u884c\u65e5\u671f\u7684\u52a0\u6e1b\uff0c\u800c\u5728Oracle\u4e2d\u5247\u4f7f\u7528 + INTERVAL<\/code>\u3002\u4f8b\u5982\uff1a<\/p>\n
-- DB2\nSELECT CURRENT DATE + 10 DAYS AS FutureDate FROM SYSIBM.SYSDUMMY1;\n\n-- Oracle\nSELECT SYSDATE + INTERVAL '10' DAY AS FutureDate FROM DUAL;\n<\/code><\/pre>\n
3. \u6578\u5b78\u51fd\u6578<\/h2>\n
\u6578\u5b78\u51fd\u6578\u5728DB2\u548cOracle\u4e2d\u4e5f\u6709\u4e00\u4e9b\u5dee\u7570\u3002<\/p>\n
3.1 \u53d6\u6574\u51fd\u6578<\/h3>\n
\u5728DB2\u4e2d\uff0c\u4f7f\u7528 ROUND()<\/code> \u51fd\u6578\u4f86\u9032\u884c\u53d6\u6574\uff0c\u800c\u5728Oracle\u4e2d\u5247\u4f7f\u7528 TRUNC()<\/code>\u3002\u4f8b\u5982\uff1a<\/p>\n
-- DB2\nSELECT ROUND(123.456) AS RoundedValue FROM SYSIBM.SYSDUMMY1;\n\n-- Oracle\nSELECT TRUNC(123.456) AS TruncatedValue FROM DUAL;\n<\/code><\/pre>\n
4. \u805a\u5408\u51fd\u6578<\/h2>\n
\u805a\u5408\u51fd\u6578\u5728DB2\u548cOracle\u4e2d\u57fa\u672c\u76f8\u4f3c\uff0c\u4f46\u5728\u67d0\u4e9b\u60c5\u6cc1\u4e0b\uff0c\u4f7f\u7528\u7684\u8a9e\u6cd5\u548c\u529f\u80fd\u53ef\u80fd\u6703\u6709\u6240\u4e0d\u540c\u3002<\/p>\n
4.1 \u8a08\u6578\u51fd\u6578<\/h3>\n
\u5728DB2\u4e2d\uff0c\u4f7f\u7528 COUNT(*)<\/code> \u4f86\u8a08\u7b97\u884c\u6578\uff0c\u800c\u5728Oracle\u4e2d\u540c\u6a23\u4f7f\u7528 COUNT(*)<\/code>\u3002\u4e0d\u904e\uff0cDB2\u9084\u652f\u6301 COUNT(DISTINCT column_name)<\/code>\uff0c\u800cOracle\u5247\u9700\u8981\u4f7f\u7528 COUNT(DISTINCT column_name)<\/code>\u3002\u4f8b\u5982\uff1a<\/p>\n
-- DB2 \u548c Oracle\nSELECT COUNT(*) AS TotalCount FROM table_name;\n<\/code><\/pre>\n
\u7e3d\u7d50<\/h2>\n
\u7e3d\u7684\u4f86\u8aaa\uff0cDB2\u548cOracle\u5728\u51fd\u6578\u7684\u4f7f\u7528\u4e0a\u5b58\u5728\u4e00\u4e9b\u5dee\u7570\uff0c\u9019\u4e9b\u5dee\u7570\u4e3b\u8981\u9ad4\u73fe\u5728\u5b57\u7b26\u4e32\u8655\u7406\u3001\u65e5\u671f\u548c\u6642\u9593\u51fd\u6578\u3001\u6578\u5b78\u51fd\u6578\u4ee5\u53ca\u805a\u5408\u51fd\u6578\u7b49\u65b9\u9762\u3002\u4e86\u89e3\u9019\u4e9b\u5dee\u7570\u5c0d\u65bc\u958b\u767c\u8005\u5728\u4e0d\u540c\u7684\u6578\u64da\u5eab\u74b0\u5883\u4e2d\u9032\u884c\u958b\u767c\u548c\u7dad\u8b77\u81f3\u95dc\u91cd\u8981\u3002<\/p>\n
\u5982\u679c\u60a8\u6b63\u5728\u5c0b\u627e\u9ad8\u6548\u7684 \u9999\u6e2fVPS<\/a> \u89e3\u6c7a\u65b9\u6848\uff0cServer.HK \u63d0\u4f9b\u591a\u7a2e\u9078\u64c7\uff0c\u6eff\u8db3\u60a8\u7684\u9700\u6c42\u3002\u7121\u8ad6\u662f\u6578\u64da\u5eab\u7ba1\u7406\u9084\u662f\u61c9\u7528\u7a0b\u5e8f\u90e8\u7f72\uff0c\u6211\u5011\u7684 \u4f3a\u670d\u5668<\/a> \u90fd\u80fd\u70ba\u60a8\u63d0\u4f9b\u7a69\u5b9a\u7684\u652f\u6301\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"
\u63a2\u7d22DB2\u8207Oracle\u4e4b\u9593\u7684\u5e38\u7528\u51fd\u6578\u5dee\u7570\uff0c\u4e86\u89e3\u5404\u81ea\u7684\u7279\u9ede\u8207\u61c9\u7528\uff0c\u63d0\u5347\u6578\u64da\u5eab\u64cd\u4f5c\u6548\u7387\u3002<\/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-60435","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/60435","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=60435"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/60435\/revisions"}],"predecessor-version":[{"id":60436,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/60435\/revisions\/60436"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=60435"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=60435"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=60435"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}