{"id":95196,"date":"2024-10-19T23:02:49","date_gmt":"2024-10-19T15:02:49","guid":{"rendered":"https:\/\/server.hk\/cnblog\/95196\/"},"modified":"2024-10-19T23:02:50","modified_gmt":"2024-10-19T15:02:50","slug":"oracle%e8%a8%98%e9%8c%84%e9%a1%9e%e5%9e%8b%e8%bd%89%e6%8f%9b","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/95196\/","title":{"rendered":"Oracle\u8a18\u9304\u985e\u578b\u8f49\u63db"},"content":{"rendered":"<h1 id=\"oracle%e8%a8%98%e9%8c%84%e9%a1%9e%e5%9e%8b%e8%bd%89%e6%8f%9b-NyPHoIsJgi\">Oracle\u8a18\u9304\u985e\u578b\u8f49\u63db<\/h1>\n<p>\u5728\u6578\u64da\u5eab\u7ba1\u7406\u4e2d\uff0c\u8a18\u9304\u985e\u578b\u8f49\u63db\u662f\u4e00\u500b\u91cd\u8981\u7684\u6982\u5ff5\uff0c\u5c24\u5176\u662f\u5728\u4f7f\u7528Oracle\u6578\u64da\u5eab\u6642\u3002\u9019\u7bc7\u6587\u7ae0\u5c07\u6df1\u5165\u63a2\u8a0eOracle\u4e2d\u7684\u8a18\u9304\u985e\u578b\u8f49\u63db\uff0c\u5305\u62ec\u5176\u5b9a\u7fa9\u3001\u7528\u9014\u4ee5\u53ca\u5982\u4f55\u5728\u5be6\u969b\u61c9\u7528\u4e2d\u9032\u884c\u8f49\u63db\u3002<\/p>\n<h2 id=\"%e4%bb%80%e9%ba%bc%e6%98%af%e8%a8%98%e9%8c%84%e9%a1%9e%e5%9e%8b%e8%bd%89%e6%8f%9b%ef%bc%9f-NyPHoIsJgi\">\u4ec0\u9ebc\u662f\u8a18\u9304\u985e\u578b\u8f49\u63db\uff1f<\/h2>\n<p>\u8a18\u9304\u985e\u578b\u8f49\u63db\u662f\u6307\u5c07\u4e00\u7a2e\u6578\u64da\u985e\u578b\u7684\u6578\u64da\u8f49\u63db\u70ba\u53e6\u4e00\u7a2e\u6578\u64da\u985e\u578b\u7684\u904e\u7a0b\u3002\u5728Oracle\u4e2d\uff0c\u9019\u901a\u5e38\u6d89\u53ca\u5230\u4e0d\u540c\u7684\u6578\u64da\u7d50\u69cb\uff0c\u4f8b\u5982\u5f9e\u4e00\u500b\u8868\u7684\u884c\u8f49\u63db\u70ba\u53e6\u4e00\u500b\u8868\u7684\u884c\uff0c\u6216\u662f\u5c07\u4e00\u500b\u8907\u96dc\u7684\u6578\u64da\u985e\u578b\u8f49\u63db\u70ba\u4e00\u500b\u7c21\u55ae\u7684\u6578\u64da\u985e\u578b\u3002<\/p>\n<h2 id=\"oracle%e4%b8%ad%e7%9a%84%e6%95%b8%e6%93%9a%e9%a1%9e%e5%9e%8b-NyPHoIsJgi\">Oracle\u4e2d\u7684\u6578\u64da\u985e\u578b<\/h2>\n<p>\u5728Oracle\u4e2d\uff0c\u6578\u64da\u985e\u578b\u4e3b\u8981\u5206\u70ba\u4ee5\u4e0b\u5e7e\u985e\uff1a<\/p>\n<ul>\n<li><strong>\u57fa\u672c\u6578\u64da\u985e\u578b\uff1a<\/strong>\u5982NUMBER\u3001VARCHAR2\u3001DATE\u7b49\u3002<\/li>\n<li><strong>\u8907\u96dc\u6578\u64da\u985e\u578b\uff1a<\/strong>\u5982OBJECT\u3001TABLE\u3001REF\u7b49\u3002<\/li>\n<li><strong>LOB\u6578\u64da\u985e\u578b\uff1a<\/strong>\u5982BLOB\u3001CLOB\u7b49\uff0c\u7528\u65bc\u5b58\u5132\u5927\u578b\u5c0d\u8c61\u3002<\/li>\n<\/ul>\n<h2 id=\"%e8%a8%98%e9%8c%84%e9%a1%9e%e5%9e%8b%e8%bd%89%e6%8f%9b%e7%9a%84%e7%94%a8%e9%80%94-NyPHoIsJgi\">\u8a18\u9304\u985e\u578b\u8f49\u63db\u7684\u7528\u9014<\/h2>\n<p>\u8a18\u9304\u985e\u578b\u8f49\u63db\u5728\u591a\u7a2e\u60c5\u6cc1\u4e0b\u662f\u5fc5\u8981\u7684\uff0c\u4f8b\u5982\uff1a<\/p>\n<ul>\n<li>\u6578\u64da\u6574\u5408\uff1a\u7576\u5f9e\u4e0d\u540c\u4f86\u6e90\u7372\u53d6\u6578\u64da\u6642\uff0c\u53ef\u80fd\u9700\u8981\u5c07\u6578\u64da\u8f49\u63db\u70ba\u7d71\u4e00\u7684\u683c\u5f0f\u3002<\/li>\n<li>\u6578\u64da\u6e05\u7406\uff1a\u5728\u6578\u64da\u6e05\u7406\u904e\u7a0b\u4e2d\uff0c\u53ef\u80fd\u9700\u8981\u5c07\u4e0d\u4e00\u81f4\u7684\u6578\u64da\u985e\u578b\u8f49\u63db\u70ba\u4e00\u81f4\u7684\u985e\u578b\u3002<\/li>\n<li>\u6027\u80fd\u512a\u5316\uff1a\u67d0\u4e9b\u6578\u64da\u985e\u578b\u5728\u67e5\u8a62\u6027\u80fd\u4e0a\u8868\u73fe\u66f4\u4f73\uff0c\u8f49\u63db\u53ef\u4ee5\u63d0\u9ad8\u67e5\u8a62\u6548\u7387\u3002<\/li>\n<\/ul>\n<h2 id=\"%e5%a6%82%e4%bd%95%e9%80%b2%e8%a1%8c%e8%a8%98%e9%8c%84%e9%a1%9e%e5%9e%8b%e8%bd%89%e6%8f%9b-NyPHoIsJgi\">\u5982\u4f55\u9032\u884c\u8a18\u9304\u985e\u578b\u8f49\u63db<\/h2>\n<p>\u5728Oracle\u4e2d\uff0c\u53ef\u4ee5\u4f7f\u7528\u591a\u7a2e\u65b9\u6cd5\u9032\u884c\u8a18\u9304\u985e\u578b\u8f49\u63db\u3002\u4ee5\u4e0b\u662f\u4e00\u4e9b\u5e38\u898b\u7684\u65b9\u6cd5\uff1a<\/p>\n<h3 id=\"1-%e4%bd%bf%e7%94%a8cast%e5%87%bd%e6%95%b8-NyPHoIsJgi\">1. \u4f7f\u7528CAST\u51fd\u6578<\/h3>\n<p>CAST\u51fd\u6578\u53ef\u4ee5\u5c07\u4e00\u500b\u6578\u64da\u985e\u578b\u8f49\u63db\u70ba\u53e6\u4e00\u500b\u6578\u64da\u985e\u578b\u3002\u5176\u8a9e\u6cd5\u5982\u4e0b\uff1a<\/p>\n<pre><code>CAST(expression AS target_data_type)<\/code><\/pre>\n<p>\u4f8b\u5982\uff0c\u5c07\u4e00\u500bVARCHAR2\u985e\u578b\u7684\u6578\u64da\u8f49\u63db\u70baNUMBER\u985e\u578b\uff1a<\/p>\n<pre><code>SELECT CAST('123' AS NUMBER) FROM dual;<\/code><\/pre>\n<h3 id=\"2-%e4%bd%bf%e7%94%a8convert%e5%87%bd%e6%95%b8-NyPHoIsJgi\">2. \u4f7f\u7528CONVERT\u51fd\u6578<\/h3>\n<p>CONVERT\u51fd\u6578\u4e3b\u8981\u7528\u65bc\u5b57\u7b26\u96c6\u7684\u8f49\u63db\uff0c\u5176\u8a9e\u6cd5\u5982\u4e0b\uff1a<\/p>\n<pre><code>CONVERT(string, target_charset)<\/code><\/pre>\n<p>\u4f8b\u5982\uff0c\u5c07\u4e00\u500b\u5b57\u7b26\u4e32\u5f9eUTF-8\u8f49\u63db\u70baASCII\uff1a<\/p>\n<pre><code>SELECT CONVERT('Hello World' USING ASCII) FROM dual;<\/code><\/pre>\n<h3 id=\"3-%e4%bd%bf%e7%94%a8to_number%e3%80%81to_char%e5%92%8cto_date%e5%87%bd%e6%95%b8-NyPHoIsJgi\">3. \u4f7f\u7528TO_NUMBER\u3001TO_CHAR\u548cTO_DATE\u51fd\u6578<\/h3>\n<p>\u9019\u4e9b\u51fd\u6578\u5c08\u9580\u7528\u65bc\u5c07\u6578\u64da\u8f49\u63db\u70ba\u7279\u5b9a\u7684\u6578\u64da\u985e\u578b\uff1a<\/p>\n<ul>\n<li><code>TO_NUMBER<\/code>\uff1a\u5c07\u5b57\u7b26\u4e32\u8f49\u63db\u70ba\u6578\u5b57\u3002<\/li>\n<li><code>TO_CHAR<\/code>\uff1a\u5c07\u6578\u5b57\u6216\u65e5\u671f\u8f49\u63db\u70ba\u5b57\u7b26\u4e32\u3002<\/li>\n<li><code>TO_DATE<\/code>\uff1a\u5c07\u5b57\u7b26\u4e32\u8f49\u63db\u70ba\u65e5\u671f\u3002<\/li>\n<\/ul>\n<p>\u4f8b\u5982\uff1a<\/p>\n<pre><code>SELECT TO_NUMBER('123.45') FROM dual;<\/code><\/pre>\n<pre><code>SELECT TO_CHAR(SYSDATE, 'YYYY-MM-DD') FROM dual;<\/code><\/pre>\n<pre><code>SELECT TO_DATE('2023-10-01', 'YYYY-MM-DD') FROM dual;<\/code><\/pre>\n<h2 id=\"%e6%b3%a8%e6%84%8f%e4%ba%8b%e9%a0%85-NyPHoIsJgi\">\u6ce8\u610f\u4e8b\u9805<\/h2>\n<p>\u5728\u9032\u884c\u8a18\u9304\u985e\u578b\u8f49\u63db\u6642\uff0c\u9700\u8981\u6ce8\u610f\u4ee5\u4e0b\u5e7e\u9ede\uff1a<\/p>\n<ul>\n<li>\u78ba\u4fdd\u6578\u64da\u7684\u517c\u5bb9\u6027\uff1a\u8f49\u63db\u524d\u9700\u78ba\u8a8d\u6e90\u6578\u64da\u662f\u5426\u7b26\u5408\u76ee\u6a19\u6578\u64da\u985e\u578b\u7684\u8981\u6c42\u3002<\/li>\n<li>\u8655\u7406\u7570\u5e38\u60c5\u6cc1\uff1a\u5728\u8f49\u63db\u904e\u7a0b\u4e2d\uff0c\u53ef\u80fd\u6703\u9047\u5230\u6578\u64da\u683c\u5f0f\u4e0d\u6b63\u78ba\u7684\u60c5\u6cc1\uff0c\u9700\u9032\u884c\u9069\u7576\u7684\u932f\u8aa4\u8655\u7406\u3002<\/li>\n<li>\u6027\u80fd\u5f71\u97ff\uff1a\u983b\u7e41\u7684\u985e\u578b\u8f49\u63db\u53ef\u80fd\u6703\u5f71\u97ff\u67e5\u8a62\u6027\u80fd\uff0c\u61c9\u8b39\u614e\u4f7f\u7528\u3002<\/li>\n<\/ul>\n<h2 id=\"%e7%b8%bd%e7%b5%90-NyPHoIsJgi\">\u7e3d\u7d50<\/h2>\n<p>Oracle\u4e2d\u7684\u8a18\u9304\u985e\u578b\u8f49\u63db\u662f\u4e00\u500b\u91cd\u8981\u7684\u6280\u8853\uff0c\u80fd\u5920\u5e6b\u52a9\u7528\u6236\u5728\u6578\u64da\u6574\u5408\u3001\u6e05\u7406\u548c\u6027\u80fd\u512a\u5316\u7b49\u65b9\u9762\u53d6\u5f97\u826f\u597d\u7684\u6548\u679c\u3002\u4e86\u89e3\u5982\u4f55\u4f7f\u7528CAST\u3001CONVERT\u53ca\u5176\u4ed6\u8f49\u63db\u51fd\u6578\uff0c\u5c07\u6709\u52a9\u65bc\u66f4\u6709\u6548\u5730\u7ba1\u7406\u548c\u64cd\u4f5c\u6578\u64da\u3002\u82e5\u60a8\u9700\u8981\u9032\u4e00\u6b65\u4e86\u89e3\u5982\u4f55\u5728\u96f2\u74b0\u5883\u4e2d\u4f7f\u7528\u9019\u4e9b\u6280\u8853\uff0c\u8acb\u53c3\u8003\u6211\u5011\u7684<a href=\"https:\/\/server.hk\">\u9999\u6e2fVPS<\/a>\u89e3\u6c7a\u65b9\u6848\uff0c\u7372\u53d6\u66f4\u591a\u8cc7\u8a0a\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u4e86\u89e3Oracle\u8a18\u9304\u985e\u578b\u8f49\u63db\u7684\u904e\u7a0b\u8207\u6280\u5de7\uff0c\u63d0\u5347\u6578\u64da\u8655\u7406\u6548\u7387\uff0c\u78ba\u4fdd\u6578\u64da\u6e96\u78ba\u6027\u8207\u4e00\u81f4\u6027\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-95196","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/95196","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=95196"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/95196\/revisions"}],"predecessor-version":[{"id":95197,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/95196\/revisions\/95197"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=95196"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=95196"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=95196"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}