{"id":96294,"date":"2024-10-20T08:13:18","date_gmt":"2024-10-20T00:13:18","guid":{"rendered":"https:\/\/server.hk\/cnblog\/96294\/"},"modified":"2024-10-20T08:13:19","modified_gmt":"2024-10-20T00:13:19","slug":"oracle%e5%ad%97%e6%ae%b5%e7%9a%84%e8%bd%89%e5%ad%97%e7%ac%a6%e4%b8%b2%e5%af%a6%e9%9a%9b%e6%93%8d%e4%bd%9c%e6%96%b9%e6%a1%88","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/96294\/","title":{"rendered":"Oracle\u5b57\u6bb5\u7684\u8f49\u5b57\u7b26\u4e32\u5be6\u969b\u64cd\u4f5c\u65b9\u6848"},"content":{"rendered":"<h1 id=\"oracle%e5%ad%97%e6%ae%b5%e7%9a%84%e8%bd%89%e5%ad%97%e7%ac%a6%e4%b8%b2%e5%af%a6%e9%9a%9b%e6%93%8d%e4%bd%9c%e6%96%b9%e6%a1%88-fXAsRdwKUq\">Oracle\u5b57\u6bb5\u7684\u8f49\u5b57\u7b26\u4e32\u5be6\u969b\u64cd\u4f5c\u65b9\u6848<\/h1>\n<p>\u5728\u6578\u64da\u5eab\u7ba1\u7406\u4e2d\uff0c\u5c07\u5b57\u6bb5\u8f49\u63db\u70ba\u5b57\u7b26\u4e32\u662f\u4e00\u500b\u5e38\u898b\u7684\u9700\u6c42\uff0c\u5c24\u5176\u662f\u5728\u4f7f\u7528Oracle\u6578\u64da\u5eab\u6642\u3002\u9019\u7bc7\u6587\u7ae0\u5c07\u63a2\u8a0e\u5982\u4f55\u5728Oracle\u4e2d\u6709\u6548\u5730\u5c07\u4e0d\u540c\u985e\u578b\u7684\u5b57\u6bb5\u8f49\u63db\u70ba\u5b57\u7b26\u4e32\uff0c\u4e26\u63d0\u4f9b\u5be6\u969b\u7684\u64cd\u4f5c\u65b9\u6848\u548c\u793a\u4f8b\u4ee3\u78bc\u3002<\/p>\n<h2 id=\"%e7%82%ba%e4%bb%80%e9%ba%bc%e9%9c%80%e8%a6%81%e8%bd%89%e6%8f%9b%e5%ad%97%e6%ae%b5%e7%82%ba%e5%ad%97%e7%ac%a6%e4%b8%b2-fXAsRdwKUq\">\u70ba\u4ec0\u9ebc\u9700\u8981\u8f49\u63db\u5b57\u6bb5\u70ba\u5b57\u7b26\u4e32<\/h2>\n<p>\u5c07\u5b57\u6bb5\u8f49\u63db\u70ba\u5b57\u7b26\u4e32\u7684\u539f\u56e0\u6709\u5f88\u591a\uff0c\u5305\u62ec\uff1a<\/p>\n<ul>\n<li>\u6578\u64da\u683c\u5f0f\u5316\uff1a\u5728\u5831\u544a\u6216\u8f38\u51fa\u4e2d\u9700\u8981\u7279\u5b9a\u7684\u683c\u5f0f\u3002<\/li>\n<li>\u6578\u64da\u6bd4\u8f03\uff1a\u5728\u67d0\u4e9b\u60c5\u6cc1\u4e0b\uff0c\u5b57\u7b26\u4e32\u6bd4\u8f03\u6bd4\u6578\u5b57\u6bd4\u8f03\u66f4\u70ba\u76f4\u89c0\u3002<\/li>\n<li>\u6578\u64da\u6574\u5408\uff1a\u5c07\u4e0d\u540c\u985e\u578b\u7684\u6578\u64da\u5408\u4f75\u70ba\u4e00\u500b\u5b57\u7b26\u4e32\u4ee5\u4fbf\u65bc\u8655\u7406\u3002<\/li>\n<\/ul>\n<h2 id=\"oracle%e4%b8%ad%e7%9a%84%e6%95%b8%e6%93%9a%e9%a1%9e%e5%9e%8b-fXAsRdwKUq\">Oracle\u4e2d\u7684\u6578\u64da\u985e\u578b<\/h2>\n<p>\u5728Oracle\u4e2d\uff0c\u5e38\u898b\u7684\u6578\u64da\u985e\u578b\u5305\u62ec\uff1a<\/p>\n<ul>\n<li><strong>VARCHAR2<\/strong>\uff1a\u53ef\u8b8a\u9577\u5ea6\u7684\u5b57\u7b26\u4e32\u3002<\/li>\n<li><strong>NUMBER<\/strong>\uff1a\u6578\u5b57\u985e\u578b\u3002<\/li>\n<li><strong>DATE<\/strong>\uff1a\u65e5\u671f\u985e\u578b\u3002<\/li>\n<li><strong>CLOB<\/strong>\uff1a\u5b57\u7b26\u5927\u578b\u5c0d\u8c61\uff0c\u7528\u65bc\u5b58\u5132\u5927\u91cf\u6587\u672c\u3002<\/li>\n<\/ul>\n<h2 id=\"%e8%bd%89%e6%8f%9b%e5%ad%97%e6%ae%b5%e7%82%ba%e5%ad%97%e7%ac%a6%e4%b8%b2%e7%9a%84%e5%9f%ba%e6%9c%ac%e6%96%b9%e6%b3%95-fXAsRdwKUq\">\u8f49\u63db\u5b57\u6bb5\u70ba\u5b57\u7b26\u4e32\u7684\u57fa\u672c\u65b9\u6cd5<\/h2>\n<p>\u5728Oracle\u4e2d\uff0c\u53ef\u4ee5\u4f7f\u7528\u591a\u7a2e\u51fd\u6578\u5c07\u5b57\u6bb5\u8f49\u63db\u70ba\u5b57\u7b26\u4e32\u3002\u4ee5\u4e0b\u662f\u4e00\u4e9b\u5e38\u7528\u7684\u65b9\u6cd5\uff1a<\/p>\n<h3 id=\"1-%e4%bd%bf%e7%94%a8to_char%e5%87%bd%e6%95%b8-fXAsRdwKUq\">1. \u4f7f\u7528TO_CHAR\u51fd\u6578<\/h3>\n<p>TO_CHAR\u51fd\u6578\u662f\u5c07\u6578\u5b57\u6216\u65e5\u671f\u8f49\u63db\u70ba\u5b57\u7b26\u4e32\u7684\u6700\u5e38\u7528\u65b9\u6cd5\u3002\u5176\u8a9e\u6cd5\u5982\u4e0b\uff1a<\/p>\n<pre><code>TO_CHAR(expression, [format])<\/code><\/pre>\n<p>\u4f8b\u5982\uff0c\u5c07\u4e00\u500b\u6578\u5b57\u8f49\u63db\u70ba\u5b57\u7b26\u4e32\uff1a<\/p>\n<pre><code>SELECT TO_CHAR(12345) AS string_value FROM dual;<\/code><\/pre>\n<p>\u5c07\u65e5\u671f\u8f49\u63db\u70ba\u5b57\u7b26\u4e32\uff1a<\/p>\n<pre><code>SELECT TO_CHAR(SYSDATE, 'YYYY-MM-DD') AS string_value FROM dual;<\/code><\/pre>\n<h3 id=\"2-%e4%bd%bf%e7%94%a8cast%e5%87%bd%e6%95%b8-fXAsRdwKUq\">2. \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\u500b\u6578\u5b57\u8f49\u63db\u70ba\u5b57\u7b26\u4e32\uff1a<\/p>\n<pre><code>SELECT CAST(12345 AS VARCHAR2(10)) AS string_value FROM dual;<\/code><\/pre>\n<h3 id=\"3-%e4%bd%bf%e7%94%a8concat%e5%87%bd%e6%95%b8-fXAsRdwKUq\">3. \u4f7f\u7528CONCAT\u51fd\u6578<\/h3>\n<p>CONCAT\u51fd\u6578\u7528\u65bc\u5c07\u5169\u500b\u5b57\u7b26\u4e32\u9023\u63a5\u5728\u4e00\u8d77\u3002\u5176\u8a9e\u6cd5\u5982\u4e0b\uff1a<\/p>\n<pre><code>CONCAT(string1, string2)<\/code><\/pre>\n<p>\u4f8b\u5982\uff0c\u5c07\u5169\u500b\u5b57\u7b26\u4e32\u9023\u63a5\uff1a<\/p>\n<pre><code>SELECT CONCAT('Hello', ' World') AS concatenated_string FROM dual;<\/code><\/pre>\n<h2 id=\"%e5%af%a6%e9%9a%9b%e6%93%8d%e4%bd%9c%e7%a4%ba%e4%be%8b-fXAsRdwKUq\">\u5be6\u969b\u64cd\u4f5c\u793a\u4f8b<\/h2>\n<p>\u4ee5\u4e0b\u662f\u4e00\u500b\u7d9c\u5408\u793a\u4f8b\uff0c\u5c55\u793a\u5982\u4f55\u5c07\u4e0d\u540c\u985e\u578b\u7684\u5b57\u6bb5\u8f49\u63db\u70ba\u5b57\u7b26\u4e32\u4e26\u9032\u884c\u64cd\u4f5c\uff1a<\/p>\n<pre><code>\nSELECT \n    TO_CHAR(employee_id) AS employee_id_str,\n    TO_CHAR(hire_date, 'YYYY-MM-DD') AS hire_date_str,\n    CAST(salary AS VARCHAR2(10)) AS salary_str,\n    CONCAT(first_name, ' ', last_name) AS full_name\nFROM employees;\n<\/code><\/pre>\n<p>\u5728\u9019\u500b\u67e5\u8a62\u4e2d\uff0c\u6211\u5011\u5c07\u54e1\u5de5ID\u3001\u96c7\u7528\u65e5\u671f\u548c\u85aa\u6c34\u8f49\u63db\u70ba\u5b57\u7b26\u4e32\uff0c\u4e26\u5c07\u540d\u5b57\u548c\u59d3\u6c0f\u9023\u63a5\u6210\u5168\u540d\u3002<\/p>\n<h2 id=\"%e6%b3%a8%e6%84%8f%e4%ba%8b%e9%a0%85-fXAsRdwKUq\">\u6ce8\u610f\u4e8b\u9805<\/h2>\n<p>\u5728\u9032\u884c\u5b57\u6bb5\u8f49\u63db\u6642\uff0c\u9700\u8981\u6ce8\u610f\u4ee5\u4e0b\u5e7e\u9ede\uff1a<\/p>\n<ul>\n<li>\u78ba\u4fdd\u8f49\u63db\u5f8c\u7684\u5b57\u7b26\u4e32\u9577\u5ea6\u4e0d\u6703\u8d85\u904e\u76ee\u6a19\u5b57\u6bb5\u7684\u6700\u5927\u9577\u5ea6\u3002<\/li>\n<li>\u5728\u8655\u7406\u65e5\u671f\u6642\uff0c\u9078\u64c7\u5408\u9069\u7684\u683c\u5f0f\u4ee5\u907f\u514d\u6df7\u6dc6\u3002<\/li>\n<li>\u5728\u9032\u884c\u5b57\u7b26\u4e32\u64cd\u4f5c\u6642\uff0c\u6ce8\u610f\u7a7a\u503c\uff08NULL\uff09\u7684\u8655\u7406\u3002<\/li>\n<\/ul>\n<h2 id=\"%e7%b8%bd%e7%b5%90-fXAsRdwKUq\">\u7e3d\u7d50<\/h2>\n<p>\u5c07Oracle\u5b57\u6bb5\u8f49\u63db\u70ba\u5b57\u7b26\u4e32\u662f\u4e00\u500b\u91cd\u8981\u7684\u64cd\u4f5c\uff0c\u80fd\u5920\u5e6b\u52a9\u7528\u6236\u66f4\u597d\u5730\u8655\u7406\u548c\u5c55\u793a\u6578\u64da\u3002\u901a\u904e\u4f7f\u7528TO_CHAR\u3001CAST\u548cCONCAT\u7b49\u51fd\u6578\uff0c\u958b\u767c\u8005\u53ef\u4ee5\u9748\u6d3b\u5730\u9032\u884c\u6578\u64da\u8f49\u63db\u548c\u683c\u5f0f\u5316\u3002\u5c0d\u65bc\u9700\u8981\u9ad8\u6548\u6578\u64da\u8655\u7406\u7684\u4f01\u696d\uff0c\u9078\u64c7\u5408\u9069\u7684\u6578\u64da\u5eab\u89e3\u6c7a\u65b9\u6848\u81f3\u95dc\u91cd\u8981\u3002\u4e86\u89e3\u5982\u4f55\u5728Oracle\u4e2d\u9032\u884c\u5b57\u6bb5\u8f49\u63db\uff0c\u5c07\u6709\u52a9\u65bc\u63d0\u5347\u6578\u64da\u7ba1\u7406\u7684\u6548\u7387\u3002<\/p>\n<p>\u5982\u679c\u60a8\u5c0d\u65bc<em><a href=\"https:\/\/server.hk\">\u9999\u6e2fVPS<\/a><\/em>\u6216\u5176\u4ed6<em><a href=\"https:\/\/server.hk\">\u4f3a\u670d\u5668<\/a><\/em>\u89e3\u6c7a\u65b9\u6848\u6709\u8208\u8da3\uff0c\u6b61\u8fce\u8a2a\u554f\u6211\u5011\u7684\u7db2\u7ad9\u4ee5\u7372\u53d6\u66f4\u591a\u4fe1\u606f\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u63a2\u7d22Oracle\u5b57\u6bb5\u8f49\u5b57\u7b26\u4e32\u7684\u5be6\u969b\u64cd\u4f5c\u65b9\u6848\uff0c\u63d0\u4f9b\u7c21\u55ae\u6b65\u9a5f\u8207\u6280\u5de7\uff0c\u52a9\u60a8\u9ad8\u6548\u8655\u7406\u6578\u64da\u8f49\u63db\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-96294","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/96294","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=96294"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/96294\/revisions"}],"predecessor-version":[{"id":96295,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/96294\/revisions\/96295"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=96294"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=96294"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=96294"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}