{"id":158351,"date":"2024-11-03T01:06:28","date_gmt":"2024-11-02T17:06:28","guid":{"rendered":"https:\/\/server.hk\/cnblog\/158351\/"},"modified":"2024-11-03T01:06:29","modified_gmt":"2024-11-02T17:06:29","slug":"%e9%ab%98%e6%95%88%e6%95%b8%e6%93%9a%e7%ae%a1%e7%90%86%ef%bc%9a%e8%bc%95%e9%ac%86%e6%9f%a5%e6%89%be%e4%b8%8d%e9%87%8d%e8%a4%87%e7%9a%84%e6%95%b8%e6%93%9a%ef%bc%88%e6%9f%a5%e6%89%be%e6%95%b8%e6%93%9a","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/158351\/","title":{"rendered":"\u9ad8\u6548\u6578\u64da\u7ba1\u7406\uff1a\u8f15\u9b06\u67e5\u627e\u4e0d\u91cd\u8907\u7684\u6578\u64da\uff08\u67e5\u627e\u6578\u64da\u5eab\u4e0d\u91cd\u8907\u7684\u6578\u64da\uff09"},"content":{"rendered":"<h1 id=\"%e9%ab%98%e6%95%88%e6%95%b8%e6%93%9a%e7%ae%a1%e7%90%86%ef%bc%9a%e8%bc%95%e9%ac%86%e6%9f%a5%e6%89%be%e4%b8%8d%e9%87%8d%e8%a4%87%e7%9a%84%e6%95%b8%e6%93%9a%ef%bc%88%e6%9f%a5%e6%89%be%e6%95%b8%e6%93%9a-aecaSWhyvx\">\u9ad8\u6548\u6578\u64da\u7ba1\u7406\uff1a\u8f15\u9b06\u67e5\u627e\u4e0d\u91cd\u8907\u7684\u6578\u64da\uff08\u67e5\u627e\u6578\u64da\u5eab\u4e0d\u91cd\u8907\u7684\u6578\u64da\uff09<\/h1>\n<p>\u5728\u7576\u4eca\u6578\u64da\u9a45\u52d5\u7684\u4e16\u754c\u4e2d\uff0c\u6578\u64da\u7ba1\u7406\u7684\u91cd\u8981\u6027\u4e0d\u8a00\u800c\u55bb\u3002\u96a8\u8457\u4f01\u696d\u548c\u7d44\u7e54\u7a4d\u7d2f\u7684\u6578\u64da\u91cf\u4e0d\u65b7\u589e\u52a0\uff0c\u5982\u4f55\u6709\u6548\u5730\u7ba1\u7406\u548c\u67e5\u627e\u4e0d\u91cd\u8907\u7684\u6578\u64da\u6210\u70ba\u4e86\u4e00\u500b\u95dc\u9375\u6311\u6230\u3002\u672c\u6587\u5c07\u63a2\u8a0e\u9ad8\u6548\u6578\u64da\u7ba1\u7406\u7684\u7b56\u7565\uff0c\u7279\u5225\u662f\u5982\u4f55\u5728\u6578\u64da\u5eab\u4e2d\u67e5\u627e\u4e0d\u91cd\u8907\u7684\u6578\u64da\u3002<\/p>\n<h2 id=\"%e7%82%ba%e4%bb%80%e9%ba%bc%e9%9c%80%e8%a6%81%e6%9f%a5%e6%89%be%e4%b8%8d%e9%87%8d%e8%a4%87%e7%9a%84%e6%95%b8%e6%93%9a%ef%bc%9f-aecaSWhyvx\">\u70ba\u4ec0\u9ebc\u9700\u8981\u67e5\u627e\u4e0d\u91cd\u8907\u7684\u6578\u64da\uff1f<\/h2>\n<p>\u91cd\u8907\u6578\u64da\u4e0d\u50c5\u6703\u6d6a\u8cbb\u5b58\u5132\u7a7a\u9593\uff0c\u9084\u53ef\u80fd\u5c0e\u81f4\u6578\u64da\u5206\u6790\u7684\u932f\u8aa4\u548c\u6c7a\u7b56\u7684\u5931\u8aa4\u3002\u7576\u6578\u64da\u5eab\u4e2d\u5b58\u5728\u91cd\u8907\u7684\u8a18\u9304\u6642\uff0c\u67e5\u8a62\u7d50\u679c\u53ef\u80fd\u6703\u53d7\u5230\u5f71\u97ff\uff0c\u5f9e\u800c\u5c0e\u81f4\u4e0d\u6e96\u78ba\u7684\u5831\u544a\u548c\u5206\u6790\u3002\u56e0\u6b64\uff0c\u78ba\u4fdd\u6578\u64da\u7684\u552f\u4e00\u6027\u662f\u6578\u64da\u7ba1\u7406\u4e2d\u7684\u4e00\u500b\u91cd\u8981\u6b65\u9a5f\u3002<\/p>\n<h2 id=\"%e6%9f%a5%e6%89%be%e4%b8%8d%e9%87%8d%e8%a4%87%e6%95%b8%e6%93%9a%e7%9a%84%e5%9f%ba%e6%9c%ac%e6%96%b9%e6%b3%95-aecaSWhyvx\">\u67e5\u627e\u4e0d\u91cd\u8907\u6578\u64da\u7684\u57fa\u672c\u65b9\u6cd5<\/h2>\n<p>\u5728\u6578\u64da\u5eab\u4e2d\u67e5\u627e\u4e0d\u91cd\u8907\u7684\u6578\u64da\u901a\u5e38\u53ef\u4ee5\u901a\u904e\u4ee5\u4e0b\u5e7e\u7a2e\u65b9\u6cd5\u4f86\u5be6\u73fe\uff1a<\/p>\n<ul>\n<li><strong>\u4f7f\u7528SQL\u67e5\u8a62\uff1a<\/strong>SQL\uff08\u7d50\u69cb\u5316\u67e5\u8a62\u8a9e\u8a00\uff09\u662f\u67e5\u8a62\u548c\u7ba1\u7406\u6578\u64da\u5eab\u7684\u6a19\u6e96\u8a9e\u8a00\u3002\u4f7f\u7528SQL\u7684 <code>SELECT DISTINCT<\/code> \u8a9e\u53e5\u53ef\u4ee5\u8f15\u9b06\u67e5\u627e\u4e0d\u91cd\u8907\u7684\u6578\u64da\u3002\u4f8b\u5982\uff1a<\/li>\n<\/ul>\n<pre><code>SELECT DISTINCT column_name FROM table_name;<\/code><\/pre>\n<p>\u9019\u689d\u67e5\u8a62\u5c07\u8fd4\u56de\u6307\u5b9a\u5217\u4e2d\u6240\u6709\u4e0d\u91cd\u8907\u7684\u503c\u3002<\/p>\n<ul>\n<li><strong>\u4f7f\u7528GROUP BY\u8a9e\u53e5\uff1a<\/strong>\u53e6\u4e00\u7a2e\u67e5\u627e\u4e0d\u91cd\u8907\u6578\u64da\u7684\u65b9\u6cd5\u662f\u4f7f\u7528 <code>GROUP BY<\/code> \u8a9e\u53e5\u3002\u9019\u7a2e\u65b9\u6cd5\u4e0d\u50c5\u53ef\u4ee5\u67e5\u627e\u4e0d\u91cd\u8907\u7684\u6578\u64da\uff0c\u9084\u53ef\u4ee5\u9032\u884c\u805a\u5408\u8a08\u7b97\u3002\u4f8b\u5982\uff1a<\/li>\n<\/ul>\n<pre><code>SELECT column_name, COUNT(*) FROM table_name GROUP BY column_name;<\/code><\/pre>\n<p>\u9019\u689d\u67e5\u8a62\u5c07\u8fd4\u56de\u6bcf\u500b\u4e0d\u91cd\u8907\u503c\u53ca\u5176\u51fa\u73fe\u7684\u6b21\u6578\u3002<\/p>\n<h2 id=\"%e6%95%b8%e6%93%9a%e6%b8%85%e7%90%86%e7%9a%84%e9%87%8d%e8%a6%81%e6%80%a7-aecaSWhyvx\">\u6578\u64da\u6e05\u7406\u7684\u91cd\u8981\u6027<\/h2>\n<p>\u5728\u67e5\u627e\u4e0d\u91cd\u8907\u6578\u64da\u4e4b\u524d\uff0c\u9032\u884c\u6578\u64da\u6e05\u7406\u662f\u81f3\u95dc\u91cd\u8981\u7684\u3002\u6578\u64da\u6e05\u7406\u7684\u904e\u7a0b\u5305\u62ec\u8b58\u5225\u548c\u522a\u9664\u91cd\u8907\u7684\u8a18\u9304\u3001\u586b\u88dc\u7f3a\u5931\u503c\u4ee5\u53ca\u6a19\u6e96\u5316\u6578\u64da\u683c\u5f0f\u3002\u9019\u4e9b\u6b65\u9a5f\u53ef\u4ee5\u5e6b\u52a9\u63d0\u9ad8\u6578\u64da\u7684\u8cea\u91cf\uff0c\u5f9e\u800c\u4f7f\u67e5\u627e\u4e0d\u91cd\u8907\u6578\u64da\u7684\u904e\u7a0b\u66f4\u52a0\u9ad8\u6548\u3002<\/p>\n<h3 id=\"%e6%95%b8%e6%93%9a%e6%b8%85%e7%90%86%e7%9a%84%e6%ad%a5%e9%a9%9f-aecaSWhyvx\">\u6578\u64da\u6e05\u7406\u7684\u6b65\u9a5f<\/h3>\n<ul>\n<li><strong>\u8b58\u5225\u91cd\u8907\u8a18\u9304\uff1a<\/strong>\u4f7f\u7528SQL\u67e5\u8a62\u6216\u6578\u64da\u5206\u6790\u5de5\u5177\u4f86\u8b58\u5225\u91cd\u8907\u7684\u6578\u64da\u3002<\/li>\n<li><strong>\u522a\u9664\u91cd\u8907\u8a18\u9304\uff1a<\/strong>\u6839\u64da\u696d\u52d9\u9700\u6c42\u9078\u64c7\u4fdd\u7559\u7684\u8a18\u9304\uff0c\u4e26\u522a\u9664\u5176\u9918\u7684\u91cd\u8907\u8a18\u9304\u3002<\/li>\n<li><strong>\u6a19\u6e96\u5316\u6578\u64da\u683c\u5f0f\uff1a<\/strong>\u78ba\u4fdd\u6240\u6709\u6578\u64da\u9075\u5faa\u76f8\u540c\u7684\u683c\u5f0f\uff0c\u4f8b\u5982\u65e5\u671f\u683c\u5f0f\u3001\u5730\u5740\u683c\u5f0f\u7b49\u3002<\/li>\n<\/ul>\n<h2 id=\"%e4%bd%bf%e7%94%a8%e6%95%b8%e6%93%9a%e5%ba%ab%e7%ae%a1%e7%90%86%e7%b3%bb%e7%b5%b1%ef%bc%88dbms%ef%bc%89-aecaSWhyvx\">\u4f7f\u7528\u6578\u64da\u5eab\u7ba1\u7406\u7cfb\u7d71\uff08DBMS\uff09<\/h2>\n<p>\u9078\u64c7\u5408\u9069\u7684\u6578\u64da\u5eab\u7ba1\u7406\u7cfb\u7d71\uff08DBMS\uff09\u4e5f\u5c0d\u9ad8\u6548\u6578\u64da\u7ba1\u7406\u81f3\u95dc\u91cd\u8981\u3002\u8a31\u591a\u73fe\u4ee3DBMS\u63d0\u4f9b\u4e86\u5167\u5efa\u7684\u5de5\u5177\u548c\u529f\u80fd\u4f86\u5e6b\u52a9\u7528\u6236\u67e5\u627e\u548c\u7ba1\u7406\u4e0d\u91cd\u8907\u7684\u6578\u64da\u3002\u4f8b\u5982\uff0cMySQL\u3001PostgreSQL\u548cMongoDB\u7b49\u6d41\u884c\u7684\u6578\u64da\u5eab\u7cfb\u7d71\u90fd\u63d0\u4f9b\u4e86\u5f37\u5927\u7684\u67e5\u8a62\u529f\u80fd\uff0c\u80fd\u5920\u8f15\u9b06\u8655\u7406\u91cd\u8907\u6578\u64da\u7684\u554f\u984c\u3002<\/p>\n<h2 id=\"%e7%b5%90%e8%ab%96-aecaSWhyvx\">\u7d50\u8ad6<\/h2>\n<p>\u9ad8\u6548\u7684\u6578\u64da\u7ba1\u7406\u4e0d\u50c5\u80fd\u63d0\u9ad8\u696d\u52d9\u904b\u71df\u7684\u6548\u7387\uff0c\u9084\u80fd\u589e\u5f37\u6578\u64da\u5206\u6790\u7684\u6e96\u78ba\u6027\u3002\u901a\u904e\u4f7f\u7528SQL\u67e5\u8a62\u3001\u9032\u884c\u6578\u64da\u6e05\u7406\u4ee5\u53ca\u9078\u64c7\u5408\u9069\u7684\u6578\u64da\u5eab\u7ba1\u7406\u7cfb\u7d71\uff0c\u4f01\u696d\u53ef\u4ee5\u8f15\u9b06\u67e5\u627e\u4e0d\u91cd\u8907\u7684\u6578\u64da\uff0c\u5f9e\u800c\u505a\u51fa\u66f4\u660e\u667a\u7684\u6c7a\u7b56\u3002<\/p>\n<p>\u5982\u9700\u4e86\u89e3\u66f4\u591a\u6709\u95dc\u6578\u64da\u7ba1\u7406\u548c\u9ad8\u6548\u6578\u64da\u8655\u7406\u7684\u8cc7\u8a0a\uff0c\u60a8\u53ef\u4ee5\u8a2a\u554f\u6211\u5011\u7684\u7db2\u7ad9 <a href=\"https:\/\/server.hk\">Server.HK<\/a>\uff0c\u63a2\u7d22\u6211\u5011\u63d0\u4f9b\u7684\u5404\u7a2e <a href=\"https:\/\/server.hk\">VPS<\/a> \u89e3\u6c7a\u65b9\u6848\uff0c\u52a9\u60a8\u5728\u6578\u64da\u7ba1\u7406\u4e0a\u66f4\u4e0a\u4e00\u5c64\u6a13\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u9ad8\u6548\u6578\u64da\u7ba1\u7406\uff0c\u8f15\u9b06\u67e5\u627e\u4e0d\u91cd\u8907\u7684\u6578\u64da\uff0c\u63d0\u5347\u6578\u64da\u5eab\u6548\u7387\uff0c\u78ba\u4fdd\u4fe1\u606f\u6e96\u78ba\u7121\u8aa4\uff0c\u52a9\u529b\u696d\u52d9\u6c7a\u7b56\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-158351","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/158351","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=158351"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/158351\/revisions"}],"predecessor-version":[{"id":158352,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/158351\/revisions\/158352"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=158351"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=158351"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=158351"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}