{"id":157834,"date":"2024-11-02T23:50:20","date_gmt":"2024-11-02T15:50:20","guid":{"rendered":"https:\/\/server.hk\/cnblog\/157834\/"},"modified":"2024-11-02T23:50:21","modified_gmt":"2024-11-02T15:50:21","slug":"%e9%ab%98%e6%95%88%e6%9f%a5%e8%a9%a2%ef%bc%8c%e9%81%bf%e5%85%8d%e9%87%8d%e8%a4%87-%e6%95%b8%e6%93%9a%e5%ba%ab%e6%b6%88%e9%99%a4%e9%87%8d%e8%a4%87%e8%aa%9e%e5%8f%a5%e6%8a%80%e5%b7%a7%ef%bc%88%e6%9f%a5","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/157834\/","title":{"rendered":"\u9ad8\u6548\u67e5\u8a62\uff0c\u907f\u514d\u91cd\u8907 \u6578\u64da\u5eab\u6d88\u9664\u91cd\u8907\u8a9e\u53e5\u6280\u5de7\uff08\u67e5\u8a62\u6578\u64da\u5eab\u6d88\u9664\u91cd\u8907\u8a9e\u53e5\uff09"},"content":{"rendered":"<h1 id=\"%e9%ab%98%e6%95%88%e6%9f%a5%e8%a9%a2%ef%bc%8c%e9%81%bf%e5%85%8d%e9%87%8d%e8%a4%87%ef%bc%9a%e6%95%b8%e6%93%9a%e5%ba%ab%e6%b6%88%e9%99%a4%e9%87%8d%e8%a4%87%e8%aa%9e%e5%8f%a5%e6%8a%80%e5%b7%a7-pnSlvVyLlE\">\u9ad8\u6548\u67e5\u8a62\uff0c\u907f\u514d\u91cd\u8907\uff1a\u6578\u64da\u5eab\u6d88\u9664\u91cd\u8907\u8a9e\u53e5\u6280\u5de7<\/h1>\n<p>\u5728\u73fe\u4eca\u7684\u6578\u64da\u9a45\u52d5\u6642\u4ee3\uff0c\u6578\u64da\u5eab\u7684\u7ba1\u7406\u548c\u67e5\u8a62\u6548\u7387\u5c0d\u65bc\u4f01\u696d\u7684\u904b\u71df\u81f3\u95dc\u91cd\u8981\u3002\u91cd\u8907\u6578\u64da\u4e0d\u50c5\u6d6a\u8cbb\u5b58\u5132\u7a7a\u9593\uff0c\u9084\u53ef\u80fd\u5c0e\u81f4\u67e5\u8a62\u7d50\u679c\u7684\u4e0d\u6e96\u78ba\u6027\u3002\u56e0\u6b64\uff0c\u5b78\u6703\u5982\u4f55\u6709\u6548\u5730\u67e5\u8a62\u6578\u64da\u5eab\u4e26\u6d88\u9664\u91cd\u8907\u8a9e\u53e5\u662f\u6bcf\u4f4d\u6578\u64da\u5eab\u7ba1\u7406\u54e1\u548c\u958b\u767c\u8005\u5fc5\u9808\u638c\u63e1\u7684\u6280\u80fd\u3002<\/p>\n<h2 id=\"%e7%82%ba%e4%bb%80%e9%ba%bc%e9%9c%80%e8%a6%81%e6%b6%88%e9%99%a4%e9%87%8d%e8%a4%87%e6%95%b8%e6%93%9a%ef%bc%9f-pnSlvVyLlE\">\u70ba\u4ec0\u9ebc\u9700\u8981\u6d88\u9664\u91cd\u8907\u6578\u64da\uff1f<\/h2>\n<p>\u91cd\u8907\u6578\u64da\u6703\u5c0d\u6578\u64da\u5eab\u7684\u6027\u80fd\u548c\u6578\u64da\u7684\u5b8c\u6574\u6027\u9020\u6210\u8ca0\u9762\u5f71\u97ff\u3002\u4ee5\u4e0b\u662f\u5e7e\u500b\u4e3b\u8981\u539f\u56e0\uff1a<\/p>\n<ul>\n<li><strong>\u5b58\u5132\u7a7a\u9593\u6d6a\u8cbb\uff1a<\/strong>\u91cd\u8907\u6578\u64da\u4f54\u7528\u984d\u5916\u7684\u5b58\u5132\u7a7a\u9593\uff0c\u589e\u52a0\u4e86\u6578\u64da\u5eab\u7684\u7dad\u8b77\u6210\u672c\u3002<\/li>\n<li><strong>\u67e5\u8a62\u6548\u7387\u4f4e\u4e0b\uff1a<\/strong>\u67e5\u8a62\u91cd\u8907\u6578\u64da\u6703\u5c0e\u81f4\u67e5\u8a62\u901f\u5ea6\u8b8a\u6162\uff0c\u5f71\u97ff\u7528\u6236\u9ad4\u9a57\u3002<\/li>\n<li><strong>\u6578\u64da\u4e0d\u4e00\u81f4\u6027\uff1a<\/strong>\u91cd\u8907\u6578\u64da\u53ef\u80fd\u5c0e\u81f4\u6578\u64da\u4e0d\u4e00\u81f4\uff0c\u5f71\u97ff\u6c7a\u7b56\u7684\u6e96\u78ba\u6027\u3002<\/li>\n<\/ul>\n<h2 id=\"%e6%b6%88%e9%99%a4%e9%87%8d%e8%a4%87%e6%95%b8%e6%93%9a%e7%9a%84%e5%9f%ba%e6%9c%ac%e6%8a%80%e5%b7%a7-pnSlvVyLlE\">\u6d88\u9664\u91cd\u8907\u6578\u64da\u7684\u57fa\u672c\u6280\u5de7<\/h2>\n<p>\u5728\u6578\u64da\u5eab\u4e2d\u6d88\u9664\u91cd\u8907\u6578\u64da\u7684\u5e38\u7528\u65b9\u6cd5\u4e3b\u8981\u6709\u4ee5\u4e0b\u5e7e\u7a2e\uff1a<\/p>\n<h3 id=\"1-%e4%bd%bf%e7%94%a8-distinct-%e9%97%9c%e9%8d%b5%e5%ad%97-pnSlvVyLlE\">1. \u4f7f\u7528 DISTINCT \u95dc\u9375\u5b57<\/h3>\n<p>\u5728 SQL \u67e5\u8a62\u4e2d\uff0c\u4f7f\u7528 <code>DISTINCT<\/code> \u95dc\u9375\u5b57\u53ef\u4ee5\u5e6b\u52a9\u6211\u5011\u7372\u53d6\u552f\u4e00\u7684\u6578\u64da\u884c\u3002\u4f8b\u5982\uff1a<\/p>\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\u552f\u4e00\u7684\u503c\uff0c\u5f9e\u800c\u6d88\u9664\u91cd\u8907\u3002<\/p>\n<h3 id=\"2-group-by-%e5%ad%90%e5%8f%a5-pnSlvVyLlE\">2. GROUP BY \u5b50\u53e5<\/h3>\n<p>\u4f7f\u7528 <code>GROUP BY<\/code> \u5b50\u53e5\u53ef\u4ee5\u5c07\u7d50\u679c\u96c6\u6309\u6307\u5b9a\u5217\u9032\u884c\u5206\u7d44\uff0c\u4e26\u4e14\u53ef\u4ee5\u8207\u805a\u5408\u51fd\u6578\u4e00\u8d77\u4f7f\u7528\u4f86\u9032\u4e00\u6b65\u5206\u6790\u6578\u64da\u3002\u4f8b\u5982\uff1a<\/p>\n<pre><code>SELECT column_name, COUNT(*) FROM table_name GROUP BY column_name;<\/code><\/pre>\n<p>\u9019\u6a23\u7684\u67e5\u8a62\u4e0d\u50c5\u80fd\u6d88\u9664\u91cd\u8907\uff0c\u9084\u80fd\u986f\u793a\u6bcf\u500b\u552f\u4e00\u503c\u7684\u51fa\u73fe\u6b21\u6578\u3002<\/p>\n<h3 id=\"3-%e4%bd%bf%e7%94%a8%e5%ad%90%e6%9f%a5%e8%a9%a2-pnSlvVyLlE\">3. \u4f7f\u7528\u5b50\u67e5\u8a62<\/h3>\n<p>\u5728\u67d0\u4e9b\u60c5\u6cc1\u4e0b\uff0c\u4f7f\u7528\u5b50\u67e5\u8a62\u53ef\u4ee5\u66f4\u9748\u6d3b\u5730\u6d88\u9664\u91cd\u8907\u6578\u64da\u3002\u4f8b\u5982\uff1a<\/p>\n<pre><code>SELECT * FROM table_name WHERE id IN (SELECT MIN(id) FROM table_name GROUP BY column_name);<\/code><\/pre>\n<p>\u9019\u689d\u67e5\u8a62\u5c07\u8fd4\u56de\u6bcf\u7d44\u91cd\u8907\u6578\u64da\u4e2d\u7684\u6700\u5c0f ID\uff0c\u5f9e\u800c\u4fdd\u7559\u552f\u4e00\u7684\u6578\u64da\u884c\u3002<\/p>\n<h2 id=\"%e6%95%b8%e6%93%9a%e6%b8%85%e7%90%86%e7%9a%84%e6%9c%80%e4%bd%b3%e5%af%a6%e8%b8%90-pnSlvVyLlE\">\u6578\u64da\u6e05\u7406\u7684\u6700\u4f73\u5be6\u8e10<\/h2>\n<p>\u9664\u4e86\u5728\u67e5\u8a62\u6642\u6d88\u9664\u91cd\u8907\u6578\u64da\uff0c\u9084\u61c9\u5b9a\u671f\u9032\u884c\u6578\u64da\u6e05\u7406\uff0c\u4ee5\u4fdd\u6301\u6578\u64da\u5eab\u7684\u5065\u5eb7\u3002\u4ee5\u4e0b\u662f\u4e00\u4e9b\u6700\u4f73\u5be6\u8e10\uff1a<\/p>\n<ul>\n<li><strong>\u5b9a\u671f\u6aa2\u67e5\u6578\u64da\u5b8c\u6574\u6027\uff1a<\/strong>\u4f7f\u7528\u5de5\u5177\u6216\u8173\u672c\u5b9a\u671f\u6aa2\u67e5\u6578\u64da\u5eab\u4e2d\u7684\u91cd\u8907\u6578\u64da\u3002<\/li>\n<li><strong>\u8a2d\u7f6e\u552f\u4e00\u7d04\u675f\uff1a<\/strong>\u5728\u6578\u64da\u5eab\u8a2d\u8a08\u968e\u6bb5\uff0c\u70ba\u9700\u8981\u552f\u4e00\u6027\u7684\u5217\u8a2d\u7f6e\u552f\u4e00\u7d04\u675f\uff0c\u4ee5\u9632\u6b62\u672a\u4f86\u7684\u91cd\u8907\u6578\u64da\u3002<\/li>\n<li><strong>\u4f7f\u7528\u6578\u64da\u6e05\u7406\u5de5\u5177\uff1a<\/strong>\u8003\u616e\u4f7f\u7528\u5c08\u696d\u7684\u6578\u64da\u6e05\u7406\u5de5\u5177\u4f86\u81ea\u52d5\u5316\u91cd\u8907\u6578\u64da\u7684\u6aa2\u6e2c\u548c\u6e05\u7406\u904e\u7a0b\u3002<\/li>\n<\/ul>\n<h2 id=\"%e7%b5%90%e8%ab%96-pnSlvVyLlE\">\u7d50\u8ad6<\/h2>\n<p>\u6d88\u9664\u91cd\u8907\u6578\u64da\u662f\u6578\u64da\u5eab\u7ba1\u7406\u4e2d\u7684\u4e00\u500b\u91cd\u8981\u65b9\u9762\uff0c\u80fd\u5920\u63d0\u9ad8\u67e5\u8a62\u6548\u7387\u548c\u6578\u64da\u7684\u6e96\u78ba\u6027\u3002\u901a\u904e\u4f7f\u7528 <code>DISTINCT<\/code>\u3001<code>GROUP BY<\/code> \u548c\u5b50\u67e5\u8a62\u7b49\u6280\u5de7\uff0c\u958b\u767c\u8005\u53ef\u4ee5\u6709\u6548\u5730\u7ba1\u7406\u6578\u64da\u5eab\u4e2d\u7684\u91cd\u8907\u6578\u64da\u3002\u6b64\u5916\uff0c\u5b9a\u671f\u9032\u884c\u6578\u64da\u6e05\u7406\u548c\u8a2d\u7f6e\u552f\u4e00\u7d04\u675f\u4e5f\u662f\u4fdd\u6301\u6578\u64da\u5eab\u5065\u5eb7\u7684\u91cd\u8981\u63aa\u65bd\u3002<\/p>\n<p>\u5982\u9700\u4e86\u89e3\u66f4\u591a\u95dc\u65bc\u9ad8\u6548\u6578\u64da\u5eab\u7ba1\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\u7684 <a href=\"https:\/\/server.hk\">VPS<\/a> \u89e3\u6c7a\u65b9\u6848\uff0c\u52a9\u60a8\u63d0\u5347\u6578\u64da\u8655\u7406\u6548\u7387\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u638c\u63e1\u9ad8\u6548\u67e5\u8a62\u6280\u5de7\uff0c\u5b78\u7fd2\u5982\u4f55\u5728\u6578\u64da\u5eab\u4e2d\u6d88\u9664\u91cd\u8907\u8a9e\u53e5\uff0c\u63d0\u5347\u6578\u64da\u8655\u7406\u6548\u7387\uff0c\u907f\u514d\u5197\u9918\u4fe1\u606f\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-157834","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/157834","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=157834"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/157834\/revisions"}],"predecessor-version":[{"id":157835,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/157834\/revisions\/157835"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=157834"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=157834"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=157834"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}