{"id":217781,"date":"2023-12-23T00:09:26","date_gmt":"2023-12-22T16:09:26","guid":{"rendered":"https:\/\/www.idc.net\/help\/217781\/"},"modified":"2023-12-23T00:09:26","modified_gmt":"2023-12-22T16:09:26","slug":"mysql%e4%bd%bf%e7%94%a8%e6%89%8b%e5%86%8c%ef%bc%9a%e4%bd%bf%e7%94%a8distinct%e5%85%b3%e9%94%ae%e5%ad%97%e4%bb%85%e8%bf%94%e5%9b%9e%e4%b8%8d%e5%90%8c%e7%9a%84%ef%bc%88%e5%94%af%e4%b8%80%e7%9a%84","status":"publish","type":"post","link":"https:\/\/idc.net\/help\/217781\/","title":{"rendered":"MySQL\u4f7f\u7528\u624b\u518c\uff1a\u4f7f\u7528DISTINCT\u5173\u952e\u5b57\u4ec5\u8fd4\u56de\u4e0d\u540c\u7684\uff08\u552f\u4e00\u7684\uff09\u503c"},"content":{"rendered":"<p><title id=\"mysql%e4%bd%bf%e7%94%a8%e6%89%8b%e5%86%8c%ef%bc%9a%e4%bd%bf%e7%94%a8distinct%e5%85%b3%e9%94%ae%e5%ad%97%e4%bb%85%e8%bf%94%e5%9b%9e%e4%b8%8d%e5%90%8c%e7%9a%84%ef%bc%88%e5%94%af%e4%b8%80%e7%9a%84-fSDqCuiqhs\">MySQL\u4f7f\u7528\u624b\u518c\uff1a\u4f7f\u7528DISTINCT\u5173\u952e\u5b57\u4ec5\u8fd4\u56de\u4e0d\u540c\u7684\uff08\u552f\u4e00\u7684\uff09\u503c<\/title><\/p>\n<h1 id=\"mysql%e4%bd%bf%e7%94%a8%e6%89%8b%e5%86%8c%ef%bc%9a%e4%bd%bf%e7%94%a8distinct%e5%85%b3%e9%94%ae%e5%ad%97%e4%bb%85%e8%bf%94%e5%9b%9e%e4%b8%8d%e5%90%8c%e7%9a%84%ef%bc%88%e5%94%af%e4%b8%80%e7%9a%84-fSDqCuiqhs\">MySQL\u4f7f\u7528\u624b\u518c\uff1a\u4f7f\u7528DISTINCT\u5173\u952e\u5b57\u4ec5\u8fd4\u56de\u4e0d\u540c\u7684\uff08\u552f\u4e00\u7684\uff09\u503c<\/h1>\n<p>\u5728MySQL\u4e2d\uff0cDISTINCT\u5173\u952e\u5b57\u7528\u4e8e\u4ece\u67e5\u8be2\u7ed3\u679c\u4e2d\u4ec5\u8fd4\u56de\u4e0d\u540c\u7684\uff08\u552f\u4e00\u7684\uff09\u503c\u3002\u5f53\u6211\u4eec\u9700\u8981\u4ece\u6570\u636e\u5e93\u4e2d\u83b7\u53d6\u67d0\u4e2a\u5217\u7684\u552f\u4e00\u503c\u65f6\uff0c\u53ef\u4ee5\u4f7f\u7528DISTINCT\u5173\u952e\u5b57\u6765\u5b9e\u73b0\u3002<\/p>\n<h2 id=\"%e4%bd%bf%e7%94%a8distinct%e5%85%b3%e9%94%ae%e5%ad%97%e7%9a%84%e8%af%ad%e6%b3%95-fSDqCuiqhs\">\u4f7f\u7528DISTINCT\u5173\u952e\u5b57\u7684\u8bed\u6cd5<\/h2>\n<p>\u4f7f\u7528DISTINCT\u5173\u952e\u5b57\u7684\u57fa\u672c\u8bed\u6cd5\u5982\u4e0b\uff1a<\/p>\n<pre><code>SELECT DISTINCT \u5217\u540d FROM \u8868\u540d;<\/code><\/pre>\n<p>\u5176\u4e2d\uff0c\u5217\u540d\u662f\u8981\u83b7\u53d6\u552f\u4e00\u503c\u7684\u5217\u7684\u540d\u79f0\uff0c\u8868\u540d\u662f\u8981\u67e5\u8be2\u7684\u8868\u7684\u540d\u79f0\u3002<\/p>\n<h2 id=\"%e4%bd%bf%e7%94%a8distinct%e5%85%b3%e9%94%ae%e5%ad%97%e7%9a%84%e7%a4%ba%e4%be%8b-fSDqCuiqhs\">\u4f7f\u7528DISTINCT\u5173\u952e\u5b57\u7684\u793a\u4f8b<\/h2>\n<p>\u5047\u8bbe\u6211\u4eec\u6709\u4e00\u4e2a\u540d\u4e3a\"customers\"\u7684\u8868\uff0c\u5176\u4e2d\u5305\u542b\u4e86\u5ba2\u6237\u7684\u59d3\u540d\u548c\u57ce\u5e02\u4fe1\u606f\u3002\u6211\u4eec\u60f3\u8981\u83b7\u53d6\u6240\u6709\u4e0d\u540c\u7684\u57ce\u5e02\u540d\u79f0\uff0c\u53ef\u4ee5\u4f7f\u7528\u4ee5\u4e0b\u67e5\u8be2\u8bed\u53e5\uff1a<\/p>\n<pre><code>SELECT DISTINCT city FROM customers;<\/code><\/pre>\n<p>\u8fd9\u5c06\u8fd4\u56de\u4e00\u4e2a\u5305\u542b\u6240\u6709\u4e0d\u540c\u57ce\u5e02\u540d\u79f0\u7684\u7ed3\u679c\u96c6\u3002<\/p>\n<h2 id=\"%e4%bd%bf%e7%94%a8distinct%e5%85%b3%e9%94%ae%e5%ad%97%e7%9a%84%e6%b3%a8%e6%84%8f%e4%ba%8b%e9%a1%b9-fSDqCuiqhs\">\u4f7f\u7528DISTINCT\u5173\u952e\u5b57\u7684\u6ce8\u610f\u4e8b\u9879<\/h2>\n<p>\u5728\u4f7f\u7528DISTINCT\u5173\u952e\u5b57\u65f6\uff0c\u9700\u8981\u6ce8\u610f\u4ee5\u4e0b\u51e0\u70b9\uff1a<\/p>\n<ul>\n<li>\u53ea\u80fd\u7528\u4e8eSELECT\u8bed\u53e5\u3002<\/li>\n<li>DISTINCT\u5173\u952e\u5b57\u4f5c\u7528\u4e8e\u6240\u6709\u5217\uff0c\u800c\u4e0d\u4ec5\u4ec5\u662f\u6307\u5b9a\u7684\u5217\u3002<\/li>\n<li>\u5982\u679c\u6307\u5b9a\u7684\u5217\u5305\u542bNULL\u503c\uff0c\u90a3\u4e48DISTINCT\u5173\u952e\u5b57\u5c06\u4f1a\u8fd4\u56de\u4e00\u4e2aNULL\u503c\u3002<\/li>\n<\/ul>\n<h2 id=\"%e4%bd%bf%e7%94%a8distinct%e5%85%b3%e9%94%ae%e5%ad%97%e7%9a%84%e5%ae%9e%e9%99%85%e5%ba%94%e7%94%a8-fSDqCuiqhs\">\u4f7f\u7528DISTINCT\u5173\u952e\u5b57\u7684\u5b9e\u9645\u5e94\u7528<\/h2>\n<p>\u4f7f\u7528DISTINCT\u5173\u952e\u5b57\u53ef\u4ee5\u89e3\u51b3\u8bb8\u591a\u5b9e\u9645\u95ee\u9898\u3002\u4ee5\u4e0b\u662f\u4e00\u4e9b\u5e38\u89c1\u7684\u5e94\u7528\u573a\u666f\uff1a<\/p>\n<ol>\n<li>\u83b7\u53d6\u552f\u4e00\u7684\u4ea7\u54c1\u7c7b\u522b\u5217\u8868\u3002<\/li>\n<li>\u7edf\u8ba1\u4e0d\u540c\u57ce\u5e02\u7684\u5ba2\u6237\u6570\u91cf\u3002<\/li>\n<li>\u67e5\u627e\u552f\u4e00\u7684\u90ae\u653f\u7f16\u7801\u3002<\/li>\n<\/ol>\n<p>\u901a\u8fc7\u4f7f\u7528DISTINCT\u5173\u952e\u5b57\uff0c\u6211\u4eec\u53ef\u4ee5\u8f7b\u677e\u5730\u4ece\u6570\u636e\u5e93\u4e2d\u83b7\u53d6\u552f\u4e00\u7684\u503c\uff0c\u4ece\u800c\u66f4\u597d\u5730\u5206\u6790\u548c\u5904\u7406\u6570\u636e\u3002<\/p>\n<h2 id=\"%e6%80%bb%e7%bb%93-fSDqCuiqhs\">\u603b\u7ed3<\/h2>\n<p>\u4f7f\u7528MySQL\u7684DISTINCT\u5173\u952e\u5b57\u53ef\u4ee5\u4ece\u67e5\u8be2\u7ed3\u679c\u4e2d\u4ec5\u8fd4\u56de\u4e0d\u540c\u7684\uff08\u552f\u4e00\u7684\uff09\u503c\u3002\u5b83\u662f\u4e00\u4e2a\u975e\u5e38\u6709\u7528\u7684\u5de5\u5177\uff0c\u53ef\u4ee5\u5e2e\u52a9\u6211\u4eec\u5904\u7406\u548c\u5206\u6790\u6570\u636e\u5e93\u4e2d\u7684\u6570\u636e\u3002\u65e0\u8bba\u662f\u83b7\u53d6\u552f\u4e00\u7684\u4ea7\u54c1\u7c7b\u522b\u5217\u8868\u8fd8\u662f\u7edf\u8ba1\u4e0d\u540c\u57ce\u5e02\u7684\u5ba2\u6237\u6570\u91cf\uff0cDISTINCT\u5173\u952e\u5b57\u90fd\u80fd\u591f\u63d0\u4f9b\u4fbf\u6377\u7684\u89e3\u51b3\u65b9\u6848\u3002<\/p>\n<p>\u5982\u679c\u60a8\u6b63\u5728\u5bfb\u627e\u9ad8\u8d28\u91cf\u7684\u9999\u6e2f\u670d\u52a1\u5668\uff0c\u540e\u6d6a\u4e91\u662f\u60a8\u7684\u9996\u9009\u3002\u6211\u4eec\u63d0\u4f9b\u53ef\u9760\u7a33\u5b9a\u7684\u9999\u6e2f\u670d\u52a1\u5668\uff0c\u4ee5\u53ca\u5176\u4ed6\u591a\u79cd\u670d\u52a1\u5668\u9009\u62e9\u3002\u8bf7\u8bbf\u95ee\u6211\u4eec\u7684\u5b98\u7f51\u4e86\u89e3\u66f4\u591a\u4fe1\u606f\uff1a<a href=\"https:\/\/idc.net\">https:\/\/idc.net<\/a>\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>MySQL\u4f7f\u7528\u624b\u518c\uff1a\u4f7f\u7528DISTINCT\u5173\u952e\u5b57\u4ec5\u8fd4\u56de\u4e0d\u540c\u7684\uff08\u552f\u4e00\u7684\uff09\u503c MySQL\u4f7f\u7528\u624b\u518c\uff1a\u4f7f\u7528DISTINC [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[197851],"tags":[],"class_list":["post-217781","post","type-post","status-publish","format-standard","hentry","category-php"],"_links":{"self":[{"href":"https:\/\/idc.net\/help\/wp-json\/wp\/v2\/posts\/217781","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/idc.net\/help\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/idc.net\/help\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/idc.net\/help\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/idc.net\/help\/wp-json\/wp\/v2\/comments?post=217781"}],"version-history":[{"count":0,"href":"https:\/\/idc.net\/help\/wp-json\/wp\/v2\/posts\/217781\/revisions"}],"wp:attachment":[{"href":"https:\/\/idc.net\/help\/wp-json\/wp\/v2\/media?parent=217781"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/idc.net\/help\/wp-json\/wp\/v2\/categories?post=217781"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/idc.net\/help\/wp-json\/wp\/v2\/tags?post=217781"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}