{"id":80132,"date":"2024-10-16T13:57:18","date_gmt":"2024-10-16T05:57:18","guid":{"rendered":"https:\/\/server.hk\/cnblog\/80132\/"},"modified":"2024-10-16T13:57:18","modified_gmt":"2024-10-16T05:57:18","slug":"mysql%e6%8c%87%e4%bb%a4-unique%ef%bc%88%e5%94%af%e4%b8%80%ef%bc%89","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/80132\/","title":{"rendered":"MySQL\u6307\u4ee4: UNIQUE\uff08\u552f\u4e00\uff09"},"content":{"rendered":"<h1 id=\"mysql%e6%8c%87%e4%bb%a4-unique%ef%bc%88%e5%94%af%e4%b8%80%ef%bc%89-GGmhxwsPFc\">MySQL\u6307\u4ee4: UNIQUE\uff08\u552f\u4e00\uff09<\/h1>\n<p>\u5728\u8cc7\u6599\u5eab\u7ba1\u7406\u7cfb\u7d71\u4e2d\uff0c\u78ba\u4fdd\u6578\u64da\u7684\u5b8c\u6574\u6027\u548c\u4e00\u81f4\u6027\u662f\u81f3\u95dc\u91cd\u8981\u7684\u3002MySQL\u4f5c\u70ba\u4e00\u500b\u6d41\u884c\u7684\u958b\u6e90\u8cc7\u6599\u5eab\u7cfb\u7d71\uff0c\u63d0\u4f9b\u4e86\u591a\u7a2e\u5de5\u5177\u4f86\u5e6b\u52a9\u958b\u767c\u8005\u7ba1\u7406\u6578\u64da\u3002\u5176\u4e2d\uff0c<code>UNIQUE<\/code>\u7d04\u675f\u662f\u4e00\u500b\u91cd\u8981\u7684\u529f\u80fd\uff0c\u80fd\u5920\u78ba\u4fdd\u67d0\u4e00\u5217\u6216\u591a\u5217\u7684\u6578\u64da\u5728\u8cc7\u6599\u8868\u4e2d\u662f\u552f\u4e00\u7684\u3002\u672c\u6587\u5c07\u6df1\u5165\u63a2\u8a0e<code>UNIQUE<\/code>\u7d04\u675f\u7684\u4f7f\u7528\u65b9\u6cd5\u53ca\u5176\u5728\u5be6\u969b\u61c9\u7528\u4e2d\u7684\u91cd\u8981\u6027\u3002<\/p>\n<h2 id=\"%e4%bb%80%e9%ba%bc%e6%98%afunique%e7%b4%84%e6%9d%9f%ef%bc%9f-GGmhxwsPFc\">\u4ec0\u9ebc\u662fUNIQUE\u7d04\u675f\uff1f<\/h2>\n<p><code>UNIQUE<\/code>\u7d04\u675f\u662f\u4e00\u7a2e\u8cc7\u6599\u5eab\u7d04\u675f\uff0c\u7528\u65bc\u78ba\u4fdd\u67d0\u4e00\u5217\u6216\u591a\u5217\u7684\u503c\u5728\u8cc7\u6599\u8868\u4e2d\u662f\u552f\u4e00\u7684\u3002\u9019\u610f\u5473\u8457\u5728\u540c\u4e00\u8cc7\u6599\u8868\u4e2d\uff0c\u4e0d\u80fd\u6709\u5169\u884c\u64c1\u6709\u76f8\u540c\u7684\u503c\u3002\u9019\u5c0d\u65bc\u9700\u8981\u552f\u4e00\u6a19\u8b58\u7684\u6578\u64da\uff08\u4f8b\u5982\u7528\u6236\u540d\u3001\u96fb\u5b50\u90f5\u4ef6\u5730\u5740\u7b49\uff09\u7279\u5225\u91cd\u8981\u3002<\/p>\n<h2 id=\"unique%e7%b4%84%e6%9d%9f%e7%9a%84%e8%aa%9e%e6%b3%95-GGmhxwsPFc\">UNIQUE\u7d04\u675f\u7684\u8a9e\u6cd5<\/h2>\n<p>\u5728MySQL\u4e2d\uff0c<code>UNIQUE<\/code>\u7d04\u675f\u53ef\u4ee5\u5728\u5275\u5efa\u8cc7\u6599\u8868\u6642\u5b9a\u7fa9\uff0c\u4e5f\u53ef\u4ee5\u5728\u8cc7\u6599\u8868\u5df2\u5b58\u5728\u7684\u60c5\u6cc1\u4e0b\u6dfb\u52a0\u3002\u4ee5\u4e0b\u662f\u5169\u7a2e\u5e38\u898b\u7684\u8a9e\u6cd5\uff1a<\/p>\n<h3 id=\"1-%e5%89%b5%e5%bb%ba%e8%b3%87%e6%96%99%e8%a1%a8%e6%99%82%e5%ae%9a%e7%be%a9unique%e7%b4%84%e6%9d%9f-GGmhxwsPFc\">1. \u5275\u5efa\u8cc7\u6599\u8868\u6642\u5b9a\u7fa9UNIQUE\u7d04\u675f<\/h3>\n<pre><code>CREATE TABLE users (\n    id INT AUTO_INCREMENT PRIMARY KEY,\n    username VARCHAR(50) NOT NULL,\n    email VARCHAR(100) NOT NULL,\n    UNIQUE (username),\n    UNIQUE (email)\n);<\/code><\/pre>\n<p>\u5728\u9019\u500b\u4f8b\u5b50\u4e2d\uff0c<code>username<\/code>\u548c<code>email<\/code>\u5217\u90fd\u88ab\u8a2d\u7f6e\u70ba\u552f\u4e00\uff0c\u9019\u610f\u5473\u8457\u6bcf\u500b\u7528\u6236\u7684\u7528\u6236\u540d\u548c\u96fb\u5b50\u90f5\u4ef6\u5730\u5740\u5fc5\u9808\u662f\u7368\u7279\u7684\u3002<\/p>\n<h3 id=\"2-%e5%9c%a8%e5%b7%b2%e5%ad%98%e5%9c%a8%e7%9a%84%e8%b3%87%e6%96%99%e8%a1%a8%e4%b8%ad%e6%b7%bb%e5%8a%a0unique%e7%b4%84%e6%9d%9f-GGmhxwsPFc\">2. \u5728\u5df2\u5b58\u5728\u7684\u8cc7\u6599\u8868\u4e2d\u6dfb\u52a0UNIQUE\u7d04\u675f<\/h3>\n<pre><code>ALTER TABLE users\nADD UNIQUE (username);<\/code><\/pre>\n<p>\u9019\u689d\u6307\u4ee4\u5c07\u5728\u5df2\u5b58\u5728\u7684<code>users<\/code>\u8cc7\u6599\u8868\u4e2d\u70ba<code>username<\/code>\u5217\u6dfb\u52a0\u552f\u4e00\u7d04\u675f\u3002<\/p>\n<h2 id=\"unique%e7%b4%84%e6%9d%9f%e7%9a%84%e7%89%b9%e9%bb%9e-GGmhxwsPFc\">UNIQUE\u7d04\u675f\u7684\u7279\u9ede<\/h2>\n<ul>\n<li><strong>\u5141\u8a31NULL\u503c\uff1a<\/strong>\u5728MySQL\u4e2d\uff0c<code>UNIQUE<\/code>\u7d04\u675f\u5141\u8a31NULL\u503c\uff0c\u4e26\u4e14\u591a\u500bNULL\u503c\u88ab\u8996\u70ba\u552f\u4e00\u3002<\/li>\n<li><strong>\u591a\u5217\u552f\u4e00\u7d04\u675f\uff1a<\/strong>\u53ef\u4ee5\u5728\u591a\u5217\u4e0a\u5b9a\u7fa9<code>UNIQUE<\/code>\u7d04\u675f\uff0c\u9019\u6a23\u53ea\u6709\u7576\u6240\u6709\u5217\u7684\u7d44\u5408\u662f\u552f\u4e00\u6642\uff0c\u8a72\u884c\u624d\u88ab\u5141\u8a31\u3002<\/li>\n<li><strong>\u6027\u80fd\u5f71\u97ff\uff1a<\/strong>\u96d6\u7136<code>UNIQUE<\/code>\u7d04\u675f\u80fd\u5920\u63d0\u9ad8\u6578\u64da\u7684\u5b8c\u6574\u6027\uff0c\u4f46\u5728\u63d2\u5165\u6216\u66f4\u65b0\u6578\u64da\u6642\uff0c\u53ef\u80fd\u6703\u5c0d\u6027\u80fd\u7522\u751f\u5f71\u97ff\uff0c\u56e0\u70ba\u7cfb\u7d71\u9700\u8981\u6aa2\u67e5\u552f\u4e00\u6027\u3002<\/li>\n<\/ul>\n<h2 id=\"%e5%af%a6%e9%9a%9b%e6%87%89%e7%94%a8%e4%b8%ad%e7%9a%84%e4%be%8b%e5%ad%90-GGmhxwsPFc\">\u5be6\u969b\u61c9\u7528\u4e2d\u7684\u4f8b\u5b50<\/h2>\n<p>\u5047\u8a2d\u6211\u5011\u6b63\u5728\u958b\u767c\u4e00\u500b\u96fb\u5b50\u5546\u52d9\u7db2\u7ad9\uff0c\u4e26\u9700\u8981\u78ba\u4fdd\u6bcf\u4f4d\u7528\u6236\u7684\u96fb\u5b50\u90f5\u4ef6\u5730\u5740\u662f\u552f\u4e00\u7684\u3002\u4f7f\u7528<code>UNIQUE<\/code>\u7d04\u675f\u53ef\u4ee5\u9632\u6b62\u7528\u6236\u8a3b\u518a\u6642\u4f7f\u7528\u91cd\u8907\u7684\u96fb\u5b50\u90f5\u4ef6\u5730\u5740\uff0c\u5f9e\u800c\u63d0\u9ad8\u7528\u6236\u9ad4\u9a57\u548c\u6578\u64da\u7684\u5b8c\u6574\u6027\u3002<\/p>\n<pre><code>CREATE TABLE customers (\n    customer_id INT AUTO_INCREMENT PRIMARY KEY,\n    name VARCHAR(100) NOT NULL,\n    email VARCHAR(100) NOT NULL,\n    UNIQUE (email)\n);<\/code><\/pre>\n<p>\u5728\u9019\u500b\u4f8b\u5b50\u4e2d\uff0c<code>email<\/code>\u5217\u88ab\u8a2d\u7f6e\u70ba\u552f\u4e00\uff0c\u9019\u6a23\u7cfb\u7d71\u5c31\u80fd\u5920\u81ea\u52d5\u963b\u6b62\u91cd\u8907\u7684\u96fb\u5b50\u90f5\u4ef6\u5730\u5740\u9032\u5165\u8cc7\u6599\u5eab\u3002<\/p>\n<h2 id=\"%e7%b8%bd%e7%b5%90-GGmhxwsPFc\">\u7e3d\u7d50<\/h2>\n<p>MySQL\u4e2d\u7684<code>UNIQUE<\/code>\u7d04\u675f\u662f\u4e00\u500b\u5f37\u5927\u7684\u5de5\u5177\uff0c\u80fd\u5920\u5e6b\u52a9\u958b\u767c\u8005\u78ba\u4fdd\u8cc7\u6599\u7684\u552f\u4e00\u6027\u548c\u5b8c\u6574\u6027\u3002\u7121\u8ad6\u662f\u5728\u5275\u5efa\u8cc7\u6599\u8868\u6642\u9084\u662f\u5728\u5f8c\u671f\u4fee\u6539\u8cc7\u6599\u8868\u7d50\u69cb\u6642\uff0c<code>UNIQUE<\/code>\u7d04\u675f\u90fd\u80fd\u5920\u6709\u6548\u5730\u9632\u6b62\u91cd\u8907\u6578\u64da\u7684\u51fa\u73fe\u3002\u5c0d\u65bc\u9700\u8981\u4fdd\u6301\u6578\u64da\u4e00\u81f4\u6027\u7684\u61c9\u7528\u5834\u666f\uff0c<code>UNIQUE<\/code>\u7d04\u675f\u662f\u4e0d\u53ef\u6216\u7f3a\u7684\u3002<\/p>\n<p>\u5982\u679c\u60a8\u6b63\u5728\u5c0b\u627e\u9ad8\u6548\u7684 <a href=\"https:\/\/server.hk\">VPS<\/a> \u89e3\u6c7a\u65b9\u6848\u4f86\u904b\u884c\u60a8\u7684MySQL\u8cc7\u6599\u5eab\uff0cServer.HK\u63d0\u4f9b\u4e86\u591a\u7a2e\u9078\u64c7\uff0c\u9069\u5408\u5404\u7a2e\u9700\u6c42\u3002\u7121\u8ad6\u662f <a href=\"https:\/\/server.hk\">\u9999\u6e2fVPS<\/a> \u9084\u662f\u5176\u4ed6\u985e\u578b\u7684 <a href=\"https:\/\/server.hk\">\u4f3a\u670d\u5668<\/a>\uff0c\u6211\u5011\u90fd\u80fd\u70ba\u60a8\u63d0\u4f9b\u7a69\u5b9a\u7684\u652f\u6301\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u4e86\u89e3MySQL\u4e2d\u7684UNIQUE\u6307\u4ee4\uff0c\u786e\u4fdd\u6570\u636e\u8868\u4e2d\u67d0\u5217\u7684\u503c\u552f\u4e00\uff0c\u907f\u514d\u91cd\u590d\u6570\u636e\uff0c\u63d0\u9ad8\u6570\u636e\u5b8c\u6574\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-80132","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/80132","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=80132"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/80132\/revisions"}],"predecessor-version":[{"id":80133,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/80132\/revisions\/80133"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=80132"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=80132"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=80132"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}