{"id":200049,"date":"2025-05-06T12:14:19","date_gmt":"2025-05-06T04:14:19","guid":{"rendered":"https:\/\/server.hk\/cnblog\/200049\/"},"modified":"2025-05-06T12:14:19","modified_gmt":"2025-05-06T04:14:19","slug":"%e4%bd%bf%e7%94%a8mysql%e4%b8%adunique%e7%b4%a2%e5%bc%95%e7%9a%84%e6%8a%80%e5%b7%a7%e5%92%8c%e8%a7%a3%e5%86%b3%e5%b8%b8%e8%a7%81%e9%97%ae%e9%a2%98","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/200049\/","title":{"rendered":"\u4f7f\u7528MySQL\u4e2dunique\u7d22\u5f15\u7684\u6280\u5de7\u548c\u89e3\u51b3\u5e38\u89c1\u95ee\u9898"},"content":{"rendered":"

<\/b> <\/p>\n

\u4f7f\u7528MySQL\u4e2dunique\u7d22\u5f15\u7684\u6280\u5de7\u548c\u89e3\u51b3\u5e38\u89c1\u95ee\u9898<\/h1>\n

\u54c8\u55bd\uff01\u5927\u5bb6\u597d\uff0c\u5f88\u9ad8\u5174\u53c8\u89c1\u9762\u4e86\uff0c\u6211\u662f\u4e3b\u673a\u5b9d\u8d1d\u7684\u4e00\u540d\u4f5c\u8005\uff0c\u4eca\u5929\u7531\u6211\u7ed9\u5927\u5bb6\u5e26\u6765\u4e00\u7bc7\uff0c\u672c\u6587\u4e3b\u8981\u4f1a\u8bb2\u5230\u7b49\u7b49\u77e5\u8bc6\u70b9\uff0c\u5e0c\u671b\u5927\u5bb6\u4e00\u8d77\u5b66\u4e60\u8fdb\u6b65\uff0c\u4e5f\u6b22\u8fce\u5927\u5bb6\u5173\u6ce8\u3001\u70b9\u8d5e\u3001\u6536\u85cf\u3001\u8f6c\u53d1! \u4e0b\u9762\u5c31\u4e00\u8d77\u6765\u770b\u770b\u5427\uff01<\/p>\n

MySQL\u4e2dunique\u7d22\u5f15\u7684\u4f7f\u7528\u6280\u5de7\u4e0e\u5e38\u89c1\u95ee\u9898\u89e3\u7b54<\/p>\n

MySQL\u662f\u4e00\u79cd\u6d41\u884c\u7684\u5173\u7cfb\u578b\u6570\u636e\u5e93\u7ba1\u7406\u7cfb\u7edf\uff0c\u5728\u5b9e\u9645\u5e94\u7528\u4e2d\uff0c\u552f\u4e00\u7d22\u5f15\uff08unique index\uff09\u5728\u6570\u636e\u8868\u8bbe\u8ba1\u4e2d\u8d77\u7740\u81f3\u5173\u91cd\u8981\u7684\u4f5c\u7528\u3002\u552f\u4e00\u7d22\u5f15\u80fd\u591f\u786e\u4fdd\u8868\u4e2d\u67d0\u4e00\u5217\u7684\u6570\u503c\u552f\u4e00\uff0c\u907f\u514d\u51fa\u73b0\u91cd\u590d\u6570\u636e\u3002\u672c\u6587\u5c06\u4ecb\u7ecdMySQL\u4e2dunique\u7d22\u5f15\u7684\u4f7f\u7528\u6280\u5de7\u4ee5\u53ca\u4e00\u4e9b\u5e38\u89c1\u95ee\u9898\u7684\u89e3\u7b54\uff0c\u5e76\u63d0\u4f9b\u5177\u4f53\u7684\u4ee3\u7801\u793a\u4f8b\u6765\u5e2e\u52a9\u8bfb\u8005\u66f4\u597d\u5730\u7406\u89e3\u3002<\/p>\n

1. \u521b\u5efa\u552f\u4e00\u7d22\u5f15<\/h3>\n

\u5728MySQL\u4e2d\uff0c\u53ef\u4ee5\u4f7f\u7528\u4ee5\u4e0b\u8bed\u6cd5\u521b\u5efa\u552f\u4e00\u7d22\u5f15\uff1a<\/p>\n

CREATE TABLE table_name (\n    column1 datatype,\n    column2 datatype,\n    ...\n    UNIQUE KEY unique_index_name (column_name)\n);<\/pre>\n
\u5728\u4e0a\u8ff0\u4ee3\u7801\u4e2d\uff0ctable_name<\/code>\u662f\u6570\u636e\u8868\u7684\u540d\u79f0\uff0ccolumn1<\/code>, column2<\/code>\u7b49\u662f\u8868\u4e2d\u7684\u5217\u540d\uff0cunique_index_name<\/code>\u662f\u552f\u4e00\u7d22\u5f15\u7684\u540d\u79f0\uff0ccolumn_name<\/code>\u662f\u9700\u8981\u8bbe\u7f6e\u4e3a\u552f\u4e00\u7d22\u5f15\u7684\u5217\u540d\u3002\u4e0b\u9762\u662f\u4e00\u4e2a\u793a\u4f8b\uff1a<\/p>\n
CREATE TABLE users (\n    id INT PRIMARY KEY,\n    username VARCHAR(50) UNIQUE,\n    email VARCHAR(50) UNIQUE\n);<\/pre>\n
\u5728\u4e0a\u9762\u7684\u793a\u4f8b\u4e2d\uff0cusername<\/code>\u548cemail<\/code>\u5217\u5206\u522b\u88ab\u8bbe\u7f6e\u4e3a\u552f\u4e00\u7d22\u5f15\uff0c\u786e\u4fdd\u7528\u6237\u540d\u548c\u90ae\u7bb1\u5730\u5740\u5728\u8868\u4e2d\u662f\u552f\u4e00\u7684\u3002<\/p>\n
2. \u63d2\u5165\u6570\u636e<\/h3>\n
\u5f53\u5411\u8868\u4e2d\u63d2\u5165\u6570\u636e\u65f6\uff0c\u5982\u679c\u8fdd\u53cd\u4e86\u552f\u4e00\u7d22\u5f15\u7684\u7ea6\u675f\u6761\u4ef6\uff0cMySQL\u5c06\u4f1a\u629b\u51fa\u9519\u8bef\u3002\u4f8b\u5982\uff0c\u5982\u679c\u5c1d\u8bd5\u63d2\u5165\u4e00\u4e2a\u5df2\u7ecf\u5b58\u5728\u7684\u7528\u6237\u540d\uff0c\u4f1a\u5bfc\u81f4\u552f\u4e00\u7d22\u5f15\u7ea6\u675f\u7684\u9519\u8bef\u3002\u4e0b\u9762\u662f\u4e00\u4e2a\u4f8b\u5b50\uff1a<\/p>\n
INSERT INTO users (id, username, email) VALUES (1, 'john_doe', 'john@example.com');\nINSERT INTO users (id, username, email) VALUES (2, 'john_doe', 'johndoe@example.com'); -- \u8fd9\u91cc\u4f1a\u62a5\u9519<\/pre>\n
\u5728\u4e0a\u8ff0\u4ee3\u7801\u4e2d\uff0c\u7b2c\u4e8c\u6761\u63d2\u5165\u8bed\u53e5\u5c1d\u8bd5\u63d2\u5165\u4e00\u4e2a\u91cd\u590d\u7684\u7528\u6237\u540djohn_doe<\/code>\uff0c\u56e0\u6b64\u4f1a\u5bfc\u81f4\u552f\u4e00\u7d22\u5f15\u7684\u9519\u8bef\u3002<\/p>\n
3. \u67e5\u8be2\u6570\u636e<\/h3>\n
\u6709\u65f6\u5019\u6211\u4eec\u9700\u8981\u67e5\u8be2\u552f\u4e00\u7d22\u5f15\u7684\u6570\u636e\uff0c\u53ef\u4ee5\u4f7f\u7528SELECT<\/code>\u8bed\u53e5\u7ed3\u5408WHERE<\/code>\u5b50\u53e5\u8fdb\u884c\u67e5\u8be2\u3002\u4e0b\u9762\u662f\u4e00\u4e2a\u793a\u4f8b\uff1a<\/p>\n
SELECT * FROM users WHERE email = 'john@example.com';<\/pre>\n
\u4e0a\u9762\u7684\u4ee3\u7801\u5c06\u8fd4\u56de\u90ae\u7bb1\u5730\u5740\u4e3ajohn@example.com<\/code>\u7684\u7528\u6237\u4fe1\u606f\u3002<\/p>\n
\u5e38\u89c1\u95ee\u9898\u89e3\u7b54<\/h3>\n
1. \u5982\u4f55\u5220\u9664\u552f\u4e00\u7d22\u5f15\uff1f<\/strong><\/p>\n
\u8981\u5220\u9664\u552f\u4e00\u7d22\u5f15\uff0c\u53ef\u4ee5\u4f7f\u7528\u4ee5\u4e0b\u8bed\u6cd5\uff1a<\/p>\n
ALTER TABLE table_name DROP INDEX unique_index_name;<\/pre>\n
\u4f8b\u5982\uff0c\u8981\u5220\u9664users<\/code>\u8868\u4e2d\u540d\u4e3ausername<\/code>\u7684\u552f\u4e00\u7d22\u5f15\uff0c\u53ef\u4ee5\u6267\u884c\u4ee5\u4e0b\u8bed\u53e5\uff1a<\/p>\n
ALTER TABLE users DROP INDEX username;<\/pre>\n
2. \u552f\u4e00\u7d22\u5f15\u7684\u6027\u80fd\u5f71\u54cd\uff1f<\/strong><\/p>\n
\u552f\u4e00\u7d22\u5f15\u7684\u5b58\u5728\u4f1a\u5728\u63d2\u5165\u3001\u66f4\u65b0\u548c\u5220\u9664\u6570\u636e\u65f6\u589e\u52a0\u4e00\u4e9b\u6027\u80fd\u5f00\u9500\uff0c\u56e0\u4e3aMySQL\u9700\u8981\u786e\u4fdd\u7d22\u5f15\u7684\u552f\u4e00\u6027\u7ea6\u675f\u3002\u56e0\u6b64\uff0c\u5728\u8bbe\u8ba1\u6570\u636e\u8868\u65f6\uff0c\u9700\u8981\u6743\u8861\u6570\u636e\u7684\u552f\u4e00\u6027\u4e0e\u6027\u80fd\u4e4b\u95f4\u7684\u5173\u7cfb\u3002<\/p>\n
3. \u5982\u4f55\u5904\u7406\u552f\u4e00\u7d22\u5f15\u9519\u8bef\uff1f<\/strong><\/p>\n
\u5f53\u552f\u4e00\u7d22\u5f15\u7684\u7ea6\u675f\u6761\u4ef6\u88ab\u8fdd\u53cd\u65f6\uff0cMySQL\u4f1a\u629b\u51fa\u9519\u8bef\u3002\u5f00\u53d1\u4eba\u5458\u53ef\u4ee5\u6355\u83b7\u8fd9\u4e9b\u9519\u8bef\u5e76\u6839\u636e\u5177\u4f53\u60c5\u51b5\u8fdb\u884c\u5904\u7406\uff0c\u4f8b\u5982\u63d0\u9192\u7528\u6237\u91cd\u65b0\u8f93\u5165\u6570\u636e\u6216\u8005\u8fdb\u884c\u5f02\u5e38\u5904\u7406\u3002<\/p>\n
\u7efc\u4e0a\u6240\u8ff0\uff0cMySQL\u4e2d\u552f\u4e00\u7d22\u5f15\u662f\u786e\u4fdd\u6570\u636e\u552f\u4e00\u6027\u7684\u91cd\u8981\u673a\u5236\uff0c\u5408\u7406\u8bbe\u8ba1\u548c\u4f7f\u7528\u552f\u4e00\u7d22\u5f15\u5bf9\u4e8e\u4fdd\u8bc1\u6570\u636e\u4e00\u81f4\u6027\u548c\u5b8c\u6574\u6027\u975e\u5e38\u91cd\u8981\u3002\u5728\u5b9e\u9645\u5f00\u53d1\u4e2d\uff0c\u5f00\u53d1\u4eba\u5458\u9700\u8981\u6ce8\u610f\u552f\u4e00\u7d22\u5f15\u7684\u521b\u5efa\u3001\u63d2\u5165\u6570\u636e\u3001\u67e5\u8be2\u6570\u636e\u7b49\u7ec6\u8282\uff0c\u5e76\u5728\u9047\u5230\u5e38\u89c1\u95ee\u9898\u65f6\u80fd\u591f\u5feb\u901f\u89e3\u51b3\u3002\u5e0c\u671b\u672c\u6587\u7684\u5185\u5bb9\u80fd\u5bf9\u8bfb\u8005\u5728MySQL\u6570\u636e\u5e93\u8bbe\u8ba1\u548c\u5e94\u7528\u4e2d\u6709\u6240\u5e2e\u52a9\u3002<\/p>\n
\u5230\u8fd9\u91cc\uff0c\u6211\u4eec\u4e5f\u5c31\u8bb2\u5b8c\u4e86\u300a\u4f7f\u7528MySQL\u4e2dunique\u7d22\u5f15\u7684\u6280\u5de7\u548c\u89e3\u51b3\u5e38\u89c1\u95ee\u9898\u300b\u7684\u5185\u5bb9\u4e86\u3002\u4e2a\u4eba\u8ba4\u4e3a\uff0c\u57fa\u7840\u77e5\u8bc6\u7684\u5b66\u4e60\u548c\u5de9\u56fa\uff0c\u662f\u4e3a\u4e86\u66f4\u597d\u7684\u5c06\u5176\u8fd0\u7528\u5230\u9879\u76ee\u4e2d\uff0c\u6b22\u8fce\u5173\u6ce8\u4e3b\u673a\u5b9d\u8d1d\u516c\u4f17\u53f7\uff0c\u5e26\u4f60\u4e86\u89e3\u66f4\u591a\u5173\u4e8e\u7d22\u5f15,unique,\u5e38\u89c1\u95ee\u9898\u7684\u77e5\u8bc6\u70b9\uff01<\/p>\n
\n
\n <\/dt>\n<\/dl>\n","protected":false},"excerpt":{"rendered":"
\u4f7f\u7528MySQL\u4e2dunique\u7d22\u5f15...<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[101],"tags":[],"class_list":["post-200049","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/200049","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"}],"author":[{"embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/comments?post=200049"}],"version-history":[{"count":0,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/200049\/revisions"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=200049"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=200049"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=200049"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}