{"id":37428,"date":"2023-12-11T14:41:27","date_gmt":"2023-12-11T06:41:27","guid":{"rendered":"https:\/\/wx.kaifamiao.info\/?p=37428"},"modified":"2023-12-11T14:41:27","modified_gmt":"2023-12-11T06:41:27","slug":"%e4%b8%ba%e4%bb%80%e4%b9%88%e7%b4%a2%e5%bc%95%e8%83%bd%e6%8f%90%e9%ab%98%e6%9f%a5%e8%af%a2%e9%80%9f%e5%ba%a6","status":"publish","type":"post","link":"http:\/\/wx.kaifamiao.info\/index.php\/2023\/12\/11\/%e4%b8%ba%e4%bb%80%e4%b9%88%e7%b4%a2%e5%bc%95%e8%83%bd%e6%8f%90%e9%ab%98%e6%9f%a5%e8%af%a2%e9%80%9f%e5%ba%a6\/","title":{"rendered":"\u4e3a\u4ec0\u4e48\u7d22\u5f15\u80fd\u63d0\u9ad8\u67e5\u8be2\u901f\u5ea6?"},"content":{"rendered":"<p>&#8220;`&#8221;<\/p>\n<blockquote><p>\u4ee5\u4e0b\u5185\u5bb9\u6574\u7406\u81ea\uff1a\u5730\u5740\uff1a https:\/\/juejin.im\/post\/5b55b842f265da0f9e589e79<br \/>\u4f5c\u8005 \uff1aJava3y<\/p>\n<\/blockquote>\n<h3>\u5148\u4ece MySQL \u7684\u57fa\u672c\u5b58\u50a8\u7ed3\u6784\u8bf4\u8d77<\/h3>\n<p>MySQL\u7684\u57fa\u672c\u5b58\u50a8\u7ed3\u6784\u662f\u9875(\u8bb0\u5f55\u90fd\u5b58\u5728\u9875\u91cc\u8fb9)\uff1a<\/p>\n<p><img decoding=\"async\" alt=\"\"MySQL\u7684\u57fa\u672c\u5b58\u50a8\u7ed3\u6784\u662f\u9875\"\" src=\"\"http:\/\/my-blog-to-use.oss-cn-beijing.aliyuncs.com\/18-10-2\/28559421.jpg\"\" style=\"\"width: 100%;\"\"><\/p>\n<p><img decoding=\"async\" alt=\"\"\"\" src=\"\"http:\/\/my-blog-to-use.oss-cn-beijing.aliyuncs.com\/18-10-2\/82053134.jpg\"\" style=\"\"width: 100%;\"\"><\/p>\n<ul>\n<li><strong>\u5404\u4e2a\u6570\u636e\u9875\u53ef\u4ee5\u7ec4\u6210\u4e00\u4e2a\u53cc\u5411\u94fe\u8868<\/strong><\/li>\n<li><strong>\u6bcf\u4e2a\u6570\u636e\u9875\u4e2d\u7684\u8bb0\u5f55\u53c8\u53ef\u4ee5\u7ec4\u6210\u4e00\u4e2a\u5355\u5411\u94fe\u8868<\/strong>\n<ul>\n<li>\u6bcf\u4e2a\u6570\u636e\u9875\u90fd\u4f1a\u4e3a\u5b58\u50a8\u5728\u5b83\u91cc\u8fb9\u513f\u7684\u8bb0\u5f55\u751f\u6210\u4e00\u4e2a\u9875\u76ee\u5f55\uff0c\u5728\u901a\u8fc7\u4e3b\u952e\u67e5\u627e\u67d0\u6761\u8bb0\u5f55\u7684\u65f6\u5019\u53ef\u4ee5\u5728\u9875\u76ee\u5f55\u4e2d\u4f7f\u7528\u4e8c\u5206\u6cd5\u5feb\u901f\u5b9a\u4f4d\u5230\u5bf9\u5e94\u7684\u69fd\uff0c\u7136\u540e\u518d\u904d\u5386\u8be5\u69fd\u5bf9\u5e94\u5206\u7ec4\u4e2d\u7684\u8bb0\u5f55\u5373\u53ef\u5feb\u901f\u627e\u5230\u6307\u5b9a\u7684\u8bb0\u5f55<\/li>\n<li>\u4ee5\u5176\u4ed6\u5217(\u975e\u4e3b\u952e)\u4f5c\u4e3a\u641c\u7d22\u6761\u4ef6\uff1a\u53ea\u80fd\u4ece\u6700\u5c0f\u8bb0\u5f55\u5f00\u59cb\u4f9d\u6b21\u904d\u5386\u5355\u94fe\u8868\u4e2d\u7684\u6bcf\u6761\u8bb0\u5f55\u3002<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<p>\u6240\u4ee5\u8bf4\uff0c\u5982\u679c\u6211\u4eec\u5199select * from user where indexname = &#8216;xxx&#8217;\u8fd9\u6837\u6ca1\u6709\u8fdb\u884c\u4efb\u4f55\u4f18\u5316\u7684sql\u8bed\u53e5\uff0c\u9ed8\u8ba4\u4f1a\u8fd9\u6837\u505a\uff1a<\/p>\n<ol>\n<li><strong>\u5b9a\u4f4d\u5230\u8bb0\u5f55\u6240\u5728\u7684\u9875\uff1a\u9700\u8981\u904d\u5386\u53cc\u5411\u94fe\u8868\uff0c\u627e\u5230\u6240\u5728\u7684\u9875<\/strong><\/li>\n<li><strong>\u4ece\u6240\u5728\u7684\u9875\u5185\u4e2d\u67e5\u627e\u76f8\u5e94\u7684\u8bb0\u5f55\uff1a\u7531\u4e8e\u4e0d\u662f\u6839\u636e\u4e3b\u952e\u67e5\u8be2\uff0c\u53ea\u80fd\u904d\u5386\u6240\u5728\u9875\u7684\u5355\u94fe\u8868\u4e86<\/strong><\/li>\n<\/ol>\n<p>\u5f88\u660e\u663e\uff0c\u5728\u6570\u636e\u91cf\u5f88\u5927\u7684\u60c5\u51b5\u4e0b\u8fd9\u6837\u67e5\u627e\u4f1a\u5f88\u6162\uff01\u8fd9\u6837\u7684\u65f6\u95f4\u590d\u6742\u5ea6\u4e3aO\uff08n\uff09\u3002<\/p>\n<h3>\u4f7f\u7528\u7d22\u5f15\u4e4b\u540e<\/h3>\n<p>\u7d22\u5f15\u505a\u4e86\u4e9b\u4ec0\u4e48\u53ef\u4ee5\u8ba9\u6211\u4eec\u67e5\u8be2\u52a0\u5feb\u901f\u5ea6\u5462\uff1f\u5176\u5b9e\u5c31\u662f\u5c06\u65e0\u5e8f\u7684\u6570\u636e\u53d8\u6210\u6709\u5e8f(\u76f8\u5bf9)\uff1a<\/p>\n<p><img decoding=\"async\" alt=\"\"\"\" src=\"\"http:\/\/my-blog-to-use.oss-cn-beijing.aliyuncs.com\/18-10-2\/5373082.jpg\"\" style=\"\"width: 100%;\"\"><\/p>\n<p>\u8981\u627e\u5230id\u4e3a8\u7684\u8bb0\u5f55\u7b80\u8981\u6b65\u9aa4\uff1a<\/p>\n<p><img decoding=\"async\" alt=\"\"\"\" src=\"\"http:\/\/my-blog-to-use.oss-cn-beijing.aliyuncs.com\/18-10-2\/89338047.jpg\"\" style=\"\"width: 100%;\"\"><\/p>\n<p>\u5f88\u660e\u663e\u7684\u662f\uff1a\u6ca1\u6709\u7528\u7d22\u5f15\u6211\u4eec\u662f\u9700\u8981\u904d\u5386\u53cc\u5411\u94fe\u8868\u6765\u5b9a\u4f4d\u5bf9\u5e94\u7684\u9875\uff0c\u73b0\u5728\u901a\u8fc7 <strong>\u201c\u76ee\u5f55\u201d<\/strong> \u5c31\u53ef\u4ee5\u5f88\u5feb\u5730\u5b9a\u4f4d\u5230\u5bf9\u5e94\u7684\u9875\u4e0a\u4e86\uff01\uff08\u4e8c\u5206\u67e5\u627e\uff0c\u65f6\u95f4\u590d\u6742\u5ea6\u8fd1\u4f3c\u4e3aO(logn)\uff09<\/p>\n<p>\u5176\u5b9e\u5e95\u5c42\u7ed3\u6784\u5c31\u662fB+\u6811\uff0cB+\u6811\u4f5c\u4e3a\u6811\u7684\u4e00\u79cd\u5b9e\u73b0\uff0c\u80fd\u591f\u8ba9\u6211\u4eec\u5f88\u5feb\u5730\u67e5\u627e\u51fa\u5bf9\u5e94\u7684\u8bb0\u5f55\u3002<\/p>\n<h1>\u5173\u4e8e\u7d22\u5f15\u5176\u4ed6\u91cd\u8981\u7684\u5185\u5bb9\u8865\u5145<\/h1>\n<blockquote><p>\u4ee5\u4e0b\u5185\u5bb9\u6574\u7406\u81ea\uff1a\u300aJava\u5de5\u7a0b\u5e08\u4fee\u70bc\u4e4b\u9053\u300b<\/p>\n<\/blockquote>\n<h3>\u6700\u5de6\u524d\u7f00\u539f\u5219<\/h3>\n<p>MySQL\u4e2d\u7684\u7d22\u5f15\u53ef\u4ee5\u4ee5\u4e00\u5b9a\u987a\u5e8f\u5f15\u7528\u591a\u5217\uff0c\u8fd9\u79cd\u7d22\u5f15\u53eb\u4f5c\u8054\u5408\u7d22\u5f15\u3002\u5982User\u8868\u7684name\u548ccity\u52a0\u8054\u5408\u7d22\u5f15\u5c31\u662f(name,city)\uff0c\u800c\u6700\u5de6\u524d\u7f00\u539f\u5219\u6307\u7684\u662f\uff0c\u5982\u679c\u67e5\u8be2\u7684\u65f6\u5019\u67e5\u8be2\u6761\u4ef6\u7cbe\u786e\u5339\u914d\u7d22\u5f15\u7684\u5de6\u8fb9\u8fde\u7eed\u4e00\u5217\u6216\u51e0\u5217\uff0c\u5219\u6b64\u5217\u5c31\u53ef\u4ee5\u88ab\u7528\u5230\u3002\u5982\u4e0b\uff1a        <\/p>\n<p><code>                                                                                       select * from user where name=xx and city=xx ; \uff0f\uff0f\u53ef\u4ee5\u547d\u4e2d\u7d22\u5f15select * from user where name=xx ; \/\/ \u53ef\u4ee5\u547d\u4e2d\u7d22\u5f15select * from user where city=xx ; \/\/ \u65e0\u6cd5\u547d\u4e2d\u7d22\u5f15            <\/code><\/p>\n<p>\u8fd9\u91cc\u9700\u8981\u6ce8\u610f\u7684\u662f\uff0c\u67e5\u8be2\u7684\u65f6\u5019\u5982\u679c\u4e24\u4e2a\u6761\u4ef6\u90fd\u7528\u4e0a\u4e86\uff0c\u4f46\u662f\u987a\u5e8f\u4e0d\u540c\uff0c\u5982 <code>city= xx and name \uff1dxx<\/code>\uff0c\u90a3\u4e48\u73b0\u5728\u7684\u67e5\u8be2\u5f15\u64ce\u4f1a\u81ea\u52a8\u4f18\u5316\u4e3a\u5339\u914d\u8054\u5408\u7d22\u5f15\u7684\u987a\u5e8f\uff0c\u8fd9\u6837\u662f\u80fd\u591f\u547d\u4e2d\u7d22\u5f15\u7684\u3002<\/p>\n<p>\u7531\u4e8e\u6700\u5de6\u524d\u7f00\u539f\u5219\uff0c\u5728\u521b\u5efa\u8054\u5408\u7d22\u5f15\u65f6\uff0c\u7d22\u5f15\u5b57\u6bb5\u7684\u987a\u5e8f\u9700\u8981\u8003\u8651\u5b57\u6bb5\u503c\u53bb\u91cd\u4e4b\u540e\u7684\u4e2a\u6570\uff0c\u8f83\u591a\u7684\u653e\u524d\u9762\u3002ORDER BY\u5b50\u53e5\u4e5f\u9075\u5faa\u6b64\u89c4\u5219\u3002<\/p>\n<h3>\u6ce8\u610f\u907f\u514d\u5197\u4f59\u7d22\u5f15<\/h3>\n<p>\u5197\u4f59\u7d22\u5f15\u6307\u7684\u662f\u7d22\u5f15\u7684\u529f\u80fd\u76f8\u540c\uff0c\u80fd\u591f\u547d\u4e2d \u5c31\u80af\u5b9a\u80fd\u547d\u4e2d \uff0c\u90a3\u4e48 \u5c31\u662f\u5197\u4f59\u7d22\u5f15\u5982\uff08name,city \uff09\u548c\uff08name \uff09\u8fd9\u4e24\u4e2a\u7d22\u5f15\u5c31\u662f\u5197\u4f59\u7d22\u5f15\uff0c\u80fd\u591f\u547d\u4e2d\u540e\u8005\u7684\u67e5\u8be2\u80af\u5b9a\u662f\u80fd\u591f\u547d\u4e2d\u524d\u8005\u7684 \u5728\u5927\u591a\u6570\u60c5\u51b5\u4e0b\uff0c\u90fd\u5e94\u8be5\u5c3d\u91cf\u6269\u5c55\u5df2\u6709\u7684\u7d22\u5f15\u800c\u4e0d\u662f\u521b\u5efa\u65b0\u7d22\u5f15\u3002<\/p>\n<p>MySQL 5.7 \u7248\u672c\u540e\uff0c\u53ef\u4ee5\u901a\u8fc7\u67e5\u8be2 sys \u5e93\u7684 <code>schema_redundant_indexes<\/code> \u8868\u6765\u67e5\u770b\u5197\u4f59\u7d22\u5f15             <\/p>\n<h3>Mysql\u5982\u4f55\u4e3a\u8868\u5b57\u6bb5\u6dfb\u52a0\u7d22\u5f15\uff1f\uff1f\uff1f<\/h3>\n<p>1.\u6dfb\u52a0PRIMARY KEY\uff08\u4e3b\u952e\u7d22\u5f15\uff09<\/p>\n<p><code>ALTER TABLE `table_name` ADD PRIMARY KEY ( `column` ) <\/code><\/p>\n<p>2.\u6dfb\u52a0UNIQUE(\u552f\u4e00\u7d22\u5f15)<\/p>\n<p><code>ALTER TABLE `table_name` ADD UNIQUE ( `column` ) <\/code><\/p>\n<p>3.\u6dfb\u52a0INDEX(\u666e\u901a\u7d22\u5f15)<\/p>\n<p><code>ALTER TABLE `table_name` ADD INDEX index_name ( `column` )<\/code><\/p>\n<p>4.\u6dfb\u52a0FULLTEXT(\u5168\u6587\u7d22\u5f15)<\/p>\n<p><code>ALTER TABLE `table_name` ADD FULLTEXT ( `column`) <\/code><\/p>\n<p>5.\u6dfb\u52a0\u591a\u5217\u7d22\u5f15<\/p>\n<p><code>ALTER TABLE `table_name` ADD INDEX index_name ( `column1`, `column2`, `column3` )<\/code><\/p>\n<h1>\u53c2\u8003<\/h1>\n<ul>\n<li>\u300aJava\u5de5\u7a0b\u5e08\u4fee\u70bc\u4e4b\u9053\u300b<\/li>\n<li>\u300aMySQL\u9ad8\u6027\u80fd\u4e66\u7c4d_\u7b2c3\u7248\u300b<\/li>\n<li>https:\/\/juejin.im\/post\/5b55b842f265da0f9e589e79<\/li>\n<\/ul>\n<pre><code>            \"```\n<\/code><\/pre>\n","protected":false},"excerpt":{"rendered":"<p>&#8220;`&#8221; \u4ee5\u4e0b\u5185\u5bb9\u6574\u7406\u81ea\uff1a\u5730\u5740\uff1a https:\/\/juejin.im\/post\/5b55 [&hellip;]<\/p>\n","protected":false},"author":7,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[101],"tags":[],"class_list":["post-37428","post","type-post","status-publish","format-standard","hentry","category-c"],"_links":{"self":[{"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/posts\/37428","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/users\/7"}],"replies":[{"embeddable":true,"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/comments?post=37428"}],"version-history":[{"count":1,"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/posts\/37428\/revisions"}],"predecessor-version":[{"id":37429,"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/posts\/37428\/revisions\/37429"}],"wp:attachment":[{"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/media?parent=37428"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/categories?post=37428"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/tags?post=37428"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}