{"id":5351,"date":"2020-07-29T21:29:05","date_gmt":"2020-07-29T13:29:05","guid":{"rendered":"http:\/\/39.97.231.10\/?p=5351"},"modified":"2020-07-29T21:29:05","modified_gmt":"2020-07-29T13:29:05","slug":"mysql%e6%80%a7%e8%83%bd%e4%bc%98%e5%8c%96-%e7%b4%a2%e5%bc%95%e4%bc%98%e5%8c%96","status":"publish","type":"post","link":"http:\/\/www.weijing.co\/?p=5351","title":{"rendered":"MySQL\u6027\u80fd\u4f18\u5316-\u7d22\u5f15\u4f18\u5316"},"content":{"rendered":"<div class=\\\"blog_content\\\">\n<div class=\\\"blog_detail\\\">\n<div>\n\u7d22\u5f15\u662f\u63d0\u9ad8\u67e5\u8be2\u6027\u80fd\u6700\u6709\u6548\u7684\u65b9\u5f0f\u4e4b\u4e00\uff0c\u5728\u8868\u7ed3\u6784\u8bbe\u8ba1\u9636\u6bb5\u5c31\u5e94\u5f53\u8003\u8651\u7d22\u5f15\u7684\u8bbe\u8ba1\uff0c\u7d22\u5f15\u4e5f\u4e0d\u662f\u8d8a\u591a\u8d8a\u597d\uff0c\u9700\u8981\u7ed3\u5408\u5177\u4f53\u7684SQL\u3001\u6267\u884c\u9891\u7387\u3001\u6570\u636e\u5206\u5e03\u7b49\u591a\u4e2a\u65b9\u9762\u7efc\u5408\u8003\u8651\u3002\u672c\u6587\u6574\u7406\u4e86MySQL\u7d22\u5f15\u4f18\u5316\u7684\u4e00\u4e9b\u539f\u5219\u3001\u7ecf\u9a8c\u548c\u6280\u5de7\u3002<br \/>\nMySQL\u7684\u7d22\u5f15\u5b9e\u73b0\u56e0\u5b58\u50a8\u5f15\u64ce\u7684\u5dee\u5f02\u800c\u7565\u6709\u4e0d\u540c\uff0c\u672c\u6587\u4e3b\u8981\u4ecb\u7ecdInnoDB\u5b58\u50a8\u5f15\u64ce\u7684\u7d22\u5f15\u4f18\u5316\u3002<\/p>\n<h4>\u4e00\u3001\u67e5\u770b\u7d22\u5f15\u4fe1\u606f<\/h4>\n<p>\u67e5\u770b\u8868\u4e2d\u6709\u54ea\u4e9b\u7d22\u5f15\uff0c\u6bd4\u5982\u4e3b\u952e\u7d22\u5f15\uff0c\u552f\u4e00\u7d22\u5f15\uff0c\u666e\u901a\u7d22\u5f15\u7b49\uff0c\u5728\u8868\u7ed3\u6784\u4e2d\u5c31\u80fd\u770b\u5230\uff0c\u5982\u4e0b\u547d\u4ee4\uff1a<br \/>\nshow create table table_name\\\\G<br \/>\n\u60f3\u8981\u770b\u5230\u7d22\u5f15\u7684\u66f4\u591a\u4fe1\u606f\uff0c\u6bd4\u5982\u7d22\u5f15\u7684\u57fa\u6570\uff0c\u7d22\u5f15\u7684\u7c7b\u578b\u7b49\uff0c\u6267\u884c\u5982\u4e0b\u547d\u4ee4\uff1a<br \/>\nshow index from table_name;<\/p>\n<h4>\u4e8c\u3001\u5224\u65adSQL\u6709\u6ca1\u6709\u4f7f\u7528\u7d22\u5f15<\/h4>\n<p>MySQL\u63d0\u4f9bexplain\u547d\u4ee4\u67e5\u770bSQL\u7684\u6267\u884c\u8ba1\u5212\uff0c\u901a\u8fc7\u6267\u884c\u8ba1\u5212\u80fd\u591f\u5224\u65adSQL\u5728\u6267\u884c\u8fc7\u7a0b\u4e2d\u662f\u5426\u4f7f\u7528\u7d22\u5f15\u3002\u6bd4\u5982\uff1a<br \/>\nexplain select * from table_name where name = \\&#8217;xxx\\&#8217;;<br \/>\n\u6839\u636eexplain\u7684\u8f93\u51fa\u7ed3\u679ckey\u5b57\u6bb5\u6765\u5224\u65ad\u662f\u5426\u4f7f\u7528\u7d22\u5f15\uff0c\u4ee5\u53ca\u4f7f\u7528\u4e86\u54ea\u4e2a\u7d22\u5f15\u3002<\/p>\n<h4>\u4e09\u3001\u7d22\u5f15\u5206\u7c7b<\/h4>\n<p>\uff081\uff09\u4e3b\u952e\u7d22\u5f15 primary key<br \/>\n\u4e3b\u952e\u7d22\u5f15\u4e0d\u5141\u8bb8\u6709\u7a7a\u503c(null)\uff0c\u4e00\u5f20\u8868\u53ea\u6709\u4e00\u4e2a\u4e3b\u952e\uff0cMySQL InnoDB\u8868\u662f\u7d22\u5f15\u7ec4\u7ec7\u8868\uff0c\u6240\u6709\u7684\u6570\u636e\u90fd\u5728\u4e3b\u952e\u7d22\u5f15\u7684\u53f6\u5b50\u8282\u70b9\u4e2d\u3002<br \/>\n\u5982\u679c\u7528\u6237\u6ca1\u6709\u5b9a\u4e49\u4e3b\u952e\uff0c\u90a3\u4e48MySQL\u4f1a\u9009\u62e9\u4e00\u4e2a\u975e\u7a7a\u552f\u4e00\u7d22\u5f15\u4f5c\u4e3a\u4e3b\u952e\uff0c\u5982\u679c\u6ca1\u6709\u975e\u7a7a\u552f\u4e00\u7d22\u5f15\uff0c\u90a3\u4e48MySQL\u4f1a\u521b\u5efa\u4e00\u4e2a\u9690\u5f0f\u7684\u4e3b\u952e\u3002<br \/>\n\uff082\uff09\u552f\u4e00\u952e\u7d22\u5f15 unique key<br \/>\n\u552f\u4e00\u7d22\u5f15\u7684\u503c\u5fc5\u987b\u552f\u4e00\uff0c\u4e0d\u5141\u8bb8\u91cd\u590d\uff0c\u4f46\u53ef\u4ee5\u4e3a\u7a7a\u503c(null)\uff0c\u4e00\u5f20\u8868\u4e2d\u53ef\u4ee5\u521b\u5efa\u591a\u4e2a\u552f\u4e00\u7d22\u5f15\u3002<br \/>\n\uff083\uff09\u666e\u901a\u7d22\u5f15<br \/>\n\u666e\u901a\u7684B+\u6811\u7d22\u5f15\uff0c\u53ef\u4ee5\u6709\u591a\u4e2a\uff0c\u5141\u8bb8\u91cd\u590d\u503c\uff0c\u4e5f\u5141\u8bb8\u4e3a\u7a7a\u503c(null)\u3002<br \/>\n\u4ee5\u4e0a\u4e09\u79cd\u7d22\u5f15\u8fd8\u53ef\u4ee5\u6839\u636e\u7d22\u5f15\u5305\u542b\u7684\u5b57\u6bb5\u6570\u91cf\u6765\u5212\u5206\uff0c\u5982\u4e0b\uff1a<br \/>\n\uff081\uff09\u5355\u5217\u7d22\u5f15\uff0c\u7d22\u5f15\u5b57\u6bb5\u53ea\u6709\u4e00\u4e2a\u3002<br \/>\n\uff082\uff09\u7ec4\u5408\u7d22\u5f15\uff0c\u7d22\u5f15\u5b57\u6bb5\u6709\u591a\u4e2a\uff0c\u5e38\u7528\u4e8e\u591a\u4e2a\u6761\u4ef6\u67e5\u8be2\uff0c\u4ee5\u53ca\u5f62\u6210\u8986\u76d6\u7d22\u5f15\uff0c\u907f\u514d\u56de\u8868\u3002<\/p>\n<h4>\u56db\u3001\u7d22\u5f15\u4f18\u5316\u7684\u539f\u5219<\/h4>\n<ol>\n<li>\u4e00\u5b9a\u8981\u6709\u4e3b\u952e\u7d22\u5f15\uff0c\u4e3b\u952e\u7d22\u5f15\u5b57\u6bb5\u5c3d\u53ef\u80fd\u7684\u5c0f\uff0c\u6700\u597d\u81ea\u589e\uff0c\u6bd4\u5982 int auto_increment\u3002<\/li>\n<li>\u4e3b\u952e\u7d22\u5f15\u4e0d\u5efa\u8bae\u4f7f\u7528md5\uff0cuuid\u8fd9\u7c7b\u65e0\u5e8f\u5b57\u7b26\u4e32\uff0c\u63d2\u5165\u6570\u636e\u4f1a\u9891\u7e41\u9875\u5206\u88c2\uff0c\u5f71\u54cd\u6027\u80fd\uff0c\u5e76\u4e14\u78c1\u76d8\u5360\u7528\u8fc7\u5927\u3002<\/li>\n<li>\u9002\u5408\u7d22\u5f15\u7684\u5217\u901a\u5e38\u662f\u51fa\u73b0\u5728where\u6761\u4ef6\u4e2d\u7684\u5217\uff0c\u6216\u8005join\u8fde\u63a5\u4e2d\u7684\u8fde\u63a5\u5b57\u6bb5\u3002<\/li>\n<li>\u5efa\u7d22\u5f15\u7684\u5217\uff0c\u4e0d\u5efa\u8bae\u4e3anull\u503c\u3002<\/li>\n<li>\u533a\u5206\u5ea6\u4e0d\u9ad8\u7684\u5b57\u6bb5\u4e0d\u9002\u5408\u5efa\u7d22\u5f15\uff0c\u6bd4\u5982\u6027\u522b\u3002<\/li>\n<li>\u7ec4\u5408\u7d22\u5f15\u5efa\u8bae\u5c06\u533a\u5206\u5ea6\u9ad8\u7684\u5b57\u6bb5\u653e\u5230\u524d\u9762\uff0c\u533a\u5206\u5ea6\u4f4e\u7684\u5b57\u6bb5\u653e\u5728\u540e\u9762\u3002<\/li>\n<li>\u5efa\u8bae\u4f7f\u7528\u77ed\u7d22\u5f15\uff0c\u5bf9\u4e8e\u957f\u5b57\u7b26\u4e32\uff0c\u5982\u679c\u5176\u524dN\u4e2a\u5b57\u7b26\u5df2\u7ecf\u6709\u5f88\u597d\u7684\u533a\u5206\u5ea6\uff0c\u53ef\u4ee5\u6307\u5b9a\u524d\u7f00\u7d22\u5f15\uff0c\u65e2\u80fd\u4f18\u5316\u67e5\u8be2\uff0c\u4e5f\u907f\u514d\u4e86\u7d22\u5f15\u8fc7\u5927\u3002<\/li>\n<li>\u4e0d\u8981\u8fc7\u5ea6\u7d22\u5f15\uff0c\u7ef4\u62a4\u7d22\u5f15\u4e5f\u662f\u6709\u6210\u672c\u7684\uff0c\u4e0d\u4ec5\u5360\u7528\u78c1\u76d8\u7a7a\u95f4\uff0c\u8fd8\u5f71\u54cd\u5199\u5165\u6027\u80fd\u3002<\/li>\n<li>\u66f4\u65b0\u9891\u7e41\u7684\u5b57\u6bb5\uff0c\u4e0d\u5efa\u8bae\u5efa\u7d22\u5f15\u3002\u66f4\u65b0\u64cd\u4f5c\u4f1a\u53d8\u66f4\u7d22\u5f15\uff0c\u5f71\u54cd\u6027\u80fd\u3002<\/li>\n<li>\u4e0d\u8981\u521b\u5efa\u5197\u4f59\u548c\u91cd\u590d\u7684\u7d22\u5f15\u3002<\/li>\n<li>\u5355\u8868\u7d22\u5f15\u5efa\u8bae\u63a7\u5236\u57285\u4e2a\u4ee5\u5185\u3002<\/li>\n<li>\u7ec4\u5408\u7d22\u5f15\u5b57\u6bb5\u6570\u5efa\u8bae\u4e0d\u8d85\u8fc75\u4e2a\u3002\u5b57\u6bb5\u8d85\u8fc75\u4e2a\u65f6\uff0c\u5b9e\u9645\u5df2\u7ecf\u8d77\u4e0d\u5230\u6709\u6548\u8fc7\u6ee4\u6570\u636e\u7684\u4f5c\u7528\u4e86\u3002<\/li>\n<\/ol>\n<h4>\u4e94\u3001\u8986\u76d6\u7d22\u5f15<\/h4>\n<p>\u8986\u76d6\u7d22\u5f15\u4e0d\u662f\u7d22\u5f15\u7c7b\u578b\uff0c\u5b83\u53ea\u662f\u4f7f\u7528\u7d22\u5f15\u7684\u4e00\u79cd\u65b9\u5f0f\uff0c\u53ea\u8bfb\u53d6\u7d22\u5f15\u6570\u636e\u5c31\u80fd\u8fd4\u56de\u7ed3\u679c\u7ed9\u7528\u6237\uff0c\u4e0d\u9700\u8981\u518d\u56de\u8868\u67e5\u8be2\u3002<br \/>\n\u8986\u76d6\u7d22\u5f15\u4f18\u70b9\uff1a<\/p>\n<ul>\n<li>\u5229\u7528\u7d22\u5f15\u76f4\u63a5\u8fd4\u56de\u6570\u636e\uff0c\u4e0d\u518d\u56de\u8868\u67e5\u8be2<\/li>\n<li>\u5229\u7528\u7d22\u5f15\u7684\u6709\u5e8f\u6027\uff0c\u907f\u514d\u4e0d\u5fc5\u8981\u7684\u6392\u5e8f<\/li>\n<\/ul>\n<p>\u6ce8\u610f\uff1a\u4f7f\u7528\u524d\u7f00\u7d22\u5f15\uff0c\u5c06\u5bfc\u81f4\u8986\u76d6\u7d22\u5f15\u4e0d\u53ef\u7528\u3002<\/p>\n<h4>\u516d\u3001\u7d22\u5f15\u4f7f\u7528\u60c5\u51b5\u76d1\u63a7<\/h4>\n<p>\u53ef\u4ee5\u901a\u8fc7\u67e5\u770bMySQL\u7684\u72b6\u6001\u53d8\u91cf\u6765\u786e\u8ba4\u7d22\u5f15\u7684\u4f7f\u7528\u60c5\u51b5\uff1a<br \/>\nshow status like \\&#8217;Handler_read%\\&#8217;;<\/p>\n<ul>\n<li>Handler_read_key\uff1a\u5982\u679c\u7d22\u5f15\u6b63\u5e38\u5de5\u4f5c\uff0c\u8be5\u503c\u5c06\u5f88\u9ad8\u3002<\/li>\n<li>Handler_read_rnd_next\uff1a\u6570\u636e\u6587\u4ef6\u4e2d\u8bfb\u53d6\u4e0b\u4e00\u884c\u7684\u8bf7\u6c42\u6570\uff0c\u5982\u679c\u6b63\u5728\u8fdb\u884c\u5927\u91cf\u7684\u8868\u626b\u63cf\uff0c\u8be5\u503c\u8f83\u9ad8\uff0c\u8bf4\u660e\u7d22\u5f15\u5229\u7528\u4e0d\u7406\u60f3\u3002<\/li>\n<\/ul>\n<\/div>\n<\/div>\n<\/div>\n","protected":false},"excerpt":{"rendered":"<p>\u7d22\u5f15\u662f\u63d0\u9ad8\u67e5\u8be2\u6027\u80fd\u6700\u6709\u6548\u7684\u65b9\u5f0f\u4e4b\u4e00\uff0c\u5728\u8868\u7ed3\u6784\u8bbe\u8ba1\u9636\u6bb5\u5c31\u5e94\u5f53\u8003\u8651\u7d22\u5f15\u7684\u8bbe\u8ba1\uff0c\u7d22\u5f15\u4e5f\u4e0d\u662f\u8d8a\u591a\u8d8a\u597d\uff0c\u9700\u8981\u7ed3\u5408\u5177\u4f53\u7684S &hellip;<\/p>\n<p class=\"read-more\"> <a class=\"\" href=\"http:\/\/www.weijing.co\/?p=5351\"> <span class=\"screen-reader-text\">MySQL\u6027\u80fd\u4f18\u5316-\u7d22\u5f15\u4f18\u5316<\/span> \u67e5\u770b\u5168\u6587 &raquo;<\/a><\/p>\n","protected":false},"author":4,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"site-sidebar-layout":"default","site-content-layout":"default","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","theme-transparent-header-meta":"default","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":""},"categories":[90,88],"tags":[],"uagb_featured_image_src":{"full":false,"thumbnail":false,"medium":false,"medium_large":false,"large":false,"1536x1536":false,"2048x2048":false,"mailpoet_newsletter_max":false,"woocommerce_thumbnail":false,"woocommerce_single":false,"woocommerce_gallery_thumbnail":false,"shop_catalog":false,"shop_single":false,"shop_thumbnail":false},"uagb_author_info":{"display_name":"weijing","author_link":"http:\/\/www.weijing.co\/?author=4"},"uagb_comment_info":0,"uagb_excerpt":"\u7d22\u5f15\u662f\u63d0\u9ad8\u67e5\u8be2\u6027\u80fd\u6700\u6709\u6548\u7684\u65b9\u5f0f\u4e4b\u4e00\uff0c\u5728\u8868\u7ed3\u6784\u8bbe\u8ba1\u9636\u6bb5\u5c31\u5e94\u5f53\u8003\u8651\u7d22\u5f15\u7684\u8bbe\u8ba1\uff0c\u7d22\u5f15\u4e5f\u4e0d\u662f\u8d8a\u591a\u8d8a\u597d\uff0c\u9700\u8981\u7ed3\u5408\u5177\u4f53\u7684S&hellip;","_links":{"self":[{"href":"http:\/\/www.weijing.co\/index.php?rest_route=\/wp\/v2\/posts\/5351"}],"collection":[{"href":"http:\/\/www.weijing.co\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/www.weijing.co\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/www.weijing.co\/index.php?rest_route=\/wp\/v2\/users\/4"}],"replies":[{"embeddable":true,"href":"http:\/\/www.weijing.co\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=5351"}],"version-history":[{"count":0,"href":"http:\/\/www.weijing.co\/index.php?rest_route=\/wp\/v2\/posts\/5351\/revisions"}],"wp:attachment":[{"href":"http:\/\/www.weijing.co\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=5351"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.weijing.co\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=5351"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.weijing.co\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=5351"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}