{"id":1946,"date":"2020-07-29T21:25:16","date_gmt":"2020-07-29T13:25:16","guid":{"rendered":"http:\/\/39.97.231.10\/?p=1946"},"modified":"2020-07-29T21:25:16","modified_gmt":"2020-07-29T13:25:16","slug":"mysql%e6%80%a7%e8%83%bd%e4%bc%98%e5%8c%96-%e5%87%bd%e6%95%b0%e8%b0%83%e7%94%a8%e4%bc%98%e5%8c%96","status":"publish","type":"post","link":"http:\/\/www.weijing.co\/?p=1946","title":{"rendered":"MySQL\u6027\u80fd\u4f18\u5316-\u51fd\u6570\u8c03\u7528\u4f18\u5316"},"content":{"rendered":"<div class=\\\"blog_content\\\">\n<div class=\\\"blog_detail\\\">\n<div>\n\u51fd\u6570\u8c03\u7528\u5728MySQL\u5185\u90e8\u5206\u4e3a\u786e\u5b9a\u6027\u51fd\u6570\u548c\u4e0d\u786e\u5b9a\u6027\u51fd\u6570\u3002\u5982\u679c\u4e00\u4e2a\u51fd\u6570\uff0c\u5bf9\u4e8e\u7ed9\u5b9a\u7684\u56fa\u5b9a\u53c2\u6570\u503c\uff0c\u591a\u6b21\u8c03\u7528\uff0c\u8fd4\u56de\u7684\u7ed3\u679c\u503c\u4e0d\u540c\uff0c\u90a3\u4e48\u8fd9\u6837\u7684\u51fd\u6570\u5c31\u79f0\u4e4b\u4e3a\u4e0d\u786e\u5b9a\u6027\u51fd\u6570\uff0c\u6bd4\u5982RAND(), UUID()\u3002\u8fd4\u56de\u7684\u7ed3\u679c\u503c\u76f8\u540c\uff0c\u5219\u4e3a\u786e\u5b9a\u6027\u51fd\u6570\uff0c\u6bd4\u5982POW(1,2)\u3002<\/p>\n<h4>1. \u786e\u5b9a\u6027\u51fd\u6570\u4e0e\u4e0d\u786e\u5b9a\u6027\u51fd\u6570\u7684\u4e3b\u8981\u533a\u522b<\/h4>\n<p>\u5148\u770b\u4e00\u4e2a\u4f8b\u5b50\uff0c\u8868\u7ed3\u6784\u5982\u4e0b\uff1a<br \/>\nCREATE TABLE t (id INT NOT NULL PRIMARY KEY, col_a VARCHAR(100));<br \/>\n\u4e24\u4e2a\u67e5\u8be2SQL\uff0c\u7b2c\u4e00\u4e2aSQL\u4f7f\u7528\u786e\u5b9a\u6027\u51fd\u6570POW()\uff0c\u7b2c\u4e8c\u4e2aSQL\u4f7f\u7528\u4e0d\u786e\u5b9a\u6027\u51fd\u6570RAND()\uff0c\u5982\u4e0b\uff1a<br \/>\n\uff081\uff09SELECT * FROM t WHERE id = POW(1,2);<br \/>\n\uff082\uff09SELECT * FROM t WHERE id = FLOOR(1 + RAND() * 49);<\/p>\n<ul>\n<li>\u5bf9\u4e8e\u7b2c\u4e00\u4e2aSQL\uff0cPOW(1,2) \u51fd\u6570\u8fd4\u56de\u7684\u662f\u4e00\u4e2a\u5e38\u91cf\u503c\uff0c\u56e0\u6b64\u8fd9\u4e2aSQL\u6700\u591a\u8fd4\u56de\u4e00\u6761\u8bb0\u5f55\u3002<\/li>\n<li>\u5bf9\u4e8e\u7b2c\u4e8c\u4e2aSQL\uff0cRAND()\u662f\u4e00\u4e2a\u4e0d\u786e\u5b9a\u51fd\u6570\uff0c\u5bf9\u4e8e\u4e0d\u786e\u5b9a\u51fd\u6570\uff0c\u8868t\u4e2d\u7684\u6bcf\u4e00\u884c\u8bb0\u5f55\u4e0e\u6761\u4ef6\u8fdb\u884c\u5339\u914d\u65f6\uff0c\u90fd\u4f1a\u5bf9where\u6761\u4ef6\u7684\u503c\u91cd\u65b0\u8fdb\u884c\u8ba1\u7b97\uff0c\u56e0\u6b64\u7b2c\u4e8c\u4e2aSQL\u6709\u53ef\u80fd\u8fd4\u56de0\u6761\uff0c1\u6761\u6216\u8005\u591a\u6761\u8bb0\u5f55\u3002<\/li>\n<li>\u4f7f\u7528\u4e0d\u786e\u5b9a\u6027\u51fd\u6570\uff0c\u65e0\u6cd5\u8d70\u7d22\u5f15\uff0c\u5927\u90e8\u5206\u573a\u666f\u90fd\u662f\u5168\u8868\u626b\u63cf\uff0c\u6027\u80fd\u4f4e\u4e0b\u3002<\/li>\n<\/ul>\n<h4>2. \u4e0d\u786e\u5b9a\u6027\u51fd\u6570\u7684\u5f71\u54cd<\/h4>\n<ol>\n<li>\u4e0d\u786e\u5b9a\u6027\u51fd\u6570\u4e0d\u80fd\u8fd4\u56de\u4e00\u4e2a\u5e38\u91cf\u503c\uff0c\u4f18\u5316\u5668\u65e0\u6cd5\u91c7\u7528\u5408\u9002\u7684\u4f18\u5316\u7b56\u7565\uff0c\u6bd4\u5982\u7d22\u5f15\u67e5\u627e\uff0c\u5bfc\u81f4\u5168\u8868\u626b\u63cf\uff0c\u5f71\u54cd\u6027\u80fd\u3002<\/li>\n<li>\u5728InnoDB\u8868\u4e2d\uff0c\u5bf9\u4e8e\u53ea\u6709\u4e00\u884c\u8bb0\u5f55\u7684\u5339\u914d\uff0c\u4e0d\u786e\u5b9a\u6027\u51fd\u6570\u53ef\u80fd\u4f1a\u5c06\u5355\u884c\u7684\u884c\u9501\u5347\u7ea7\u6210\u4e00\u4e2a\u8303\u56f4\u9501\u3002<\/li>\n<li>\u5728\u57fa\u4e8estatement\u7684binlog\u683c\u5f0f\u590d\u5236\u65f6\uff0c\u4f7f\u7528\u4e0d\u786e\u5b9a\u6027\u51fd\u6570\u4f1a\u5bfc\u81f4\u4e3b\u4ece\u6570\u636e\u4e0d\u4e00\u81f4\u3002<\/li>\n<\/ol>\n<h4>3. \u4e0d\u786e\u5b9a\u6027\u51fd\u6570\u7684\u4f18\u5316<\/h4>\n<ol>\n<li>\u4f7f\u7528\u53d8\u91cf\u6765\u5b58\u50a8\u4e0d\u786e\u5b9a\u51fd\u6570\u7684\u8fd4\u56de\u503c\uff0c\u4f18\u5316\u5668\u5728\u5904\u7406\u53d8\u91cf\u65f6\uff0c\u56e0\u4e3a\u5176\u503c\u5df2\u7ecf\u786e\u5b9a\uff0c\u53ef\u4ee5\u5f53\u4f5c\u4e00\u4e2a\u5e38\u91cf\u6765\u5904\u7406\u3002<br \/>\nSET @keyval = FLOOR(1 + RAND() * 49);<br \/>\nUPDATE t SET col_a = some_expr WHERE id = @keyval;<\/li>\n<li>\u5c06\u4e0d\u786e\u5b9a\u51fd\u6570\u8f6c\u79fb\u5230\u4e1a\u52a1\u4ee3\u7801\u4e2d\uff0c\u4e1a\u52a1\u6267\u884c\u4e0d\u786e\u5b9a\u51fd\u6570\uff0c\u5c06\u8fd4\u56de\u7684\u7ed3\u679c(\u5e38\u91cf)\u4f5c\u4e3a\u53c2\u6570\uff0c\u62fc\u63a5\u5230SQL\u4e2d\uff0c\u63d0\u9ad8SQL\u6027\u80fd\u3002<\/li>\n<\/ol>\n<\/div>\n<\/div>\n<\/div>\n","protected":false},"excerpt":{"rendered":"<p>\u51fd\u6570\u8c03\u7528\u5728MySQL\u5185\u90e8\u5206\u4e3a\u786e\u5b9a\u6027\u51fd\u6570\u548c\u4e0d\u786e\u5b9a\u6027\u51fd\u6570\u3002\u5982\u679c\u4e00\u4e2a\u51fd\u6570\uff0c\u5bf9\u4e8e\u7ed9\u5b9a\u7684\u56fa\u5b9a\u53c2\u6570\u503c\uff0c\u591a\u6b21\u8c03\u7528\uff0c\u8fd4\u56de\u7684\u7ed3\u679c &hellip;<\/p>\n<p class=\"read-more\"> <a class=\"\" href=\"http:\/\/www.weijing.co\/?p=1946\"> <span class=\"screen-reader-text\">MySQL\u6027\u80fd\u4f18\u5316-\u51fd\u6570\u8c03\u7528\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":"\u51fd\u6570\u8c03\u7528\u5728MySQL\u5185\u90e8\u5206\u4e3a\u786e\u5b9a\u6027\u51fd\u6570\u548c\u4e0d\u786e\u5b9a\u6027\u51fd\u6570\u3002\u5982\u679c\u4e00\u4e2a\u51fd\u6570\uff0c\u5bf9\u4e8e\u7ed9\u5b9a\u7684\u56fa\u5b9a\u53c2\u6570\u503c\uff0c\u591a\u6b21\u8c03\u7528\uff0c\u8fd4\u56de\u7684\u7ed3\u679c&hellip;","_links":{"self":[{"href":"http:\/\/www.weijing.co\/index.php?rest_route=\/wp\/v2\/posts\/1946"}],"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=1946"}],"version-history":[{"count":0,"href":"http:\/\/www.weijing.co\/index.php?rest_route=\/wp\/v2\/posts\/1946\/revisions"}],"wp:attachment":[{"href":"http:\/\/www.weijing.co\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1946"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.weijing.co\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1946"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.weijing.co\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1946"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}