{"id":75792,"date":"2024-10-16T01:16:17","date_gmt":"2024-10-15T17:16:17","guid":{"rendered":"https:\/\/server.hk\/cnblog\/75792\/"},"modified":"2024-10-16T01:16:18","modified_gmt":"2024-10-15T17:16:18","slug":"mysql-%e6%9f%a5%e8%a9%a2%ef%bc%8c%e6%98%afjoin%e6%80%a7%e8%83%bd%e5%a5%bd%ef%bc%8c%e9%82%84%e6%98%afin%e4%b8%80%e4%b8%8b%e6%9b%b4%e5%bf%ab%e5%91%a2%ef%bc%9f","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/75792\/","title":{"rendered":"MySQL \u67e5\u8a62\uff0c\u662fJOIN\u6027\u80fd\u597d\uff0c\u9084\u662fIN\u4e00\u4e0b\u66f4\u5feb\u5462\uff1f"},"content":{"rendered":"<h1 id=\"mysql-%e6%9f%a5%e8%a9%a2%ef%bc%9ajoin-%e6%80%a7%e8%83%bd%e5%a5%bd%ef%bc%8c%e9%82%84%e6%98%af-in-%e6%9b%b4%e5%bf%ab%ef%bc%9f-kKMmCVyeOR\">MySQL \u67e5\u8a62\uff1aJOIN \u6027\u80fd\u597d\uff0c\u9084\u662f IN \u66f4\u5feb\uff1f<\/h1>\n<p>\u5728\u6578\u64da\u5eab\u7ba1\u7406\u7cfb\u7d71\u4e2d\uff0cMySQL \u662f\u4e00\u500b\u5ee3\u6cdb\u4f7f\u7528\u7684\u9078\u64c7\uff0c\u5c24\u5176\u662f\u5728\u8655\u7406\u5927\u91cf\u6578\u64da\u6642\u3002\u7576\u6211\u5011\u9700\u8981\u5f9e\u591a\u500b\u8868\u4e2d\u6aa2\u7d22\u6578\u64da\u6642\uff0c\u901a\u5e38\u6703\u9762\u81e8\u4f7f\u7528 JOIN \u6216 IN \u7684\u9078\u64c7\u3002\u9019\u5169\u7a2e\u65b9\u6cd5\u5404\u6709\u5176\u512a\u7f3a\u9ede\uff0c\u4e86\u89e3\u5b83\u5011\u7684\u6027\u80fd\u5dee\u7570\u5c0d\u65bc\u512a\u5316\u67e5\u8a62\u81f3\u95dc\u91cd\u8981\u3002<\/p>\n<h2 id=\"join-%e7%9a%84%e5%9f%ba%e6%9c%ac%e6%a6%82%e5%bf%b5-kKMmCVyeOR\">JOIN \u7684\u57fa\u672c\u6982\u5ff5<\/h2>\n<p>JOIN \u662f\u4e00\u7a2e\u7528\u65bc\u5f9e\u5169\u500b\u6216\u591a\u500b\u8868\u4e2d\u6839\u64da\u76f8\u95dc\u5217\u6aa2\u7d22\u6578\u64da\u7684\u64cd\u4f5c\u3002MySQL \u652f\u6301\u591a\u7a2e JOIN \u985e\u578b\uff0c\u5305\u62ec INNER JOIN\u3001LEFT JOIN\u3001RIGHT JOIN \u548c FULL OUTER JOIN\u3002\u4ee5\u4e0b\u662f\u4e00\u500b\u7c21\u55ae\u7684 INNER JOIN \u793a\u4f8b\uff1a<\/p>\n<pre><code>SELECT a.id, a.name, b.order_date \nFROM customers a \nINNER JOIN orders b ON a.id = b.customer_id;<\/code><\/pre>\n<p>\u5728\u9019\u500b\u67e5\u8a62\u4e2d\uff0c\u6211\u5011\u5f9e customers \u8868\u548c orders \u8868\u4e2d\u6aa2\u7d22\u6578\u64da\uff0c\u6839\u64da customer_id \u9032\u884c\u5339\u914d\u3002JOIN \u7684\u512a\u52e2\u5728\u65bc\u5b83\u80fd\u5920\u6709\u6548\u5730\u5408\u4f75\u591a\u500b\u8868\u7684\u6578\u64da\uff0c\u4e26\u4e14\u5728\u8655\u7406\u5927\u91cf\u6578\u64da\u6642\uff0c\u901a\u5e38\u80fd\u5920\u4fdd\u6301\u826f\u597d\u7684\u6027\u80fd\u3002<\/p>\n<h2 id=\"in-%e7%9a%84%e5%9f%ba%e6%9c%ac%e6%a6%82%e5%bf%b5-kKMmCVyeOR\">IN \u7684\u57fa\u672c\u6982\u5ff5<\/h2>\n<p>IN \u662f\u4e00\u7a2e\u7528\u65bc\u6aa2\u67e5\u67d0\u500b\u503c\u662f\u5426\u5b58\u5728\u65bc\u4e00\u7d44\u503c\u4e2d\u7684\u64cd\u4f5c\u3002\u9019\u901a\u5e38\u7528\u65bc\u904e\u6ffe\u67e5\u8a62\u7d50\u679c\u3002\u4ee5\u4e0b\u662f\u4e00\u500b\u4f7f\u7528 IN \u7684\u793a\u4f8b\uff1a<\/p>\n<pre><code>SELECT * \nFROM orders \nWHERE customer_id IN (1, 2, 3, 4);<\/code><\/pre>\n<p>\u5728\u9019\u500b\u67e5\u8a62\u4e2d\uff0c\u6211\u5011\u6aa2\u7d22\u6240\u6709 customer_id \u70ba 1\u30012\u30013 \u6216 4 \u7684\u8a02\u55ae\u3002IN \u7684\u512a\u52e2\u5728\u65bc\u5176\u8a9e\u6cd5\u7c21\u55ae\uff0c\u4e26\u4e14\u5728\u8655\u7406\u5c0f\u578b\u6578\u64da\u96c6\u6642\u6027\u80fd\u826f\u597d\u3002<\/p>\n<h2 id=\"%e6%80%a7%e8%83%bd%e6%af%94%e8%bc%83-kKMmCVyeOR\">\u6027\u80fd\u6bd4\u8f03<\/h2>\n<p>\u5728\u9078\u64c7\u4f7f\u7528 JOIN \u9084\u662f IN \u6642\uff0c\u6027\u80fd\u7684\u5dee\u7570\u901a\u5e38\u53d6\u6c7a\u65bc\u6578\u64da\u7684\u5927\u5c0f\u548c\u7d50\u69cb\u3002\u4ee5\u4e0b\u662f\u4e00\u4e9b\u8003\u91cf\u56e0\u7d20\uff1a<\/p>\n<ul>\n<li><strong>\u6578\u64da\u91cf\uff1a<\/strong>\u7576\u6d89\u53ca\u5230\u5927\u91cf\u6578\u64da\u6642\uff0cJOIN \u901a\u5e38\u8868\u73fe\u66f4\u597d\u3002\u56e0\u70ba JOIN \u53ef\u4ee5\u5229\u7528\u7d22\u5f15\u4f86\u52a0\u901f\u67e5\u8a62\uff0c\u800c IN \u5728\u8655\u7406\u5927\u91cf\u503c\u6642\u53ef\u80fd\u6703\u8b8a\u5f97\u7de9\u6162\u3002<\/li>\n<li><strong>\u7d22\u5f15\uff1a<\/strong>\u5982\u679c\u76f8\u95dc\u5217\u6709\u7d22\u5f15\uff0cJOIN \u7684\u6027\u80fd\u6703\u986f\u8457\u63d0\u9ad8\u3002\u76f8\u53cd\uff0cIN \u67e5\u8a62\u7684\u6027\u80fd\u53ef\u80fd\u6703\u53d7\u5230\u672a\u7d22\u5f15\u5217\u7684\u5f71\u97ff\u3002<\/li>\n<li><strong>\u67e5\u8a62\u8a08\u5283\uff1a<\/strong>MySQL \u7684\u67e5\u8a62\u512a\u5316\u5668\u6703\u6839\u64da\u6578\u64da\u7684\u7d71\u8a08\u4fe1\u606f\u9078\u64c7\u6700\u4f73\u7684\u57f7\u884c\u8a08\u5283\u3002\u4f7f\u7528 EXPLAIN \u8a9e\u53e5\u53ef\u4ee5\u5e6b\u52a9\u6211\u5011\u4e86\u89e3\u67e5\u8a62\u7684\u57f7\u884c\u8a08\u5283\uff0c\u5f9e\u800c\u505a\u51fa\u66f4\u660e\u667a\u7684\u9078\u64c7\u3002<\/li>\n<\/ul>\n<h2 id=\"%e5%af%a6%e9%9a%9b%e6%a1%88%e4%be%8b%e5%88%86%e6%9e%90-kKMmCVyeOR\">\u5be6\u969b\u6848\u4f8b\u5206\u6790<\/h2>\n<p>\u5047\u8a2d\u6211\u5011\u6709\u4e00\u500b customers \u8868\u548c\u4e00\u500b orders \u8868\uff0ccustomers \u8868\u6709 100,000 \u689d\u8a18\u9304\uff0c\u800c orders \u8868\u6709 1,000,000 \u689d\u8a18\u9304\u3002\u4ee5\u4e0b\u662f\u4f7f\u7528 JOIN \u548c IN \u7684\u6027\u80fd\u6e2c\u8a66\uff1a<\/p>\n<pre><code>-- \u4f7f\u7528 JOIN\nEXPLAIN SELECT a.id, a.name, b.order_date \nFROM customers a \nINNER JOIN orders b ON a.id = b.customer_id \nWHERE a.id &lt; 1000;\n\n-- \u4f7f\u7528 IN\nEXPLAIN SELECT * \nFROM orders \nWHERE customer_id IN (SELECT id FROM customers WHERE id &lt; 1000);<\/code><\/pre>\n<p>\u6839\u64da\u6e2c\u8a66\u7d50\u679c\uff0cJOIN \u901a\u5e38\u6703\u6bd4 IN \u66f4\u5feb\uff0c\u7279\u5225\u662f\u5728\u6578\u64da\u91cf\u8f03\u5927\u7684\u60c5\u6cc1\u4e0b\u3002\u9019\u662f\u56e0\u70ba JOIN \u53ef\u4ee5\u76f4\u63a5\u5229\u7528\u7d22\u5f15\uff0c\u800c IN \u9700\u8981\u5148\u57f7\u884c\u5b50\u67e5\u8a62\uff0c\u7136\u5f8c\u518d\u9032\u884c\u5339\u914d\u3002<\/p>\n<h2 id=\"%e7%b5%90%e8%ab%96-kKMmCVyeOR\">\u7d50\u8ad6<\/h2>\n<p>\u5728 MySQL \u67e5\u8a62\u4e2d\uff0c\u9078\u64c7\u4f7f\u7528 JOIN \u9084\u662f IN \u53d6\u6c7a\u65bc\u5177\u9ad4\u7684\u4f7f\u7528\u5834\u666f\u548c\u6578\u64da\u7d50\u69cb\u3002\u4e00\u822c\u4f86\u8aaa\uff0c\u7576\u8655\u7406\u5927\u91cf\u6578\u64da\u6642\uff0cJOIN \u7684\u6027\u80fd\u66f4\u4f73\uff0c\u800c IN \u66f4\u9069\u5408\u5c0f\u578b\u6578\u64da\u96c6\u3002\u4e86\u89e3\u9019\u4e9b\u5dee\u7570\u53ef\u4ee5\u5e6b\u52a9\u958b\u767c\u8005\u512a\u5316\u67e5\u8a62\uff0c\u63d0\u9ad8\u6578\u64da\u6aa2\u7d22\u7684\u6548\u7387\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\u7684 MySQL \u6578\u64da\u5eab\uff0cServer.HK \u63d0\u4f9b\u591a\u7a2e\u9078\u64c7\uff0c\u6eff\u8db3\u4e0d\u540c\u9700\u6c42\u7684\u5ba2\u6236\u3002\u7121\u8ad6\u662f <a href=\"https:\/\/server.hk\">\u9999\u6e2f\u4f3a\u670d\u5668<\/a> \u9084\u662f <a href=\"https:\/\/server.hk\">\u4e91\u4f3a\u670d\u5668<\/a>\uff0c\u6211\u5011\u90fd\u80fd\u70ba\u60a8\u63d0\u4f9b\u7a69\u5b9a\u7684\u6027\u80fd\u548c\u53ef\u9760\u7684\u652f\u6301\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u63a2\u7d22MySQL\u67e5\u8a62\u6027\u80fd\uff0c\u5206\u6790JOIN\u8207IN\u7684\u901f\u5ea6\u5dee\u7570\uff0c\u5e6b\u52a9\u4f60\u9078\u64c7\u6700\u4f73\u7684\u6578\u64da\u6aa2\u7d22\u65b9\u6cd5\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-75792","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/75792","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=75792"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/75792\/revisions"}],"predecessor-version":[{"id":75793,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/75792\/revisions\/75793"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=75792"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=75792"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=75792"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}