{"id":78552,"date":"2024-10-16T11:59:16","date_gmt":"2024-10-16T03:59:16","guid":{"rendered":"https:\/\/server.hk\/cnblog\/78552\/"},"modified":"2024-10-16T11:59:16","modified_gmt":"2024-10-16T03:59:16","slug":"mysql%e6%8c%87%e4%bb%a4-foreign-key%ef%bc%88%e5%a4%96%e9%8d%b5%ef%bc%89","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/78552\/","title":{"rendered":"MySQL\u6307\u4ee4: FOREIGN KEY\uff08\u5916\u9375\uff09"},"content":{"rendered":"<h1 id=\"mysql%e6%8c%87%e4%bb%a4-foreign-key%ef%bc%88%e5%a4%96%e9%8d%b5%ef%bc%89-VaIxZEmLix\">MySQL\u6307\u4ee4: FOREIGN KEY\uff08\u5916\u9375\uff09<\/h1>\n<p>\u5728\u95dc\u806f\u5f0f\u8cc7\u6599\u5eab\u4e2d\uff0c\u5916\u9375\uff08FOREIGN KEY\uff09\u662f\u4e00\u500b\u91cd\u8981\u7684\u6982\u5ff5\uff0c\u5b83\u7528\u65bc\u5efa\u7acb\u548c\u5f37\u5316\u8cc7\u6599\u8868\u4e4b\u9593\u7684\u95dc\u806f\u6027\u3002MySQL\u4f5c\u70ba\u4e00\u500b\u6d41\u884c\u7684\u8cc7\u6599\u5eab\u7ba1\u7406\u7cfb\u7d71\uff0c\u63d0\u4f9b\u4e86\u5c0d\u5916\u9375\u7684\u652f\u6301\uff0c\u4f7f\u5f97\u8cc7\u6599\u7684\u5b8c\u6574\u6027\u548c\u4e00\u81f4\u6027\u5f97\u4ee5\u7dad\u8b77\u3002\u672c\u6587\u5c07\u6df1\u5165\u63a2\u8a0eMySQL\u4e2d\u7684\u5916\u9375\uff0c\u5305\u62ec\u5176\u5b9a\u7fa9\u3001\u7528\u9014\u3001\u4ee5\u53ca\u5982\u4f55\u5728\u8cc7\u6599\u8868\u4e2d\u5be6\u73fe\u5916\u9375\u7d04\u675f\u3002<\/p>\n<h2 id=\"%e5%a4%96%e9%8d%b5%e7%9a%84%e5%ae%9a%e7%be%a9-VaIxZEmLix\">\u5916\u9375\u7684\u5b9a\u7fa9<\/h2>\n<p>\u5916\u9375\u662f\u4e00\u500b\u8cc7\u6599\u8868\u4e2d\u7684\u6b04\u4f4d\uff08\u6216\u6b04\u4f4d\u7d44\u5408\uff09\uff0c\u5b83\u6307\u5411\u53e6\u4e00\u500b\u8cc7\u6599\u8868\u7684\u4e3b\u9375\u3002\u9019\u7a2e\u95dc\u806f\u4f7f\u5f97\u8cc7\u6599\u5eab\u80fd\u5920\u4fdd\u6301\u8cc7\u6599\u7684\u5b8c\u6574\u6027\uff0c\u78ba\u4fdd\u5728\u4e00\u500b\u8cc7\u6599\u8868\u4e2d\u5f15\u7528\u7684\u8cc7\u6599\u5728\u53e6\u4e00\u500b\u8cc7\u6599\u8868\u4e2d\u662f\u5b58\u5728\u7684\u3002\u5916\u9375\u7684\u4e3b\u8981\u529f\u80fd\u662f\u9632\u6b62\u7121\u6548\u8cc7\u6599\u7684\u63d2\u5165\uff0c\u4e26\u5728\u8cc7\u6599\u66f4\u65b0\u6216\u522a\u9664\u6642\u7dad\u8b77\u8cc7\u6599\u7684\u4e00\u81f4\u6027\u3002<\/p>\n<h2 id=\"%e5%a4%96%e9%8d%b5%e7%9a%84%e7%94%a8%e9%80%94-VaIxZEmLix\">\u5916\u9375\u7684\u7528\u9014<\/h2>\n<ul>\n<li><strong>\u8cc7\u6599\u5b8c\u6574\u6027\uff1a<\/strong>\u5916\u9375\u7d04\u675f\u78ba\u4fdd\u4e86\u8cc7\u6599\u7684\u6b63\u78ba\u6027\uff0c\u9632\u6b62\u4e86\u5b64\u7acb\u7684\u8cc7\u6599\u51fa\u73fe\u3002<\/li>\n<li><strong>\u95dc\u806f\u67e5\u8a62\uff1a<\/strong>\u900f\u904e\u5916\u9375\uff0c\u4f7f\u7528\u8005\u53ef\u4ee5\u8f15\u9b06\u5730\u9032\u884c\u591a\u8868\u67e5\u8a62\uff0c\u7372\u53d6\u76f8\u95dc\u8cc7\u6599\u3002<\/li>\n<li><strong>\u8cc7\u6599\u66f4\u65b0\u8207\u522a\u9664\u7684\u63a7\u5236\uff1a<\/strong>\u5916\u9375\u53ef\u4ee5\u8a2d\u7f6e\u7d1a\u806f\u66f4\u65b0\u6216\u522a\u9664\uff0c\u9019\u6a23\u5728\u4e3b\u8868\u8cc7\u6599\u8b8a\u66f4\u6642\uff0c\u5f9e\u8868\u7684\u8cc7\u6599\u4e5f\u6703\u81ea\u52d5\u66f4\u65b0\u6216\u522a\u9664\u3002<\/li>\n<\/ul>\n<h2 id=\"%e5%a6%82%e4%bd%95%e5%9c%a8mysql%e4%b8%ad%e4%bd%bf%e7%94%a8%e5%a4%96%e9%8d%b5-VaIxZEmLix\">\u5982\u4f55\u5728MySQL\u4e2d\u4f7f\u7528\u5916\u9375<\/h2>\n<p>\u5728MySQL\u4e2d\uff0c\u5275\u5efa\u5916\u9375\u7d04\u675f\u7684\u57fa\u672c\u8a9e\u6cd5\u5982\u4e0b\uff1a<\/p>\n<pre><code>CREATE TABLE \u5b50\u8868 (\n    id INT PRIMARY KEY,\n    \u4e3b\u8868_id INT,\n    FOREIGN KEY (\u4e3b\u8868_id) REFERENCES \u4e3b\u8868(id)\n);<\/code><\/pre>\n<p>\u5728\u9019\u500b\u4f8b\u5b50\u4e2d\uff0c<code>\u5b50\u8868<\/code>\u4e2d\u7684<code>\u4e3b\u8868_id<\/code>\u6b04\u4f4d\u662f\u5916\u9375\uff0c\u5b83\u53c3\u8003\u4e86<code>\u4e3b\u8868<\/code>\u4e2d\u7684<code>id<\/code>\u6b04\u4f4d\u3002\u9019\u6a23\u7684\u8a2d\u7f6e\u78ba\u4fdd\u4e86<code>\u5b50\u8868<\/code>\u4e2d\u7684\u6bcf\u4e00\u500b<code>\u4e3b\u8868_id<\/code>\u503c\u90fd\u5fc5\u9808\u5728<code>\u4e3b\u8868<\/code>\u4e2d\u5b58\u5728\u3002<\/p>\n<h3 id=\"%e5%a4%96%e9%8d%b5%e7%b4%84%e6%9d%9f%e7%9a%84%e9%81%b8%e9%a0%85-VaIxZEmLix\">\u5916\u9375\u7d04\u675f\u7684\u9078\u9805<\/h3>\n<p>\u5728\u5b9a\u7fa9\u5916\u9375\u6642\uff0c\u53ef\u4ee5\u4f7f\u7528\u4e00\u4e9b\u9078\u9805\u4f86\u63a7\u5236\u5176\u884c\u70ba\uff1a<\/p>\n<ul>\n<li><strong>ON DELETE CASCADE\uff1a<\/strong>\u7576\u4e3b\u8868\u4e2d\u7684\u8cc7\u6599\u88ab\u522a\u9664\u6642\uff0c\u6240\u6709\u5f15\u7528\u8a72\u8cc7\u6599\u7684\u5b50\u8868\u8cc7\u6599\u4e5f\u6703\u81ea\u52d5\u522a\u9664\u3002<\/li>\n<li><strong>ON UPDATE CASCADE\uff1a<\/strong>\u7576\u4e3b\u8868\u4e2d\u7684\u8cc7\u6599\u88ab\u66f4\u65b0\u6642\uff0c\u6240\u6709\u5f15\u7528\u8a72\u8cc7\u6599\u7684\u5b50\u8868\u8cc7\u6599\u4e5f\u6703\u81ea\u52d5\u66f4\u65b0\u3002<\/li>\n<li><strong>SET NULL\uff1a<\/strong>\u7576\u4e3b\u8868\u4e2d\u7684\u8cc7\u6599\u88ab\u522a\u9664\u6216\u66f4\u65b0\u6642\uff0c\u5b50\u8868\u4e2d\u5c0d\u61c9\u7684\u5916\u9375\u6b04\u4f4d\u6703\u88ab\u8a2d\u7f6e\u70baNULL\u3002<\/li>\n<\/ul>\n<h2 id=\"%e7%af%84%e4%be%8b-VaIxZEmLix\">\u7bc4\u4f8b<\/h2>\n<p>\u4ee5\u4e0b\u662f\u4e00\u500b\u5b8c\u6574\u7684\u7bc4\u4f8b\uff0c\u5c55\u793a\u5982\u4f55\u5275\u5efa\u5169\u500b\u8cc7\u6599\u8868\u4e26\u8a2d\u7f6e\u5916\u9375\u7d04\u675f\uff1a<\/p>\n<pre><code>CREATE TABLE \u4e3b\u8868 (\n    id INT AUTO_INCREMENT PRIMARY KEY,\n    name VARCHAR(100) NOT NULL\n);\n\nCREATE TABLE \u5b50\u8868 (\n    id INT AUTO_INCREMENT PRIMARY KEY,\n    \u4e3b\u8868_id INT,\n    description TEXT,\n    FOREIGN KEY (\u4e3b\u8868_id) REFERENCES \u4e3b\u8868(id) ON DELETE CASCADE\n);<\/code><\/pre>\n<p>\u5728\u9019\u500b\u7bc4\u4f8b\u4e2d\uff0c<code>\u4e3b\u8868<\/code>\u5305\u542b\u4e00\u500b\u81ea\u589e\u7684\u4e3b\u9375<code>id<\/code>\uff0c\u800c<code>\u5b50\u8868<\/code>\u5247\u6709\u4e00\u500b\u5916\u9375<code>\u4e3b\u8868_id<\/code>\uff0c\u5b83\u53c3\u8003\u4e86<code>\u4e3b\u8868<\/code>\u7684<code>id<\/code>\u3002\u7576<code>\u4e3b\u8868<\/code>\u4e2d\u7684\u4e00\u689d\u8a18\u9304\u88ab\u522a\u9664\u6642\uff0c\u6240\u6709\u5f15\u7528\u8a72\u8a18\u9304\u7684<code>\u5b50\u8868<\/code>\u8cc7\u6599\u4e5f\u6703\u88ab\u81ea\u52d5\u522a\u9664\u3002<\/p>\n<h2 id=\"%e7%b5%90%e8%ab%96-VaIxZEmLix\">\u7d50\u8ad6<\/h2>\n<p>\u5916\u9375\u5728MySQL\u4e2d\u626e\u6f14\u8457\u81f3\u95dc\u91cd\u8981\u7684\u89d2\u8272\uff0c\u5b83\u4e0d\u50c5\u6709\u52a9\u65bc\u7dad\u8b77\u8cc7\u6599\u7684\u5b8c\u6574\u6027\uff0c\u9084\u80fd\u4fc3\u9032\u8cc7\u6599\u8868\u4e4b\u9593\u7684\u95dc\u806f\u67e5\u8a62\u3002\u900f\u904e\u6b63\u78ba\u5730\u4f7f\u7528\u5916\u9375\u7d04\u675f\uff0c\u958b\u767c\u8005\u53ef\u4ee5\u78ba\u4fdd\u8cc7\u6599\u5eab\u7684\u7a69\u5b9a\u6027\u548c\u4e00\u81f4\u6027\uff0c\u5f9e\u800c\u63d0\u9ad8\u61c9\u7528\u7a0b\u5f0f\u7684\u53ef\u9760\u6027\u3002<\/p>\n<p>\u5982\u9700\u4e86\u89e3\u66f4\u591a\u95dc\u65bc<code>VPS<\/code>\u3001<code>\u9999\u6e2fVPS<\/code>\u53ca\u5176\u4ed6<code>\u4f3a\u670d\u5668<\/code>\u89e3\u6c7a\u65b9\u6848\uff0c\u8acb\u8a2a\u554f\u6211\u5011\u7684\u7db2\u7ad9 <a href=\"https:\/\/server.hk\">Server.HK<\/a>\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u4e86\u89e3MySQL\u4e2d\u7684FOREIGN KEY\uff08\u5916\u9375\uff09\u6307\u4ee4\uff0c\u5b78\u7fd2\u5982\u4f55\u5efa\u7acb\u548c\u7ba1\u7406\u8cc7\u6599\u8868\u4e4b\u9593\u7684\u95dc\u806f\u6027\uff0c\u78ba\u4fdd\u6578\u64da\u5b8c\u6574\u6027\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-78552","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/78552","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=78552"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/78552\/revisions"}],"predecessor-version":[{"id":78553,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/78552\/revisions\/78553"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=78552"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=78552"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=78552"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}