{"id":175511,"date":"2024-11-08T06:29:17","date_gmt":"2024-11-07T22:29:17","guid":{"rendered":"https:\/\/server.hk\/cnblog\/175511\/"},"modified":"2024-11-08T06:29:18","modified_gmt":"2024-11-07T22:29:18","slug":"%e5%a6%82%e4%bd%95%e4%bd%bf%e7%94%a8%e6%95%b8%e6%93%9a%e5%ba%ab%e5%af%a6%e7%8f%be%e6%a8%b9%e5%bd%a2%e7%b5%90%e6%a7%8b%ef%bc%9f-%e6%95%b8%e6%93%9a%e5%ba%ab%e5%af%a6%e7%8f%be%e6%a8%b9%e5%bd%a2","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/175511\/","title":{"rendered":"\u5982\u4f55\u4f7f\u7528\u6578\u64da\u5eab\u5be6\u73fe\u6a39\u5f62\u7d50\u69cb\uff1f (\u6578\u64da\u5eab\u5be6\u73fe\u6a39\u5f62)"},"content":{"rendered":"<h1 id=\"%e5%a6%82%e4%bd%95%e4%bd%bf%e7%94%a8%e6%95%b8%e6%93%9a%e5%ba%ab%e5%af%a6%e7%8f%be%e6%a8%b9%e5%bd%a2%e7%b5%90%e6%a7%8b%ef%bc%9f-%e6%95%b8%e6%93%9a%e5%ba%ab%e5%af%a6%e7%8f%be%e6%a8%b9%e5%bd%a2-hnplwuuddx\">\u5982\u4f55\u4f7f\u7528\u6578\u64da\u5eab\u5be6\u73fe\u6a39\u5f62\u7d50\u69cb\uff1f (\u6578\u64da\u5eab\u5be6\u73fe\u6a39\u5f62)<\/h1>\n<p>\u6a39\u5f62\u7d50\u69cb\u662f\u4e00\u7a2e\u5e38\u898b\u7684\u6578\u64da\u7d50\u69cb\uff0c\u5ee3\u6cdb\u61c9\u7528\u65bc\u5404\u7a2e\u5834\u666f\uff0c\u5982\u6587\u4ef6\u7cfb\u7d71\u3001\u7d44\u7e54\u7d50\u69cb\u3001\u5206\u985e\u76ee\u9304\u7b49\u3002\u5728\u6578\u64da\u5eab\u4e2d\u5be6\u73fe\u6a39\u5f62\u7d50\u69cb\u53ef\u4ee5\u5e6b\u52a9\u6211\u5011\u66f4\u6709\u6548\u5730\u7ba1\u7406\u548c\u67e5\u8a62\u6578\u64da\u3002\u672c\u6587\u5c07\u63a2\u8a0e\u5982\u4f55\u5728\u6578\u64da\u5eab\u4e2d\u5be6\u73fe\u6a39\u5f62\u7d50\u69cb\uff0c\u4e26\u63d0\u4f9b\u4e00\u4e9b\u5be6\u7528\u7684\u793a\u4f8b\u548c\u4ee3\u78bc\u7247\u6bb5\u3002<\/p>\n<h2 id=\"%e6%a8%b9%e5%bd%a2%e7%b5%90%e6%a7%8b%e7%9a%84%e5%9f%ba%e6%9c%ac%e6%a6%82%e5%bf%b5-hnplwuuddx\">\u6a39\u5f62\u7d50\u69cb\u7684\u57fa\u672c\u6982\u5ff5<\/h2>\n<p>\u6a39\u5f62\u7d50\u69cb\u7531\u7bc0\u9ede\u7d44\u6210\uff0c\u6bcf\u500b\u7bc0\u9ede\u53ef\u4ee5\u6709\u96f6\u500b\u6216\u591a\u500b\u5b50\u7bc0\u9ede\u3002\u6a39\u7684\u9802\u90e8\u7a31\u70ba\u6839\u7bc0\u9ede\uff0c\u6c92\u6709\u7236\u7bc0\u9ede\u7684\u7bc0\u9ede\u7a31\u70ba\u8449\u5b50\u7bc0\u9ede\u3002\u6a39\u5f62\u7d50\u69cb\u7684\u7279\u9ede\u662f\u5c64\u6b21\u6027\uff0c\u9019\u4f7f\u5f97\u5b83\u975e\u5e38\u9069\u5408\u7528\u65bc\u8868\u793a\u5c64\u7d1a\u95dc\u4fc2\u7684\u6578\u64da\u3002<\/p>\n<h2 id=\"%e5%9c%a8%e6%95%b8%e6%93%9a%e5%ba%ab%e4%b8%ad%e5%af%a6%e7%8f%be%e6%a8%b9%e5%bd%a2%e7%b5%90%e6%a7%8b%e7%9a%84%e6%96%b9%e6%b3%95-hnplwuuddx\">\u5728\u6578\u64da\u5eab\u4e2d\u5be6\u73fe\u6a39\u5f62\u7d50\u69cb\u7684\u65b9\u6cd5<\/h2>\n<p>\u5728\u6578\u64da\u5eab\u4e2d\u5be6\u73fe\u6a39\u5f62\u7d50\u69cb\u6709\u5e7e\u7a2e\u5e38\u898b\u7684\u65b9\u6cd5\uff0c\u4ee5\u4e0b\u662f\u5176\u4e2d\u4e09\u7a2e\uff1a<\/p>\n<h3 id=\"1-%e8%87%aa%e5%bc%95%e7%94%a8%e6%a8%a1%e5%9e%8b-hnplwuuddx\">1. \u81ea\u5f15\u7528\u6a21\u578b<\/h3>\n<p>\u81ea\u5f15\u7528\u6a21\u578b\u662f\u6700\u7c21\u55ae\u7684\u6a39\u5f62\u7d50\u69cb\u5be6\u73fe\u65b9\u5f0f\u3002\u5728\u9019\u7a2e\u6a21\u578b\u4e2d\uff0c\u8868\u4e2d\u6709\u4e00\u500b\u5916\u9375\u5b57\u6bb5\u6307\u5411\u540c\u4e00\u8868\u7684\u4e3b\u9375\uff0c\u9019\u6a23\u53ef\u4ee5\u5f62\u6210\u7236\u5b50\u95dc\u4fc2\u3002<\/p>\n<pre><code>CREATE TABLE categories (\n    id INT PRIMARY KEY,\n    name VARCHAR(100),\n    parent_id INT,\n    FOREIGN KEY (parent_id) REFERENCES categories(id)\n);\n<\/code><\/pre>\n<p>\u5728\u9019\u500b\u4f8b\u5b50\u4e2d\uff0c<code>parent_id<\/code>\u5b57\u6bb5\u6307\u5411\u540c\u4e00\u8868\u7684<code>id<\/code>\uff0c\u5f9e\u800c\u5f62\u6210\u6a39\u5f62\u7d50\u69cb\u3002\u6839\u7bc0\u9ede\u7684<code>parent_id<\/code>\u53ef\u4ee5\u8a2d\u7f6e\u70baNULL\u3002<\/p>\n<h3 id=\"2-%e9%82%8a%e5%88%97%e8%a1%a8%e6%a8%a1%e5%9e%8b-hnplwuuddx\">2. \u908a\u5217\u8868\u6a21\u578b<\/h3>\n<p>\u908a\u5217\u8868\u6a21\u578b\u5c07\u6a39\u5f62\u7d50\u69cb\u7684\u6bcf\u4e00\u689d\u908a\u90fd\u5b58\u5132\u70ba\u4e00\u689d\u8a18\u9304\u3002\u9019\u7a2e\u65b9\u6cd5\u901a\u5e38\u9700\u8981\u5169\u500b\u5b57\u6bb5\u4f86\u8868\u793a\u7236\u7bc0\u9ede\u548c\u5b50\u7bc0\u9ede\u3002<\/p>\n<pre><code>CREATE TABLE edges (\n    parent_id INT,\n    child_id INT,\n    PRIMARY KEY (parent_id, child_id),\n    FOREIGN KEY (parent_id) REFERENCES categories(id),\n    FOREIGN KEY (child_id) REFERENCES categories(id)\n);\n<\/code><\/pre>\n<p>\u9019\u7a2e\u65b9\u6cd5\u7684\u512a\u9ede\u662f\u53ef\u4ee5\u8f15\u9b06\u5730\u67e5\u8a62\u6574\u500b\u6a39\u7684\u7d50\u69cb\uff0c\u4f46\u5728\u67e5\u8a62\u6642\u53ef\u80fd\u9700\u8981\u591a\u6b21\u806f\u63a5\u3002<\/p>\n<h3 id=\"3-%e5%b5%8c%e5%a5%97%e9%9b%86%e6%a8%a1%e5%9e%8b-hnplwuuddx\">3. \u5d4c\u5957\u96c6\u6a21\u578b<\/h3>\n<p>\u5d4c\u5957\u96c6\u6a21\u578b\u4f7f\u7528\u5169\u500b\u984d\u5916\u7684\u5b57\u6bb5\u4f86\u8868\u793a\u6bcf\u500b\u7bc0\u9ede\u7684\u5de6\u503c\u548c\u53f3\u503c\u3002\u9019\u7a2e\u65b9\u6cd5\u53ef\u4ee5\u9ad8\u6548\u5730\u67e5\u8a62\u6574\u500b\u6a39\u7684\u7d50\u69cb\uff0c\u4f46\u5728\u63d2\u5165\u548c\u522a\u9664\u7bc0\u9ede\u6642\u9700\u8981\u66f4\u65b0\u591a\u500b\u8a18\u9304\u3002<\/p>\n<pre><code>CREATE TABLE nested_categories (\n    id INT PRIMARY KEY,\n    name VARCHAR(100),\n    lft INT,\n    rgt INT\n);\n<\/code><\/pre>\n<p>\u5728\u9019\u500b\u6a21\u578b\u4e2d\uff0c<code>lft<\/code>\u548c<code>rgt<\/code>\u5b57\u6bb5\u7528\u4f86\u8868\u793a\u7bc0\u9ede\u7684\u7bc4\u570d\uff0c\u9019\u6a23\u53ef\u4ee5\u5feb\u901f\u67e5\u8a62\u67d0\u500b\u7bc0\u9ede\u7684\u6240\u6709\u5b50\u7bc0\u9ede\u3002<\/p>\n<h2 id=\"%e6%9f%a5%e8%a9%a2%e6%a8%b9%e5%bd%a2%e7%b5%90%e6%a7%8b%e7%9a%84%e7%a4%ba%e4%be%8b-hnplwuuddx\">\u67e5\u8a62\u6a39\u5f62\u7d50\u69cb\u7684\u793a\u4f8b<\/h2>\n<p>\u4ee5\u4e0b\u662f\u4f7f\u7528\u81ea\u5f15\u7528\u6a21\u578b\u67e5\u8a62\u6a39\u5f62\u7d50\u69cb\u7684\u793a\u4f8b\uff1a<\/p>\n<pre><code>SELECT * FROM categories WHERE parent_id IS NULL; -- \u67e5\u8a62\u6240\u6709\u6839\u7bc0\u9ede\nSELECT * FROM categories WHERE parent_id = 1; -- \u67e5\u8a62\u67d0\u500b\u7bc0\u9ede\u7684\u5b50\u7bc0\u9ede\n<\/code><\/pre>\n<p>\u4f7f\u7528\u5d4c\u5957\u96c6\u6a21\u578b\u67e5\u8a62\u6240\u6709\u5b50\u7bc0\u9ede\u7684\u793a\u4f8b\uff1a<\/p>\n<pre><code>SELECT * FROM nested_categories WHERE lft BETWEEN ? AND ?; -- \u67e5\u8a62\u67d0\u500b\u7bc0\u9ede\u7684\u6240\u6709\u5b50\u7bc0\u9ede\n<\/code><\/pre>\n<h2 id=\"%e7%b8%bd%e7%b5%90-hnplwuuddx\">\u7e3d\u7d50<\/h2>\n<p>\u5728\u6578\u64da\u5eab\u4e2d\u5be6\u73fe\u6a39\u5f62\u7d50\u69cb\u6709\u591a\u7a2e\u65b9\u6cd5\uff0c\u6bcf\u7a2e\u65b9\u6cd5\u90fd\u6709\u5176\u512a\u7f3a\u9ede\u3002\u81ea\u5f15\u7528\u6a21\u578b\u7c21\u55ae\u6613\u7528\uff0c\u908a\u5217\u8868\u6a21\u578b\u9069\u5408\u65bc\u9700\u8981\u983b\u7e41\u67e5\u8a62\u7684\u5834\u666f\uff0c\u800c\u5d4c\u5957\u96c6\u6a21\u578b\u5247\u5728\u67e5\u8a62\u6548\u7387\u4e0a\u8868\u73fe\u512a\u7570\u3002\u6839\u64da\u5177\u9ad4\u9700\u6c42\u9078\u64c7\u5408\u9069\u7684\u5be6\u73fe\u65b9\u5f0f\uff0c\u53ef\u4ee5\u6709\u6548\u5730\u7ba1\u7406\u548c\u67e5\u8a62\u6a39\u5f62\u7d50\u69cb\u7684\u6578\u64da\u3002<\/p>\n<p>\u5982\u679c\u60a8\u9700\u8981\u9ad8\u6548\u7684\u6578\u64da\u5eab\u89e3\u6c7a\u65b9\u6848\uff0c\u8003\u616e\u4f7f\u7528<a href=\"https:\/\/server.hk\">\u9999\u6e2fVPS<\/a>\u4f86\u90e8\u7f72\u60a8\u7684\u61c9\u7528\u7a0b\u5e8f\uff0c\u4eab\u53d7\u7a69\u5b9a\u7684\u6027\u80fd\u548c\u9748\u6d3b\u7684\u914d\u7f6e\u9078\u64c7\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u5b78\u7fd2\u5982\u4f55\u5728\u6578\u64da\u5eab\u4e2d\u5be6\u73fe\u6a39\u5f62\u7d50\u69cb\uff0c\u63a2\u7d22\u4e0d\u540c\u65b9\u6cd5\u8207\u6700\u4f73\u5be6\u8e10\uff0c\u63d0\u5347\u6578\u64da\u7ba1\u7406\u8207\u67e5\u8a62\u6548\u7387\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-175511","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/175511","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=175511"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/175511\/revisions"}],"predecessor-version":[{"id":175512,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/175511\/revisions\/175512"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=175511"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=175511"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=175511"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}