{"id":187508,"date":"2024-11-11T14:51:21","date_gmt":"2024-11-11T06:51:21","guid":{"rendered":"https:\/\/server.hk\/cnblog\/187508\/"},"modified":"2024-11-11T14:51:23","modified_gmt":"2024-11-11T06:51:23","slug":"%e6%95%b8%e6%93%9a%e5%ba%ab%e4%b8%80%e8%a1%8c%e5%ae%b9%e9%87%8f%e5%88%b0%e5%ba%95%e6%9c%89%e5%a4%9a%e5%a4%a7%ef%bc%9f-%e6%95%b8%e6%93%9a%e5%ba%ab%e4%b8%80%e8%a1%8c%e5%ae%b9%e9%87%8f%e5%a4%9a%e5%a4%a7","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/187508\/","title":{"rendered":"\u6578\u64da\u5eab\u4e00\u884c\u5bb9\u91cf\u5230\u5e95\u6709\u591a\u5927\uff1f (\u6578\u64da\u5eab\u4e00\u884c\u5bb9\u91cf\u591a\u5927)"},"content":{"rendered":"<h1 id=\"%e6%95%b8%e6%93%9a%e5%ba%ab%e4%b8%80%e8%a1%8c%e5%ae%b9%e9%87%8f%e5%88%b0%e5%ba%95%e6%9c%89%e5%a4%9a%e5%a4%a7%ef%bc%9f-TiJXUCsUaD\">\u6578\u64da\u5eab\u4e00\u884c\u5bb9\u91cf\u5230\u5e95\u6709\u591a\u5927\uff1f<\/h1>\n<p>\u5728\u6578\u64da\u5eab\u8a2d\u8a08\u4e2d\uff0c\u884c\u7684\u5bb9\u91cf\u662f\u5f71\u97ff\u6027\u80fd\u548c\u5b58\u5132\u6548\u7387\u7684\u91cd\u8981\u56e0\u7d20\u3002\u6bcf\u4e00\u884c\u7684\u5bb9\u91cf\u53d6\u6c7a\u65bc\u591a\u500b\u56e0\u7d20\uff0c\u5305\u62ec\u6578\u64da\u985e\u578b\u3001\u6578\u64da\u5eab\u7cfb\u7d71\u7684\u8a2d\u8a08\u4ee5\u53ca\u884c\u7684\u7d50\u69cb\u3002\u672c\u6587\u5c07\u6df1\u5165\u63a2\u8a0e\u6578\u64da\u5eab\u4e00\u884c\u7684\u5bb9\u91cf\uff0c\u4e26\u63d0\u4f9b\u4e00\u4e9b\u5be6\u969b\u7684\u4f8b\u5b50\u548c\u4ee3\u78bc\u793a\u4f8b\uff0c\u4ee5\u5e6b\u52a9\u8b80\u8005\u66f4\u597d\u5730\u7406\u89e3\u9019\u4e00\u6982\u5ff5\u3002<\/p>\n<h2 id=\"%e6%95%b8%e6%93%9a%e5%ba%ab%e8%a1%8c%e7%9a%84%e5%9f%ba%e6%9c%ac%e6%a6%82%e5%bf%b5-TiJXUCsUaD\">\u6578\u64da\u5eab\u884c\u7684\u57fa\u672c\u6982\u5ff5<\/h2>\n<p>\u5728\u6578\u64da\u5eab\u4e2d\uff0c\u884c\uff08Row\uff09\u662f\u8868\u683c\u4e2d\u7684\u4e00\u500b\u8a18\u9304\uff0c\u6bcf\u4e00\u884c\u5305\u542b\u591a\u500b\u5217\uff08Column\uff09\u3002\u6bcf\u4e00\u5217\u90fd\u6709\u5176\u7279\u5b9a\u7684\u6578\u64da\u985e\u578b\uff0c\u4f8b\u5982\u6574\u6578\u3001\u6d6e\u9ede\u6578\u3001\u5b57\u7b26\u4e32\u7b49\u3002\u884c\u7684\u5bb9\u91cf\u662f\u6307\u4e00\u884c\u4e2d\u6240\u6709\u5217\u6240\u4f54\u7528\u7684\u7e3d\u5b57\u7bc0\u6578\u3002<\/p>\n<h2 id=\"%e5%bd%b1%e9%9f%bf%e8%a1%8c%e5%ae%b9%e9%87%8f%e7%9a%84%e5%9b%a0%e7%b4%a0-TiJXUCsUaD\">\u5f71\u97ff\u884c\u5bb9\u91cf\u7684\u56e0\u7d20<\/h2>\n<ul>\n<li><strong>\u6578\u64da\u985e\u578b\uff1a<\/strong>\u4e0d\u540c\u7684\u6578\u64da\u985e\u578b\u4f54\u7528\u7684\u5b57\u7bc0\u6578\u4e0d\u540c\u3002\u4f8b\u5982\uff0c\u6574\u6578\u985e\u578b\u901a\u5e38\u4f54\u75284\u62168\u500b\u5b57\u7bc0\uff0c\u800c\u5b57\u7b26\u4e32\u985e\u578b\u7684\u5bb9\u91cf\u5247\u53d6\u6c7a\u65bc\u5b57\u7b26\u4e32\u7684\u9577\u5ea6\u3002<\/li>\n<li><strong>NULL\u503c\uff1a<\/strong>\u5728\u6578\u64da\u5eab\u4e2d\uff0cNULL\u503c\u901a\u5e38\u4e0d\u4f54\u7528\u5b58\u5132\u7a7a\u9593\uff0c\u4f46\u5728\u67d0\u4e9b\u60c5\u6cc1\u4e0b\uff0c\u6578\u64da\u5eab\u7cfb\u7d71\u53ef\u80fd\u6703\u70baNULL\u503c\u4fdd\u7559\u984d\u5916\u7684\u5143\u6578\u64da\u3002<\/li>\n<li><strong>\u884c\u7684\u7d50\u69cb\uff1a<\/strong>\u67d0\u4e9b\u6578\u64da\u5eab\u7cfb\u7d71\u652f\u6301\u884c\u7684\u58d3\u7e2e\uff0c\u9019\u53ef\u4ee5\u6e1b\u5c11\u884c\u7684\u5be6\u969b\u5b58\u5132\u9700\u6c42\u3002<\/li>\n<li><strong>\u7d22\u5f15\uff1a<\/strong>\u5982\u679c\u884c\u4e2d\u5305\u542b\u7d22\u5f15\uff0c\u9019\u4e5f\u6703\u5f71\u97ff\u884c\u7684\u5bb9\u91cf\uff0c\u56e0\u70ba\u7d22\u5f15\u9700\u8981\u984d\u5916\u7684\u5b58\u5132\u7a7a\u9593\u3002<\/li>\n<\/ul>\n<h2 id=\"%e6%95%b8%e6%93%9a%e5%ba%ab%e8%a1%8c%e5%ae%b9%e9%87%8f%e7%9a%84%e8%a8%88%e7%ae%97-TiJXUCsUaD\">\u6578\u64da\u5eab\u884c\u5bb9\u91cf\u7684\u8a08\u7b97<\/h2>\n<p>\u70ba\u4e86\u8a08\u7b97\u4e00\u884c\u7684\u5bb9\u91cf\uff0c\u6211\u5011\u53ef\u4ee5\u4f7f\u7528\u4ee5\u4e0b\u516c\u5f0f\uff1a<\/p>\n<pre><code>\u884c\u5bb9\u91cf = \u52171\u7684\u5b57\u7bc0\u6578 + \u52172\u7684\u5b57\u7bc0\u6578 + ... + \u5217N\u7684\u5b57\u7bc0\u6578<\/code><\/pre>\n<p>\u4f8b\u5982\uff0c\u5047\u8a2d\u6211\u5011\u6709\u4e00\u500b\u8868\u683c\uff0c\u5305\u542b\u4ee5\u4e0b\u5217\uff1a<\/p>\n<ul>\n<li>\u6574\u6578\u578b\uff08INT\uff09\uff1a4\u5b57\u7bc0<\/li>\n<li>\u6d6e\u9ede\u578b\uff08FLOAT\uff09\uff1a4\u5b57\u7bc0<\/li>\n<li>\u5b57\u7b26\u4e32\u578b\uff08VARCHAR(100)\uff09\uff1a\u6700\u5927100\u5b57\u7bc0<\/li>\n<\/ul>\n<p>\u90a3\u9ebc\uff0c\u9019\u4e00\u884c\u7684\u6700\u5927\u5bb9\u91cf\u5c07\u662f\uff1a<\/p>\n<pre><code>\u884c\u5bb9\u91cf = 4 + 4 + 100 = 108\u5b57\u7bc0<\/code><\/pre>\n<h2 id=\"%e5%af%a6%e9%9a%9b%e6%a1%88%e4%be%8b%e5%88%86%e6%9e%90-TiJXUCsUaD\">\u5be6\u969b\u6848\u4f8b\u5206\u6790<\/h2>\n<p>\u5728\u5be6\u969b\u61c9\u7528\u4e2d\uff0c\u6578\u64da\u5eab\u7684\u884c\u5bb9\u91cf\u53ef\u80fd\u6703\u53d7\u5230\u591a\u7a2e\u56e0\u7d20\u7684\u5f71\u97ff\u3002\u4f8b\u5982\uff0c\u5728\u4e00\u500b\u7528\u65bc\u96fb\u5b50\u5546\u52d9\u7684\u6578\u64da\u5eab\u4e2d\uff0c\u53ef\u80fd\u6703\u6709\u5927\u91cf\u7684\u5b57\u7b26\u4e32\u578b\u6578\u64da\uff08\u5982\u7522\u54c1\u540d\u7a31\u3001\u63cf\u8ff0\u7b49\uff09\uff0c\u9019\u6703\u986f\u8457\u589e\u52a0\u6bcf\u884c\u7684\u5bb9\u91cf\u3002\u53e6\u4e00\u65b9\u9762\uff0c\u5c0d\u65bc\u4e00\u500b\u53ea\u5305\u542b\u6578\u5b57\u7684\u6578\u64da\u5eab\uff0c\u884c\u7684\u5bb9\u91cf\u5247\u6703\u76f8\u5c0d\u8f03\u5c0f\u3002<\/p>\n<p>\u4ee5\u4e0b\u662f\u4e00\u500b\u7c21\u55ae\u7684SQL\u793a\u4f8b\uff0c\u5c55\u793a\u5982\u4f55\u5275\u5efa\u4e00\u500b\u5305\u542b\u4e0d\u540c\u6578\u64da\u985e\u578b\u7684\u8868\uff1a<\/p>\n<pre><code>CREATE TABLE Products (\n    ProductID INT,\n    ProductName VARCHAR(100),\n    Price FLOAT\n);<\/code><\/pre>\n<p>\u5728\u9019\u500b\u4f8b\u5b50\u4e2d\uff0c\u6bcf\u4e00\u884c\u7684\u5bb9\u91cf\u5c07\u53d6\u6c7a\u65bc\u6bcf\u500b\u7522\u54c1\u7684\u540d\u7a31\u9577\u5ea6\uff0c\u4f46\u6574\u9ad4\u7d50\u69cb\u4ecd\u7136\u9075\u5faa\u4e0a\u8ff0\u8a08\u7b97\u65b9\u6cd5\u3002<\/p>\n<h2 id=\"%e7%b5%90%e8%ab%96-TiJXUCsUaD\">\u7d50\u8ad6<\/h2>\n<p>\u6578\u64da\u5eab\u4e00\u884c\u7684\u5bb9\u91cf\u662f\u8a2d\u8a08\u548c\u6027\u80fd\u512a\u5316\u4e2d\u7684\u4e00\u500b\u91cd\u8981\u8003\u91cf\u56e0\u7d20\u3002\u4e86\u89e3\u884c\u7684\u5bb9\u91cf\u5982\u4f55\u53d7\u5230\u6578\u64da\u985e\u578b\u3001NULL\u503c\u3001\u884c\u7d50\u69cb\u548c\u7d22\u5f15\u7b49\u56e0\u7d20\u7684\u5f71\u97ff\uff0c\u53ef\u4ee5\u5e6b\u52a9\u958b\u767c\u8005\u5728\u8a2d\u8a08\u6578\u64da\u5eab\u6642\u505a\u51fa\u66f4\u660e\u667a\u7684\u6c7a\u7b56\u3002\u96a8\u8457\u6578\u64da\u91cf\u7684\u589e\u9577\uff0c\u5408\u7406\u7684\u884c\u5bb9\u91cf\u8a2d\u8a08\u5c07\u6709\u52a9\u65bc\u63d0\u9ad8\u6578\u64da\u5eab\u7684\u6027\u80fd\u548c\u6548\u7387\u3002<\/p>\n<p>\u5982\u679c\u60a8\u5c0d\u65bc\u6578\u64da\u5eab\u7684\u8a2d\u8a08\u548c\u7ba1\u7406\u6709\u9032\u4e00\u6b65\u7684\u9700\u6c42\uff0c\u6216\u8005\u60f3\u8981\u4e86\u89e3\u66f4\u591a\u95dc\u65bc<a href=\"https:\/\/server.hk\">\u9999\u6e2fVPS<\/a>\u548c<a href=\"https:\/\/server.hk\">\u96f2\u4f3a\u670d\u5668<\/a>\u7684\u8cc7\u8a0a\uff0c\u6b61\u8fce\u8a2a\u554f\u6211\u5011\u7684\u7db2\u7ad9\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u4e86\u89e3\u6578\u64da\u5eab\u4e00\u884c\u5bb9\u91cf\u7684\u5927\u5c0f\uff0c\u63a2\u8a0e\u5f71\u97ff\u56e0\u7d20\u53ca\u6700\u4f73\u5be6\u8e10\uff0c\u52a9\u60a8\u512a\u5316\u6578\u64da\u5b58\u5132\u8207\u7ba1\u7406\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-187508","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/187508","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=187508"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/187508\/revisions"}],"predecessor-version":[{"id":187509,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/187508\/revisions\/187509"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=187508"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=187508"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=187508"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}