{"id":185594,"date":"2024-11-10T22:53:32","date_gmt":"2024-11-10T14:53:32","guid":{"rendered":"https:\/\/server.hk\/cnblog\/185594\/"},"modified":"2024-11-10T22:53:33","modified_gmt":"2024-11-10T14:53:33","slug":"%e8%a6%96%e5%9c%96%e9%99%90%e5%88%b6%e6%95%b8%e6%93%9a%e5%ba%ab%e6%95%b8%e6%93%9a%e4%bf%ae%e6%94%b9%e8%83%bd%e5%8a%9b%ef%bc%88%e4%bd%bf%e7%94%a8%e8%a6%96%e5%9c%96%e4%bf%ae%e6%94%b9%e6%95%b8%e6%93%9a","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/185594\/","title":{"rendered":"\u8996\u5716\u9650\u5236\u6578\u64da\u5eab\u6578\u64da\u4fee\u6539\u80fd\u529b\uff08\u4f7f\u7528\u8996\u5716\u4fee\u6539\u6578\u64da\u5eab\u6578\u64da\u7684\u9650\u5236\uff09"},"content":{"rendered":"<h1 id=\"%e8%a6%96%e5%9c%96%e9%99%90%e5%88%b6%e6%95%b8%e6%93%9a%e5%ba%ab%e6%95%b8%e6%93%9a%e4%bf%ae%e6%94%b9%e8%83%bd%e5%8a%9b%ef%bc%88%e4%bd%bf%e7%94%a8%e8%a6%96%e5%9c%96%e4%bf%ae%e6%94%b9%e6%95%b8%e6%93%9a-TTklHNPHdI\">\u8996\u5716\u9650\u5236\u6578\u64da\u5eab\u6578\u64da\u4fee\u6539\u80fd\u529b\uff08\u4f7f\u7528\u8996\u5716\u4fee\u6539\u6578\u64da\u5eab\u6578\u64da\u7684\u9650\u5236\uff09<\/h1>\n<p>\u5728\u6578\u64da\u5eab\u7ba1\u7406\u7cfb\u7d71\u4e2d\uff0c\u8996\u5716\uff08View\uff09\u662f\u4e00\u7a2e\u865b\u64ec\u8868\u683c\uff0c\u5b83\u662f\u57fa\u65bc\u4e00\u500b\u6216\u591a\u500b\u57fa\u790e\u8868\u683c\u7684\u67e5\u8a62\u7d50\u679c\u3002\u8996\u5716\u7684\u4e3b\u8981\u529f\u80fd\u662f\u63d0\u4f9b\u4e00\u500b\u7c21\u5316\u7684\u6578\u64da\u8a2a\u554f\u65b9\u5f0f\uff0c\u4e26\u4e14\u53ef\u4ee5\u7528\u4f86\u96b1\u85cf\u6578\u64da\u7684\u8907\u96dc\u6027\u3002\u7136\u800c\uff0c\u4f7f\u7528\u8996\u5716\u4f86\u4fee\u6539\u6578\u64da\u5eab\u4e2d\u7684\u6578\u64da\u6642\uff0c\u5b58\u5728\u4e00\u4e9b\u9650\u5236\u3002\u672c\u6587\u5c07\u63a2\u8a0e\u9019\u4e9b\u9650\u5236\u53ca\u5176\u80cc\u5f8c\u7684\u539f\u56e0\u3002<\/p>\n<h2 id=\"%e8%a6%96%e5%9c%96%e7%9a%84%e5%9f%ba%e6%9c%ac%e6%a6%82%e5%bf%b5-TTklHNPHdI\">\u8996\u5716\u7684\u57fa\u672c\u6982\u5ff5<\/h2>\n<p>\u8996\u5716\u662f\u4e00\u7a2e\u865b\u64ec\u8868\u683c\uff0c\u4e26\u4e0d\u5132\u5b58\u6578\u64da\uff0c\u800c\u662f\u52d5\u614b\u751f\u6210\u7684\u3002\u7528\u6236\u53ef\u4ee5\u901a\u904e\u67e5\u8a62\u8996\u5716\u4f86\u7372\u53d6\u6578\u64da\uff0c\u9019\u4f7f\u5f97\u8996\u5716\u5728\u6578\u64da\u5b89\u5168\u6027\u548c\u6578\u64da\u62bd\u8c61\u65b9\u9762\u5177\u6709\u91cd\u8981\u4f5c\u7528\u3002\u8996\u5716\u53ef\u4ee5\u7528\u4f86\u9650\u5236\u7528\u6236\u5c0d\u57fa\u790e\u8868\u683c\u7684\u76f4\u63a5\u8a2a\u554f\uff0c\u5f9e\u800c\u4fdd\u8b77\u654f\u611f\u6578\u64da\u3002<\/p>\n<h2 id=\"%e8%a6%96%e5%9c%96%e7%9a%84%e4%bf%ae%e6%94%b9%e8%83%bd%e5%8a%9b-TTklHNPHdI\">\u8996\u5716\u7684\u4fee\u6539\u80fd\u529b<\/h2>\n<p>\u96d6\u7136\u8996\u5716\u53ef\u4ee5\u7528\u4f86\u67e5\u8a62\u6578\u64da\uff0c\u4f46\u4e26\u975e\u6240\u6709\u7684\u8996\u5716\u90fd\u53ef\u4ee5\u7528\u4f86\u4fee\u6539\u6578\u64da\u3002\u6839\u64da SQL \u6a19\u6e96\uff0c\u53ea\u6709\u67d0\u4e9b\u985e\u578b\u7684\u8996\u5716\u53ef\u4ee5\u9032\u884c\u6578\u64da\u7684\u63d2\u5165\u3001\u66f4\u65b0\u6216\u522a\u9664\u64cd\u4f5c\u3002\u4ee5\u4e0b\u662f\u4e00\u4e9b\u5f71\u97ff\u8996\u5716\u4fee\u6539\u80fd\u529b\u7684\u56e0\u7d20\uff1a<\/p>\n<ul>\n<li><strong>\u57fa\u790e\u8868\u7684\u7d50\u69cb\uff1a<\/strong>\u5982\u679c\u8996\u5716\u662f\u57fa\u65bc\u591a\u500b\u57fa\u790e\u8868\u7684\u806f\u63a5\uff0c\u5247\u901a\u5e38\u7121\u6cd5\u9032\u884c\u4fee\u6539\u64cd\u4f5c\u3002\u9019\u662f\u56e0\u70ba\u6578\u64da\u5eab\u7121\u6cd5\u78ba\u5b9a\u61c9\u8a72\u5c07\u4fee\u6539\u61c9\u7528\u5230\u54ea\u4e00\u500b\u57fa\u790e\u8868\u3002<\/li>\n<li><strong>\u805a\u5408\u51fd\u6578\u7684\u4f7f\u7528\uff1a<\/strong>\u5982\u679c\u8996\u5716\u4e2d\u4f7f\u7528\u4e86\u805a\u5408\u51fd\u6578\uff08\u5982 SUM\u3001AVG \u7b49\uff09\uff0c\u5247\u8a72\u8996\u5716\u4e5f\u7121\u6cd5\u9032\u884c\u4fee\u6539\u64cd\u4f5c\uff0c\u56e0\u70ba\u805a\u5408\u51fd\u6578\u7684\u7d50\u679c\u4e26\u4e0d\u5c0d\u61c9\u65bc\u57fa\u790e\u8868\u4e2d\u7684\u5177\u9ad4\u884c\u3002<\/li>\n<li><strong>DISTINCT \u95dc\u9375\u5b57\uff1a<\/strong>\u4f7f\u7528 DISTINCT \u95dc\u9375\u5b57\u7684\u8996\u5716\u4e5f\u7121\u6cd5\u9032\u884c\u4fee\u6539\uff0c\u56e0\u70ba\u9019\u6703\u5c0e\u81f4\u6578\u64da\u7684\u4e0d\u78ba\u5b9a\u6027\u3002<\/li>\n<li><strong>\u8a08\u7b97\u5217\uff1a<\/strong>\u5982\u679c\u8996\u5716\u4e2d\u5305\u542b\u8a08\u7b97\u5217\uff0c\u5247\u9019\u4e9b\u5217\u7684\u503c\u662f\u57fa\u65bc\u5176\u4ed6\u5217\u8a08\u7b97\u5f97\u51fa\u7684\uff0c\u56e0\u6b64\u7121\u6cd5\u76f4\u63a5\u4fee\u6539\u3002<\/li>\n<\/ul>\n<h2 id=\"%e5%8f%af%e6%9b%b4%e6%96%b0%e8%a6%96%e5%9c%96%e7%9a%84%e6%a2%9d%e4%bb%b6-TTklHNPHdI\">\u53ef\u66f4\u65b0\u8996\u5716\u7684\u689d\u4ef6<\/h2>\n<p>\u5118\u7ba1\u5b58\u5728\u4e0a\u8ff0\u9650\u5236\uff0c\u4ecd\u7136\u6709\u4e00\u4e9b\u60c5\u6cc1\u4e0b\u8996\u5716\u662f\u53ef\u66f4\u65b0\u7684\u3002\u4ee5\u4e0b\u662f\u4e00\u4e9b\u53ef\u66f4\u65b0\u8996\u5716\u7684\u689d\u4ef6\uff1a<\/p>\n<ul>\n<li><strong>\u55ae\u4e00\u57fa\u790e\u8868\uff1a<\/strong>\u5982\u679c\u8996\u5716\u662f\u57fa\u65bc\u55ae\u4e00\u57fa\u790e\u8868\uff0c\u4e26\u4e14\u6c92\u6709\u4f7f\u7528\u805a\u5408\u51fd\u6578\u6216 DISTINCT\uff0c\u5247\u8a72\u8996\u5716\u901a\u5e38\u662f\u53ef\u66f4\u65b0\u7684\u3002<\/li>\n<li><strong>\u6240\u6709\u5217\u90fd\u53ef\u66f4\u65b0\uff1a<\/strong>\u8996\u5716\u4e2d\u7684\u6240\u6709\u5217\u90fd\u5fc5\u9808\u80fd\u5920\u6620\u5c04\u5230\u57fa\u790e\u8868\u4e2d\u7684\u5217\uff0c\u4e26\u4e14\u9019\u4e9b\u5217\u5fc5\u9808\u662f\u53ef\u66f4\u65b0\u7684\u3002<\/li>\n<li><strong>\u7121\u9700\u8a08\u7b97\u5217\uff1a<\/strong>\u8996\u5716\u4e2d\u4e0d\u61c9\u5305\u542b\u8a08\u7b97\u5217\uff0c\u56e0\u70ba\u9019\u6703\u5f71\u97ff\u6578\u64da\u7684\u66f4\u65b0\u80fd\u529b\u3002<\/li>\n<\/ul>\n<h2 id=\"%e7%a4%ba%e4%be%8b-TTklHNPHdI\">\u793a\u4f8b<\/h2>\n<p>\u4ee5\u4e0b\u662f\u4e00\u500b\u7c21\u55ae\u7684\u793a\u4f8b\uff0c\u5c55\u793a\u5982\u4f55\u5275\u5efa\u4e00\u500b\u53ef\u66f4\u65b0\u7684\u8996\u5716\uff1a<\/p>\n<pre><code>CREATE TABLE Employees (\n    ID INT PRIMARY KEY,\n    Name VARCHAR(100),\n    Salary DECIMAL(10, 2)\n);\n\nCREATE VIEW EmployeeView AS\nSELECT ID, Name, Salary\nFROM Employees;\n<\/code><\/pre>\n<p>\u5728\u9019\u500b\u4f8b\u5b50\u4e2d\uff0c<code>EmployeeView<\/code> \u662f\u4e00\u500b\u57fa\u65bc\u55ae\u4e00\u57fa\u790e\u8868 <code>Employees<\/code> \u7684\u8996\u5716\uff0c\u56e0\u6b64\u53ef\u4ee5\u9032\u884c\u66f4\u65b0\u64cd\u4f5c\uff1a<\/p>\n<pre><code>UPDATE EmployeeView\nSET Salary = Salary * 1.1\nWHERE ID = 1;\n<\/code><\/pre>\n<h2 id=\"%e7%b5%90%e8%ab%96-TTklHNPHdI\">\u7d50\u8ad6<\/h2>\n<p>\u8996\u5716\u5728\u6578\u64da\u5eab\u4e2d\u63d0\u4f9b\u4e86\u4e00\u7a2e\u9748\u6d3b\u7684\u6578\u64da\u8a2a\u554f\u65b9\u5f0f\uff0c\u4f46\u5728\u6578\u64da\u4fee\u6539\u65b9\u9762\u5b58\u5728\u4e00\u5b9a\u7684\u9650\u5236\u3002\u4e86\u89e3\u9019\u4e9b\u9650\u5236\u6709\u52a9\u65bc\u6578\u64da\u5eab\u7ba1\u7406\u54e1\u548c\u958b\u767c\u8005\u5728\u8a2d\u8a08\u6578\u64da\u5eab\u67b6\u69cb\u6642\u505a\u51fa\u66f4\u660e\u667a\u7684\u6c7a\u7b56\u3002\u96d6\u7136\u8996\u5716\u53ef\u4ee5\u7c21\u5316\u6578\u64da\u8a2a\u554f\uff0c\u4f46\u5728\u4f7f\u7528\u8996\u5716\u9032\u884c\u6578\u64da\u4fee\u6539\u6642\uff0c\u5fc5\u9808\u8003\u616e\u5230\u5176\u53ef\u66f4\u65b0\u6027\u548c\u57fa\u790e\u8868\u7684\u7d50\u69cb\u3002<\/p>\n<p>\u5982\u9700\u4e86\u89e3\u66f4\u591a\u6709\u95dc <a href=\"https:\/\/server.hk\">\u9999\u6e2fVPS<\/a> \u548c\u6578\u64da\u5eab\u7ba1\u7406\u7684\u8cc7\u8a0a\uff0c\u8acb\u8a2a\u554f\u6211\u5011\u7684\u7db2\u7ad9\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u63a2\u8a0e\u8996\u5716\u5728\u6578\u64da\u5eab\u4e2d\u4fee\u6539\u6578\u64da\u7684\u9650\u5236\uff0c\u4e86\u89e3\u5176\u5c0d\u6578\u64da\u5b8c\u6574\u6027\u548c\u5b89\u5168\u6027\u7684\u5f71\u97ff\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-185594","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/185594","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=185594"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/185594\/revisions"}],"predecessor-version":[{"id":185595,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/185594\/revisions\/185595"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=185594"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=185594"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=185594"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}