{"id":144075,"date":"2024-11-01T04:51:32","date_gmt":"2024-10-31T20:51:32","guid":{"rendered":"https:\/\/server.hk\/cnblog\/144075\/"},"modified":"2024-11-01T04:51:33","modified_gmt":"2024-10-31T20:51:33","slug":"sql-%e8%aa%9e%e8%a8%80%ef%bc%9addl%e3%80%81dml%e3%80%81dql%e3%80%81dcl-%e8%a9%b3%e8%a7%a3","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/144075\/","title":{"rendered":"SQL \u8a9e\u8a00\uff1aDDL\u3001DML\u3001DQL\u3001DCL \u8a73\u89e3"},"content":{"rendered":"<h1 id=\"sql-%e8%aa%9e%e8%a8%80%ef%bc%9addl%e3%80%81dml%e3%80%81dql%e3%80%81dcl-%e8%a9%b3%e8%a7%a3-PYmDGucBzT\">SQL \u8a9e\u8a00\uff1aDDL\u3001DML\u3001DQL\u3001DCL \u8a73\u89e3<\/h1>\n<p>SQL\uff08\u7d50\u69cb\u5316\u67e5\u8a62\u8a9e\u8a00\uff09\u662f\u4e00\u7a2e\u7528\u65bc\u7ba1\u7406\u548c\u64cd\u4f5c\u95dc\u4fc2\u578b\u6578\u64da\u5eab\u7684\u6a19\u6e96\u8a9e\u8a00\u3002\u5b83\u7684\u529f\u80fd\u5f37\u5927\uff0c\u80fd\u5920\u57f7\u884c\u5404\u7a2e\u6578\u64da\u64cd\u4f5c\uff0c\u4e26\u4e14\u88ab\u5ee3\u6cdb\u61c9\u7528\u65bc\u5404\u7a2e\u6578\u64da\u5eab\u7cfb\u7d71\u4e2d\u3002SQL \u8a9e\u8a00\u53ef\u4ee5\u6839\u64da\u5176\u529f\u80fd\u5206\u70ba\u56db\u500b\u4e3b\u8981\u985e\u5225\uff1aDDL\uff08\u6578\u64da\u5b9a\u7fa9\u8a9e\u8a00\uff09\u3001DML\uff08\u6578\u64da\u64cd\u4f5c\u8a9e\u8a00\uff09\u3001DQL\uff08\u6578\u64da\u67e5\u8a62\u8a9e\u8a00\uff09\u548c DCL\uff08\u6578\u64da\u63a7\u5236\u8a9e\u8a00\uff09\u3002\u672c\u6587\u5c07\u8a73\u7d30\u4ecb\u7d39\u9019\u56db\u7a2e\u8a9e\u8a00\u7684\u7279\u9ede\u53ca\u5176\u7528\u6cd5\u3002<\/p>\n<h2 id=\"1-ddl%ef%bc%88%e6%95%b8%e6%93%9a%e5%ae%9a%e7%be%a9%e8%aa%9e%e8%a8%80%ef%bc%89-PYmDGucBzT\">1. DDL\uff08\u6578\u64da\u5b9a\u7fa9\u8a9e\u8a00\uff09<\/h2>\n<p>DDL \u7528\u65bc\u5b9a\u7fa9\u6578\u64da\u5eab\u7d50\u69cb\u548c\u6a21\u5f0f\u3002\u5b83\u5305\u62ec\u5275\u5efa\u3001\u4fee\u6539\u548c\u522a\u9664\u6578\u64da\u5eab\u53ca\u5176\u8868\u683c\u7684\u547d\u4ee4\u3002\u5e38\u898b\u7684 DDL \u547d\u4ee4\u6709\uff1a<\/p>\n<ul>\n<li><code>CREATE<\/code>\uff1a\u7528\u65bc\u5275\u5efa\u65b0\u7684\u6578\u64da\u5eab\u6216\u8868\u683c\u3002<\/li>\n<li><code>ALTER<\/code>\uff1a\u7528\u65bc\u4fee\u6539\u73fe\u6709\u7684\u6578\u64da\u5eab\u6216\u8868\u683c\u7d50\u69cb\u3002<\/li>\n<li><code>DROP<\/code>\uff1a\u7528\u65bc\u522a\u9664\u6578\u64da\u5eab\u6216\u8868\u683c\u3002<\/li>\n<\/ul>\n<p>\u4f8b\u5982\uff0c\u4ee5\u4e0b SQL \u8a9e\u53e5\u5275\u5efa\u4e00\u500b\u540d\u70ba <code>employees<\/code> \u7684\u8868\u683c\uff1a<\/p>\n<pre><code>CREATE TABLE employees (\n    id INT PRIMARY KEY,\n    name VARCHAR(100),\n    position VARCHAR(100),\n    salary DECIMAL(10, 2)\n);<\/code><\/pre>\n<h2 id=\"2-dml%ef%bc%88%e6%95%b8%e6%93%9a%e6%93%8d%e4%bd%9c%e8%aa%9e%e8%a8%80%ef%bc%89-PYmDGucBzT\">2. DML\uff08\u6578\u64da\u64cd\u4f5c\u8a9e\u8a00\uff09<\/h2>\n<p>DML \u7528\u65bc\u5c0d\u6578\u64da\u5eab\u4e2d\u7684\u6578\u64da\u9032\u884c\u64cd\u4f5c\uff0c\u5305\u62ec\u63d2\u5165\u3001\u66f4\u65b0\u548c\u522a\u9664\u6578\u64da\u3002\u5e38\u898b\u7684 DML \u547d\u4ee4\u6709\uff1a<\/p>\n<ul>\n<li><code>INSERT<\/code>\uff1a\u7528\u65bc\u5411\u8868\u683c\u4e2d\u63d2\u5165\u65b0\u6578\u64da\u3002<\/li>\n<li><code>UPDATE<\/code>\uff1a\u7528\u65bc\u66f4\u65b0\u8868\u683c\u4e2d\u7684\u73fe\u6709\u6578\u64da\u3002<\/li>\n<li><code>DELETE<\/code>\uff1a\u7528\u65bc\u522a\u9664\u8868\u683c\u4e2d\u7684\u6578\u64da\u3002<\/li>\n<\/ul>\n<p>\u4f8b\u5982\uff0c\u4ee5\u4e0b SQL \u8a9e\u53e5\u5411 <code>employees<\/code> \u8868\u683c\u4e2d\u63d2\u5165\u4e00\u689d\u65b0\u8a18\u9304\uff1a<\/p>\n<pre><code>INSERT INTO employees (id, name, position, salary) \nVALUES (1, 'John Doe', 'Software Engineer', 60000.00);<\/code><\/pre>\n<h2 id=\"3-dql%ef%bc%88%e6%95%b8%e6%93%9a%e6%9f%a5%e8%a9%a2%e8%aa%9e%e8%a8%80%ef%bc%89-PYmDGucBzT\">3. DQL\uff08\u6578\u64da\u67e5\u8a62\u8a9e\u8a00\uff09<\/h2>\n<p>DQL \u7528\u65bc\u67e5\u8a62\u6578\u64da\u5eab\u4e2d\u7684\u6578\u64da\uff0c\u6700\u5e38\u7528\u7684\u547d\u4ee4\u662f <code>SELECT<\/code>\u3002\u9019\u500b\u547d\u4ee4\u53ef\u4ee5\u7528\u4f86\u6aa2\u7d22\u4e00\u500b\u6216\u591a\u500b\u8868\u683c\u4e2d\u7684\u6578\u64da\u3002<\/p>\n<p>\u4f8b\u5982\uff0c\u4ee5\u4e0b SQL \u8a9e\u53e5\u67e5\u8a62 <code>employees<\/code> \u8868\u683c\u4e2d\u7684\u6240\u6709\u8a18\u9304\uff1a<\/p>\n<pre><code>SELECT * FROM employees;<\/code><\/pre>\n<p>\u6b64\u5916\uff0cDQL \u9084\u53ef\u4ee5\u4f7f\u7528\u689d\u4ef6\u904e\u6ffe\u6578\u64da\uff0c\u4f8b\u5982\uff1a<\/p>\n<pre><code>SELECT * FROM employees WHERE salary &gt; 50000;<\/code><\/pre>\n<h2 id=\"4-dcl%ef%bc%88%e6%95%b8%e6%93%9a%e6%8e%a7%e5%88%b6%e8%aa%9e%e8%a8%80%ef%bc%89-PYmDGucBzT\">4. DCL\uff08\u6578\u64da\u63a7\u5236\u8a9e\u8a00\uff09<\/h2>\n<p>DCL \u7528\u65bc\u63a7\u5236\u5c0d\u6578\u64da\u5eab\u7684\u8a2a\u554f\u6b0a\u9650\u3002\u5e38\u898b\u7684 DCL \u547d\u4ee4\u6709\uff1a<\/p>\n<ul>\n<li><code>GRANT<\/code>\uff1a\u7528\u65bc\u6388\u4e88\u7528\u6236\u5c0d\u6578\u64da\u5eab\u7684\u8a2a\u554f\u6b0a\u9650\u3002<\/li>\n<li><code>REVOKE<\/code>\uff1a\u7528\u65bc\u64a4\u92b7\u7528\u6236\u7684\u8a2a\u554f\u6b0a\u9650\u3002<\/li>\n<\/ul>\n<p>\u4f8b\u5982\uff0c\u4ee5\u4e0b SQL \u8a9e\u53e5\u6388\u4e88\u7528\u6236 <code>user1<\/code> \u5c0d <code>employees<\/code> \u8868\u683c\u7684\u67e5\u8a62\u6b0a\u9650\uff1a<\/p>\n<pre><code>GRANT SELECT ON employees TO user1;<\/code><\/pre>\n<h2 id=\"%e7%b8%bd%e7%b5%90-PYmDGucBzT\">\u7e3d\u7d50<\/h2>\n<p>SQL \u8a9e\u8a00\u7684\u56db\u500b\u4e3b\u8981\u985e\u5225\u2014\u2014DDL\u3001DML\u3001DQL \u548c DCL\uff0c\u5404\u81ea\u64c1\u6709\u4e0d\u540c\u7684\u529f\u80fd\u548c\u7528\u9014\u3002\u4e86\u89e3\u9019\u4e9b\u8a9e\u8a00\u7684\u57fa\u672c\u6982\u5ff5\u548c\u7528\u6cd5\uff0c\u5c0d\u65bc\u6578\u64da\u5eab\u7ba1\u7406\u548c\u64cd\u4f5c\u81f3\u95dc\u91cd\u8981\u3002\u7121\u8ad6\u662f\u5275\u5efa\u6578\u64da\u5eab\u7d50\u69cb\uff0c\u9084\u662f\u9032\u884c\u6578\u64da\u67e5\u8a62\u548c\u63a7\u5236\u8a2a\u554f\u6b0a\u9650\uff0cSQL \u90fd\u662f\u4e0d\u53ef\u6216\u7f3a\u7684\u5de5\u5177\u3002<\/p>\n<p>\u5982\u679c\u60a8\u5c0d\u65bc\u6578\u64da\u5eab\u7ba1\u7406\u6709\u9032\u4e00\u6b65\u7684\u9700\u6c42\uff0c\u8003\u616e\u4f7f\u7528 <a href=\"https:\/\/server.hk\">\u9999\u6e2fVPS<\/a> \u670d\u52d9\u4f86\u642d\u5efa\u60a8\u7684\u6578\u64da\u5eab\u74b0\u5883\uff0c\u4eab\u53d7\u9ad8\u6548\u7a69\u5b9a\u7684\u6027\u80fd\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u6df1\u5165\u4e86\u89e3 SQL \u8a9e\u8a00\u7684\u56db\u5927\u985e\u5225\uff1aDDL\u3001DML\u3001DQL \u548c DCL\uff0c\u638c\u63e1\u6578\u64da\u5eab\u7ba1\u7406\u7684\u57fa\u790e\u8207\u61c9\u7528\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-144075","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/144075","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=144075"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/144075\/revisions"}],"predecessor-version":[{"id":144076,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/144075\/revisions\/144076"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=144075"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=144075"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=144075"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}