{"id":905,"date":"2022-03-19T18:16:17","date_gmt":"2022-03-19T10:16:17","guid":{"rendered":"https:\/\/www.buyao007.icu\/?p=905"},"modified":"2022-03-19T21:25:01","modified_gmt":"2022-03-19T13:25:01","slug":"4-sql%e8%af%ad%e5%8f%a5%e4%b9%8bddl%e6%95%b0%e6%8d%ae%e5%ae%9a%e4%b9%89%e8%af%ad%e8%a8%80","status":"publish","type":"post","link":"https:\/\/www.buyao007.icu\/?p=905","title":{"rendered":"4.SQL\u8bed\u53e5\u4e4bDDL\u6570\u636e\u5b9a\u4e49\u8bed\u8a00"},"content":{"rendered":"\n<p>\u5b59\u5bcc\u9633\uff0c \u6c5f\u6e56\u4eba\u79f0\u6ca1\u4eba\u79f0\u3002\u591a\u5e74\u4e92\u8054\u7f51\u8fd0\u7ef4\u5de5\u4f5c\u7ecf\u9a8c\uff0c\u66fe\u8d1f\u8d23\u8fc7\u5b59\u5e03\u65af\u5927\u89c4\u6a21\u96c6\u7fa4\u67b6\u6784\u81ea\u52a8\u5316\u8fd0\u7ef4\u7ba1\u7406\u5de5\u4f5c\u3002\u64c5\u957fWeb\u96c6\u7fa4\u67b6\u6784\u4e0e\u81ea\u52a8\u5316\u8fd0\u7ef4\uff0c\u66fe\u8d1f\u8d23\u56fd\u5185\u67d0\u5927\u578b\u535a\u5ba2\u7f51\u7ad9\u8fd0\u7ef4\u5de5\u4f5c\u3002<\/p>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"toc_0\">1.SQL\u4ecb\u7ecd<\/h2>\n\n\n\n<p><strong><em>1.\u7b80\u4ecb<\/em><\/strong><\/p>\n\n\n\n<p>\u7ed3\u6784\u5316\u67e5\u8be2\u8bed\u8a00\uff0c\u5728RDBMS\u4e2d\u901a\u7528\u7684\u4e00\u7c7b\u8bed\u8a00\uff0c\u7b26\u5408SQL89 SQL92 SQL99\u7b49\u56fd\u9645\u6807\u51c6\u3002<\/p>\n\n\n\n<p><strong><em>2.SQL\u79cd\u7c7b<\/em><\/strong><\/p>\n\n\n\n<p>DDL\uff1a \u6570\u636e\u5b9a\u4e49\u8bed\u8a00<br>DCL\uff1a \u6570\u636e\u63a7\u5236\u8bed\u8a00<br>DML\uff1a \u6570\u636e\u64cd\u4f5c\u8bed\u8a00<br>DQL\uff1a \u6570\u636e\u67e5\u8be2\u8bed\u8a00<\/p>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"toc_0\">2.DDL\u6570\u636e\u5b9a\u4e49\u8bed\u8a00\u4e4b\u5e93\u5b9a\u4e49<\/h2>\n\n\n\n<p><strong><em>1.\u589e<\/em><\/strong><\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>mysql> CREATE DATABASE wordpress CHARSET utf8mb4;<\/code><\/pre>\n\n\n\n<p><strong><em>2.\u67e5<\/em><\/strong><\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>#\u67e5\u8be2\u6240\u6709\u5e93\r\nmysql> show databases;\r\n#\u67e5\u8be2\u5e93\u7684\u521b\u5efa\u8bed\u53e5\r\nmysql> show create database test;\r<\/code><\/pre>\n\n\n\n<p><strong><em>3.\u5220<\/em><\/strong><\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>mysql> drop database wordpress;<\/code><\/pre>\n\n\n\n<p><strong><em>4.\u6539<\/em><\/strong><\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>mysql> alter database wordpress charset utf8;<\/code><\/pre>\n\n\n\n<p><strong><em>5.\u89c4\u8303<\/em><\/strong><\/p>\n\n\n\n<p>1.\u7981\u6b62\u7ebf\u4e0a\u4e1a\u52a1\u7cfb\u7edf\u51fa\u73b0drop\u64cd\u4f5c\u3002<br>2.\u5e93\u540d\u4e0d\u80fd\u662f\u5927\u5199\u5b57\u6bcd\uff0c\u4e0d\u80fd\u662f\u5173\u952e\u5b57\uff0c\u4e0d\u80fd\u662f\u6570\u5b57\u5f00\u5934\u3002<br>3.\u663e\u5f0f\u7684\u8bbe\u7f6e\u5b57\u7b26\u96c6\uff0c\u5fc5\u987b\u8bbe\u7f6echarset<\/p>\n\n\n\n<h2 class=\"wp-block-heading\" id=\"toc_0\">2.DDL\u6570\u636e\u5b9a\u4e49\u8bed\u8a00\u4e4b\u8868\u5b9a\u4e49<\/h2>\n\n\n\n<p><strong><em>1.\u589e<\/em><\/strong><\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>mysql> CREATE TABLE stu (\r\n    -> id INT NOT NULL PRIMARY KEY auto_increment COMMENT '\u5b66\u53f7',\r\n    -> sname VARCHAR(64) NOT NULL COMMENT '\u59d3\u540d',\r\n    -> age TINYINT UNSIGNED NOT NULL DEFAULT 99 COMMENT '\u5e74\u9f84',\r\n    -> gender ENUM('M','F','N') NOT NULL DEFAULT 'N' COMMENT '\u6027\u522b',\r\n    -> telnu CHAR(15) NOT NULL DEFAULT '0' COMMENT '\u624b\u673a\u53f7'\r\n    -> )ENGINE=INNODB CHARSET=utf8mb4 COMMENT '\u5b66\u751f\u8868';\r<\/code><\/pre>\n\n\n\n<p><strong><em>2.\u67e5<\/em><\/strong><\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>use test; &amp;&amp; show tables; == show tables from mysql;\u67e5\u8be2\u6240\u6709\u8868\r\ndesc student;==show columns from student;\u67e5\u770b\u8868\u7684\u63cf\u8ff0\u4fe1\u606f\r\nshow create table test.student;\u67e5\u770btest\u5e93student\u8868\u7684\u521b\u5efa\u547d\u4ee4\r<\/code><\/pre>\n\n\n\n<p><strong><em>3.\u6539<\/em><\/strong><\/p>\n\n\n\n<pre class=\"wp-block-code\"><code><strong>#\u5728sname\u5217\u4e4b\u540e\u6dfb\u52a0\u5217\u540db \u6570\u636e\u7c7b\u578b\u4e3a\u6570\u5b57int \u7ea6\u675f\u4e3a\u975e\u7a7a<\/strong>\r\nmysql> ALTER TABLE test.stu ADD b INT not null AFTER sname ;\r\n<strong>#\u5728\u6700\u540e\u4e00\u5217\u6dfb\u52a0addr\u5217<\/strong>\r\nALTER TABLE stu ADD COLUMN addr VARCHAR(100) NOT NULL COMMENT '\u5730\u5740';\r\n<strong>#\u5728\u7b2c\u4e00\u5217\u6dfb\u52a0c\u5217<\/strong>\r\nmysql> alter table test.stu add c int first;\r\n###\u6ce8\u610f\u4e0d\u5efa\u8bae\u5f80\u4e2d\u95f4\u63d2\u548c\u5f80\u7b2c\u4e00\u5217\u63d2\uff0c\u4f1a\u9020\u6210\u963b\u585e\uff0c\u4e3b\u8981\u7528\u4e8e\u5728\u6700\u540e\u5217\u63d2\u5165\u5217\uff0c8.0\u4e4b\u524d\u7684\u7248\u672c\u5c3d\u91cf\u4e0d\u8981\u5728\u4e1a\u52a1\u7e41\u5fd9\u7684\u65f6\u95f4\u505aDDL\u7684\u64cd\u4f5c\u3002\r\n<strong>#\u4fee\u6539sname\u5217\u7684\u5c5e\u6027<\/strong>\r\nmysql> ALTER TABLE test.stu MODIFY sname VARCHAR(128) NOT NULL COMMENT 'xm';\r\n\u6ce8\u610f\uff0c\u8fd9\u4e2a\u5728\u4e1a\u52a1\u7e41\u5fd9\u671f\u4e5f\u4e0d\u80fd\u968f\u4fbf\u6539\uff0c\u4e5f\u4f1a\u9020\u6210\u963b\u585e\uff0c\u4e0d\u8bba\u4ec0\u4e48\u7248\u672c\uff0c\u90fd\u4e0d\u8981\u5728\u4e1a\u52a1\u7e41\u5fd9\u65f6\u505a\r\n<strong>#\u4fee\u6539sname\u5217\u7684\u540d\u5b57\u4e3astusnane\u5e76\u4fee\u6539\u5c5e\u6027<\/strong>\r\nmysql> alter table test.stu change sname stusname varchar(64) not null COMMENT 'xm';\r<\/code><\/pre>\n\n\n\n<p><strong><em>4.\u5220<\/em><\/strong><\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>#\u5220\u9664\u5217a\r\nmysql> alter table test.stu drop a;\r\n\u5220\u9664\u6574\u4e2a\u8868\r\ndrop table test.stu;\r<\/code><\/pre>\n\n\n\n<p><strong><em>5.\u89c4\u8303<\/em><\/strong><\/p>\n\n\n\n<p>1.\u5efa\u8868\uff1a\u8868\u540d\u5c0f\u5199\uff0c\u5efa\u8bae\u683c\u5f0fwp_user\uff0c\u4e0d\u8981\u51fa\u73b0\u6570\u5b57\u5f00\u5934\u548c\u5927\u5199\u5b57\u6bcd<br>2.\u663e\u793a\u7684\u8bbe\u7f6e\u5b58\u50a8\u5f15\u64ce\\\u5b57\u7b26\u96c6\\\u8868\u7684\u6ce8\u91ca<br>3.\u5217\u540d\u8981\u548c\u4e1a\u52a1\u6709\u5173\u7cfb<br>4.\u5217\u7684\u6570\u636e\u7c7b\u578b\uff0c\u8bb2\u7a76\uff1a\u5b8c\u6574\\\u7b80\u77ed\\\u5408\u9002<br>5.\u6bcf\u4e2a\u8868\u5fc5\u987b\u8981\u6709\u4e3b\u952e\uff0c\u800c\u4e14\u5c3d\u91cf\u662f\u81ea\u589e\u7684\u548c\u4e1a\u52a1\u65e0\u5173\u5217\uff08\u4f8b\u5982\u6570\u5b57\u5217\uff09<br>6.\u6bcf\u4e2a\u5217\u5c3d\u91cf\u662f\u975e\u7a7a\u7684\uff0c\u800c\u4e14\u8bbe\u7f6e\u9ed8\u8ba4\u503c<br>7.\u6bcf\u4e2a\u5217\u8981\u6709\u6ce8\u91ca<br>8.\u53d8\u957f\u5217\uff0c\u9009\u62e9varchar\u7c7b\u578b\uff0c\u5b9a\u957f\u5217\u4e00\u822c\u9009\u62e9char\u3002<br>9.\u5927\u5b57\u6bb5\u5c3d\u91cf\u4e0d\u8981\u5728mysql\u6570\u636e\u5e93\uff0c\u53ef\u4ee5\u9009\u62e9\u4ee5\u9644\u4ef6\u7684\u5f62\u5f0f\uff0c\u53ef\u4ee5\u9009\u62e9ES\u5b58\u50a8<br>10.\u5bf9\u4e8eOnline-DDL\uff0c\u5bf9\u4e8e\u8ffd\u52a0\u5217\u53ef\u4ee5online\u7684\uff0c\u6dfb\u52a0\u7d22\u5f15\u53ef\u4ee5online\uff088.0\uff09\u5176\u4ed6\u60c5\u51b5\u4e0b\uff0c\u9700\u8981\u5728\u6570\u636e\u5e93\u4f4e\u8c37\u65f6\u95f4\u70b9\u53bb\u505a\uff0c\u5982\u679c\u5f88\u7d27\u6025\uff0cpt-osc\u6216\u8005gh-ost<br>11.\u7981\u6b62\u7ebf\u4e0a\u4e1a\u52a1\u7cfb\u7edf\u51fa\u73b0drop\u64cd\u4f5c<\/p>\n\n\n\n<p><\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u5b59\u5bcc\u9633\uff0c \u6c5f\u6e56\u4eba\u79f0\u6ca1\u4eba\u79f0\u3002\u591a\u5e74\u4e92\u8054\u7f51\u8fd0\u7ef4\u5de5\u4f5c\u7ecf\u9a8c\uff0c\u66fe\u8d1f\u8d23\u8fc7\u5b59\u5e03\u65af\u5927\u89c4\u6a21\u96c6\u7fa4\u67b6\u6784\u81ea\u52a8\u5316\u8fd0\u7ef4\u7ba1\u7406\u5de5\u4f5c\u3002\u64c5\u957fWeb\u96c6 [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":246,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[29],"tags":[],"_links":{"self":[{"href":"https:\/\/www.buyao007.icu\/index.php?rest_route=\/wp\/v2\/posts\/905"}],"collection":[{"href":"https:\/\/www.buyao007.icu\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.buyao007.icu\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.buyao007.icu\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.buyao007.icu\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=905"}],"version-history":[{"count":3,"href":"https:\/\/www.buyao007.icu\/index.php?rest_route=\/wp\/v2\/posts\/905\/revisions"}],"predecessor-version":[{"id":910,"href":"https:\/\/www.buyao007.icu\/index.php?rest_route=\/wp\/v2\/posts\/905\/revisions\/910"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.buyao007.icu\/index.php?rest_route=\/wp\/v2\/media\/246"}],"wp:attachment":[{"href":"https:\/\/www.buyao007.icu\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=905"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.buyao007.icu\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=905"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.buyao007.icu\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=905"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}