{"id":189,"date":"2024-06-15T17:51:58","date_gmt":"2024-06-15T09:51:58","guid":{"rendered":"http:\/\/zhaoyanqi.cn\/?p=189"},"modified":"2024-06-19T22:13:21","modified_gmt":"2024-06-19T14:13:21","slug":"mysql%e5%b8%b8%e7%94%a8%e5%91%bd%e4%bb%a4%ef%bc%88%e5%90%ab%e7%a4%ba%e4%be%8b%ef%bc%89","status":"publish","type":"post","link":"https:\/\/zhaoyanqi.cn\/?p=189","title":{"rendered":"Mysql\u5e38\u7528\u547d\u4ee4\uff08\u542b\u793a\u4f8b\uff09"},"content":{"rendered":"\n<h3 class=\"wp-block-heading\" id=\"71e3d10e\">1. \u8fde\u63a5\u548c\u9000\u51fa<\/h3>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"86361507\">\u8fde\u63a5\u5230 MySQL<\/h4>\n\n\n\n<p id=\"ua87b105c\"><strong>\u547d\u4ee4\uff1a<\/strong><\/p>\n\n\n\n<pre id=\"8a6afd3d\" class=\"wp-block-code\"><code>mysql -u &#91;username] -p<\/code><\/pre>\n\n\n\n<ul class=\"wp-block-list\">\n<li><code><strong>-u [username]<\/strong><\/code>\uff1a\u6307\u5b9a\u8fde\u63a5 MySQL \u4f7f\u7528\u7684\u7528\u6237\u540d\u3002<\/li>\n\n\n\n<li><code><strong>-p<\/strong><\/code>\uff1a\u63d0\u793a\u8f93\u5165\u5bc6\u7801\u3002<\/li>\n<\/ul>\n\n\n\n<p id=\"u7cab9ed4\"><strong>\u793a\u4f8b\uff1a<\/strong><\/p>\n\n\n\n<pre id=\"56787c00\" class=\"wp-block-code\"><code>mysql -u root -p<\/code><\/pre>\n\n\n\n<p id=\"u1dc09936\">\u7cfb\u7edf\u4f1a\u63d0\u793a\u60a8\u8f93\u5165\u5bc6\u7801\uff0c\u8f93\u5165\u5bc6\u7801\u540e\u5373\u53ef\u8fde\u63a5\u5230 MySQL\u3002<\/p>\n\n\n\n<p id=\"ua53b2544\"><strong>\u5b9e\u9645\u6848\u4f8b\uff1a<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u5f00\u53d1\u73af\u5883<\/strong>\uff1a\u5f00\u53d1\u4eba\u5458\u4f7f\u7528 <code>mysql -u dev_user -p<\/code> \u547d\u4ee4\u8fde\u63a5\u5230 MySQL \u6570\u636e\u5e93\uff0c\u4ee5\u4fbf\u6d4b\u8bd5\u548c\u5f00\u53d1\u5e94\u7528\u7a0b\u5e8f\u3002<\/li>\n\n\n\n<li><strong>\u751f\u4ea7\u73af\u5883<\/strong>\uff1aDBA \u4f7f\u7528 <code>mysql -u admin -p<\/code> \u547d\u4ee4\u8fde\u63a5\u5230\u751f\u4ea7\u6570\u636e\u5e93\uff0c\u8fdb\u884c\u7ef4\u62a4\u548c\u7ba1\u7406\u3002<\/li>\n<\/ul>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"93c895ab\">\u9000\u51fa MySQL<\/h4>\n\n\n\n<p id=\"ub1890571\"><strong>\u547d\u4ee4\uff1a<\/strong><\/p>\n\n\n\n<pre id=\"91f2275f\" class=\"wp-block-code\"><code>EXIT;<\/code><\/pre>\n\n\n\n<p id=\"ub7c13a97\">\u6216<\/p>\n\n\n\n<pre id=\"77ac59d1\" class=\"wp-block-code\"><code>QUIT;<\/code><\/pre>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u8fd9\u4e24\u4e2a\u547d\u4ee4\u90fd\u7528\u4e8e\u5b89\u5168\u9000\u51fa MySQL \u4f1a\u8bdd\u3002<\/li>\n<\/ul>\n\n\n\n<p id=\"uffe16b15\"><strong>\u5b9e\u9645\u6848\u4f8b\uff1a<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u5f00\u53d1\u73af\u5883<\/strong>\uff1a\u5f00\u53d1\u4eba\u5458\u5728\u5b8c\u6210\u6570\u636e\u5e93\u67e5\u8be2\u540e\u4f7f\u7528 <code>EXIT;<\/code> \u9000\u51fa MySQL \u4f1a\u8bdd\u3002<\/li>\n\n\n\n<li><strong>\u751f\u4ea7\u73af\u5883<\/strong>\uff1aDBA \u5728\u6267\u884c\u5b8c\u7ba1\u7406\u4efb\u52a1\u540e\u4f7f\u7528 <code>QUIT;<\/code> \u9000\u51fa MySQL \u4f1a\u8bdd\u3002<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"ca5ac2ed\">2. \u6570\u636e\u5e93\u64cd\u4f5c<\/h3>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"9537af57\">\u663e\u793a\u6240\u6709\u6570\u636e\u5e93<\/h4>\n\n\n\n<p id=\"uca2fa269\"><strong>\u547d\u4ee4\uff1a<\/strong><\/p>\n\n\n\n<pre id=\"09ae5cac\" class=\"wp-block-code\"><code>SHOW DATABASES;<\/code><\/pre>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u5217\u51fa MySQL \u670d\u52a1\u5668\u4e0a\u7684\u6240\u6709\u6570\u636e\u5e93\u3002<\/li>\n<\/ul>\n\n\n\n<p id=\"u5bca26ec\"><strong>\u5b9e\u9645\u6848\u4f8b\uff1a<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u5f00\u53d1\u73af\u5883<\/strong>\uff1a\u5f00\u53d1\u4eba\u5458\u4f7f\u7528 <code>SHOW DATABASES;<\/code> \u67e5\u770b\u73b0\u6709\u6570\u636e\u5e93\uff0c\u786e\u8ba4\u5b58\u50a8\u4f4d\u7f6e\u548c\u540d\u79f0\u3002<\/li>\n\n\n\n<li><strong>\u751f\u4ea7\u73af\u5883<\/strong>\uff1aDBA \u4f7f\u7528 <code>SHOW DATABASES;<\/code> \u68c0\u67e5\u548c\u7ba1\u7406\u670d\u52a1\u5668\u4e0a\u7684\u6240\u6709\u6570\u636e\u5e93\u3002<\/li>\n<\/ul>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"157d5306\">\u521b\u5efa\u6570\u636e\u5e93<\/h4>\n\n\n\n<p id=\"u3397960f\"><strong>\u547d\u4ee4\uff1a<\/strong><\/p>\n\n\n\n<pre id=\"d74ee359\" class=\"wp-block-code\"><code>CREATE DATABASE &#91;database_name];<\/code><\/pre>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u521b\u5efa\u4e00\u4e2a\u65b0\u6570\u636e\u5e93\u3002<\/li>\n<\/ul>\n\n\n\n<p id=\"uc9f41154\"><strong>\u793a\u4f8b\uff1a<\/strong><\/p>\n\n\n\n<pre id=\"429aeb07\" class=\"wp-block-code\"><code>CREATE DATABASE project_db;<\/code><\/pre>\n\n\n\n<p id=\"u73c518f7\"><strong>\u5b9e\u9645\u6848\u4f8b\uff1a<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u9879\u76ee\u542f\u52a8<\/strong>\uff1aDBA \u521b\u5efa\u4e00\u4e2a\u65b0\u6570\u636e\u5e93 <code>project_db<\/code> \u6765\u5b58\u50a8\u9879\u76ee\u76f8\u5173\u7684\u6570\u636e\u3002<\/li>\n<\/ul>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"17d6bfc2\">\u5220\u9664\u6570\u636e\u5e93<\/h4>\n\n\n\n<p id=\"ubd8d747c\"><strong>\u547d\u4ee4\uff1a<\/strong><\/p>\n\n\n\n<pre id=\"0085aa0f\" class=\"wp-block-code\"><code>DROP DATABASE &#91;database_name];<\/code><\/pre>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u5220\u9664\u4e00\u4e2a\u5df2\u6709\u6570\u636e\u5e93\u3002<\/li>\n<\/ul>\n\n\n\n<p id=\"u8d5d7dde\"><strong>\u793a\u4f8b\uff1a<\/strong><\/p>\n\n\n\n<pre id=\"455cfc92\" class=\"wp-block-code\"><code>DROP DATABASE project_db;<\/code><\/pre>\n\n\n\n<p id=\"u963d2af8\"><strong>\u5b9e\u9645\u6848\u4f8b\uff1a<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u9879\u76ee\u7ed3\u675f\u6216\u91cd\u6784<\/strong>\uff1aDBA \u5220\u9664\u4e0d\u518d\u9700\u8981\u7684\u6570\u636e\u5e93 <code>project_db<\/code>\uff0c\u91ca\u653e\u8d44\u6e90\u3002<\/li>\n<\/ul>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"6e32191e\">\u4f7f\u7528\u6570\u636e\u5e93<\/h4>\n\n\n\n<p id=\"u72b492e0\"><strong>\u547d\u4ee4\uff1a<\/strong><\/p>\n\n\n\n<pre id=\"2a8e4483\" class=\"wp-block-code\"><code>USE &#91;database_name];<\/code><\/pre>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u5207\u6362\u5230\u6307\u5b9a\u6570\u636e\u5e93\u3002<\/li>\n<\/ul>\n\n\n\n<p id=\"ucbaeac60\"><strong>\u793a\u4f8b\uff1a<\/strong><\/p>\n\n\n\n<pre id=\"94f14a63\" class=\"wp-block-code\"><code>USE project_db;<\/code><\/pre>\n\n\n\n<p id=\"u44aa909d\"><strong>\u5b9e\u9645\u6848\u4f8b\uff1a<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u6267\u884c SQL \u8bed\u53e5\u524d<\/strong>\uff1a\u5f00\u53d1\u4eba\u5458\u5207\u6362\u5230\u76ee\u6807\u6570\u636e\u5e93 <code>project_db<\/code>\uff0c\u4ee5\u786e\u4fdd\u5728\u6b63\u786e\u7684\u6570\u636e\u5e93\u4e2d\u6267\u884c\u64cd\u4f5c\u3002<\/li>\n<\/ul>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"f99c242d\">\u67e5\u770b\u5f53\u524d\u4f7f\u7528\u7684\u6570\u636e\u5e93<\/h4>\n\n\n\n<p id=\"u5e509394\"><strong>\u547d\u4ee4\uff1a<\/strong><\/p>\n\n\n\n<pre id=\"e0ace7cb\" class=\"wp-block-code\"><code>SELECT DATABASE();<\/code><\/pre>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u8fd4\u56de\u5f53\u524d\u4f7f\u7528\u7684\u6570\u636e\u5e93\u540d\u79f0\u3002<\/li>\n<\/ul>\n\n\n\n<p id=\"u932451aa\"><strong>\u5b9e\u9645\u6848\u4f8b\uff1a<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u786e\u8ba4\u5f53\u524d\u6570\u636e\u5e93<\/strong>\uff1a\u5f00\u53d1\u4eba\u5458\u6216 DBA \u4f7f\u7528 <code>SELECT DATABASE();<\/code> \u786e\u8ba4\u5f53\u524d\u64cd\u4f5c\u7684\u6570\u636e\u5e93\uff0c\u907f\u514d\u5728\u9519\u8bef\u7684\u6570\u636e\u5e93\u4e2d\u6267\u884c\u64cd\u4f5c\u3002<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"c0402ecc\">3. \u8868\u64cd\u4f5c<\/h3>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"319d9d42\">\u663e\u793a\u6240\u6709\u8868<\/h4>\n\n\n\n<p id=\"ub1355ba2\"><strong>\u547d\u4ee4\uff1a<\/strong><\/p>\n\n\n\n<pre id=\"eef84d61\" class=\"wp-block-code\"><code>SHOW TABLES;<\/code><\/pre>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u5217\u51fa\u5f53\u524d\u6570\u636e\u5e93\u4e2d\u7684\u6240\u6709\u8868\u3002<\/li>\n<\/ul>\n\n\n\n<p id=\"ucb7d4065\"><strong>\u5b9e\u9645\u6848\u4f8b\uff1a<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u67e5\u770b\u8868<\/strong>\uff1a\u5f00\u53d1\u4eba\u5458\u6216 DBA \u4f7f\u7528 <code>SHOW TABLES;<\/code> \u67e5\u770b\u5f53\u524d\u6570\u636e\u5e93\u4e2d\u7684\u6240\u6709\u8868\uff0c\u4e86\u89e3\u6570\u636e\u5e93\u7ed3\u6784\u3002<\/li>\n<\/ul>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"b9cdb1ae\">\u521b\u5efa\u8868<\/h4>\n\n\n\n<p id=\"u64ce43ab\"><strong>\u547d\u4ee4\uff1a<\/strong><\/p>\n\n\n\n<pre id=\"6956b684\" class=\"wp-block-code\"><code>CREATE TABLE &#91;table_name] (\n    column1 datatype constraints,\n    column2 datatype constraints,\n    ...\n) ENGINE=InnoDB;<\/code><\/pre>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u521b\u5efa\u4e00\u4e2a\u65b0\u8868\uff0c\u5b9a\u4e49\u5217\u540d\u3001\u6570\u636e\u7c7b\u578b\u548c\u7ea6\u675f\u3002<\/li>\n<\/ul>\n\n\n\n<p id=\"u4d409123\"><strong>\u793a\u4f8b\uff1a<\/strong><\/p>\n\n\n\n<pre id=\"033ec39e\" class=\"wp-block-code\"><code>CREATE TABLE employees (\n    employee_id INT AUTO_INCREMENT PRIMARY KEY,\n    name VARCHAR(100),\n    position VARCHAR(50),\n    salary DECIMAL(10, 2),\n    hire_date DATE\n) ENGINE=InnoDB;<\/code><\/pre>\n\n\n\n<p id=\"u5a410c38\"><strong>\u5b9e\u9645\u6848\u4f8b\uff1a<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>HR \u7cfb\u7edf<\/strong>\uff1a\u521b\u5efa <code>employees<\/code> \u8868\u6765\u5b58\u50a8\u5458\u5de5\u4fe1\u606f\u3002<\/li>\n<\/ul>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"0849f91a\">\u5220\u9664\u8868<\/h4>\n\n\n\n<p id=\"ub0ead866\"><strong>\u547d\u4ee4\uff1a<\/strong><\/p>\n\n\n\n<pre id=\"91eb162c\" class=\"wp-block-code\"><code>DROP TABLE &#91;table_name];<\/code><\/pre>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u5220\u9664\u4e00\u4e2a\u5df2\u6709\u8868\u3002<\/li>\n<\/ul>\n\n\n\n<p id=\"u6f0a8a18\"><strong>\u793a\u4f8b\uff1a<\/strong><\/p>\n\n\n\n<pre id=\"00f5a317\" class=\"wp-block-code\"><code>DROP TABLE employees;<\/code><\/pre>\n\n\n\n<p id=\"u86a25693\"><strong>\u5b9e\u9645\u6848\u4f8b\uff1a<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u91cd\u6784\u6570\u636e\u5e93<\/strong>\uff1a\u5220\u9664\u4e0d\u518d\u9700\u8981\u7684\u8868 <code>employees<\/code>\uff0c\u6e05\u7406\u6570\u636e\u5e93\u7ed3\u6784\u3002<\/li>\n<\/ul>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"b13411d7\">\u67e5\u770b\u8868\u7ed3\u6784<\/h4>\n\n\n\n<p id=\"u6052d4be\"><strong>\u547d\u4ee4\uff1a<\/strong><\/p>\n\n\n\n<pre id=\"62988553\" class=\"wp-block-code\"><code>DESCRIBE &#91;table_name];<\/code><\/pre>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u663e\u793a\u8868\u7684\u5217\u3001\u6570\u636e\u7c7b\u578b\u3001\u7ea6\u675f\u548c\u5176\u4ed6\u4fe1\u606f\u3002<\/li>\n<\/ul>\n\n\n\n<p id=\"u958e6c66\"><strong>\u793a\u4f8b\uff1a<\/strong><\/p>\n\n\n\n<pre id=\"96a9f012\" class=\"wp-block-code\"><code>DESCRIBE employees;<\/code><\/pre>\n\n\n\n<p id=\"u96079802\"><strong>\u5b9e\u9645\u6848\u4f8b\uff1a<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u4e86\u89e3\u8868\u7ed3\u6784<\/strong>\uff1a\u5f00\u53d1\u4eba\u5458\u6216 DBA \u4f7f\u7528 <code>DESCRIBE employees;<\/code> \u67e5\u770b <code>employees<\/code> \u8868\u7684\u7ed3\u6784\uff0c\u4ee5\u4fbf\u4e86\u89e3\u8868\u5217\u53ca\u5176\u6570\u636e\u7c7b\u578b\u3002<\/li>\n<\/ul>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"f12bed28\">\u4fee\u6539\u8868\u7ed3\u6784<\/h4>\n\n\n\n<h5 class=\"wp-block-heading\" id=\"c2cea09d\">\u6dfb\u52a0\u65b0\u5217<\/h5>\n\n\n\n<p id=\"u5f3739a2\"><strong>\u547d\u4ee4\uff1a<\/strong><\/p>\n\n\n\n<pre id=\"2f3c8a5e\" class=\"wp-block-code\"><code>ALTER TABLE &#91;table_name] ADD &#91;column_name] &#91;datatype] &#91;constraints];<\/code><\/pre>\n\n\n\n<p id=\"ue7d477ea\"><strong>\u793a\u4f8b\uff1a<\/strong><\/p>\n\n\n\n<pre id=\"e338a6c6\" class=\"wp-block-code\"><code>ALTER TABLE employees ADD age INT;<\/code><\/pre>\n\n\n\n<p id=\"u94174bb9\"><strong>\u5b9e\u9645\u6848\u4f8b\uff1a<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u9700\u6c42\u53d8\u66f4<\/strong>\uff1a\u5728 <code>employees<\/code> \u8868\u4e2d\u6dfb\u52a0\u5e74\u9f84\u5b57\u6bb5\u3002<\/li>\n<\/ul>\n\n\n\n<h5 class=\"wp-block-heading\" id=\"D7BKD\">\u6dfb\u52a0\u65b0\u5217\u5e76\u6307\u5b9a\u4f4d\u7f6e<\/h5>\n\n\n\n<p id=\"u3b3a6ad3\"><strong>\u547d\u4ee4\uff1a<\/strong><\/p>\n\n\n\n<pre id=\"tOvDB\" class=\"wp-block-code\"><code>ALTER TABLE &#91;table_name] ADD &#91;column_name] &#91;datatype] &#91;constraints] &#91;FIRST | AFTER existing_column];<\/code><\/pre>\n\n\n\n<ul class=\"wp-block-list\">\n<li><code><strong>FIRST<\/strong><\/code>\uff1a\u5c06\u65b0\u5217\u6dfb\u52a0\u5230\u8868\u7684\u7b2c\u4e00\u4e2a\u4f4d\u7f6e\u3002<\/li>\n\n\n\n<li><code><strong>AFTER existing_column<\/strong><\/code>\uff1a\u5c06\u65b0\u5217\u6dfb\u52a0\u5230\u6307\u5b9a\u5217\u4e4b\u540e\u3002<\/li>\n<\/ul>\n\n\n\n<p id=\"uaa9b5f4d\"><strong>\u793a\u4f8b\uff1a<\/strong><\/p>\n\n\n\n<pre id=\"FR1Gy\" class=\"wp-block-code\"><code>ALTER TABLE employees ADD age INT AFTER name;<\/code><\/pre>\n\n\n\n<p id=\"ucdd4505f\"><strong>\u5b9e\u9645\u6848\u4f8b\uff1a<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u9700\u6c42\u53d8\u66f4<\/strong>\uff1a\u5728 <code>employees<\/code> \u8868\u4e2d <code>name<\/code> \u5217\u4e4b\u540e\u6dfb\u52a0 <code>age<\/code> \u5b57\u6bb5\u3002<\/li>\n<\/ul>\n\n\n\n<h5 class=\"wp-block-heading\" id=\"z8kbu\">\u4fee\u6539\u5217\u6570\u636e\u7c7b\u578b\u5e76\u6307\u5b9a\u4f4d\u7f6e<\/h5>\n\n\n\n<p id=\"uf7559158\"><strong>\u547d\u4ee4\uff1a<\/strong><\/p>\n\n\n\n<pre id=\"a5dxx\" class=\"wp-block-code\"><code>ALTER TABLE &#91;table_name] MODIFY &#91;column_name] &#91;new_datatype] &#91;constraints] &#91;FIRST | AFTER existing_column];<\/code><\/pre>\n\n\n\n<p id=\"u68fb99c0\"><strong>\u793a\u4f8b\uff1a<\/strong><\/p>\n\n\n\n<pre id=\"XC6Xp\" class=\"wp-block-code\"><code>ALTER TABLE employees MODIFY age SMALLINT AFTER position;<\/code><\/pre>\n\n\n\n<p id=\"u32a3f038\"><strong>\u5b9e\u9645\u6848\u4f8b\uff1a<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u4f18\u5316\u6570\u636e\u7c7b\u578b<\/strong>\uff1a\u4fee\u6539 <code>employees<\/code> \u8868\u4e2d <code>age<\/code> \u5b57\u6bb5\u7684\u6570\u636e\u7c7b\u578b\uff0c\u5e76\u5c06\u5176\u79fb\u52a8\u5230 <code>position<\/code> \u5217\u4e4b\u540e\u3002<\/li>\n<\/ul>\n\n\n\n<h5 class=\"wp-block-heading\" id=\"A3yW6\">\u91cd\u547d\u540d\u5217\u5e76\u6307\u5b9a\u4f4d\u7f6e<\/h5>\n\n\n\n<p id=\"u2bfddb6c\"><strong>\u547d\u4ee4\uff1a<\/strong><\/p>\n\n\n\n<pre id=\"TiQkZ\" class=\"wp-block-code\"><code>ALTER TABLE &#91;table_name] CHANGE &#91;old_column_name] &#91;new_column_name] &#91;new_datatype] &#91;constraints] &#91;FIRST | AFTER existing_column];<\/code><\/pre>\n\n\n\n<p id=\"u71706194\"><strong>\u793a\u4f8b\uff1a<\/strong><\/p>\n\n\n\n<pre id=\"eOXxU\" class=\"wp-block-code\"><code>ALTER TABLE employees CHANGE age employee_age INT AFTER position;<\/code><\/pre>\n\n\n\n<p id=\"ub17125c7\"><strong>\u5b9e\u9645\u6848\u4f8b\uff1a<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u63d0\u9ad8\u53ef\u8bfb\u6027<\/strong>\uff1a\u5c06 <code>age<\/code> \u5b57\u6bb5\u91cd\u547d\u540d\u4e3a <code>employee_age<\/code>\uff0c\u5e76\u5c06\u5176\u79fb\u52a8\u5230 <code>position<\/code> \u5217\u4e4b\u540e\u3002<\/li>\n<\/ul>\n\n\n\n<h5 class=\"wp-block-heading\" id=\"4da9d437\">\u4fee\u6539\u5217\u6570\u636e\u7c7b\u578b<\/h5>\n\n\n\n<p id=\"u0491d2c0\"><strong>\u547d\u4ee4\uff1a<\/strong><\/p>\n\n\n\n<pre id=\"fe215432\" class=\"wp-block-code\"><code>ALTER TABLE &#91;table_name] MODIFY &#91;column_name] &#91;new_datatype];<\/code><\/pre>\n\n\n\n<p id=\"u2e2bb418\"><strong>\u793a\u4f8b\uff1a<\/strong><\/p>\n\n\n\n<pre id=\"960ea037\" class=\"wp-block-code\"><code>ALTER TABLE employees MODIFY age SMALLINT;<\/code><\/pre>\n\n\n\n<p id=\"u387fba41\"><strong>\u5b9e\u9645\u6848\u4f8b\uff1a<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u4f18\u5316\u6570\u636e\u7c7b\u578b<\/strong>\uff1a\u7531\u4e8e\u5e74\u9f84\u6570\u636e\u91cf\u5c0f\uff0c\u4fee\u6539 <code>employees<\/code> \u8868\u4e2d <code>age<\/code> \u5b57\u6bb5\u7684\u6570\u636e\u7c7b\u578b\u3002<\/li>\n<\/ul>\n\n\n\n<h5 class=\"wp-block-heading\" id=\"bd7eb2e3\">\u91cd\u547d\u540d\u5217<\/h5>\n\n\n\n<p id=\"uc4d19dec\"><strong>\u547d\u4ee4\uff1a<\/strong><\/p>\n\n\n\n<pre id=\"962e8ce9\" class=\"wp-block-code\"><code>ALTER TABLE &#91;table_name] CHANGE &#91;old_column_name] &#91;new_column_name] &#91;new_datatype];<\/code><\/pre>\n\n\n\n<p id=\"u9e1ff64a\"><strong>\u793a\u4f8b\uff1a<\/strong><\/p>\n\n\n\n<pre id=\"f90fc7ce\" class=\"wp-block-code\"><code>ALTER TABLE employees CHANGE age employee_age INT;<\/code><\/pre>\n\n\n\n<p id=\"u87509db3\"><strong>\u5b9e\u9645\u6848\u4f8b\uff1a<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u63d0\u9ad8\u53ef\u8bfb\u6027<\/strong>\uff1a\u5c06 <code>age<\/code> \u5b57\u6bb5\u91cd\u547d\u540d\u4e3a <code>employee_age<\/code>\uff0c\u4f7f\u5b57\u6bb5\u540d\u79f0\u66f4\u5177\u63cf\u8ff0\u6027\u3002<\/li>\n<\/ul>\n\n\n\n<h5 class=\"wp-block-heading\" id=\"3aac0e33\">\u5220\u9664\u5217<\/h5>\n\n\n\n<p id=\"u4748a624\"><strong>\u547d\u4ee4\uff1a<\/strong><\/p>\n\n\n\n<pre id=\"b6c88c6f\" class=\"wp-block-code\"><code>ALTER TABLE &#91;table_name] DROP COLUMN &#91;column_name];<\/code><\/pre>\n\n\n\n<p id=\"u5e541c6d\"><strong>\u793a\u4f8b\uff1a<\/strong><\/p>\n\n\n\n<pre id=\"4df9cbf5\" class=\"wp-block-code\"><code>ALTER TABLE employees DROP COLUMN employee_age;<\/code><\/pre>\n\n\n\n<p id=\"ua6230090\"><strong>\u5b9e\u9645\u6848\u4f8b\uff1a<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u9700\u6c42\u53d8\u66f4<\/strong>\uff1a\u5220\u9664\u4e0d\u518d\u9700\u8981\u7684 <code>employee_age<\/code> \u5b57\u6bb5\u3002<\/li>\n<\/ul>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"57f49417\">\u590d\u5236\u8868\u7ed3\u6784\u548c\u6570\u636e<\/h4>\n\n\n\n<h5 class=\"wp-block-heading\" id=\"b92b7b6a\">\u590d\u5236\u8868\u7ed3\u6784<\/h5>\n\n\n\n<p id=\"uf514fcbf\"><strong>\u547d\u4ee4\uff1a<\/strong><\/p>\n\n\n\n<pre id=\"00456bec\" class=\"wp-block-code\"><code>CREATE TABLE &#91;new_table_name] LIKE &#91;existing_table_name];<\/code><\/pre>\n\n\n\n<p id=\"u578b4320\"><strong>\u793a\u4f8b\uff1a<\/strong><\/p>\n\n\n\n<pre id=\"74dd7069\" class=\"wp-block-code\"><code>CREATE TABLE employees_backup LIKE employees;<\/code><\/pre>\n\n\n\n<p id=\"u45e075af\"><strong>\u5b9e\u9645\u6848\u4f8b\uff1a<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u6570\u636e\u5907\u4efd<\/strong>\uff1a\u5728\u8fdb\u884c\u5927\u89c4\u6a21\u6570\u636e\u4fee\u6539\u524d\uff0c\u5907\u4efd <code>employees<\/code> \u8868\u7684\u7ed3\u6784\u3002<\/li>\n<\/ul>\n\n\n\n<h5 class=\"wp-block-heading\" id=\"65b5f47b\">\u590d\u5236\u8868\u6570\u636e<\/h5>\n\n\n\n<p id=\"u412af599\"><strong>\u547d\u4ee4\uff1a<\/strong><\/p>\n\n\n\n<pre id=\"a0c54953\" class=\"wp-block-code\"><code>INSERT INTO &#91;new_table_name] SELECT * FROM &#91;existing_table_name];<\/code><\/pre>\n\n\n\n<p id=\"ub8593dec\"><strong>\u793a\u4f8b\uff1a<\/strong><\/p>\n\n\n\n<pre id=\"95a129e5\" class=\"wp-block-code\"><code>INSERT INTO employees_backup SELECT * FROM employees;<\/code><\/pre>\n\n\n\n<p id=\"u6fc234cc\"><strong>\u5b9e\u9645\u6848\u4f8b\uff1a<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u6570\u636e\u5907\u4efd<\/strong>\uff1a\u5728\u8fdb\u884c\u5927\u89c4\u6a21\u6570\u636e\u4fee\u6539\u524d\uff0c\u5907\u4efd <code>employees<\/code> \u8868\u7684\u6570\u636e\u3002<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"4644e272\">4. \u6570\u636e\u64cd\u4f5c<\/h3>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"131d2cc4\">\u63d2\u5165\u6570\u636e<\/h4>\n\n\n\n<p id=\"ubc82e631\"><strong>\u547d\u4ee4\uff1a<\/strong><\/p>\n\n\n\n<pre id=\"de1c345c\" class=\"wp-block-code\"><code>INSERT INTO &#91;table_name] (&#91;column1], &#91;column2], ...) VALUES (&#91;value1], &#91;value2], ...);<\/code><\/pre>\n\n\n\n<p id=\"ub00088e0\"><strong>\u793a\u4f8b\uff1a<\/strong><\/p>\n\n\n\n<pre id=\"6111c129\" class=\"wp-block-code\"><code>INSERT INTO employees (name, position, salary, hire_date) VALUES ('John Doe', 'Manager', 75000, '2022-01-15');<\/code><\/pre>\n\n\n\n<p id=\"u2902e615\"><strong>\u5b9e\u9645\u6848\u4f8b\uff1a<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>HR \u7cfb\u7edf<\/strong>\uff1a\u5728 <code>employees<\/code> \u8868\u4e2d\u6dfb\u52a0\u65b0\u5458\u5de5 <code>John Doe<\/code> \u7684\u4fe1\u606f\u3002<\/li>\n<\/ul>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"c7bf12ad\">\u6279\u91cf\u63d2\u5165\u6570\u636e<\/h4>\n\n\n\n<p id=\"u56bc70a6\"><strong>\u547d\u4ee4\uff1a<\/strong><\/p>\n\n\n\n<pre id=\"8cfc4f08\" class=\"wp-block-code\"><code>INSERT INTO &#91;table_name] (&#91;column1], &#91;column2], ...) VALUES \n(&#91;value1], &#91;value2], ...),\n(&#91;value3], &#91;value4], ...),\n...;<\/code><\/pre>\n\n\n\n<p id=\"ud19eacf3\"><strong>\u793a\u4f8b\uff1a<\/strong><\/p>\n\n\n\n<pre id=\"8375b24a\" class=\"wp-block-code\"><code>INSERT INTO employees (name, position, salary, hire_date) VALUES \n('Alice Smith', 'Developer', 60000, '2021-05-22'),\n('Bob Johnson', 'Designer', 55000, '2020-11-02'),\n('Charlie Brown', 'Analyst', 50000, '2019-08-18');<\/code><\/pre>\n\n\n\n<p id=\"u6e278eb0\"><strong>\u5b9e\u9645\u6848\u4f8b\uff1a<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>HR \u7cfb\u7edf<\/strong>\uff1a\u6279\u91cf\u6dfb\u52a0\u591a\u540d\u5458\u5de5\u7684\u4fe1\u606f\u3002<\/li>\n<\/ul>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"67b6bec1\">\u66f4\u65b0\u6570\u636e<\/h4>\n\n\n\n<h5 class=\"wp-block-heading\" id=\"2ce29fbb\">\u66f4\u5355\u6761\u8bb0\u5f55<\/h5>\n\n\n\n<p id=\"u1e117bdb\"><strong>\u547d\u4ee4\uff1a<\/strong><\/p>\n\n\n\n<pre id=\"c826d534\" class=\"wp-block-code\"><code>UPDATE &#91;table_name] SET &#91;column1] = &#91;value1], &#91;column2] = &#91;value2], ... WHERE &#91;condition];<\/code><\/pre>\n\n\n\n<p id=\"ucfbb0ce3\"><strong>\u793a\u4f8b\uff1a<\/strong><\/p>\n\n\n\n<pre id=\"e48a96f6\" class=\"wp-block-code\"><code>UPDATE employees SET salary = 80000 WHERE name = 'John Doe';<\/code><\/pre>\n\n\n\n<p id=\"u7f0f9ba9\"><strong>\u5b9e\u9645\u6848\u4f8b\uff1a<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u5458\u5de5\u52a0\u85aa<\/strong>\uff1a\u66f4\u65b0 <code>John Doe<\/code> \u7684\u85aa\u8d44\u4fe1\u606f\u3002<\/li>\n<\/ul>\n\n\n\n<h5 class=\"wp-block-heading\" id=\"a41dd95f\">\u66f4\u65b0\u591a\u6761\u8bb0\u5f55<\/h5>\n\n\n\n<p id=\"u0ee0f37d\"><strong>\u547d\u4ee4\uff1a<\/strong><\/p>\n\n\n\n<pre id=\"c826d534-1\" class=\"wp-block-code\"><code>UPDATE &#91;table_name] SET &#91;column1] = &#91;value1], &#91;column2] = &#91;value2], ... WHERE &#91;condition];<\/code><\/pre>\n\n\n\n<p id=\"u5265e2fa\"><strong>\u793a\u4f8b\uff1a<\/strong><\/p>\n\n\n\n<pre id=\"f5b0bfa8\" class=\"wp-block-code\"><code>UPDATE employees SET position = 'Senior Developer' WHERE position = 'Developer';<\/code><\/pre>\n\n\n\n<p id=\"u56f4ca16\"><strong>\u5b9e\u9645\u6848\u4f8b\uff1a<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u804c\u4f4d\u5347\u7ea7<\/strong>\uff1a\u66f4\u65b0\u6240\u6709 <code>Developer<\/code> \u7684\u804c\u4f4d\u4e3a <code>Senior Developer<\/code>\u3002<\/li>\n<\/ul>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"40f8f022\">\u5220\u9664\u6570\u636e<\/h4>\n\n\n\n<h5 class=\"wp-block-heading\" id=\"457f3a5d\">\u5220\u9664\u5355\u6761\u8bb0\u5f55<\/h5>\n\n\n\n<p id=\"u3e448980\"><strong>\u547d\u4ee4\uff1a<\/strong><\/p>\n\n\n\n<pre id=\"21ba390f\" class=\"wp-block-code\"><code>DELETE FROM &#91;table_name] WHERE &#91;condition];<\/code><\/pre>\n\n\n\n<p id=\"u6401ce5a\"><strong>\u793a\u4f8b\uff1a<\/strong><\/p>\n\n\n\n<pre id=\"98a2c981\" class=\"wp-block-code\"><code>DELETE FROM employees WHERE name = 'Charlie Brown';<\/code><\/pre>\n\n\n\n<p id=\"u074fd4ac\"><strong>\u5b9e\u9645\u6848\u4f8b\uff1a<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u5458\u5de5\u79bb\u804c<\/strong>\uff1a\u5220\u9664 <code>Charlie Brown<\/code> \u7684\u4fe1\u606f\u3002<\/li>\n<\/ul>\n\n\n\n<h5 class=\"wp-block-heading\" id=\"533129a9\">\u5220\u9664\u591a\u6761\u8bb0\u5f55<\/h5>\n\n\n\n<p id=\"ub3e57a30\"><strong>\u547d\u4ee4\uff1a<\/strong><\/p>\n\n\n\n<pre id=\"21ba390f-1\" class=\"wp-block-code\"><code>DELETE FROM &#91;table_name] WHERE &#91;condition];<\/code><\/pre>\n\n\n\n<p id=\"u8c39d4d8\"><strong>\u793a\u4f8b\uff1a<\/strong><\/p>\n\n\n\n<pre id=\"ec36446c\" class=\"wp-block-code\"><code>DELETE FROM employees WHERE hire_date &lt; '2020-01-01';<\/code><\/pre>\n\n\n\n<p id=\"u8b37d86e\"><strong>\u5b9e\u9645\u6848\u4f8b\uff1a<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u6e05\u7406\u5386\u53f2\u6570\u636e<\/strong>\uff1a\u5220\u9664 2020 \u5e74\u4e4b\u524d\u5165\u804c\u7684\u5458\u5de5\u8bb0\u5f55\u3002<\/li>\n<\/ul>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"818d0053\">\u67e5\u8be2\u6570\u636e<\/h4>\n\n\n\n<h5 class=\"wp-block-heading\" id=\"4859414a\">\u67e5\u8be2\u6240\u6709\u6570\u636e<\/h5>\n\n\n\n<p id=\"uf5345515\"><strong>\u547d\u4ee4\uff1a<\/strong><\/p>\n\n\n\n<pre id=\"7eaf9f1a\" class=\"wp-block-code\"><code>SELECT * FROM &#91;table_name];<\/code><\/pre>\n\n\n\n<p id=\"u2ab67387\"><strong>\u793a\u4f8b\uff1a<\/strong><\/p>\n\n\n\n<pre id=\"3684a07c\" class=\"wp-block-code\"><code>SELECT * FROM employees;<\/code><\/pre>\n\n\n\n<p id=\"u0b774d1f\"><strong>\u5b9e\u9645\u6848\u4f8b\uff1a<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u67e5\u770b\u6240\u6709\u5458\u5de5\u4fe1\u606f<\/strong>\uff1aHR \u7cfb\u7edf\u4e2d\u67e5\u770b <code>employees<\/code> \u8868\u7684\u6240\u6709\u8bb0\u5f55\u3002<\/li>\n<\/ul>\n\n\n\n<h5 class=\"wp-block-heading\" id=\"26cd742b\">\u67e5\u8be2\u7279\u5b9a\u5217<\/h5>\n\n\n\n<p id=\"u89f7fa19\"><strong>\u547d\u4ee4\uff1a<\/strong><\/p>\n\n\n\n<pre id=\"5a603b9a\" class=\"wp-block-code\"><code>SELECT &#91;column1], &#91;column2], ... FROM &#91;table_name];<\/code><\/pre>\n\n\n\n<p id=\"u7596f49e\"><strong>\u793a\u4f8b\uff1a<\/strong><\/p>\n\n\n\n<pre id=\"947a0fa4\" class=\"wp-block-code\"><code>SELECT name, position FROM employees;<\/code><\/pre>\n\n\n\n<p id=\"u4319a056\"><strong>\u5b9e\u9645\u6848\u4f8b\uff1a<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u67e5\u8be2\u7279\u5b9a\u4fe1\u606f<\/strong>\uff1a\u67e5\u8be2\u6240\u6709\u5458\u5de5\u7684\u59d3\u540d\u548c\u804c\u4f4d\u3002<\/li>\n<\/ul>\n\n\n\n<h5 class=\"wp-block-heading\" id=\"298efb99\">\u4f7f\u7528\u6761\u4ef6\u67e5\u8be2<\/h5>\n\n\n\n<p id=\"uacc85b6f\"><strong>\u547d\u4ee4\uff1a<\/strong><\/p>\n\n\n\n<pre id=\"2b09ccd8\" class=\"wp-block-code\"><code>SELECT * FROM &#91;table_name] WHERE &#91;condition];<\/code><\/pre>\n\n\n\n<p id=\"uc064051c\"><strong>\u793a\u4f8b\uff1a<\/strong><\/p>\n\n\n\n<pre id=\"c418b823\" class=\"wp-block-code\"><code>SELECT * FROM employees WHERE position = 'Manager';<\/code><\/pre>\n\n\n\n<p id=\"ubb0b763c\"><strong>\u5b9e\u9645\u6848\u4f8b\uff1a<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u7b5b\u9009\u7279\u5b9a\u8bb0\u5f55<\/strong>\uff1a\u67e5\u8be2\u6240\u6709\u7ecf\u7406\u7684\u4fe1\u606f\u3002<\/li>\n<\/ul>\n\n\n\n<h5 class=\"wp-block-heading\" id=\"51c0e3ac\">\u4f7f\u7528\u6a21\u7cca\u67e5\u8be2<\/h5>\n\n\n\n<p id=\"ucfc539d7\"><strong>\u547d\u4ee4\uff1a<\/strong><\/p>\n\n\n\n<pre id=\"9d49cb96\" class=\"wp-block-code\"><code>SELECT * FROM &#91;table_name] WHERE &#91;column] LIKE '&#91;pattern]';<\/code><\/pre>\n\n\n\n<p id=\"u808691b2\"><strong>\u793a\u4f8b\uff1a<\/strong><\/p>\n\n\n\n<pre id=\"989b7779\" class=\"wp-block-code\"><code>SELECT * FROM employees WHERE name LIKE 'A%';<\/code><\/pre>\n\n\n\n<p id=\"ue1c1ec42\"><strong>\u5b9e\u9645\u6848\u4f8b\uff1a<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u6a21\u7cca\u641c\u7d22<\/strong>\uff1a\u67e5\u8be2\u540d\u5b57\u4ee5 &#8216;A&#8217; \u5f00\u5934\u7684\u5458\u5de5\u3002<\/li>\n<\/ul>\n\n\n\n<h5 class=\"wp-block-heading\" id=\"c12c8c4a\">\u4f7f\u7528\u6392\u5e8f<\/h5>\n\n\n\n<p id=\"u80b03e03\"><strong>\u547d\u4ee4\uff1a<\/strong><\/p>\n\n\n\n<pre id=\"5be537b5\" class=\"wp-block-code\"><code>SELECT * FROM &#91;table_name] ORDER BY &#91;column1] &#91;ASC|DESC], &#91;column2] &#91;ASC|DESC], ...;<\/code><\/pre>\n\n\n\n<p id=\"ua18d4b5e\"><strong>\u793a\u4f8b\uff1a<\/strong><\/p>\n\n\n\n<pre id=\"92723e12\" class=\"wp-block-code\"><code>SELECT * FROM employees ORDER BY hire_date DESC;<\/code><\/pre>\n\n\n\n<p id=\"u48fbbedc\"><strong>\u5b9e\u9645\u6848\u4f8b\uff1a<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u6392\u5e8f\u67e5\u8be2\u7ed3\u679c<\/strong>\uff1a\u6309\u5165\u804c\u65e5\u671f\u5012\u5e8f\u67e5\u8be2\u6240\u6709\u5458\u5de5\u4fe1\u606f\u3002<\/li>\n<\/ul>\n\n\n\n<h5 class=\"wp-block-heading\" id=\"9e212ac1\">\u4f7f\u7528\u5206\u9875<\/h5>\n\n\n\n<p id=\"u65890779\"><strong>\u547d\u4ee4\uff1a<\/strong><\/p>\n\n\n\n<pre id=\"3b5a4ed3\" class=\"wp-block-code\"><code>SELECT * FROM &#91;table_name] LIMIT &#91;offset], &#91;row_count];<\/code><\/pre>\n\n\n\n<p id=\"u56d29fa2\"><strong>\u793a\u4f8b\uff1a<\/strong><\/p>\n\n\n\n<pre id=\"8808293b\" class=\"wp-block-code\"><code>SELECT * FROM employees LIMIT 5 OFFSET 10;<\/code><\/pre>\n\n\n\n<p id=\"u68009e2c\"><strong>\u5b9e\u9645\u6848\u4f8b\uff1a<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u5206\u9875\u663e\u793a<\/strong>\uff1a\u5206\u9875\u663e\u793a\u5458\u5de5\u4fe1\u606f\uff0c\u6bcf\u9875 5 \u6761\u8bb0\u5f55\uff0c\u4ece\u7b2c 11 \u6761\u5f00\u59cb\u3002<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"c0590742\">5. \u7528\u6237\u548c\u6743\u9650\u7ba1\u7406<\/h3>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"ac5b586c\">\u521b\u5efa\u7528\u6237<\/h4>\n\n\n\n<p id=\"u95167fbe\"><strong>\u547d\u4ee4\uff1a<\/strong><\/p>\n\n\n\n<pre id=\"93308021\" class=\"wp-block-code\"><code>CREATE USER '&#91;username]'@'&#91;host]' IDENTIFIED BY '&#91;password]';<\/code><\/pre>\n\n\n\n<p id=\"u6e174f66\"><strong>\u793a\u4f8b\uff1a<\/strong><\/p>\n\n\n\n<pre id=\"b9f31ffa\" class=\"wp-block-code\"><code>CREATE USER 'new_user'@'localhost' IDENTIFIED BY 'password123';<\/code><\/pre>\n\n\n\n<p id=\"u404d358a\"><strong>\u5b9e\u9645\u6848\u4f8b\uff1a<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u65b0\u5f00\u53d1\u4eba\u5458\u5165\u804c<\/strong>\uff1a\u4e3a\u65b0\u5f00\u53d1\u4eba\u5458\u521b\u5efa\u6570\u636e\u5e93\u8bbf\u95ee\u8d26\u53f7\u3002<\/li>\n<\/ul>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"10991ce4\">\u5220\u9664\u7528\u6237<\/h4>\n\n\n\n<p id=\"u92996cbb\"><strong>\u547d\u4ee4\uff1a<\/strong><\/p>\n\n\n\n<pre id=\"590fb859\" class=\"wp-block-code\"><code>DROP USER '&#91;username]'@'&#91;host]';<\/code><\/pre>\n\n\n\n<p id=\"u79b8a549\"><strong>\u793a\u4f8b\uff1a<\/strong><\/p>\n\n\n\n<pre id=\"fe8b074b\" class=\"wp-block-code\"><code>DROP USER 'new_user'@'localhost';<\/code><\/pre>\n\n\n\n<p id=\"u9f7a088b\"><strong>\u5b9e\u9645\u6848\u4f8b\uff1a<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u5f00\u53d1\u4eba\u5458\u79bb\u804c<\/strong>\uff1a\u5220\u9664\u79bb\u804c\u5458\u5de5\u7684\u6570\u636e\u5e93\u8bbf\u95ee\u8d26\u53f7\u3002<\/li>\n<\/ul>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"c27d86fd\">\u6388\u4e88\u6743\u9650<\/h4>\n\n\n\n<h5 class=\"wp-block-heading\" id=\"807f6a1d\">\u6388\u4e88\u5168\u90e8\u6743\u9650<\/h5>\n\n\n\n<p id=\"u1e154995\"><strong>\u547d\u4ee4\uff1a<\/strong><\/p>\n\n\n\n<pre id=\"c6bd96ad\" class=\"wp-block-code\"><code>GRANT ALL PRIVILEGES ON &#91;database_name].* TO '&#91;username]'@'&#91;host]';<\/code><\/pre>\n\n\n\n<p id=\"u75021561\"><strong>\u793a\u4f8b\uff1a<\/strong><\/p>\n\n\n\n<pre id=\"bb45bc36\" class=\"wp-block-code\"><code>GRANT ALL PRIVILEGES ON project_db.* TO 'new_user'@'localhost';<\/code><\/pre>\n\n\n\n<p id=\"u71d32f88\"><strong>\u5b9e\u9645\u6848\u4f8b\uff1a<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u8d4b\u4e88\u6743\u9650<\/strong>\uff1a\u4e3a\u65b0\u5f00\u53d1\u4eba\u5458\u6388\u4e88 <code>project_db<\/code> \u6570\u636e\u5e93\u7684\u6240\u6709\u6743\u9650\u3002<\/li>\n<\/ul>\n\n\n\n<h5 class=\"wp-block-heading\" id=\"011d5059\">\u6388\u4e88\u7279\u5b9a\u6743\u9650<\/h5>\n\n\n\n<p id=\"u5867a41e\"><strong>\u547d\u4ee4\uff1a<\/strong><\/p>\n\n\n\n<pre id=\"c6318b02\" class=\"wp-block-code\"><code>GRANT &#91;privilege1], &#91;privilege2], ... ON &#91;database_name].* TO '&#91;username]'@'&#91;host]';<\/code><\/pre>\n\n\n\n<p id=\"u28d311af\"><strong>\u793a\u4f8b\uff1a<\/strong><\/p>\n\n\n\n<pre id=\"6d53b6c5\" class=\"wp-block-code\"><code>GRANT SELECT, INSERT, UPDATE ON project_db.* TO 'new_user'@'localhost';<\/code><\/pre>\n\n\n\n<p id=\"uae0d9ea6\"><strong>\u5b9e\u9645\u6848\u4f8b\uff1a<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u9650\u5b9a\u6743\u9650<\/strong>\uff1a\u4e3a\u5f00\u53d1\u4eba\u5458\u6388\u4e88 <code>project_db<\/code> \u6570\u636e\u5e93\u7684\u67e5\u8be2\u3001\u63d2\u5165\u548c\u66f4\u65b0\u6743\u9650\u3002<\/li>\n<\/ul>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"2cb06618\">\u64a4\u9500\u6743\u9650<\/h4>\n\n\n\n<p id=\"u0904c1d1\"><strong>\u547d\u4ee4\uff1a<\/strong><\/p>\n\n\n\n<pre id=\"837bdd4d\" class=\"wp-block-code\"><code>REVOKE &#91;privilege1], &#91;privilege2], ... ON &#91;database_name].* FROM '&#91;username]'@'&#91;host]';<\/code><\/pre>\n\n\n\n<p id=\"u75aceffe\"><strong>\u793a\u4f8b\uff1a<\/strong><\/p>\n\n\n\n<pre id=\"a27224ab\" class=\"wp-block-code\"><code>REVOKE ALL PRIVILEGES ON project_db.* FROM 'new_user'@'localhost';<\/code><\/pre>\n\n\n\n<p id=\"uf6b6b992\"><strong>\u5b9e\u9645\u6848\u4f8b\uff1a<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u6536\u56de\u6743\u9650<\/strong>\uff1a\u9650\u5236\u5f00\u53d1\u4eba\u5458\u7684\u6570\u636e\u5e93\u8bbf\u95ee\u6743\u9650\u3002<\/li>\n<\/ul>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"642ae04c\">\u5237\u65b0\u6743\u9650<\/h4>\n\n\n\n<p id=\"u534a96ba\"><strong>\u547d\u4ee4\uff1a<\/strong><\/p>\n\n\n\n<pre id=\"93a09434\" class=\"wp-block-code\"><code>FLUSH PRIVILEGES;<\/code><\/pre>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"1231b633\">6. \u5907\u4efd\u548c\u6062\u590d<\/h3>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"9524a334\">\u5907\u4efd\u6570\u636e\u5e93<\/h4>\n\n\n\n<p id=\"ubfe9feac\"><strong>\u547d\u4ee4\uff1a<\/strong><\/p>\n\n\n\n<pre id=\"555533c9\" class=\"wp-block-code\"><code>mysqldump -u &#91;username] -p &#91;database_name] &gt; &#91;backup_file.sql]<\/code><\/pre>\n\n\n\n<p id=\"u0c8c77f3\"><strong>\u793a\u4f8b\uff1a<\/strong><\/p>\n\n\n\n<pre id=\"5799db77\" class=\"wp-block-code\"><code>mysqldump -u root -p project_db &gt; backup.sql<\/code><\/pre>\n\n\n\n<p id=\"u0fe8a8f6\"><strong>\u5b9e\u9645\u6848\u4f8b\uff1a<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u5b9a\u671f\u5907\u4efd<\/strong>\uff1a\u5b9a\u671f\u5907\u4efd<\/li>\n<\/ul>\n\n\n\n<p id=\"u9ccc24b2\"><code>project_db<\/code> \u6570\u636e\u5e93\u4ee5\u9632\u6570\u636e\u4e22\u5931\u3002<\/p>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"adbfa98b\">\u6062\u590d\u6570\u636e\u5e93<\/h4>\n\n\n\n<p id=\"u4e240e2e\"><strong>\u547d\u4ee4\uff1a<\/strong><\/p>\n\n\n\n<pre id=\"c86ba951\" class=\"wp-block-code\"><code>mysql -u &#91;username] -p &#91;database_name] &lt; &#91;backup_file.sql]<\/code><\/pre>\n\n\n\n<p id=\"uff73cad8\"><strong>\u793a\u4f8b\uff1a<\/strong><\/p>\n\n\n\n<pre id=\"49d5cf89\" class=\"wp-block-code\"><code>mysql -u root -p project_db &lt; backup.sql<\/code><\/pre>\n\n\n\n<p id=\"uc142dd3b\"><strong>\u5b9e\u9645\u6848\u4f8b\uff1a<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u6570\u636e\u6062\u590d<\/strong>\uff1a\u4ece\u5907\u4efd\u6587\u4ef6\u6062\u590d <code>project_db<\/code> \u6570\u636e\u5e93\u3002<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"1a8a233f\">7. \u7cfb\u7edf\u547d\u4ee4<\/h3>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"06e4aa65\">\u67e5\u770b MySQL \u670d\u52a1\u5668\u72b6\u6001<\/h4>\n\n\n\n<p id=\"ue51580a6\"><strong>\u547d\u4ee4\uff1a<\/strong><\/p>\n\n\n\n<pre id=\"9db62d4d\" class=\"wp-block-code\"><code>mysqladmin -u &#91;username] -p status<\/code><\/pre>\n\n\n\n<p id=\"u2c62a53c\"><strong>\u793a\u4f8b\uff1a<\/strong><\/p>\n\n\n\n<pre id=\"gIMiB\" class=\"wp-block-code\"><code>mysqladmin -u remote_user666 -p -h 192.168.1.121 -P 3366 status<\/code><\/pre>\n\n\n\n<p id=\"ud26466ef\"><strong>\u5b9e\u9645\u6848\u4f8b\uff1a<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u68c0\u67e5\u72b6\u6001<\/strong>\uff1aDBA \u68c0\u67e5 MySQL \u670d\u52a1\u5668\u7684\u8fd0\u884c\u72b6\u6001\u3002<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"K3DYK\">8. \u5e38\u7528\u5feb\u6377\u547d\u4ee4<\/h3>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"Q6S1E\">\u67e5\u770b\u5f53\u524d\u6570\u636e\u5e93<\/h4>\n\n\n\n<p id=\"ufaaef7d1\"><strong>\u547d\u4ee4\uff1a<\/strong><\/p>\n\n\n\n<pre id=\"mJaxr\" class=\"wp-block-code\"><code>SELECT DATABASE();<\/code><\/pre>\n\n\n\n<p id=\"ue2483544\"><strong>\u5b9e\u9645\u6848\u4f8b\uff1a<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u786e\u8ba4\u5f53\u524d\u6570\u636e\u5e93<\/strong>\uff1a\u5f00\u53d1\u4eba\u5458\u6216 DBA \u4f7f\u7528 <code>SELECT DATABASE();<\/code> \u786e\u8ba4\u5f53\u524d\u64cd\u4f5c\u7684\u6570\u636e\u5e93\u3002<\/li>\n<\/ul>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"AQzMV\">\u67e5\u770b\u5f53\u524d\u7528\u6237<\/h4>\n\n\n\n<p id=\"u1e967711\"><strong>\u547d\u4ee4\uff1a<\/strong><\/p>\n\n\n\n<pre id=\"tgvAf\" class=\"wp-block-code\"><code>SELECT USER();<\/code><\/pre>\n\n\n\n<p id=\"u47906a8f\"><strong>\u5b9e\u9645\u6848\u4f8b\uff1a<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u786e\u8ba4\u7528\u6237\u8eab\u4efd<\/strong>\uff1a\u5f00\u53d1\u4eba\u5458\u6216 DBA \u4f7f\u7528 <code>SELECT USER();<\/code> \u786e\u8ba4\u5f53\u524d\u8fde\u63a5 MySQL \u7684\u7528\u6237\u8eab\u4efd\u3002<\/li>\n<\/ul>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"scepw\">\u67e5\u770b MySQL \u7248\u672c<\/h4>\n\n\n\n<p id=\"u7f6727b8\"><strong>\u547d\u4ee4\uff1a<\/strong><\/p>\n\n\n\n<pre id=\"Ua8TH\" class=\"wp-block-code\"><code>SELECT VERSION();<\/code><\/pre>\n\n\n\n<p id=\"u54cb86cb\"><strong>\u5b9e\u9645\u6848\u4f8b\uff1a<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u68c0\u67e5\u7248\u672c\u4fe1\u606f<\/strong>\uff1a\u5f00\u53d1\u4eba\u5458\u6216 DBA \u4f7f\u7528 <code>SELECT VERSION();<\/code> \u68c0\u67e5 MySQL \u670d\u52a1\u5668\u7684\u7248\u672c\u4fe1\u606f\uff0c\u4ee5\u786e\u4fdd\u517c\u5bb9\u6027\u3002<\/li>\n<\/ul>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"saJnn\">\u67e5\u770b\u5f53\u524d\u65e5\u671f\u548c\u65f6\u95f4<\/h4>\n\n\n\n<p id=\"u74df92af\"><strong>\u547d\u4ee4\uff1a<\/strong><\/p>\n\n\n\n<pre id=\"WrKeA\" class=\"wp-block-code\"><code>SELECT NOW();<\/code><\/pre>\n\n\n\n<p id=\"u8d9d3a29\"><strong>\u5b9e\u9645\u6848\u4f8b\uff1a<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u8bb0\u5f55\u65e5\u5fd7<\/strong>\uff1a\u5f00\u53d1\u4eba\u5458\u6216 DBA \u4f7f\u7528 <code>SELECT NOW();<\/code> \u83b7\u53d6\u5f53\u524d\u65e5\u671f\u548c\u65f6\u95f4\uff0c\u7528\u4e8e\u8bb0\u5f55\u65e5\u5fd7\u6216\u8fdb\u884c\u65f6\u95f4\u6233\u6bd4\u5bf9\u3002<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\" id=\"ewJ1z\">9. \u9ad8\u7ea7\u67e5\u8be2<\/h3>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"xnrLb\">\u805a\u5408\u51fd\u6570<\/h4>\n\n\n\n<h5 class=\"wp-block-heading\" id=\"G2BVa\">\u8ba1\u6570<\/h5>\n\n\n\n<p id=\"u1e8e9f70\"><strong>\u547d\u4ee4\uff1a<\/strong><\/p>\n\n\n\n<pre id=\"CHrez\" class=\"wp-block-code\"><code>SELECT COUNT(*) FROM &#91;table_name];<\/code><\/pre>\n\n\n\n<p id=\"u6995de33\"><strong>\u793a\u4f8b\uff1a<\/strong><\/p>\n\n\n\n<pre id=\"pX1OE\" class=\"wp-block-code\"><code>SELECT COUNT(*) FROM employees;<\/code><\/pre>\n\n\n\n<p id=\"u87d47935\"><strong>\u5b9e\u9645\u6848\u4f8b\uff1a<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u7edf\u8ba1\u5458\u5de5\u603b\u6570<\/strong>\uff1aHR \u7cfb\u7edf\u4e2d\u7edf\u8ba1\u516c\u53f8\u5458\u5de5\u603b\u6570\u3002<\/li>\n<\/ul>\n\n\n\n<h5 class=\"wp-block-heading\" id=\"oinKP\">\u6c42\u548c<\/h5>\n\n\n\n<p id=\"u1f64dd7e\"><strong>\u547d\u4ee4\uff1a<\/strong><\/p>\n\n\n\n<pre id=\"noZNr\" class=\"wp-block-code\"><code>SELECT SUM(&#91;column]) FROM &#91;table_name];<\/code><\/pre>\n\n\n\n<p id=\"uf208d8c5\"><strong>\u793a\u4f8b\uff1a<\/strong><\/p>\n\n\n\n<pre id=\"ISpAh\" class=\"wp-block-code\"><code>SELECT SUM(salary) FROM employees;<\/code><\/pre>\n\n\n\n<p id=\"uda63734b\"><strong>\u5b9e\u9645\u6848\u4f8b\uff1a<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u8ba1\u7b97\u603b\u5de5\u8d44\u652f\u51fa<\/strong>\uff1a\u8ba1\u7b97\u516c\u53f8\u603b\u5de5\u8d44\u652f\u51fa\u3002<\/li>\n<\/ul>\n\n\n\n<h5 class=\"wp-block-heading\" id=\"aIUsV\">\u5e73\u5747\u503c<\/h5>\n\n\n\n<p id=\"u33638cb7\"><strong>\u547d\u4ee4\uff1a<\/strong><\/p>\n\n\n\n<pre id=\"V2SuX\" class=\"wp-block-code\"><code>SELECT AVG(&#91;column]) FROM &#91;table_name];<\/code><\/pre>\n\n\n\n<p id=\"u4eb53813\"><strong>\u793a\u4f8b\uff1a<\/strong><\/p>\n\n\n\n<pre id=\"dWpwc\" class=\"wp-block-code\"><code>SELECT AVG(salary) FROM employees;<\/code><\/pre>\n\n\n\n<p id=\"ud017f1e8\"><strong>\u5b9e\u9645\u6848\u4f8b\uff1a<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u8ba1\u7b97\u5e73\u5747\u5de5\u8d44<\/strong>\uff1a\u8ba1\u7b97\u5458\u5de5\u7684\u5e73\u5747\u5de5\u8d44\u3002<\/li>\n<\/ul>\n\n\n\n<h5 class=\"wp-block-heading\" id=\"Og7DK\">\u6700\u5927\u503c\u548c\u6700\u5c0f\u503c<\/h5>\n\n\n\n<p id=\"u72ea25f7\"><strong>\u547d\u4ee4\uff1a<\/strong><\/p>\n\n\n\n<pre id=\"AyB0q\" class=\"wp-block-code\"><code>SELECT MAX(&#91;column]), MIN(&#91;column]) FROM &#91;table_name];<\/code><\/pre>\n\n\n\n<p id=\"u292b518e\"><strong>\u793a\u4f8b\uff1a<\/strong><\/p>\n\n\n\n<pre id=\"jlRBr\" class=\"wp-block-code\"><code>SELECT MAX(salary), MIN(salary) FROM employees;<\/code><\/pre>\n\n\n\n<p id=\"u96ad77ff\"><strong>\u5b9e\u9645\u6848\u4f8b\uff1a<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u627e\u51fa\u6700\u9ad8\u548c\u6700\u4f4e\u5de5\u8d44<\/strong>\uff1a\u627e\u51fa\u516c\u53f8\u6700\u9ad8\u548c\u6700\u4f4e\u5de5\u8d44\u3002<\/li>\n<\/ul>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"kIZTf\">\u5206\u7ec4\u67e5\u8be2<\/h4>\n\n\n\n<p id=\"u27db03ee\"><strong>\u547d\u4ee4\uff1a<\/strong><\/p>\n\n\n\n<pre id=\"sVlgw\" class=\"wp-block-code\"><code>SELECT &#91;column], COUNT(*) FROM &#91;table_name] GROUP BY &#91;column];<\/code><\/pre>\n\n\n\n<p id=\"uf50ab309\"><strong>\u793a\u4f8b\uff1a<\/strong><\/p>\n\n\n\n<pre id=\"BDiUc\" class=\"wp-block-code\"><code>SELECT position, COUNT(*) FROM employees GROUP BY position;<\/code><\/pre>\n\n\n\n<p id=\"u74318064\"><strong>\u5b9e\u9645\u6848\u4f8b\uff1a<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u7edf\u8ba1\u804c\u4f4d\u5458\u5de5\u6570\u91cf<\/strong>\uff1a\u7edf\u8ba1\u6bcf\u4e2a\u804c\u4f4d\u7684\u5458\u5de5\u6570\u91cf\u3002<\/li>\n<\/ul>\n\n\n\n<h4 class=\"wp-block-heading\" id=\"xsrtu\">\u591a\u8868\u8fde\u63a5<\/h4>\n\n\n\n<h5 class=\"wp-block-heading\" id=\"PahX2\">\u5185\u8fde\u63a5<\/h5>\n\n\n\n<p id=\"uc9b3dda8\"><strong>\u547d\u4ee4\uff1a<\/strong><\/p>\n\n\n\n<pre id=\"ScNq3\" class=\"wp-block-code\"><code>SELECT &#91;columns] FROM &#91;table1]\nJOIN &#91;table2] ON &#91;table1.column] = &#91;table2.column];<\/code><\/pre>\n\n\n\n<p id=\"u5663727f\"><strong>\u793a\u4f8b\uff1a<\/strong><\/p>\n\n\n\n<pre id=\"U2YNE\" class=\"wp-block-code\"><code>SELECT employees.name, departments.department_name\nFROM employees\nJOIN departments ON employees.department_id = departments.department_id;<\/code><\/pre>\n\n\n\n<p id=\"uc2cd8035\"><strong>\u5b9e\u9645\u6848\u4f8b\uff1a<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u67e5\u8be2\u5458\u5de5\u6240\u5c5e\u90e8\u95e8<\/strong>\uff1a\u67e5\u8be2\u5458\u5de5\u6240\u5c5e\u7684\u90e8\u95e8\u4fe1\u606f\u3002<\/li>\n<\/ul>\n\n\n\n<h5 class=\"wp-block-heading\" id=\"L01iA\">\u5de6\u8fde\u63a5<\/h5>\n\n\n\n<p id=\"uac9969ec\"><strong>\u547d\u4ee4\uff1a<\/strong><\/p>\n\n\n\n<pre id=\"iTjYj\" class=\"wp-block-code\"><code>SELECT &#91;columns] FROM &#91;table1]\nLEFT JOIN &#91;table2] ON &#91;table1.column] = &#91;table2.column];<\/code><\/pre>\n\n\n\n<p id=\"u522a2a04\"><strong>\u793a\u4f8b\uff1a<\/strong><\/p>\n\n\n\n<pre id=\"IdSl0\" class=\"wp-block-code\"><code>SELECT employees.name, orders.order_id\nFROM employees\nLEFT JOIN orders ON employees.employee_id = orders.employee_id;<\/code><\/pre>\n\n\n\n<p id=\"u0bad96c1\"><strong>\u5b9e\u9645\u6848\u4f8b\uff1a<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u67e5\u8be2\u5458\u5de5\u53ca\u5176\u8ba2\u5355\u4fe1\u606f<\/strong>\uff1a\u67e5\u8be2\u6240\u6709\u5458\u5de5\u53ca\u5176\u8ba2\u5355\u4fe1\u606f\uff08\u5305\u62ec\u6ca1\u6709\u8ba2\u5355\u7684\u5458\u5de5\uff09\u3002<\/li>\n<\/ul>\n\n\n\n<h5 class=\"wp-block-heading\" id=\"eLPNd\">\u53f3\u8fde\u63a5<\/h5>\n\n\n\n<p id=\"u12a0844c\"><strong>\u547d\u4ee4\uff1a<\/strong><\/p>\n\n\n\n<pre id=\"TuK0Z\" class=\"wp-block-code\"><code>SELECT &#91;columns] FROM &#91;table1]\nRIGHT JOIN &#91;table2] ON &#91;table1.column] = &#91;table2.column];<\/code><\/pre>\n\n\n\n<p id=\"u7d356aa7\"><strong>\u793a\u4f8b\uff1a<\/strong><\/p>\n\n\n\n<pre id=\"COqYi\" class=\"wp-block-code\"><code>SELECT employees.name, orders.order_id\nFROM employees\nRIGHT JOIN orders ON employees.employee_id = orders.employee_id;<\/code><\/pre>\n\n\n\n<p id=\"uef464c61\"><strong>\u5b9e\u9645\u6848\u4f8b\uff1a<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>\u67e5\u8be2\u8ba2\u5355\u53ca\u5176\u76f8\u5173\u5458\u5de5\u4fe1\u606f<\/strong>\uff1a\u67e5\u8be2\u6240\u6709\u8ba2\u5355\u53ca\u5176\u76f8\u5173\u5458\u5de5\u4fe1\u606f\uff08\u5305\u62ec\u6ca1\u6709\u5173\u8054\u5458\u5de5\u7684\u8ba2\u5355\uff09\u3002<\/li>\n<\/ul>\n","protected":false},"excerpt":{"rendered":"<p>1. \u8fde\u63a5\u548c\u9000\u51fa \u8fde\u63a5\u5230 MySQL \u547d\u4ee4\uff1a \u793a\u4f8b\uff1a \u7cfb\u7edf\u4f1a\u63d0\u793a\u60a8\u8f93\u5165\u5bc6\u7801\uff0c\u8f93\u5165\u5bc6\u7801\u540e\u5373\u53ef\u8fde\u63a5\u5230 MySQL\u3002 [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[16,8],"tags":[11],"class_list":["post-189","post","type-post","status-publish","format-standard","hentry","category-mysql_basic_management","category-mysql","tag-frequently_used_blogs"],"_links":{"self":[{"href":"https:\/\/zhaoyanqi.cn\/index.php?rest_route=\/wp\/v2\/posts\/189","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/zhaoyanqi.cn\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/zhaoyanqi.cn\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/zhaoyanqi.cn\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/zhaoyanqi.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=189"}],"version-history":[{"count":1,"href":"https:\/\/zhaoyanqi.cn\/index.php?rest_route=\/wp\/v2\/posts\/189\/revisions"}],"predecessor-version":[{"id":190,"href":"https:\/\/zhaoyanqi.cn\/index.php?rest_route=\/wp\/v2\/posts\/189\/revisions\/190"}],"wp:attachment":[{"href":"https:\/\/zhaoyanqi.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=189"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/zhaoyanqi.cn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=189"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/zhaoyanqi.cn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=189"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}