{"id":341,"date":"2025-09-28T14:22:48","date_gmt":"2025-09-28T06:22:48","guid":{"rendered":"http:\/\/43.139.99.192\/?p=341"},"modified":"2025-09-28T14:22:49","modified_gmt":"2025-09-28T06:22:49","slug":"%e6%b5%85%e5%ad%a6mysql","status":"publish","type":"post","link":"http:\/\/43.139.99.192\/index.php\/2025\/09\/28\/%e6%b5%85%e5%ad%a6mysql\/","title":{"rendered":"\u6d45\u5b66MySQL"},"content":{"rendered":"\n<p class=\"wp-block-paragraph\">\u5feb\u901f\u8fc7\u4e00\u904dMySQL\u7684\u6838\u5fc3\u77e5\u8bc6\u3002<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">\u7b2c\u4e00\u90e8\u5206\uff1a\u6838\u5fc3\u6982\u5ff5 &#8211; \u8fde\u63a5\uff08JOIN\uff09<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">\u60f3\u8c61\u4e00\u4e0b\uff0c\u6211\u4eec\u6709\u4e24\u5f20Excel\u8868\u683c\uff1a<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u200b<strong>\u200b\u88681\uff1a\u5458\u5de5\u8868 (employees)\u200b<\/strong>\u200b<\/p>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th>id<\/th><th>name<\/th><th>department_id<\/th><\/tr><\/thead><tbody><tr><td>1<\/td><td>\u5f20\u4e09<\/td><td>1<\/td><\/tr><tr><td>2<\/td><td>\u674e\u56db<\/td><td>2<\/td><\/tr><tr><td>3<\/td><td>\u738b\u4e94<\/td><td>1<\/td><\/tr><tr><td>4<\/td><td>\u8d75\u516d<\/td><td>(NULL)<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">\u200b<strong>\u200b\u88682\uff1a\u90e8\u95e8\u8868 (departments)\u200b<\/strong>\u200b<\/p>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th>id<\/th><th>department_name<\/th><\/tr><\/thead><tbody><tr><td>1<\/td><td>\u6280\u672f\u90e8<\/td><\/tr><tr><td>2<\/td><td>\u9500\u552e\u90e8<\/td><\/tr><tr><td>3<\/td><td>\u884c\u653f\u90e8<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">\u73b0\u5728\uff0c\u6211\u4eec\u60f3\u628a\u4e24\u4e2a\u8868\u7684\u4fe1\u606f\u5408\u5e76\u8d77\u6765\u770b\uff0c\u8fd9\u5c31\u9700\u8981\u201c\u8fde\u63a5\u201d\u3002<\/p>\n\n\n\n<h4 class=\"wp-block-heading\">1. \u5185\u8fde\u63a5 (INNER JOIN)<\/h4>\n\n\n\n<p class=\"wp-block-paragraph\">\u200b<strong>\u200b\u901a\u4fd7\u7406\u89e3\uff1a\u53d6\u4e24\u4e2a\u8868\u7684\u201c\u4ea4\u96c6\u201d\u3002\u53ea\u8fd4\u56de\u4e24\u4e2a\u8868\u4e2d\u80fd\u5b8c\u5168\u5339\u914d\u4e0a\u7684\u884c\u3002\u200b<\/strong>\u200b<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u200b<strong>\u200b\u573a\u666f\uff1a\u200b<\/strong>\u200b \u6211\u60f3\u77e5\u9053\u6bcf\u4e2a\u5458\u5de5\u5c5e\u4e8e\u54ea\u4e2a\u90e8\u95e8\uff0c\u200b<strong>\u200b\u4f46\u53ea\u5173\u5fc3\u90a3\u4e9b\u5df2\u7ecf\u5206\u914d\u4e86\u90e8\u95e8\u7684\u5458\u5de5\u200b<\/strong>\u200b\u3002<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>SELECT employees.name, departments.department_name\nFROM employees\nINNER JOIN departments ON employees.department_id = departments.id;<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u200b<strong>\u200b\u7ed3\u679c\uff1a\u200b<\/strong>\u200b<\/p>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th>name<\/th><th>department_name<\/th><\/tr><\/thead><tbody><tr><td>\u5f20\u4e09<\/td><td>\u6280\u672f\u90e8<\/td><\/tr><tr><td>\u674e\u56db<\/td><td>\u9500\u552e\u90e8<\/td><\/tr><tr><td>\u738b\u4e94<\/td><td>\u6280\u672f\u90e8<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">\u200b<strong>\u200b\u4f60\u53d1\u73b0\u4e86\u4ec0\u4e48\uff1f\u200b<\/strong>\u200b<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u5458\u5de5\u201c\u8d75\u516d\u201d\u4e0d\u89c1\u4e86\uff0c\u56e0\u4e3a\u4ed6\u7684<code>department_id<\/code>\u662fNULL\uff0c\u5728\u90e8\u95e8\u8868\u91cc\u627e\u4e0d\u5230\u5339\u914d\u9879\u3002<\/li>\n\n\n\n<li>\u90e8\u95e8\u201c\u884c\u653f\u90e8\u201d\u4e5f\u4e0d\u89c1\uff0c\u56e0\u4e3a\u5458\u5de5\u8868\u91cc\u6ca1\u4eba\u5c5e\u4e8e\u90e8\u95e83\u3002<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">\u200b<strong>\u200bINNER JOIN \u5c31\u50cf\u4e00\u6b21\u4e25\u683c\u7684\u76f8\u4eb2\u5927\u4f1a\uff0c\u5fc5\u987b\u7537\u5973\u53cc\u65b9\u90fd\u770b\u5bf9\u773c\uff08\u5339\u914d\u4e0a\uff09\u624d\u4f1a\u6210\u529f\u3002\u200b<\/strong>\u200b<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h4 class=\"wp-block-heading\">2. \u5de6\u5916\u8fde\u63a5 (LEFT OUTER JOIN \u6216 LEFT JOIN)<\/h4>\n\n\n\n<p class=\"wp-block-paragraph\">\u200b<strong>\u200b\u901a\u4fd7\u7406\u89e3\uff1a\u4ee5\u5de6\u8868\u4e3a\u4e3b\u3002\u8fd4\u56de\u5de6\u8868\u7684\u6240\u6709\u8bb0\u5f55\uff0c\u4ee5\u53ca\u53f3\u8868\u4e2d\u80fd\u5339\u914d\u4e0a\u7684\u8bb0\u5f55\u3002\u53f3\u8868\u5339\u914d\u4e0d\u4e0a\u7684\u5730\u65b9\u5c31\u7528NULL\u586b\u5145\u3002\u200b<\/strong>\u200b<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u200b<strong>\u200b\u573a\u666f\uff1a\u200b<\/strong>\u200b \u6211\u60f3\u5217\u51fa\u200b<strong>\u200b\u6240\u6709\u5458\u5de5\u200b<\/strong>\u200b\uff0c\u5e76\u663e\u793a\u4ed6\u4eec\u7684\u90e8\u95e8\u4fe1\u606f\u3002\u5c31\u7b97\u4ed6\u6ca1\u90e8\u95e8\uff08\u6bd4\u5982\u65b0\u5458\u5de5\uff09\uff0c\u6211\u4e5f\u8981\u770b\u5230\u4ed6\u7684\u540d\u5b57\u3002<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>SELECT employees.name, departments.department_name\nFROM employees\nLEFT JOIN departments ON employees.department_id = departments.id;<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u200b<strong>\u200b\u7ed3\u679c\uff1a\u200b<\/strong>\u200b<\/p>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th>name<\/th><th>department_name<\/th><\/tr><\/thead><tbody><tr><td>\u5f20\u4e09<\/td><td>\u6280\u672f\u90e8<\/td><\/tr><tr><td>\u674e\u56db<\/td><td>\u9500\u552e\u90e8<\/td><\/tr><tr><td>\u738b\u4e94<\/td><td>\u6280\u672f\u90e8<\/td><\/tr><tr><td>\u8d75\u516d<\/td><td>(NULL)<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">\u200b<strong>\u200b\u4f60\u53d1\u73b0\u4e86\u4ec0\u4e48\uff1f\u200b<\/strong>\u200b<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u200b<strong>\u200b\u5de6\u8868\uff08\u5458\u5de5\u8868\uff09\u200b<\/strong>\u200b \u7684\u6240\u6709\u8bb0\u5f55\u90fd\u51fa\u6765\u4e86\u3002<\/li>\n\n\n\n<li>\u8d75\u516d\u867d\u7136\u6ca1\u90e8\u95e8\uff0c\u4f46\u4ed6\u7684\u540d\u5b57\u4f9d\u7136\u5728\u3002<\/li>\n\n\n\n<li>\u90e8\u95e8\u201c\u884c\u653f\u90e8\u201d\u8fd8\u662f\u6ca1\u51fa\u73b0\uff0c\u56e0\u4e3a\u5b83\u662f\u53f3\u8868\u72ec\u6709\u7684\u3002<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">\u200b<strong>\u200bLEFT JOIN \u5c31\u50cf\u4fdd\u62a4\u5de6\u8868\u7684\u201c\u62a4\u728a\u5b50\u201d\u5bb6\u957f\uff1a\u201c\u6211\u5de6\u8868\u7684\u4eba\u4e00\u4e2a\u90fd\u4e0d\u80fd\u5c11\uff01\u53f3\u8868\u4f60\u770b\u7740\u914d\uff0c\u914d\u4e0d\u4e0a\u5c31\u7a7a\u7740\u3002\u201d\u200b<\/strong>\u200b<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h4 class=\"wp-block-heading\">3. \u53f3\u5916\u8fde\u63a5 (RIGHT OUTER JOIN \u6216 RIGHT JOIN)<\/h4>\n\n\n\n<p class=\"wp-block-paragraph\">\u200b<strong>\u200b\u901a\u4fd7\u7406\u89e3\uff1a\u4ee5\u53f3\u8868\u4e3a\u4e3b\u3002\u8fd4\u56de\u53f3\u8868\u7684\u6240\u6709\u8bb0\u5f55\uff0c\u4ee5\u53ca\u5de6\u8868\u4e2d\u80fd\u5339\u914d\u4e0a\u7684\u8bb0\u5f55\u3002\u5de6\u8868\u5339\u914d\u4e0d\u4e0a\u7684\u5730\u65b9\u5c31\u7528NULL\u586b\u5145\u3002\u200b<\/strong>\u200b<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u200b<strong>\u200b\u573a\u666f\uff1a\u200b<\/strong>\u200b \u6211\u60f3\u5217\u51fa\u200b<strong>\u200b\u6240\u6709\u90e8\u95e8\u200b<\/strong>\u200b\uff0c\u5e76\u770b\u770b\u6bcf\u4e2a\u90e8\u95e8\u6709\u54ea\u4e9b\u5458\u5de5\u3002\u5c31\u7b97\u67d0\u4e2a\u90e8\u95e8\u4e00\u4e2a\u4eba\u90fd\u6ca1\u6709\uff08\u6bd4\u5982\u521a\u6210\u7acb\u7684\u90e8\u95e8\uff09\uff0c\u6211\u4e5f\u8981\u770b\u5230\u8fd9\u4e2a\u90e8\u95e8\u3002<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>SELECT employees.name, departments.department_name\nFROM employees\nRIGHT JOIN departments ON employees.department_id = departments.id;<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u200b<strong>\u200b\u7ed3\u679c\uff1a\u200b<\/strong>\u200b<\/p>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th>name<\/th><th>department_name<\/th><\/tr><\/thead><tbody><tr><td>\u5f20\u4e09<\/td><td>\u6280\u672f\u90e8<\/td><\/tr><tr><td>\u674e\u56db<\/td><td>\u9500\u552e\u90e8<\/td><\/tr><tr><td>(NULL)<\/td><td>\u884c\u653f\u90e8<\/td><\/tr><tr><td>\u738b\u4e94<\/td><td>\u6280\u672f\u90e8<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">\u200b<strong>\u200b\u4f60\u53d1\u73b0\u4e86\u4ec0\u4e48\uff1f\u200b<\/strong>\u200b<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u200b<strong>\u200b\u53f3\u8868\uff08\u90e8\u95e8\u8868\uff09\u200b<\/strong>\u200b \u7684\u6240\u6709\u8bb0\u5f55\u90fd\u51fa\u6765\u4e86\u3002<\/li>\n\n\n\n<li>\u201c\u884c\u653f\u90e8\u201d\u867d\u7136\u6ca1\u5458\u5de5\uff0c\u4f46\u90e8\u95e8\u540d\u663e\u793a\u51fa\u6765\u4e86\u3002<\/li>\n\n\n\n<li>\u5458\u5de5\u201c\u8d75\u516d\u201d\u4e0d\u89c1\u4e86\uff0c\u56e0\u4e3a\u4ed6\u662f\u5de6\u8868\u72ec\u6709\u7684\u3002<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">\u200b<strong>\u200bRIGHT JOIN \u548c LEFT JOIN \u53cd\u8fc7\u6765\uff0c\u662f\u201c\u62a4\u7740\u201d\u53f3\u8868\u7684\u5bb6\u957f\u3002\u200b<\/strong>\u200b<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h4 class=\"wp-block-heading\">4. \u5916\u8fde\u63a5 (FULL OUTER JOIN)<\/h4>\n\n\n\n<p class=\"wp-block-paragraph\">\u200b<strong>\u200b\u901a\u4fd7\u7406\u89e3\uff1a\u53d6\u4e24\u4e2a\u8868\u7684\u201c\u5e76\u96c6\u201d\u3002\u8fd4\u56de\u5de6\u53f3\u4e24\u8868\u7684\u6240\u6709\u8bb0\u5f55\uff0c\u5339\u914d\u4e0d\u4e0a\u7684\u5730\u65b9\u90fd\u7528NULL\u586b\u5145\u3002\u200b<\/strong>\u200b<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u200b<strong>\u200b\u573a\u666f\uff1a\u200b<\/strong>\u200b \u6211\u60f3\u505a\u4e00\u4e2a\u5168\u91cf\u7684\u6838\u5bf9\u6e05\u5355\uff0c\u65e2\u8981\u770b\u5230\u6240\u6709\u5458\u5de5\uff08\u5305\u62ec\u6ca1\u90e8\u95e8\u7684\uff09\uff0c\u4e5f\u8981\u770b\u5230\u6240\u6709\u90e8\u95e8\uff08\u5305\u62ec\u6ca1\u5458\u5de5\u7684\uff09\u3002<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>-- \u6ce8\u610f\uff1aMySQL\u4e0d\u76f4\u63a5\u652f\u6301FULL OUTER JOIN\uff0c\u4f46\u53ef\u4ee5\u7528LEFT JOIN\u548cRIGHT JOIN\u7684UNION\u6765\u5b9e\u73b0\nSELECT employees.name, departments.department_name\nFROM employees\nLEFT JOIN departments ON employees.department_id = departments.id\nUNION\nSELECT employees.name, departments.department_name\nFROM employees\nRIGHT JOIN departments ON employees.department_id = departments.id;<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">\u200b<strong>\u200b\u7ed3\u679c\uff1a\u200b<\/strong>\u200b<\/p>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th>name<\/th><th>department_name<\/th><\/tr><\/thead><tbody><tr><td>\u5f20\u4e09<\/td><td>\u6280\u672f\u90e8<\/td><\/tr><tr><td>\u674e\u56db<\/td><td>\u9500\u552e\u90e8<\/td><\/tr><tr><td>\u738b\u4e94<\/td><td>\u6280\u672f\u90e8<\/td><\/tr><tr><td>\u8d75\u516d<\/td><td>(NULL)<\/td><\/tr><tr><td>(NULL)<\/td><td>\u884c\u653f\u90e8<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">\u200b<strong>\u200b\u4f60\u53d1\u73b0\u4e86\u4ec0\u4e48\uff1f\u200b<\/strong>\u200b<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u4e24\u4e2a\u8868\u7684\u6570\u636e\u5168\u90fd\u51fa\u6765\u4e86\uff01\u4e00\u4e2a\u90fd\u6ca1\u5c11\u3002<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">\u200b<strong>\u200bFULL OUTER JOIN \u5c31\u50cf\u4e00\u4e2a\u5927\u56e2\u5706\uff0c\u8c01\u90fd\u4e0d\u80fd\u5c11\u3002\u200b<\/strong>\u200b<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">\u5feb\u901f\u8bb0\u5fc6\u53e3\u8bc0<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u200b<strong>\u200bINNER JOIN\u200b<\/strong>\u200b\uff1a \u4fe9\u90fd\u6709\u7684\u624d\u8981 \u2192 \u200b<strong>\u200b\u4ea4\u96c6\u200b<\/strong>\u200b<\/li>\n\n\n\n<li>\u200b<strong>\u200bLEFT JOIN\u200b<\/strong>\u200b\uff1a \u5de6\u8868\u5168\u8981\uff0c\u53f3\u8868\u770b\u7740\u914d \u2192 \u200b<strong>\u200b\u4fdd\u5de6\u200b<\/strong>\u200b<\/li>\n\n\n\n<li>\u200b<strong>\u200bRIGHT JOIN\u200b<\/strong>\u200b\uff1a \u53f3\u8868\u5168\u8981\uff0c\u5de6\u8868\u770b\u7740\u914d \u2192 \u200b<strong>\u200b\u4fdd\u53f3\u200b<\/strong>\u200b<\/li>\n\n\n\n<li>\u200b<strong>\u200bFULL JOIN\u200b<\/strong>\u200b\uff1a \u6211\u5168\u90fd\u8981\uff01 \u2192 \u200b<strong>\u200b\u5e76\u96c6\u200b<\/strong>\u200b<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">\u7b2c\u4e8c\u90e8\u5206\uff1aMySQL \u5feb\u901f\u5165\u95e8\u77e5\u8bc6\u6811<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">\u5149\u4f1a\u8fde\u63a5\u8fd8\u4e0d\u591f\uff0c\u6211\u4eec\u6765\u642d\u5efa\u4e00\u4e2aMySQL\u7684\u77e5\u8bc6\u6846\u67b6\u3002<\/p>\n\n\n\n<h4 class=\"wp-block-heading\">1. \u6570\u636e\u5e93\u662f\u5565\uff1f<\/h4>\n\n\n\n<p class=\"wp-block-paragraph\">\u5c31\u662f\u4e00\u4e2a\u9ad8\u7ea7\u7684\u3001\u591a\u7528\u6237\u7684Excel\u6587\u4ef6\uff0c\u80fd\u5b89\u5168\u3001\u9ad8\u6548\u5730\u5b58\u50a8\u548c\u7ba1\u7406\u5927\u91cf\u6570\u636e\u3002<\/p>\n\n\n\n<h4 class=\"wp-block-heading\">2. SQL\u662f\u5565\uff1f<\/h4>\n\n\n\n<p class=\"wp-block-paragraph\">\u662f\u8ddf\u6570\u636e\u5e93\u201c\u8bf4\u8bdd\u201d\u7684\u8bed\u8a00\u3002\u4f60\u4e0b\u547d\u4ee4\uff0c\u5b83\u53bb\u6267\u884c\u3002<\/p>\n\n\n\n<h4 class=\"wp-block-heading\">3. \u5fc5\u987b\u638c\u63e1\u7684\u56db\u5927\u6838\u5fc3\u64cd\u4f5c\uff08CRUD\uff09<\/h4>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u200b<strong>\u200bC (Create &#8211; \u589e)\u200b<\/strong>\u200b\uff1a \u5f80\u8868\u91cc\u63d2\u65b0\u6570\u636e\u3002 <code>INSERT INTO employees (name, department_id) VALUES ('\u94b1\u4e03', 2);<\/code><\/li>\n\n\n\n<li>\u200b<strong>\u200bR (Read &#8211; \u67e5)\u200b<\/strong>\u200b\uff1a \u4ece\u8868\u91cc\u8bfb\u6570\u636e\u3002\u8fd9\u662f\u4f60\u6700\u5e38\u7528\u7684\u64cd\u4f5c\uff01 <code>SELECT name, department_id FROM employees WHERE department_id = 1; -- \u67e5\u627e\u6280\u672f\u90e8\u6240\u6709\u4eba<\/code><\/li>\n\n\n\n<li>\u200b<strong>\u200bU (Update &#8211; \u6539)\u200b<\/strong>\u200b\uff1a \u4fee\u6539\u8868\u91cc\u5df2\u6709\u7684\u6570\u636e\u3002 <code>UPDATE employees SET department_id = 3 WHERE name = '\u8d75\u516d'; -- \u7ed9\u8d75\u516d\u5206\u914d\u5230\u884c\u653f\u90e8<\/code><\/li>\n\n\n\n<li>\u200b<strong>\u200bD (Delete &#8211; \u5220)\u200b<\/strong>\u200b\uff1a \u4ece\u8868\u91cc\u5220\u9664\u6570\u636e\u3002\uff08\u200b<strong>\u200b\u614e\u7528\uff01\u200b<\/strong>\u200b\uff09 <code>DELETE FROM employees WHERE name = '\u94b1\u4e03'; -- \u5f00\u9664\u94b1\u4e03<\/code><\/li>\n<\/ul>\n\n\n\n<h4 class=\"wp-block-heading\">4. \u5173\u952e\u5b50\u53e5\uff08\u8ba9\u67e5\u8be2\u66f4\u7cbe\u51c6\uff09<\/h4>\n\n\n\n<ul class=\"wp-block-list\">\n<li><code>WHERE<\/code>\uff1a \u8fc7\u6ee4\u6761\u4ef6\uff0c\u50cfExcel\u7684\u7b5b\u9009\u529f\u80fd\u3002<code>WHERE age > 18<\/code><\/li>\n\n\n\n<li><code>ORDER BY<\/code>\uff1a \u6392\u5e8f\u3002<code>ORDER BY score DESC<\/code>(\u6309\u5206\u6570\u964d\u5e8f\u6392)<\/li>\n\n\n\n<li><code>GROUP BY<\/code>\uff1a \u5206\u7ec4\uff0c\u5e38\u548c\u7edf\u8ba1\u51fd\u6570\u4e00\u8d77\u7528\u3002 <code>-- \u7edf\u8ba1\u6bcf\u4e2a\u90e8\u95e8\u6709\u591a\u5c11\u4eba SELECT department_id, COUNT(*) as employee_count FROM employees GROUP BY department_id;<\/code><\/li>\n\n\n\n<li><code>HAVING<\/code>\uff1a \u5bf9\u5206\u7ec4\u540e\u7684\u7ed3\u679c\u8fdb\u884c\u8fc7\u6ee4\uff0c\u548c<code>WHERE<\/code>\u7c7b\u4f3c\uff0c\u4f46\u7528\u5728<code>GROUP BY<\/code>\u4e4b\u540e\u3002<\/li>\n<\/ul>\n\n\n\n<h4 class=\"wp-block-heading\">5. \u7ed9\u5c0f\u767d\u7684\u5b66\u4e60\u8def\u5f84\u5efa\u8bae<\/h4>\n\n\n\n<ol class=\"wp-block-list\">\n<li>\u200b<strong>\u200b\u7b2c\u4e00\u6b65\uff1a\u5b89\u88c5MySQL\u200b<\/strong>\u200b \u53bbMySQL\u5b98\u7f51\u4e0b\u8f7dMySQL Community Server\uff0c\u6216\u8005\u5b89\u88c5XAMPP\/MAMP\u8fd9\u7c7b\u96c6\u6210\u73af\u5883\uff0c\u66f4\u7b80\u5355\u3002<\/li>\n\n\n\n<li>\u200b<strong>\u200b\u7b2c\u4e8c\u6b65\uff1a\u7ec3\u719fCRUD\u200b<\/strong>\u200b \u81ea\u5df1\u521b\u5efa\u4e00\u5f20\u8868\uff0c\u6bd4\u5982<code>\u5b66\u751f\u8868\uff08id\uff0c \u59d3\u540d\uff0c \u6210\u7ee9\uff09<\/code>\uff0c\u75af\u72c2\u7ec3\u4e60\u589e\u3001\u5220\u3001\u6539\u3001\u67e5\u3002<\/li>\n\n\n\n<li>\u200b<strong>\u200b\u7b2c\u4e09\u6b65\uff1a\u7406\u89e3\u201c\u5173\u7cfb\u201d\u200b<\/strong>\u200b \u518d\u521b\u5efa\u4e00\u5f20<code>\u8bfe\u7a0b\u8868<\/code>\uff0c\u7136\u540e\u7528<code>\u5b66\u751fID<\/code>\u628a\u4e24\u5f20\u8868\u5173\u8054\u8d77\u6765\u3002\u8fd9\u65f6\u4f60\u5c31\u53ef\u4ee5\u7ec3\u4e60\u4eca\u5929\u5b66\u7684\u5404\u79cd<code>JOIN<\/code>\u4e86\u3002<\/li>\n\n\n\n<li>\u200b<strong>\u200b\u7b2c\u56db\u6b65\uff1a\u5b9e\u6218\u5c0f\u9879\u76ee\u200b<\/strong>\u200b \u5c1d\u8bd5\u8bbe\u8ba1\u4e00\u4e2a\u201c\u4e2a\u4eba\u535a\u5ba2\u7cfb\u7edf\u201d\u7684\u6570\u636e\u5e93\uff1a\n<ul class=\"wp-block-list\">\n<li><code>\u7528\u6237\u8868<\/code>\uff1a\u5b58\u7528\u6237\u4fe1\u606f\u3002<\/li>\n\n\n\n<li><code>\u6587\u7ae0\u8868<\/code>\uff1a\u5b58\u6587\u7ae0\uff0c\u91cc\u9762\u6709\u4e00\u4e2a<code>\u7528\u6237ID<\/code>\u5b57\u6bb5\u6307\u5411\u662f\u8c01\u5199\u7684\u3002 \u7136\u540e\u4f60\u5c31\u53ef\u4ee5\u7528JOIN\u67e5\u8be2\u51fa\u201c\u67d0\u7528\u6237\u5199\u7684\u6240\u6709\u6587\u7ae0\u201d\u4e86\u3002<\/li>\n<\/ul>\n<\/li>\n<\/ol>\n\n\n\n<h3 class=\"wp-block-heading\">\u603b\u7ed3<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u200b<strong>\u200b\u8fde\u63a5\uff08JOIN\uff09\u200b<\/strong>\u200b \u662fSQL\u7684\u6838\u5fc3\uff0c\u7528\u4e8e\u5408\u5e76\u591a\u4e2a\u76f8\u5173\u8054\u7684\u8868\u7684\u6570\u636e\u3002<\/li>\n\n\n\n<li>\u200b<strong>\u200b\u5185\u8fde\u63a5\u200b<\/strong>\u200b \u6700\u5e38\u7528\uff0c\u200b<strong>\u200b\u5de6\u8fde\u63a5\u200b<\/strong>\u200b \u4e5f\u975e\u5e38\u5e38\u89c1\uff0c\u52a1\u5fc5\u638c\u63e1\u3002<\/li>\n\n\n\n<li>\u5b66\u4e60MySQL\u4e0d\u8981\u6015\uff0c\u5c31\u4ece\u6700\u57fa\u7840\u7684<code>CREATE DATABASE<\/code>, <code>CREATE TABLE<\/code>, <code>INSERT<\/code>, <code>SELECT<\/code>\u5f00\u59cb\u52a8\u624b\u6572\u4ee3\u7801\u3002<\/li>\n\n\n\n<li>\u9047\u5230\u62a5\u9519\u662f\u6b63\u5e38\u7684\uff0c\u90a3\u662f\u7535\u8111\u5728\u6559\u4f60\u6b63\u786e\u7684\u8bed\u6cd5\uff0c\u4ed4\u7ec6\u8bfb\u9519\u8bef\u4fe1\u606f\u3002<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">\u4f60\u5df2\u7ecf\u8fc8\u51fa\u4e86\u975e\u5e38\u91cd\u8981\u7684\u4e00\u6b65\uff01\u7406\u89e3\u4e86\u8fde\u63a5\uff0c\u5c31\u7b49\u4e8e\u6253\u5f00\u4e86\u5173\u7cfb\u578b\u6570\u636e\u5e93\u7684\u5927\u95e8\u3002\u63a5\u4e0b\u6765\u5c31\u662f\u591a\u7ec3\u4e60\uff0c\u628a\u77e5\u8bc6\u53d8\u6210\u4f60\u7684\u672c\u80fd\u3002\u52a0\u6cb9\uff01\u5982\u679c\u8fd8\u6709\u4efb\u4f55\u95ee\u9898\uff0c\u968f\u65f6\u53ef\u4ee5\u518d\u95ee\u6211\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u5feb\u901f\u8fc7\u4e00\u904dMySQL\u7684\u6838\u5fc3\u77e5\u8bc6\u3002 \u7b2c\u4e00\u90e8\u5206\uff1a\u6838\u5fc3\u6982\u5ff5 &#8211; \u8fde\u63a5\uff08JOIN\uff09 \u60f3\u8c61\u4e00\u4e0b\uff0c\u6211\u4eec\u6709\u4e24\u5f20E [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-341","post","type-post","status-publish","format-standard","hentry","category-text"],"_links":{"self":[{"href":"http:\/\/43.139.99.192\/index.php\/wp-json\/wp\/v2\/posts\/341","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/43.139.99.192\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/43.139.99.192\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/43.139.99.192\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/43.139.99.192\/index.php\/wp-json\/wp\/v2\/comments?post=341"}],"version-history":[{"count":1,"href":"http:\/\/43.139.99.192\/index.php\/wp-json\/wp\/v2\/posts\/341\/revisions"}],"predecessor-version":[{"id":342,"href":"http:\/\/43.139.99.192\/index.php\/wp-json\/wp\/v2\/posts\/341\/revisions\/342"}],"wp:attachment":[{"href":"http:\/\/43.139.99.192\/index.php\/wp-json\/wp\/v2\/media?parent=341"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/43.139.99.192\/index.php\/wp-json\/wp\/v2\/categories?post=341"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/43.139.99.192\/index.php\/wp-json\/wp\/v2\/tags?post=341"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}