{"id":3750,"date":"2025-05-28T23:52:08","date_gmt":"2025-05-28T15:52:08","guid":{"rendered":"https:\/\/www.laixuexila.com\/?p=3750"},"modified":"2025-05-28T23:52:08","modified_gmt":"2025-05-28T15:52:08","slug":"%e5%a6%82%e4%bd%95%e4%bd%bf%e7%94%a8-mysql-%e8%a7%a6%e5%8f%91%e5%99%a8%ef%bc%88trigger%ef%bc%89%e5%ae%9e%e7%8e%b0%e6%95%b0%e6%8d%ae%e5%ba%93%e4%bb%bb%e5%8a%a1%e8%87%aa%e5%8a%a8%e5%8c%96%ef%bc%9f","status":"publish","type":"post","link":"https:\/\/www.laixuexila.com\/index.php\/2025\/05\/28\/%e5%a6%82%e4%bd%95%e4%bd%bf%e7%94%a8-mysql-%e8%a7%a6%e5%8f%91%e5%99%a8%ef%bc%88trigger%ef%bc%89%e5%ae%9e%e7%8e%b0%e6%95%b0%e6%8d%ae%e5%ba%93%e4%bb%bb%e5%8a%a1%e8%87%aa%e5%8a%a8%e5%8c%96%ef%bc%9f\/","title":{"rendered":"\u5982\u4f55\u4f7f\u7528\u00a0MySQL \u89e6\u53d1\u5668\uff08Trigger\uff09\u5b9e\u73b0\u6570\u636e\u5e93\u4efb\u52a1\u81ea\u52a8\u5316\uff1f"},"content":{"rendered":"\n<p>\u4f7f\u7528 <strong>MySQL \u89e6\u53d1\u5668\uff08Trigger\uff09<\/strong> \u53ef\u4ee5\u5b9e\u73b0<strong>\u6570\u636e\u5e93\u4efb\u52a1\u81ea\u52a8\u5316<\/strong>\uff0c\u4f8b\u5982\uff1a<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u81ea\u52a8\u7ef4\u62a4\u5ba1\u8ba1\u65e5\u5fd7\uff1b<\/li>\n\n\n\n<li>\u81ea\u52a8\u66f4\u65b0\u7edf\u8ba1\u5b57\u6bb5\uff1b<\/li>\n\n\n\n<li>\u6570\u636e\u540c\u6b65\uff1b<\/li>\n\n\n\n<li>\u81ea\u52a8\u751f\u6210\u65f6\u95f4\u6233\uff1b<\/li>\n\n\n\n<li>\u7ea6\u675f\u6027\u4e1a\u52a1\u89c4\u5219\uff08\u66f4\u590d\u6742\u7684\u9650\u5236\uff09\u7b49\u3002<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">\u4e00\u3001\u4ec0\u4e48\u662f MySQL \u89e6\u53d1\u5668\uff1f<\/h2>\n\n\n\n<p>\u89e6\u53d1\u5668\u662f\u4e00\u79cd\u7279\u6b8a\u7684\u5b58\u50a8\u5bf9\u8c61\uff0c<strong>\u5728\u6307\u5b9a\u8868\u7684 INSERT\u3001UPDATE \u6216 DELETE \u64cd\u4f5c\u53d1\u751f\u524d\u540e\u81ea\u52a8\u6267\u884c\u4e00\u6bb5 SQL \u4ee3\u7801<\/strong>\u3002<\/p>\n\n\n\n<p>\u89e6\u53d1\u5668\u6267\u884c\u65f6\u95f4\u5206\u4e24\u7c7b\uff1a<\/p>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th>\u89e6\u53d1\u65f6\u95f4<\/th><th>\u63cf\u8ff0<\/th><\/tr><\/thead><tbody><tr><td>BEFORE<\/td><td>\u5728 SQL \u64cd\u4f5c\u6267\u884c\u4e4b\u524d\u89e6\u53d1<\/td><\/tr><tr><td>AFTER<\/td><td>\u5728 SQL \u64cd\u4f5c\u6267\u884c\u4e4b\u540e\u89e6\u53d1<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<p>\u89e6\u53d1\u4e8b\u4ef6\u7c7b\u578b\u5305\u62ec\uff1a<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>INSERT<\/li>\n\n\n\n<li>UPDATE<\/li>\n\n\n\n<li>DELETE<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">\u4e8c\u3001\u8bed\u6cd5\u7ed3\u6784<\/h2>\n\n\n\n<pre class=\"wp-block-code\"><code>CREATE TRIGGER trigger_name\n{BEFORE | AFTER} {INSERT | UPDATE | DELETE}\nON table_name\nFOR EACH ROW\nBEGIN\n    -- \u6267\u884c\u7684 SQL \u8bed\u53e5\u5757\nEND;<\/code><\/pre>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">\u4e09\u3001\u5e38\u7528\u89e6\u53d1\u5668\u793a\u4f8b<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\">\u793a\u4f8b 1\uff1a\u81ea\u52a8\u8bb0\u5f55\u7528\u6237\u53d8\u66f4\u65e5\u5fd7<\/h3>\n\n\n\n<h4 class=\"wp-block-heading\">\u573a\u666f\uff1a\u5bf9 <code>users<\/code> \u8868\u7684\u66f4\u65b0\u64cd\u4f5c\uff0c\u8bb0\u5f55\u5230 <code>user_logs<\/code> \u65e5\u5fd7\u8868\u4e2d\u3002<\/h4>\n\n\n\n<pre class=\"wp-block-code\"><code>-- 1. \u521b\u5efa\u65e5\u5fd7\u8868\nCREATE TABLE user_logs (\n    id INT AUTO_INCREMENT PRIMARY KEY,\n    user_id INT,\n    old_email VARCHAR(100),\n    new_email VARCHAR(100),\n    changed_at DATETIME\n);\n\n-- 2. \u521b\u5efa\u89e6\u53d1\u5668\nDELIMITER $$\n\nCREATE TRIGGER log_user_update\nAFTER UPDATE ON users\nFOR EACH ROW\nBEGIN\n    INSERT INTO user_logs (user_id, old_email, new_email, changed_at)\n    VALUES (OLD.id, OLD.email, NEW.email, NOW());\nEND$$\n\nDELIMITER ;<\/code><\/pre>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">\u793a\u4f8b 2\uff1a\u81ea\u52a8\u66f4\u65b0\u65f6\u95f4\u6233<\/h3>\n\n\n\n<pre class=\"wp-block-code\"><code>ALTER TABLE orders ADD COLUMN updated_at DATETIME;\n\nDELIMITER $$\n\nCREATE TRIGGER update_timestamp\nBEFORE UPDATE ON orders\nFOR EACH ROW\nBEGIN\n    SET NEW.updated_at = NOW();\nEND$$\n\nDELIMITER ;<\/code><\/pre>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h3 class=\"wp-block-heading\">\u793a\u4f8b 3\uff1a\u9632\u6b62\u975e\u6cd5\u5220\u9664\uff08\u7ea6\u675f\u4e1a\u52a1\u89c4\u5219\uff09<\/h3>\n\n\n\n<pre class=\"wp-block-code\"><code>DELIMITER $$\n\nCREATE TRIGGER prevent_admin_delete\nBEFORE DELETE ON users\nFOR EACH ROW\nBEGIN\n    IF OLD.role = 'admin' THEN\n        SIGNAL SQLSTATE '45000'\n        SET MESSAGE_TEXT = '\u7981\u6b62\u5220\u9664\u7ba1\u7406\u5458\u8d26\u6237';\n    END IF;\nEND$$\n\nDELIMITER ;<\/code><\/pre>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">\u56db\u3001\u89e6\u53d1\u5668\u4e2d\u7684 <code>NEW<\/code> \u548c <code>OLD<\/code><\/h2>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th>\u4f5c\u7528<\/th><th>INSERT<\/th><th>UPDATE<\/th><th>DELETE<\/th><\/tr><\/thead><tbody><tr><td><code>NEW<\/code><\/td><td>\u2705<\/td><td>\u2705<\/td><td>\u274c<\/td><\/tr><tr><td><code>OLD<\/code><\/td><td>\u274c<\/td><td>\u2705<\/td><td>\u2705<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<ul class=\"wp-block-list\">\n<li><code>NEW.column_name<\/code>\uff1a\u65b0\u503c\uff08\u63d2\u5165\u6216\u66f4\u65b0\u4e4b\u540e\uff09<\/li>\n\n\n\n<li><code>OLD.column_name<\/code>\uff1a\u65e7\u503c\uff08\u66f4\u65b0\u4e4b\u524d\u6216\u5220\u9664\u4e4b\u524d\uff09<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">\u4e94\u3001\u6ce8\u610f\u4e8b\u9879<\/h2>\n\n\n\n<ol class=\"wp-block-list\">\n<li>\u4e00\u4e2a\u8868\u540c\u4e00\u7c7b\u578b\u6700\u591a\u6709 <strong>\u4e00\u4e2a BEFORE \u548c\u4e00\u4e2a AFTER \u7684\u540c\u7c7b\u578b\u89e6\u53d1\u5668<\/strong>\uff1b<\/li>\n\n\n\n<li><code>FOR EACH ROW<\/code> \u662f\u5fc5\u987b\u7684 \u2014\u2014 \u6bcf\u4e00\u884c\u6570\u636e\u89e6\u53d1\u4e00\u6b21\uff1b<\/li>\n\n\n\n<li>\u89e6\u53d1\u5668\u4e2d\u4e0d\u80fd\u4f7f\u7528\u4e8b\u52a1\u63a7\u5236\u8bed\u53e5\uff08\u5982 <code>COMMIT<\/code>, <code>ROLLBACK<\/code>\uff09\uff1b<\/li>\n\n\n\n<li>\u89e6\u53d1\u5668\u4e0d\u8981\u8fc7\u4e8e\u590d\u6742\uff0c\u5426\u5219\u4f1a<strong>\u6027\u80fd\u4e0b\u964d<\/strong>\uff1b<\/li>\n\n\n\n<li>\u8c03\u8bd5\u56f0\u96be \u2014\u2014 \u63a8\u8350\u5728\u65e5\u5fd7\u8868\u8bb0\u5f55\u6216\u914d\u5408 <code>SIGNAL<\/code> \u62a5\u9519\u6392\u67e5\uff1b<\/li>\n\n\n\n<li>MySQL \u4e0d\u652f\u6301\u5bf9 <code>VIEW<\/code> \u6216 <code>\u4e34\u65f6\u8868<\/code> \u521b\u5efa\u89e6\u53d1\u5668\u3002<\/li>\n<\/ol>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">\u516d\u3001\u5e38\u89c1\u5e94\u7528\u573a\u666f<\/h2>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th>\u5e94\u7528\u573a\u666f<\/th><th>\u5b9e\u4f8b\u8bf4\u660e<\/th><\/tr><\/thead><tbody><tr><td>\u6570\u636e\u5ba1\u8ba1<\/td><td>\u7528\u6237\u4fe1\u606f\u53d8\u66f4\u65f6\u81ea\u52a8\u8bb0\u5f55\u65e5\u5fd7\u8868<\/td><\/tr><tr><td>\u81ea\u52a8\u7ef4\u62a4\u66f4\u65b0\u65f6\u95f4<\/td><td>\u81ea\u52a8\u8bbe\u7f6e <code>updated_at<\/code> \u5b57\u6bb5<\/td><\/tr><tr><td>\u6570\u636e\u81ea\u52a8\u6e05\u6d17<\/td><td>\u5728\u5199\u5165\u65f6\u7edf\u4e00\u683c\u5f0f\u5316\u5b57\u6bb5\uff08\u5982\u90ae\u7bb1\u8f6c\u5c0f\u5199\uff09<\/td><\/tr><tr><td>\u7ea7\u8054\u66f4\u65b0<\/td><td>\u8ba2\u5355\u72b6\u6001\u53d8\u66f4\u65f6\u540c\u6b65\u66f4\u65b0\u5e93\u5b58\u8868<\/td><\/tr><tr><td>\u5b89\u5168\u63a7\u5236<\/td><td>\u9650\u5236\u5220\u9664\u67d0\u4e9b\u5173\u952e\u8bb0\u5f55\uff0c\u5982\u7ba1\u7406\u5458\u3001\u6838\u5fc3\u914d\u7f6e\u7b49<\/td><\/tr><tr><td>\u7edf\u8ba1\u7ef4\u62a4<\/td><td>\u8bb0\u5f55\u6bcf\u7c7b\u5546\u54c1\u9500\u91cf\u53d8\u52a8\uff0c\u81ea\u52a8\u66f4\u65b0\u7edf\u8ba1\u8868<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">\u4e03\u3001\u76f8\u5173\u5b98\u65b9\u6587\u6863\u4e0e\u53c2\u8003\u8d44\u6599<\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li><a href=\"https:\/\/dev.mysql.com\/doc\/refman\/8.0\/en\/triggers.html\">MySQL \u5b98\u65b9\u6587\u6863 &#8211; Triggers<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/juejin.cn\/post\/6986284818691049479\">\u89e6\u53d1\u5668\u6700\u4f73\u5b9e\u8df5\u4e0e\u6027\u80fd\u6307\u5357\uff08\u6398\u91d1\uff09<\/a><\/li>\n\n\n\n<li><a href=\"https:\/\/dev.mysql.com\/doc\/refman\/8.0\/en\/signal.html\">MySQL SIGNAL \u7528\u6cd5\u8be6\u89e3\uff08\u7528\u4e8e\u89e6\u53d1\u5668\u629b\u9519\uff09<\/a><\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">\u603b\u7ed3<\/h2>\n\n\n\n<p>MySQL \u89e6\u53d1\u5668\u662f<strong>\u5f3a\u5927\u7684\u6570\u636e\u5e93\u81ea\u52a8\u5316\u5de5\u5177<\/strong>\uff0c\u9002\u5408\u7528\u4e8e\uff1a<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u5ba1\u8ba1\u4e0e\u65e5\u5fd7\uff1b<\/li>\n\n\n\n<li>\u81ea\u52a8\u5b57\u6bb5\u66f4\u65b0\uff1b<\/li>\n\n\n\n<li>\u6570\u636e\u4e00\u81f4\u6027\u68c0\u67e5\u4e0e\u5b89\u5168\u9632\u62a4\u3002<\/li>\n<\/ul>\n\n\n\n<p>\u4f46\u4e5f\u9700\u63a7\u5236\u590d\u6742\u5ea6\u3001\u6ce8\u610f\u6027\u80fd\u3002\u5efa\u8bae\uff1a<strong>\u903b\u8f91\u590d\u6742\u65f6\u4f7f\u7528\u5b58\u50a8\u8fc7\u7a0b\u6216\u5e94\u7528\u5c42\u5904\u7406\u66f4\u53ef\u63a7\u3002<\/strong><\/p>\n\n\n\n<p>\u66f4\u591a\u8be6\u7ec6\u5185\u5bb9\u8bf7\u5173\u6ce8\u5176\u4ed6\u76f8\u5173\u6587\u7ae0\uff01<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u4f7f\u7528 MySQL \u89e6\u53d1\u5668\uff08Trigger\uff09 \u53ef\u4ee5\u5b9e\u73b0\u6570\u636e\u5e93\u4efb\u52a1\u81ea\u52a8\u5316\uff0c\u4f8b\u5982\uff1a \u4e00\u3001\u4ec0\u4e48\u662f MySQL \u89e6\u53d1\u5668\uff1f [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":3751,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[35],"tags":[],"class_list":["post-3750","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-mysql"],"_links":{"self":[{"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/posts\/3750","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/comments?post=3750"}],"version-history":[{"count":1,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/posts\/3750\/revisions"}],"predecessor-version":[{"id":3752,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/posts\/3750\/revisions\/3752"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/media\/3751"}],"wp:attachment":[{"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/media?parent=3750"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/categories?post=3750"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.laixuexila.com\/index.php\/wp-json\/wp\/v2\/tags?post=3750"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}