{"id":75702,"date":"2024-10-16T00:30:18","date_gmt":"2024-10-15T16:30:18","guid":{"rendered":"https:\/\/server.hk\/cnblog\/75702\/"},"modified":"2024-10-16T00:30:18","modified_gmt":"2024-10-15T16:30:18","slug":"mysql-5%e8%a7%b8%e7%99%bc%e5%99%a8%e7%9a%84%e5%af%a6%e9%9a%9b%e6%93%8d%e4%bd%9c%e5%8a%9f%e8%83%bd%e6%9c%89%e5%93%aa%e4%ba%9b%ef%bc%9f","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/75702\/","title":{"rendered":"MySQL 5\u89f8\u767c\u5668\u7684\u5be6\u969b\u64cd\u4f5c\u529f\u80fd\u6709\u54ea\u4e9b\uff1f"},"content":{"rendered":"<h1 id=\"mysql-5%e8%a7%b8%e7%99%bc%e5%99%a8%e7%9a%84%e5%af%a6%e9%9a%9b%e6%93%8d%e4%bd%9c%e5%8a%9f%e8%83%bd%e6%9c%89%e5%93%aa%e4%ba%9b%ef%bc%9f-WLGUSxeJCP\">MySQL 5\u89f8\u767c\u5668\u7684\u5be6\u969b\u64cd\u4f5c\u529f\u80fd\u6709\u54ea\u4e9b\uff1f<\/h1>\n<p>\u5728\u8cc7\u6599\u5eab\u7ba1\u7406\u7cfb\u7d71\u4e2d\uff0c\u89f8\u767c\u5668\uff08Trigger\uff09\u662f\u4e00\u7a2e\u7279\u6b8a\u7684\u5132\u5b58\u7a0b\u5e8f\uff0c\u5b83\u6703\u5728\u7279\u5b9a\u4e8b\u4ef6\u767c\u751f\u6642\u81ea\u52d5\u57f7\u884c\u3002MySQL 5\u4f5c\u70ba\u4e00\u500b\u6d41\u884c\u7684\u958b\u6e90\u8cc7\u6599\u5eab\u7cfb\u7d71\uff0c\u63d0\u4f9b\u4e86\u5f37\u5927\u7684\u89f8\u767c\u5668\u529f\u80fd\uff0c\u80fd\u5920\u5e6b\u52a9\u958b\u767c\u8005\u81ea\u52d5\u5316\u8a31\u591a\u64cd\u4f5c\u3002\u672c\u6587\u5c07\u63a2\u8a0eMySQL 5\u89f8\u767c\u5668\u7684\u5be6\u969b\u64cd\u4f5c\u529f\u80fd\u53ca\u5176\u61c9\u7528\u5834\u666f\u3002<\/p>\n<h2 id=\"%e8%a7%b8%e7%99%bc%e5%99%a8%e7%9a%84%e5%9f%ba%e6%9c%ac%e6%a6%82%e5%bf%b5-WLGUSxeJCP\">\u89f8\u767c\u5668\u7684\u57fa\u672c\u6982\u5ff5<\/h2>\n<p>\u89f8\u767c\u5668\u662f\u4e00\u7a2e\u8207\u8868\u683c\u76f8\u95dc\u806f\u7684\u7a0b\u5e8f\uff0c\u7576\u5c0d\u8a72\u8868\u683c\u57f7\u884cINSERT\u3001UPDATE\u6216DELETE\u64cd\u4f5c\u6642\uff0c\u89f8\u767c\u5668\u6703\u81ea\u52d5\u57f7\u884c\u9810\u5b9a\u7fa9\u7684SQL\u8a9e\u53e5\u3002\u9019\u4f7f\u5f97\u89f8\u767c\u5668\u6210\u70ba\u5be6\u73fe\u8cc7\u6599\u5b8c\u6574\u6027\u548c\u81ea\u52d5\u5316\u4efb\u52d9\u7684\u6709\u6548\u5de5\u5177\u3002<\/p>\n<h2 id=\"%e8%a7%b8%e7%99%bc%e5%99%a8%e7%9a%84%e9%a1%9e%e5%9e%8b-WLGUSxeJCP\">\u89f8\u767c\u5668\u7684\u985e\u578b<\/h2>\n<p>\u5728MySQL 5\u4e2d\uff0c\u89f8\u767c\u5668\u4e3b\u8981\u6709\u4ee5\u4e0b\u4e09\u7a2e\u985e\u578b\uff1a<\/p>\n<ul>\n<li><strong>BEFORE\u89f8\u767c\u5668\uff1a<\/strong>\u5728\u57f7\u884cINSERT\u3001UPDATE\u6216DELETE\u64cd\u4f5c\u4e4b\u524d\u89f8\u767c\u3002<\/li>\n<li><strong>AFTER\u89f8\u767c\u5668\uff1a<\/strong>\u5728\u57f7\u884cINSERT\u3001UPDATE\u6216DELETE\u64cd\u4f5c\u4e4b\u5f8c\u89f8\u767c\u3002<\/li>\n<li><strong>INSTEAD OF\u89f8\u767c\u5668\uff1a<\/strong>\u4e3b\u8981\u7528\u65bc\u8996\u5716\uff0c\u7576\u5c0d\u8996\u5716\u57f7\u884c\u64cd\u4f5c\u6642\uff0c\u66ff\u4ee3\u8a72\u64cd\u4f5c\u3002<\/li>\n<\/ul>\n<h2 id=\"%e8%a7%b8%e7%99%bc%e5%99%a8%e7%9a%84%e5%af%a6%e9%9a%9b%e6%93%8d%e4%bd%9c%e5%8a%9f%e8%83%bd-WLGUSxeJCP\">\u89f8\u767c\u5668\u7684\u5be6\u969b\u64cd\u4f5c\u529f\u80fd<\/h2>\n<p>MySQL 5\u7684\u89f8\u767c\u5668\u53ef\u4ee5\u5be6\u73fe\u591a\u7a2e\u5be6\u969b\u64cd\u4f5c\u529f\u80fd\uff0c\u4ee5\u4e0b\u662f\u4e00\u4e9b\u5e38\u898b\u7684\u61c9\u7528\u5834\u666f\uff1a<\/p>\n<h3 id=\"1-%e8%87%aa%e5%8b%95%e8%a8%98%e9%8c%84%e8%ae%8a%e6%9b%b4-WLGUSxeJCP\">1. \u81ea\u52d5\u8a18\u9304\u8b8a\u66f4<\/h3>\n<p>\u89f8\u767c\u5668\u53ef\u4ee5\u7528\u4f86\u81ea\u52d5\u8a18\u9304\u8cc7\u6599\u8868\u7684\u8b8a\u66f4\u3002\u4f8b\u5982\uff0c\u7576\u67d0\u500b\u8868\u683c\u7684\u8cc7\u6599\u88ab\u66f4\u65b0\u6642\uff0c\u53ef\u4ee5\u81ea\u52d5\u5c07\u8b8a\u66f4\u8a18\u9304\u5230\u53e6\u4e00\u500b\u65e5\u8a8c\u8868\u4e2d\u3002\u4ee5\u4e0b\u662f\u4e00\u500b\u793a\u4f8b\uff1a<\/p>\n<pre><code>\nCREATE TRIGGER log_update\nAFTER UPDATE ON your_table\nFOR EACH ROW\nBEGIN\n    INSERT INTO log_table (old_value, new_value, change_time)\n    VALUES (OLD.value, NEW.value, NOW());\nEND;\n<\/code><\/pre>\n<h3 id=\"2-%e5%af%a6%e7%8f%be%e8%b3%87%e6%96%99%e5%ae%8c%e6%95%b4%e6%80%a7-WLGUSxeJCP\">2. \u5be6\u73fe\u8cc7\u6599\u5b8c\u6574\u6027<\/h3>\n<p>\u89f8\u767c\u5668\u53ef\u4ee5\u7528\u4f86\u5f37\u5236\u57f7\u884c\u8cc7\u6599\u5b8c\u6574\u6027\u898f\u5247\u3002\u4f8b\u5982\uff0c\u5728\u63d2\u5165\u8cc7\u6599\u4e4b\u524d\u6aa2\u67e5\u67d0\u500b\u6b04\u4f4d\u7684\u503c\u662f\u5426\u7b26\u5408\u7279\u5b9a\u689d\u4ef6\uff1a<\/p>\n<pre><code>\nCREATE TRIGGER check_value\nBEFORE INSERT ON your_table\nFOR EACH ROW\nBEGIN\n    IF NEW.value &lt; 0 THEN\n        SIGNAL SQLSTATE &#039;45000&#039; SET MESSAGE_TEXT = &#039;Value must be non-negative&#039;;\n    END IF;\nEND;\n<\/code><\/pre>\n<h3 id=\"3-%e8%87%aa%e5%8b%95%e8%a8%88%e7%ae%97%e5%92%8c%e6%9b%b4%e6%96%b0-WLGUSxeJCP\">3. \u81ea\u52d5\u8a08\u7b97\u548c\u66f4\u65b0<\/h3>\n<p>\u89f8\u767c\u5668\u9084\u53ef\u4ee5\u7528\u4f86\u81ea\u52d5\u8a08\u7b97\u548c\u66f4\u65b0\u5176\u4ed6\u6b04\u4f4d\u7684\u503c\u3002\u4f8b\u5982\uff0c\u7576\u63d2\u5165\u4e00\u689d\u8a02\u55ae\u6642\uff0c\u81ea\u52d5\u8a08\u7b97\u7e3d\u91d1\u984d\uff1a<\/p>\n<pre><code>\nCREATE TRIGGER calculate_total\nAFTER INSERT ON orders\nFOR EACH ROW\nBEGIN\n    UPDATE orders\n    SET total_amount = NEW.quantity * NEW.unit_price\n    WHERE id = NEW.id;\nEND;\n<\/code><\/pre>\n<h2 id=\"%e8%a7%b8%e7%99%bc%e5%99%a8%e7%9a%84%e6%b3%a8%e6%84%8f%e4%ba%8b%e9%a0%85-WLGUSxeJCP\">\u89f8\u767c\u5668\u7684\u6ce8\u610f\u4e8b\u9805<\/h2>\n<p>\u96d6\u7136\u89f8\u767c\u5668\u63d0\u4f9b\u4e86\u5f37\u5927\u7684\u529f\u80fd\uff0c\u4f46\u5728\u4f7f\u7528\u6642\u4e5f\u9700\u8981\u6ce8\u610f\u4ee5\u4e0b\u5e7e\u9ede\uff1a<\/p>\n<ul>\n<li>\u89f8\u767c\u5668\u7684\u57f7\u884c\u53ef\u80fd\u6703\u5f71\u97ff\u6027\u80fd\uff0c\u7279\u5225\u662f\u5728\u5927\u91cf\u8cc7\u6599\u64cd\u4f5c\u6642\u3002<\/li>\n<li>\u904e\u591a\u7684\u89f8\u767c\u5668\u53ef\u80fd\u6703\u5c0e\u81f4\u908f\u8f2f\u8907\u96dc\uff0c\u589e\u52a0\u7dad\u8b77\u96e3\u5ea6\u3002<\/li>\n<li>\u89f8\u767c\u5668\u4e2d\u7684\u932f\u8aa4\u53ef\u80fd\u6703\u5c0e\u81f4\u8cc7\u6599\u5eab\u64cd\u4f5c\u5931\u6557\uff0c\u56e0\u6b64\u9700\u8981\u8b39\u614e\u8a2d\u8a08\u548c\u6e2c\u8a66\u3002<\/li>\n<\/ul>\n<h2 id=\"%e7%b8%bd%e7%b5%90-WLGUSxeJCP\">\u7e3d\u7d50<\/h2>\n<p>MySQL 5\u7684\u89f8\u767c\u5668\u529f\u80fd\u5f37\u5927\uff0c\u80fd\u5920\u81ea\u52d5\u5316\u8a31\u591a\u8cc7\u6599\u5eab\u64cd\u4f5c\uff0c\u63d0\u5347\u8cc7\u6599\u5b8c\u6574\u6027\u548c\u7cfb\u7d71\u6548\u7387\u3002\u7121\u8ad6\u662f\u81ea\u52d5\u8a18\u9304\u8b8a\u66f4\u3001\u5f37\u5236\u8cc7\u6599\u5b8c\u6574\u6027\uff0c\u9084\u662f\u81ea\u52d5\u8a08\u7b97\u548c\u66f4\u65b0\uff0c\u89f8\u767c\u5668\u90fd\u80fd\u63d0\u4f9b\u6709\u6548\u7684\u89e3\u6c7a\u65b9\u6848\u3002\u5c0d\u65bc\u9700\u8981\u9ad8\u6548\u7ba1\u7406\u8cc7\u6599\u7684\u4f01\u696d\u4f86\u8aaa\uff0c\u5408\u7406\u4f7f\u7528\u89f8\u767c\u5668\u5c07\u5927\u5927\u63d0\u9ad8\u5de5\u4f5c\u6548\u7387\u3002<\/p>\n<p>\u5982\u9700\u4e86\u89e3\u66f4\u591a\u95dc\u65bc<em><a href=\"https:\/\/server.hk\">\u9999\u6e2fVPS<\/a><\/em>\u53ca\u5176\u76f8\u95dc\u670d\u52d9\uff0c\u8acb\u8a2a\u554f\u6211\u5011\u7684\u7db2\u7ad9\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u63a2\u7d22MySQL 5\u89f8\u767c\u5668\u7684\u5be6\u969b\u64cd\u4f5c\u529f\u80fd\uff0c\u5305\u62ec\u81ea\u52d5\u5316\u6578\u64da\u8655\u7406\u3001\u6578\u64da\u5b8c\u6574\u6027\u7dad\u8b77\u53ca\u4e8b\u4ef6\u9a45\u52d5\u7684\u89f8\u767c\u6a5f\u5236\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-75702","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/75702","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=75702"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/75702\/revisions"}],"predecessor-version":[{"id":75703,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/75702\/revisions\/75703"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=75702"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=75702"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=75702"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}