{"id":200065,"date":"2025-05-06T09:48:10","date_gmt":"2025-05-06T01:48:10","guid":{"rendered":"https:\/\/server.hk\/cnblog\/200065\/"},"modified":"2025-05-06T09:48:10","modified_gmt":"2025-05-06T01:48:10","slug":"%e6%b7%b1%e5%85%a5%e6%8e%a2%e8%ae%a8mysql%e8%a7%a6%e5%8f%91%e5%99%a8%e7%9a%84%e5%ae%9a%e4%b9%89%e5%92%8c%e6%93%8d%e4%bd%9c%e6%ad%a5%e9%aa%a4","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/200065\/","title":{"rendered":"\u6df1\u5165\u63a2\u8ba8MySQL\u89e6\u53d1\u5668\u7684\u5b9a\u4e49\u548c\u64cd\u4f5c\u6b65\u9aa4"},"content":{"rendered":"

<\/b> <\/p>\n

\u6df1\u5165\u63a2\u8ba8MySQL\u89e6\u53d1\u5668\u7684\u5b9a\u4e49\u548c\u64cd\u4f5c\u6b65\u9aa4<\/h1>\n

MySQL\u89e6\u53d1\u5668\u662f\u4e00\u79cd\u7279\u6b8a\u7684\u5b58\u50a8\u8fc7\u7a0b\uff0c\u53ef\u4ee5\u5728\u8868\u53d1\u751f\u7279\u5b9a\u4e8b\u4ef6\u65f6\u81ea\u52a8\u6267\u884c\uff0c\u5982\u63d2\u5165\u3001\u66f4\u65b0\u6216\u5220\u9664\u64cd\u4f5c\u3002\u89e6\u53d1\u5668\u5e7f\u6cdb\u5e94\u7528\u4e8e\u81ea\u52a8\u5316\u6570\u636e\u5904\u7406\u3001\u7ef4\u62a4\u6570\u636e\u4e00\u81f4\u6027\u7b49\u573a\u666f\u3002\u901a\u8fc7CREATE TRIGGER\u8bed\u53e5\u5b9a\u4e49\u89e6\u53d1\u5668\uff0c\u6307\u5b9a\u89e6\u53d1\u4e8b\u4ef6\u3001\u6240\u5c5e\u8868\u548c\u6267\u884c\u7684SQL\u8bed\u53e5\u3002\u672c\u6587\u5c06\u6df1\u5165\u63a2\u8ba8MySQL\u89e6\u53d1\u5668\u7684\u5b9a\u4e49\u548c\u4f7f\u7528\u65b9\u6cd5\uff0c\u5e76\u63d0\u4f9b\u5177\u4f53\u7684\u4ee3\u7801\u793a\u4f8b\uff0c\u5e2e\u52a9\u5f00\u53d1\u4eba\u5458\u638c\u63e1\u89e6\u53d1\u5668\u5728\u5b9e\u9645\u5f00\u53d1\u4e2d\u7684\u5e94\u7528\u6280\u5de7\u3002<\/p>\n

MySQL\u89e6\u53d1\u5668\u7684\u5b9a\u4e49\u4e0e\u4f7f\u7528\u65b9\u6cd5\u8be6\u89e3 <\/p>\n

MySQL\u89e6\u53d1\u5668\u662f\u4e00\u79cd\u7279\u6b8a\u7684\u5b58\u50a8\u8fc7\u7a0b\uff0c\u53ef\u4ee5\u5728\u8868\u53d1\u751f\u7279\u5b9a\u4e8b\u4ef6\u65f6\u81ea\u52a8\u6267\u884c\u3002\u89e6\u53d1\u5668\u53ef\u4ee5\u7528\u4e8e\u5b9e\u73b0 \u6570\u636e\u7684\u81ea\u52a8\u5316\u5904\u7406\u3001\u6570\u636e\u4e00\u81f4\u6027\u7ef4\u62a4\u7b49\u529f\u80fd\u3002\u672c\u6587\u5c06\u8be6\u7ec6\u4ecb\u7ecdMySQL\u89e6\u53d1\u5668\u7684\u5b9a\u4e49\u4e0e\u4f7f\u7528\u65b9\u6cd5\uff0c\u5e76\u63d0\u4f9b\u5177\u4f53\u7684\u4ee3\u7801\u793a\u4f8b\u3002<\/p>\n

    \n
  1. \u89e6\u53d1\u5668\u7684\u5b9a\u4e49
    \u5728MySQL\u4e2d\uff0c\u89e6\u53d1\u5668\u7684\u5b9a\u4e49\u662f\u901a\u8fc7CREATE TRIGGER\u8bed\u53e5\u6765\u5b9e\u73b0\u7684\u3002CREATE TRIGGER\u8bed\u6cd5\u5982\u4e0b\uff1a<\/li>\n<\/ol>\n
    CREATE TRIGGER trigger_name\nBEFORE\/AFTER INSERT\/UPDATE\/DELETE\nON table_name FOR EACH ROW\nBEGIN\n    -- \u89e6\u53d1\u5668\u6267\u884c\u7684SQL\u8bed\u53e5\nEND;<\/pre>\n
    \u5176\u4e2d\uff0cCREATE TRIGGER\u7528\u4e8e\u5b9a\u4e49\u89e6\u53d1\u5668\uff0ctrigger_name\u4e3a\u89e6\u53d1\u5668\u7684\u540d\u79f0\uff0cBEFORE\/AFTER\u8868\u793a\u89e6\u53d1\u5668\u662f\u5728\u4e8b\u4ef6\u524d\u8fd8\u662f\u4e8b\u4ef6\u540e\u6267\u884c\uff0cINSERT\/UPDATE\/DELETE\u8868\u793a\u89e6\u53d1\u5668\u662f\u9488\u5bf9\u63d2\u5165\u3001\u66f4\u65b0\u8fd8\u662f\u5220\u9664\u64cd\u4f5c\uff0ctable_name\u4e3a\u89e6\u53d1\u5668\u6240\u5c5e\u7684\u8868\u540d\uff0cFOR EACH ROW\u8868\u793a\u89e6\u53d1\u5668\u5bf9\u6bcf\u4e00\u884c\u6570\u636e\u90fd\u6267\u884c\u4e00\u6b21\uff0cBEGIN\u548cEND\u4e4b\u95f4\u662f\u89e6\u53d1\u5668\u5177\u4f53\u6267\u884c\u7684SQL\u8bed\u53e5\u3002<\/p>\n
      \n
    1. \u89e6\u53d1\u5668\u7684\u4f7f\u7528\u65b9\u6cd5
      \u63a5\u4e0b\u6765\uff0c\u6211\u4eec\u4ee5\u4e00\u4e2a\u5177\u4f53\u7684\u793a\u4f8b\u6765\u6f14\u793aMySQL\u89e6\u53d1\u5668\u7684\u4f7f\u7528\u65b9\u6cd5\u3002\u5047\u8bbe\u6211\u4eec\u6709\u4e00\u5f20\u5b66\u751f\u8868(student)\uff0c\u5176\u4e2d\u5305\u542b\u5b66\u751f\u7684\u59d3\u540d(name)\u548c\u6210\u7ee9(score)\u5b57\u6bb5\uff0c\u6211\u4eec\u5e0c\u671b\u5728\u63d2\u5165\u65b0\u7684\u5b66\u751f\u6570\u636e\u65f6\uff0c\u81ea\u52a8\u8ba1\u7b97\u8be5\u5b66\u751f\u7684\u6210\u7ee9\u7b49\u7ea7(level)\u3002<\/li>\n<\/ol>\n
      \u9996\u5148\uff0c\u6211\u4eec\u521b\u5efa\u4e00\u4e2a\u540d\u4e3astudent_level\u7684\u89e6\u53d1\u5668\uff0c\u4ee3\u7801\u5982\u4e0b\uff1a<\/p>\n
      DELIMITER $$\n\nCREATE TRIGGER student_level_trigger\nBEFORE INSERT ON student\nFOR EACH ROW\nBEGIN\n    DECLARE level VARCHAR(10);\n    IF NEW.score >= 90 THEN\n        SET level = 'A';\n    ELSEIF NEW.score >= 80 THEN\n        SET level = 'B';\n    ELSEIF NEW.score >= 70 THEN\n        SET level = 'C';\n    ELSE\n        SET level = 'D';\n    END IF;\n    \n    SET NEW.level = level;\nEND;\n$$\n\nDELIMITER ;<\/pre>\n
      \u5728\u4e0a\u9762\u7684\u4ee3\u7801\u4e2d\uff0c\u6211\u4eec\u521b\u5efa\u4e86\u4e00\u4e2aBEFORE INSERT\u7c7b\u578b\u7684\u89e6\u53d1\u5668student_level_trigger\uff0c\u5f53\u6709\u65b0\u7684\u5b66\u751f\u6570\u636e\u63d2\u5165\u65f6\uff0c\u89e6\u53d1\u5668\u4f1a\u6839\u636e\u5b66\u751f\u7684\u6210\u7ee9\u81ea\u52a8\u8bbe\u7f6e\u5b66\u751f\u7684\u7b49\u7ea7\uff0c\u5e76\u66f4\u65b0\u5230level\u5b57\u6bb5\u4e2d\u3002<\/p>\n
      \u63a5\u7740\uff0c\u6211\u4eec\u63d2\u5165\u4e00\u6761\u5b66\u751f\u6570\u636e\u6d4b\u8bd5\u89e6\u53d1\u5668\u662f\u5426\u751f\u6548\uff1a<\/p>\n
      INSERT INTO student(name, score) VALUES('\u5c0f\u660e', 85);<\/pre>\n
      \u6267\u884c\u4e0a\u8ff0\u63d2\u5165\u8bed\u53e5\u540e\uff0c\u67e5\u8be2student\u8868\u7684\u6570\u636e\uff0c\u53ef\u4ee5\u770b\u5230\u8be5\u5b66\u751f\u7684\u7b49\u7ea7\u5df2\u7ecf\u88ab\u8ba1\u7b97\u5e76\u586b\u5145\u5230level\u5b57\u6bb5\u4e2d\u3002<\/p>\n
      \u603b\u7ed3\uff1a\u672c\u6587\u8be6\u7ec6\u4ecb\u7ecd\u4e86MySQL\u89e6\u53d1\u5668\u7684\u5b9a\u4e49\u4e0e\u4f7f\u7528\u65b9\u6cd5\uff0c\u5e76\u901a\u8fc7\u5177\u4f53\u7684\u793a\u4f8b\u6f14\u793a\u4e86\u89e6\u53d1\u5668\u7684\u5b9e\u9645\u5e94\u7528\u3002\u89e6\u53d1\u5668\u662fMySQL\u4e2d\u975e\u5e38\u5f3a\u5927\u7684\u529f\u80fd\uff0c\u80fd\u591f\u5b9e\u73b0\u6570\u636e\u5904\u7406\u7684\u81ea\u52a8\u5316\u3001\u6570\u636e\u4e00\u81f4\u6027\u7684\u7ef4\u62a4\u7b49\u529f\u80fd\uff0c\u5f00\u53d1\u4eba\u5458\u53ef\u4ee5\u6839\u636e\u5b9e\u9645\u9700\u6c42\u7075\u6d3b\u8fd0\u7528\u89e6\u53d1\u5668\u6765\u63d0\u9ad8\u6570\u636e\u5904\u7406\u7684\u6548\u7387\u548c\u51c6\u786e\u6027\u3002<\/p>\n
      \u4ee5\u4e0a\u5c31\u662f\u300a\u6df1\u5165\u63a2\u8ba8MySQL\u89e6\u53d1\u5668\u7684\u5b9a\u4e49\u548c\u64cd\u4f5c\u6b65\u9aa4\u300b\u7684\u8be6\u7ec6\u5185\u5bb9\uff0c\u66f4\u591a\u5173\u4e8emysql,\u4f7f\u7528,\u89e6\u53d1\u5668\u7684\u8d44\u6599\u8bf7\u5173\u6ce8\u4e3b\u673a\u5b9d\u8d1d\u516c\u4f17\u53f7\uff01<\/p>\n
      \n
      \n <\/dt>\n<\/dl>\n","protected":false},"excerpt":{"rendered":"
      \u6df1\u5165\u63a2\u8ba8MySQL\u89e6\u53d1\u5668\u7684\u5b9a\u4e49\u548c...<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[101],"tags":[],"class_list":["post-200065","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/200065","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"}],"author":[{"embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/comments?post=200065"}],"version-history":[{"count":0,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/200065\/revisions"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=200065"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=200065"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=200065"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}